World Central Kitchen
C19HCC webinars
|
About Us | NJPRF World Central Kitchen |
C19HCC C19HCC webinars |
COVID-19 Return to Life 2020 (Part 1)Please take the COVID-19 Ventilation Survey - Since mid-2020 when it was disclosed that COVID-19 is airborne, the guidance has been to increase ventilation inside public spaces. However, do people know what increasing ventilation means and have they taken steps to properly increase ventilation. This systems engineering analysis is constantly being updated. This web page is the most current. April 14, 2020 Initial Release. Last Modified: 04/01/2021 COVID-19 Return To Life (PDF) usually out of date
A book was produced that includes the 2020 COVID-19 research published on this website and additional systems engineering content: COVID-19 A Systems Perspective. The COVID-19 pandemic is a massive disaster. Returning to normal life will not be a trivial exercise. This research will be done real time by the people. There will be different policies and procedures that will be developed around the world that reflect different systems. Each of these systems will have different performance characteristics with the ultimate test being how many people will get sick and die. Once again, a systems perspective will be used to understand the various Return to Life systems that will be developed. Since the start of the COVID-19 disaster many are just focused on return to work. However, that system boundary is incorrect, it is too small. The system boundary is clearly - Return to Life. A quick note about the systems perspective and this analysis. In a systems engineering effort for a problem of this magnitude all technologies and products are examined that may be able to address the need and provide a viable solution. This requires massive resources and in the past the US government and a handful of systems engineering companies performed this type of systems engineering. This is called large complex systems engineering. Examples of large complex systems engineering from the previous century are the US Space Program, Air Defense, Air Traffic Control, etc. The following was offered as a definition of Systems Engineering from Systems Engineering Design: Discipline that concentrates on the design and application of the whole (system) as distinct from the parts. It involves looking at a problem in its entirety, taking into account all the facets and all the variables and relating the social to the technical aspect. -- Simon Ramo. For the specialists that are working their respective areas, in a systems effort they are represented and sit at the systems engineering table. As they present their analysis findings their work informs other specialists in completely different analysis areas. It is this cross fertilization that allows all specialists to broaden their perspectives and enables them to detect new patterns in their own body of work, especially if they are stuck. Systems engineering is the mechanism that allows specialists to quickly and effectively communicate their analysis to completely different areas and significantly shift the overall results in a positive direction. This systems engineering analysis is offered in that spirit of an effective systems engineering activity. One of the key challenges in systems engineering is to determine the key needs, key analysis, key requirements, and key system architecture approaches that will solve the problem. This is very difficult because there is the important consideration to filter out the noise (irrelevant) while not losing what may be the answer. There is an old saying that practitioners use to communicate this challenge: We don't care about how many angels can dance on the head of a pin and we can't throw out the baby with the bathwater. One of the important elements that the systems perspective provides is that it includes the human condition in the system. The system solution must include the reality that people are part of the system and that they do not behave rationally. So the system must account for irrational human behavior otherwise it will fail or have very poor performance characteristics. Without the systems perspective this is always lost. The purpose of all the analysis is to enable the development of potential architecture and design solutions. Eventually the architecture(s) and design(s) must be selected. This is a long hard read. Use the table of contents to navigate. It is constantly being updated and follows the natural flow of all systems engineering efforts; some analysis is a dead end and is abandoned, some analysis converges, some analysis diverges, and some analysis stays at a steady state level until new information surfaces, typically from a specialist on the team. More information on the systems perspective for this problem is available as part of this systems engineering analysis at: Systems Perspective.
.
|
Research
COVID-19 FAQ
Clean Air Buildings Building Ventilation (video2)
My Systems Work
COVID-19
Systems Software
Other Researchers
How Can Airborne
Transmission of COVID 19 Indoors be Minimized? What We Know Now final
.
local
transcript |
The 1918 Flu Pandemic (Spanish flu - wrongly named it did not originate in Spain) started in 1918 and lasted until 1920. It ran through four waves of outbreak. The second wave was more deadly than the first. A third wave of the flu started in late January 1919. In the Spring of 1920 a fourth wave occurred in: New York City the United Kingdom, Austria, Scandinavia, South American islands. It infected 500 million people, about a third of the world's population at the time. The death toll is estimated to have been anywhere from 17 million to 50 million, and possibly as high as 100 million, making it one of the deadliest pandemics in human history [1]. [spreadsheet 2020-1]
1918 Flu Pandemic |
Most suggest that a large factor in the worldwide occurrence of the 1918 Flu Pandemic was increased travel. Modern transportation systems made it easier for World War I soldiers, sailors, and civilian travelers to spread the disease. Another was lies and denial by governments, leaving the population ill-prepared to handle the outbreaks. Eventually the tools used to contain the 1918 Flu Pandemic were masks, shutdown of businesses and other public gathering, and quarantine.
The US was very different at the time. Most of the people were still living on farms and were more self-sufficient than city dwellers. The people were also more spread out and not concentrated in large urban centers. This meant that the 1918 Flu Pandemic spread was naturally slower than what may happen today. There was also the ability for sections of the country to isolate themselves from the pandemic. This is not possible today. So, without conscious effort the spread of COVID-19 will not be 2 years but can happen in the span of months overwhelming the civilization and causing massive collapse.
If the COVID-19 disaster follows the 1918 Flu Pandemic trend it is possible to make some predictions.
The analysis approach is to map the 2020 COVID-19 disaster dates to the 1918 Flu Pandemic graph. The mapping is not exact because there was a trend departure after the first wave. In the 1918 pandemic the number of deaths dropped significantly after the first wave. In the 2020 disaster the number of deaths did not drop. A reasonable explanation is that in 1918 there was no air conditioning and the people were living outside and so the infection rate dropped significantly in 1918 as opposed to 2020. There is a huge point of infection that occurred in the early Fall of 1918. A reasonable explanation is that children went back to school and the windows were closed in schools as the cold months started. A reasonable assumption is that the same thing will happen with the COVID-19 disaster when children return back to school.
Multiple assumptions were made to predict what may happen going forward. The first is that the number in early fall is a new plateau and that plateau will be the departure point for the second wave. The second assumption is that the second wave just follows the trend from that departure point. The third assumption is that there is no peak in the second wave and that there is a constant moving forward from early fall.
Assumption 1
The high plateau is the new infection starting point.
[spreadsheet 2020-1] |
Assumption 2
The high plateau is ignored and the trend is just followed.
[spreadsheet 2020-2] |
In both cases the death rates are horrific and unacceptable given that this is the 21st century and we know much more than people knew in 1918.
Assumption 3
The 1918 trend is ignored, stability has been reached.
[spreadsheet 2020-3] |
Assumption 3
Stability ignored, massive political pressure to open in October 2020. |
The COVID-19 disaster is not following the 1918 trend. This is a bad turn of events. Either we failed to have a return to life system that was as good or better than the 1918 system or something is very different. The difference might be associated with the nature of the virus or the change in our life styles. In 1918 a large portion of the US population was still agrarian not living and working in cities.
Assumption 3
The COVID-19 disaster is not following the 1918 trend. |
Assumption 3
The COVID-19 disaster is not following the 1918 trend. |
The results are as follows [spreadsheet 2020-1 to 3]:
Scenario |
Total Deaths |
Total Deaths |
Total Deaths (August 2021) |
Based on Data |
Comment |
| Assumption 1: New starting point | 475,678 |
603,928 |
- |
Nov 01, 2020 |
Hospitals will be overwhelmed |
| Assumption 1: New starting point | 289,102 |
344,107 |
- |
Dec 01, 2020 |
Infections are significantly up in November Deaths lag infections |
| Assumption 1: New starting point | 305,252 |
407,794 |
- |
Dec 10, 2020 |
Hospitals will be overwhelmed Starting to see the effects of air travel during Thanksgiving Holiday |
| Assumption 2: Follow 1918 trend | 426,359 |
530,644 |
- |
Nov 01, 2020 |
Hospitals will be overwhelmed |
| Assumption 3: Constant rate | 275,555 |
365,905 |
Nov 01, 2020 |
Still tragic and the disaster continues until herd immunity is reached | |
| Assumption 3: Constant rate | 306,218 |
454,487 |
- |
Dec 01, 2020 |
Hospitals will be overwhelmed |
| Assumption 3: Constant rate | 339,302 |
628,178 |
866,052 |
Dec 10, 2020 |
Hospitals will be overwhelmed Starting to see the effects of air travel during Thanksgiving Holiday |
| Assumption 3: Constant rate | - |
690,023 |
996,147 |
Feb 01, 2021 |
New virus strains appear in US |
| Assumption 3: Constant rate | - |
660,098 |
919,672 |
Mar 01, 2021 |
Holiday travel done, vaccinations started |
| Assumption 3: Constant rate | - |
608,403 |
723,231 |
Apr 01, 2021 |
54.61 million people fully vaccinated |
As far as differences in the behavior of the people, it is probably the same, however the root cause of the behavior is probably different. In 1918 people were ignorant of the science that would eventually become standard health care in the coming century. They just did not know through no fault of their own. In 2020 the people had access to all the knowledge and technologies from the previous century and many decided to reject that knowledge and the technologies. They consciously decided to remain ignorant. I call these people stupid because you can't fix stupid.
In 1918 it is possible that the people were not stupid, just ignorant, and once they learned about the science they respected the findings and did what was need. In other words there were fewer stupid people in 1918. When I refer to the people I am not just talking about the masses, I am primarily referring to the leaders in the society especially government, higher education institutions especially engineering schools, local school boards, some companies, ministries, most small business owners, home owner associations with club houses, etc. because they significantly influenced the stupid masses to follow their toxic internal agendas. It was not enough for engineering schools to have their faculty publish their research on UV and HVAC systems. They should have implemented those findings in their classrooms, dorms, and other campus facilities. For example there are small business owners and home owner associations installing UV systems and upgrading their HVAC systems.
Some are contacting industry and finding that elite facilities and hospitals are using proven UV and HVAC technology to maintain their facilities clean and safe. This includes intelligent people associated with small businesses like restaurants [8] [9] [10] [11], home owners associations with club houses [12] [13], homeless shelters [14], and school systems [15] [16]. The problem is they are in the minority and because of that simple fact the COVID-19 disaster will be significantly prolonged. Only government action can change this sad simple fact.
Unfortunately there is additional analysis suggesting that the COVID-19 disaster will not end like the 1918 flu because the population is significantly larger. This means it will take longer for herd immunity to be reached than in 1918 and many people will be infected by the virus with long term health impacts or loss of life [2]. That is why a vaccine is critical. The vaccine will quickly increase the herd immunity without leading to significant loss of life or health to those that are vaccinated. If there is a vaccine these are the possible results [spreadsheet Vaccine].
Population |
Naturally |
Vaccine |
Vaccinated |
Exposed |
Deaths |
Deaths |
Deaths |
Comment |
328,000,000 |
10% |
70% |
70% |
134,480,000 |
2,689,600 |
4,034,400 |
4,706,800 |
Likely vaccine result with some natural immunity |
328,000,000 |
10% |
90% |
90% |
29,520,000 |
590,400 |
885,600 |
1,033,200 |
Unlikely vaccine result with some natural immunity |
328,000,000 |
0% |
70% |
70% |
167,280,000 |
3,345,600 |
5,018,400 |
5,854,800 |
Likely vaccine result with no natural immunity |
328,000,000 |
0% |
90% |
90% |
62,320,000 |
1,246,400 |
1,869,600 |
2,181,200 |
Unlikely vaccine result with no natural immunity |
. |
|
|
|
|
|
|
|
|
328,000,000 |
0% |
0% |
0% |
328,000,000 |
6,560,000 |
9,840,000 |
11,480,000 |
No vaccine, natural herd immunity |
328,000,000 |
10% |
0% |
0% |
295,200,000 |
5,904,000 |
8,856,000 |
10,332,000 |
No vaccine, natural herd immunity |
Notes:
Directly Related External Research - COVID19 Trend Analysis Case Study
Everyone is referring to COVID-19 as a pandemic [3]. From a systems perspective it is a disaster because it did not need to happen and it did not need to get out of control. We had the expertise and the tools but we failed as a people [4] [5] [6]. This may be one of the greatest failures in human history and once the world eventually overcomes this disaster almost every institution will be changed especially in the US.
The mass media provided some insight into the process at the White House. The experts provided the science and data in terms that were very easy to understand. President Trump understood the information. Why the President provided a different message than the findings presented at the briefings is a mystery. Instead the President provided the wrong message to the people basically undermining all the findings. What is also a mystery is why the White House staff responsible for implementing policy implemented policy that was counter to the briefings presented by the experts. The briefings included: where we were, where we are, and the possible scenarios moving forward. Simple examples like wearing a mask, social distance of 6 feet or more, and telework especially if you are in the vulnerable category were all undermined. As a result people died needlessly [4] [5] [6] [7]. The disclosures also included:
This is not 1918. This is 2020. We have massive technology and industrial capacity. That technology and industrial capacity needs to be put to work to stop this disaster from unfolding. A vaccine, social distancing and masks are all reasonable approaches from 1918. However in 2020 we know and can do much more. Why haven't we started?
From this analysis:
The choice is simple. We either go to work and start applying our technology and engineering to transform our indoor spaces or we watch people die as we live in fear for years moving forward. Read this analysis. Look at the proposed legislation. Hold all people in positions of authority accountable. It is your / our life!
The following is an excerpt [16]:
November 10, 2020. ROCK HILL, SC.The Chester County School District announced in October that they would use ultraviolet lights to help fight the spread of COVID-19. Lewisville Elementary, in Richburg, will be the first in the district to use this technology -- and one of the first in the nation, said district Public Information Officer Chris Christoff.
“We’re extremely honored to be among the first to utilize this technology,” said Chester County School District Superintendent Antwon Sutton at the time. “We’ve chosen Lewisville Elementary based on the fact that elementary schools have been identified as more high risk when it comes to exposure.”
The technology is already being installed, and the district anticipates completion this month, Christoff said.
Is UV technology safe? Will it be effective? Here’s what The Herald found out.
The lights being used in Chester are called Germicidal Ultraviolet lights, also known as GUV. They will use 254 UV-C light -- 254 being the wavelength. There will be some overhead GUV lights installed throughout the schools, Christoff said. The units, provided by NetZero USA, also will include hand-held units, which will be used to disinfect classrooms and surfaces
GUV of this type is not new technology. Articles on GUV date back to 1947 -- when it was used in a school outside of Philadelphia.
The effectiveness of GUV has been proven. A study done in South Africa, which was published in the U.S. Library of Medicine, states: “Upper room germicidal UV air disinfection with air mixing was highly effective in reducing tuberculosis transmission under hospital conditions.” Edward Nardell, a doctor and professor of medicine at Harvard Medical School, contributed to the study. He said it proved “80% efficacy,” in stopping the spread of tuberculosis.
GUV does work on COVID-19, the virus caused by the novel coronavirus. It disinfects by destroying the virus in the air. “UV works on every single kind of pathogen there is. It works on COVID,” Nardell said.
The reason this technology seems new to us is that it has not been necessary for a while. Since studies in the 1940s, which focused on stopping the spread of measles, the U.S. hasn’t needed this technology, Nardell said. Schools that are implementing this technology during the coronavirus pandemic are among the first to use UV light in decades.
GUV is safe as long as it is installed properly. Ceiling fans and proper ventilation are important, Nardell said. He recommends that any school installing this program has an outside professional -- someone who has no stake in the game -- come and check that the system is installed correctly before they turn it on.
If the above guidelines are followed, students will not experience side effects. “There’s not much we don’t know,” Nardell said. “It doesn’t cause skin cancer, it doesn’t cause cataracts, it can’t even give you a good sunburn.” It can cause irritation of the skin and eyes; the eyes are the most sensitive. If students are complaining of eye irritation, Nardell said, the system has not been properly installed.
Other schools are currently using this technology. Cambridge Friend’s School in Cambridge, Mass., installed Upper Room GUV lights (GUV light installed in the ceiling) earlier this year.
It won’t necessarily control the spread of coronavirus, unless exposure is strictly unlimited. In past studies, like the one in Philadelphia, the technology wasn’t effective in stopping the spread of disease because children rode the bus after school. Without the GUV technology, the disease (measles in their case) was quickly spread in other environments. Unless children are being strictly isolated outside of school, they will still be susceptible to the virus, Nardell said. The study in South Africa showed more effectiveness because it took place in hospital conditions where patients were strictly isolated.
It should be most helpful to teachers, who don’t mingle with students outside of school. “You may not protect every kid from this, if they’re touching and in close contact, but you could certainly protect your teachers,” Nardell said.
The big question is what have all organizations done to make everyone more safe from the COVID-19 disaster in 2020 and what will happen in 2021? Will the stupid continue to prevail?
References:
[1] Spanish Flu, webpage https://en.wikipedia.org/wiki/Spanish_flu, April 2020.
[2] See section Death Rates.
[3] COVID-19 Pandemic, webpage https://en.wikipedia.org/wiki/Coronavirus_disease_2019, April 2020.
[4] Former COVID-19 Task Force Member Describes Political Pressure On Scientists, The Rachel Maddow Show, MSNBC, September 25, 2020. webpage https://www.msnbc.com/rachel-maddow-show, MSNBC youtube channel https://www.youtube.com/watch?v=xBlG-WmjJC0, September 2020. Former COVID-19 Task Force Member Describes Political Pressure On Scientists
[5] Olivia Troye Says Trump Continuously Undermined Doctors on Coronavirus Task Force, The View, ABC Television, September 25, 2020. webpage The View youtube channel https://www.youtube.com/watch?v=Krg_xSDKIH4, September 2020. Olivia Troye Says Trump Continuously Undermined Doctors on Coronavirus Task Force
[6] Olivia Troye Responds to Claim That She's a "Disgruntled Employee", The View, ABC Television, September 25, 2020. webpage The View youtube channel webpage https://www.youtube.com/watch?v=HDcDHe4syZE, September 2020. Olivia Troye Responds to Claim That She's a "Disgruntled Employee"
[7] No social distancing and few masks as crowd waits for Trump rally in Nevada, CNN, September 12, 2020. webpage https://www.cnn.com/2020/09/12/politics/trump-nevada-rally-face-masks-social-distancing/index.html, December 2020. No social distancing and few masks as crowd waits for Trump rally in Nevada
[8] The Blind Horse Becomes First Restaurant In The United States To Install Far-UVC Light Technology For Real-Time Virus Mitigation And Indoor Sanitization, Globe Newswire, October 13, 2020. webpage https://www.globenewswire.com/news-release/2020/10/13/2107717/0/en/THE-BLIND-HORSE-BECOMES-FIRST-RESTAURANT- IN-THE-UNITED-STATES-TO-INSTALL-FAR-UVC-LIGHT-TECHNOLOGY-FOR-REAL-TIME- VIRUS-MITIGATION-AND-INDOOR-SANITIZATION.html, January 2021.
[9] Wisconsin Restaurant Installs COVID-Killing UV Lights, Spectrum News1, October 14, 2020. webpage https://spectrumnews1.com/wi/madison/coronavirus/2020/10/14/wisconsin-restaurant-installs-covid-killing-uv-lights-, January 2021. Wisconsin Restaurant Installs COVID-Killing UV Lights
[10] With winter approaching, some restaurants turn to UV light to make indoors safer, Products that use UV rays to purify the air are popping up in restaurants., September 02, 2020. webpage https://www.restaurantbusinessonline.com/technology/winter-approaching-some-restaurants-turn-uv-light-make-indoors-safer, January 2021. With winter approaching, some restaurants turn to UV light to make indoors safer
[11] Breathe Easier: Seattle-area restaurants invest in fancy air filtration systems, seattlerefined Sinclair Broadcast Group, October 02, 2020, webpage http://seattlerefined.com/eat-drink/breathe-easier-forward-thinking-restaurants-invest-in-air-filtration-systems, January 2021. Breathe Easier: Seattle-area restaurants invest in fancy air filtration systems
[12] Margate condo first in state to install ultraviolet light sanitizing technology, they say, Press Of Atlantic City, September 09, 2020. webpage https://pressofatlanticcity.com/margate-condo-first-in-state-to-install-ultraviolet-light-sanitizing-technology-they-say/article_5c259798-7c35-5ad8-be85-e5b7a5838aa3.html, January 2021. Margate condo first in state to install ultraviolet light sanitizing technology, they say
[13] Technology at the Forefront for Healthier High-Rise Buildings, The COVID-19 pandemic has real estate developers turning to new tech, like UV light treatments and touchless entrances, to create safer environments for residents, Mansion Global June 07, 2020. webpage https://www.mansionglobal.com/articles/technology-at-the-forefront-for-healthier-high-rise-buildings-216579, January 2021. Technology at the Forefront for Healthier High-Rise Buildings
[14] UV lights, ozone cleaners, sanitizers help shelter keep homeless safe, Catholic News Service, June 16, 2020. webpage https://angelusnews.com/news/nation/uv-lights-ozone-cleaners-sanitizers-help-shelter-keep-homeless-safe/, January 2021. UV lights, ozone cleaners, sanitizers help shelter keep homeless safe
[15] High school installs ultraviolet light system to keep students safe, WNNC, May 20, 2020. webpage https://www.wcnc.com/article/news/health/coronavirus/queens-grant-high-school-uv-light-system-coronavirus/275-c3e54672-905f-4fab-8e5f-8c58d5ca49f3, January 2021. High school installs ultraviolet light system to keep students safe
[16] Some SC schools to use ultraviolet light to fight coronavirus. A few things to know. The Herald November 10, 2020. webpage https://www.heraldonline.com/news/coronavirus/article247021112.html, January 2021. Some SC schools to use ultraviolet light to fight coronavirus. A few things to know
There are many stakeholder views that have been offered to society on the COVID-19 disaster as of May 2020 except for the Engineering Stakeholder. This analysis adds the engineering perspective to the current set of stakeholders. Stakeholders not offered in this analysis are those in denial and those focused strictly on making money by returning to the days before the disaster. They are an example of stakeholders that must be removed from the discussion because it is impossible to develop a solution with them at the stakeholder table.
The engineering perspective on the COVID-19 disaster begins with examining the current system space. The stakeholder needs of the people are reasonable and must be met. Healthcare stakeholders are using a 14th century approach to deal with the crisis when they focus on masks and social distancing. Healthcare stakeholders are also relying on a cure or disease management both of which are years away. The Engineering stakeholders were not even at the table as of May 2020 except in support of the healthcare stakeholders. By August 2020 there was some movement on the ventilation engineering perspective but at an extreme management damage control distance. No numbers and actionable solutions have been provided as part of official guidance. Only statements of increasing ventilation have been provided.
Today we rely on our physical structures to live. This means that the physical structures must somehow reduce the concentration or eliminate viruses. During the energy crisis of the 1970's all HVAC systems were modified to reduce the amount of external air to reduce the amount of fuel consumption. This eventually translated to dollars and today there is a heavy emphasis to reduce HVAC airflow because of costs. This must change immediately. The airflow in all buildings must be massively increased. The air must be subjected to proper filtration and when possible to massive amounts of UV-C that will destroy viruses and bacteria. Once these measures are attempted, they need to be tested in lab settings to see if they work and then tuned to get the maximum benefit without compromise. Specifications then need to be developed for HVAC systems for every type of building setting. Proposed legislation text has been provided as part of this analysis. The same applies to all the engineering solutions offered in all the proposed Decontamination Architectures.
All aircraft and cruise ships must have their HVAC systems tested for virus containment and social distancing must be maintained. The assumption is that these HVAC systems are safe but that may not be the case. This system engineering analysis suggests that the initial virus spread was because of the poor HVAC systems and extremely close social distances of 1 foot on both cruise ships and airplanes. The materials used in these transportation systems also might be suspect. If that is the case, changing these materials will be problematic and similar to what the healthcare stakeholders are doing as they pursue a cure. It is years away. There may be a protocol based on decontamination that may help to reduce the concentration or eliminate the virus. Once again tests need to be performed under controlled lab conditions and then specifications developed for proper system management. Proposed legislation text has been provided as part of this analysis.
Even though massive resources are being applied to develop a successful vaccine, it is clear from a systems perspective that the vaccine will not immediately stop the pandemic. In the best case scenario there is a successful vaccine but it will take 2 or more years for the virus to be removed. In the worst case no vaccine is found. In the middle case there is a vaccine but it will not be 100% effective. This will lengthen the time for the virus to be removed from 2 years to perhaps decades matching what occurred with other efforts to eradicate diseases via vaccination.
Building ventilation is the one area where changes can be quickly implemented and have a direct effect on minimizing or perhaps even stopping the spread of the virus. There has been evidence that our buildings have been spreading illness for decades after the energy crisis when the building ventilation systems reduced the ventilation rates to save on energy costs. Fortunately there were few life threatening diseases that were partially airborne. Mold has been found in HVAC systems causing allergic reactions and people would get sick with the flu or the cold and just complain about the poor air in buildings. Now there is a virus that kills and the ventilation systems of small spaces (e.g. classrooms, restaurants, small office buildings) must be modified because the risk of infection is very high. The large indoor spaces (e.g. big box stores, large office buildings) also must have their ventilation systems modified even though the risk of infection is lower. There also needs to be proper guidance given to people who have a COVID-19 family member in the home. Opening the windows is insufficient and the ventilation must be mechanically augmented with window and or whole house fans. Empirical data from ground transportation systems shows that there is almost no risk of COVID-19 infection. Using the disclosed ventilation rates of ground transportation systems, the same analysis used for buildings was applied to the ground transportation. The ground transportation results confirmed the models and added confidence to the analysis performed on large and small indoor spaces and outdoor venues. It is because of these results that these recommendations are being restated and emphasized.
As of August 2020 we see that most management in the US has ignored human behavior and structured systems that do not account for failures because of non-compliant human behavior. For example, not all people will wear masks, but more importantly people that will wear masks are unable to wear them 100% of the time. The analysis clearly shows that just 1 hour of not wearing a mask in a small indoor space with inadequate ventilation, such as during a meal or an 8 hour work shift will lead to infection. Management has failed to communicate the differences between small indoor spaces, large indoor spaces, and outside venues. Applying the same approach to these radically different settings is completely inappropriate and has caused the disaster to get worse.
In 3 years all public buildings will be updated in some way because the virus is now in the environment. The worldwide pandemic will end eventually, then the local US epidemic will end, but people will continue to get sick and die from this virus for decades even with the vaccine. This virus was not contained, it is out, so we do not know what the future holds for other strains and infections.
Updating pubic buildings much like happened in the 1940's, 50s, and 60s will happen in this new century. This generation will relearn what was old knowledge in the past. People don't know that forced air heating was introduced to provide for a healthier environment. They don't know the ceiling level UV lights were found everywhere in bars, restaurants, public restrooms and that you could go to a local store and buy them for your small business for $25. They don't know that 2 generations ago people needed to figure out how to keep someone alive on an airplane flying above 15,000 feet and that knowledge was used to develop the modern HVAC systems. They also don't know what happened during the energy crisis and how the HVAC systems were changed and became problematic. Finally because everyone became very healthy by the 1970s all the UV lights were thrown away.
As far as the legal approach of having people sign release documents - it will not protect anyone from infection, loss of health, or death. If there is an event, it shows there was no due diligence to provide a safe public space and the release document at that point is useless. To even consider such actions shows a severe decline in the civilization and no systems perspective.
This systems engineering analysis began on April 14, 2020 and on November 22, 2020 a major connection was made on how the virus might be eradicated. As in most complex system solutions there is no one single approach that will work. The world has been waiting for a vaccine but in order to eradicate the virus traditional engineering must be applied to update the infrastructure. The following table illustrates this finding.
Naturally |
Vaccine |
Vaccinated |
Exposed |
Deaths |
Deaths |
Deaths |
UV-C or |
Deaths |
Ventilation |
Deaths |
10% |
70% |
70% |
150,552,000 |
3,011,040 |
4,516,560 |
5,269,320 |
90% |
526,932 |
28% |
379,391 |
10% |
90% |
90% |
56,088,000 |
1,121,760 |
1,682,640 |
1,963,080 |
90% |
196,308 |
28% |
141,342 |
0% |
70% |
70% |
167,280,000 |
3,345,600 |
5,018,400 |
5,854,800 |
90% |
585,480 |
28% |
421,546 |
0% |
90% |
90% |
62,320,000 |
1,246,400 |
1,869,600 |
2,181,200 |
90% |
218,120 |
28% |
157,046 |
. |
|
|
|
|
|
|
|
|
||
0% |
0% |
0% |
328,000,000 |
6,560,000 |
9,840,000 |
11,480,000 |
90% |
1,148,000 |
28% |
826,560 |
10% |
0% |
0% |
295,200,000 |
5,904,000 |
8,856,000 |
10,332,000 |
90% |
1,033,200 |
28% |
743,904 |
Note: Ventilation works only when it is turned on. The HVAC fan(s) must run 1 hour before and 1 hour after the facility opens to the public.
This table shows that all three approaches of Vaccine, UV, and Ventilation are needed to eradicate the virus. Since the virus is airborne and the risk of outside infection is very small, the UV approach is more effective than the vaccine approach, if done alone. However, as of November 2020, it appears that there will be a viable vaccine. The current systems problem is ensuring that Vaccine, UV, and Ventilation subsystems are rolled out as soon as possible. If we just rely on the vaccine those that do not develop immunity and those that are not vaccinated will continue to be at risk and spread the virus. Relying on just the vaccine will lead to more death / loss of health, increase the time to eradicate the virus, and it will also fail to protect us against future viruses.
Once the vaccine is available this system will exist in most hospitals, some homeless shelters, and many elite buildings because they currently have UV and very effective ventilation systems. The trick is to ensure that this system will exist in all schools, small public buildings like restaurants, bars, retail shops, and in office buildings. The cost to roll out UV across the entire US infrastructure is in section UV Infrastructure Cost Estimates. The analysis showing the history and effectiveness of UV is in section Ultraviolet Germicidal Irradiation (UVGI) - Open Air.
Once the vaccine is introduced it will take years for the virus to be eradicated. As other mitigation strategies are added to the system in the form of different subsystems the eradication time will decrease. The challenge is to determine the eradication time as each subsystem is added to the total system solution.
| Subsystem | Fully Implemented | Eradication Time |
| Vaccine acceptance & distribution with annual vaccinations until virus eradicated | 2 years |
V years |
| UV Infrastructure | 1 year |
V- UV years |
| Ventilation Recommendations | 1 month |
V - UV - VR years |
| Ventilation Upgrades | 1 year |
V - UV - VR - VU years |
It is possible that the virus will never be eradicated and instead the focus should be on the number of lives saved with the introduction of each subsystem. This takes the analysis back to the original presentation of lives saved with the use of Vaccine(s), UV, and Ventilation. What is not shown is treatment to improve outcomes.
At what point will herd immunity take effect and translate into stopping the pandemic. Because this virus is so contagious it is likely the herd immunity number will be very high. The following table shows different herd immunity levels and estimates for COVID-19 [1].
Disease |
Transmission |
R0 |
HIT or HIL |
Comment |
Measles |
Airborne |
12-18 |
92-95% |
Previous epidemics. |
Pertussis |
Airborne droplet |
12-17 |
92-94% |
Previous epidemics. |
Diphtheria |
Saliva |
6-7 |
83-86% |
Previous epidemics. |
Rubella |
Airborne droplet |
6-7 |
83-86% |
Previous epidemics. |
Smallpox |
Airborne droplet |
5-7 |
80-86% |
Previous epidemics. |
Polio |
Fecal-oral route |
5-7 |
80-86% |
Previous epidemics. |
Mumps |
Airborne droplet |
4-7 |
75-86% |
Previous epidemics. |
|
||||
COVID-19 (COVID-19 pandemic) [A] [B] |
Airborne droplet |
2.5-4 |
60-75% |
These metrics (numbers) do not reflect that this became a massive pandemic. |
|
||||
SARS (2002-2004 SARS outbreak) [C] |
Airborne droplet |
2-5 |
50-80% |
Did not reach pandemic levels. Why? |
|
||||
Ebola (Ebola virus epidemic in West Africa) |
Bodily fluids |
1.5-2.5 |
33-60% |
Why was this contained? Was it because it was not airborne? |
|
||||
Influenza (influenza pandemics) |
Airborne droplet |
1.5-1.8 [D] |
33-44% |
This is a low R0 number yet there are flu pandemics. |
Herd Immunity Threshold (HIT) or Herd Immunity Level (HIL)
R0 basic reproduction number, the average number of new infections caused
by each case
Eventually the COVID-19 herd immunity level will stabilize around a number that will be part of history. What is missing from the dialog is will the virus be eliminated even if the pandemic is stopped. The reality is the virus will not be eliminated [2]. All herd immunity suggests is that the rate of transmission will be sufficiently reduced to a level where it is not an epidemic or pandemic. However, people will continue to be infected unless they are naturally immune, they are vaccinated, or they are not exposed because of external factors such as being outside, or when indoors having a very disease safe environment using technology such as effective forced air HVAC systems and or UV systems.
If we fail to contain this disaster the impact is in section Life Expectancy.
So why did it take this long to reach this conclusion?
April 2020: From
the start of this disaster we were told that this was not an airborne contagion.
This analysis like many others went down the path of decontamination.
May 2020: Elements
about the virus behavior were not making sense. This analysis started to
go down the path of ventilation and impacts on airborne virus decontamination.
June 2020: This
analysis indicated that the virus spread was not initially impacting poor
communities and that countries with populations that tend to live outside
were having less impact from the virus. This analysis provided numbers on
the effects of airborne indoor and outside virus transmission and made
connections to empirical data. This was very difficult because the official
position was that the virus did not have an airborne element.
July 2020: This
analysis developed and provided proposed legislation for the US Government
to investigate ventilation and UV and roll out solutions to all public schools.
It included budget estimates and performance time frames.
October 2020: The
airborne transmission element of the virus was publicly acknowledged. This
analysis was delayed in performing detailed UV analysis until that
acknowledgement permeated the social consciousness. Prior to that time this
analysis provided high level analysis of UV as part of the Ventilation analysis.
This analysis was waiting for organizations chartered with dealing with this
disaster to move forward.
November 2020:
Between October and November the UV analysis was matured and the findings
were published. It was clear in June 2020 that it was time to develop the
UV analysis, instead proposed legislation was offered in July 2020. That
is a loss of 4 months.
November 22, 2020:
The connection was made and the numbers published showing that the vaccine
is not enough to contain the virus in a reasonable time. The solution must
include UV and ventilation infrastructure upgrades.
Author Comment: It took this long to reach this conclusion because critical information was suppressed and this led to false paths that delayed the findings. The root cause is compromised management and disregard for the systems perspective.
References:
[1] Herd_Immunity, https://en.wikipedia.org/wiki/Herd_immunity, November 2020.
[2] The 1918 flu is still with us: The deadliest pandemic ever is still causing problems today, Washington Post, September 3, 2020. webpage https://www.washingtonpost.com/history/2020/09/01/1918-flu-pandemic-end, November 2020. The 1918 flu is still with us: The deadliest pandemic ever is still causing problems today
[A] COVID-19 herd immunity: where are we?, Emerging disease epidemiology unit, Institut Pasteur, Paris, France. PACRI unit, Conservatoire National des Arts et Métiers, Paris, France. Mathematical Modelling of Infectious Diseases Unit, Institut Pasteur, UMR2000, CNRS, Paris, France, September 9, 2020. National Institute of Health (NIH), US Government. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7480627/pdf/41577_2020_Article_451.pdf, November 2020. COVID-19 herd immunity: where are we? . local
[B] Herd Immunity: Understanding COVID-19, University of Chicago, May 19, 2020. National Institute of Health (NIH), US Government. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7236739/pdf/main.pdf, November 2020. Herd Immunity: Understanding COVID-19 . local
[C] Different Epidemic Curves for Severe Acute Respiratory Syndrome Reveal Similar Impacts of Control Measures, National Institute for Public Health and the Environment, Bilthoven, the Netherlands, March 29, 2004. National Institute of Health (NIH), US Government. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7110200/pdf/kwh255.pdf, November 2020. Different Epidemic Curves for Severe Acute Respiratory Syndrome Reveal Similar Impacts of Control Measures . local
These are some key extracts directly from the new CDC Guidance:
This is the link to the new CDC guidance on Opening Schools and UV: https://www.cdc.gov/coronavirus/2019-ncov/community/ventilation.html.
The CDC guidance now has research results and numbers that are found in this systems analysis.
Consider using ultraviolet germicidal irradiation (UVGI) as a supplement to help inactivate SARS-CoV-2, especially if options for increasing room ventilation are limited.
$1500 (approximately): adding upper room UVGI
Germicidal Ultraviolet (GUV), or Ultraviolet Germicidal Irradiation (UVGI), is a disinfection tool used in many different settings, such as residential, commercial, educational, and healthcare. The technology uses ultraviolet (UV) energy to inactivate (kill) microorganisms, including viruses, when designed and installed correctly.
Upper-room (or upper-air) GUV uses specially designed GUV fixtures mounted on walls or ceilings to create a disinfection zone of ultraviolet (UV) energy that is focused up and away from people. These fixtures disinfect air as it circulates from mechanical ventilation, ceiling fans, or natural air movement.
Can be used in any indoor environment; most useful in spaces highly occupied with people who are or may be sick.
Far-UV is one of many emerging technologies that have become popular during the COVID-19 pandemic. While standard GUV fixtures emit UV energy at a wavelength around 254 nanometers (nm), far-UV devices use different lamps to emit UV energy at a wavelength around 222 nm.
A major difference between the two technologies is that standard GUV systems are specifically designed to avoid exposing people to the UV energy, while many far-UV devices are marketed as safe for exposing people and their direct environment to UV energy. A review of peer-reviewed literature indicates that far-UV wavelengths can effectively inactivate microorganisms, including human coronaviruses, when appropriate UV doses are applied.
There is now ammunition that can be used to update the schools and other small public spaces.
More ventilation is NOT the appropriate response.
By January 2021 many are wondering what the school ventilation requirements should be to safely open and resume semi normal operations.
The appropriate response is specific numbers known as performance requirements understood by engineers, HVAC, and contagious disease specialists in the industry.
Once the public is educated then they will also understand the numbers and why they are so important to their safety and health.
The only reason the ventilation story broke is because of this systems approach to the research.
Engineers and scientists were signing letters and petitions but they were being ignored because they did not disclose the numbers. The reason they did not disclose numbers is because the numbers are stamped proprietary, they have professional licensees, and they signed non-disclosure agreements because that is what is required in that industry.
This research is based on systems analysis with no industry ties so it was able to disclose and publish the numbers. The numbers are derived using very basic engineering principles and 5th grade math so they can't be dismissed.
Within 24 hours of publishing the numbers, which included small indoor, large indoor, and outside spaces in different scenarios, the story broke in the popular media. Rather than disclose the numbers the term more ventilation was released to the public, whatever that means.
This research offers proposed legislation to determine the final numbers and then provides the required budget to do the research to confirm or change the numbers found in this research and then update all the schools. The legislation identified $100 billion to update all the schools.
So this is where we are and that is about the amount of money in the proposed President Biden's American Rescue Plan of 2021 for schools.
Now the next step is to make sure the money is not squandered and the proper engineering is performed, even though the public is still in the dark of what is required.
So what is the proper engineering?
The basic terms that are used for ventilation are air update changes per hour.
Industry uses AUC (air update changes) or ACH (air changes per hour).
There are subtle differences where one represents fresh air and one represents filtered air but for this research and analysis they are interchangeable because the filtered air is like the fresh air from a virus perspective. It is a reasonable assumption that the filtration works and the air is clean. This research uses AUC in most of the analysis report.
Some of the AUC numbers are:
25 Hospital operating room
4 typical house but only if the fans runs 24/7, if HVAC is not running then it is 0
1 typical classroom today, it is supposed to be 4
120 typical bar in the 1960's and 1970's when exhaust fans ran
20-30 ground transportation
50 -100 what is recommended in this report to stop infection in a small space
So now the problem surfaces, proper engineering gets in the way of costs:
The HVAC systems need to go from 1 to 25 AUC, the operating costs will increase, perhaps not the full 25 times, but probably 10 times if only the HVAC system is used.
This research suggests numbers need to be 50 - 100 AUC. Until the research in the proposed legislation is performed that is the official unofficial number.
This research found that the AUC number was lost to history and it is probably at least 50 years old, until now, and it explains a typical bar from 50+ years ago.
So what can be done?
Outside of eliminating the contagion, moving classrooms outside, or opening many windows, the alternative is to use ceiling level UV-C fixtures that were used in the last century.
The ceiling level UV-C is a ventilation system and it can offer an eAUC of up to 24.
Today there is new technology called Far UV-222 that is an alternative and makes life easier in the long term.
Far UV-222 may offer an eAUC from 50 - 100 if carefully designed.
So the solution is to use these UV systems + upgraded HVAC systems.
The HVAC systems need to be bought up to 6 AUC.
In most cases this is just a minor HVAC fan upgrade, assuming it is a modern HVAC system (last 50 years).
So the total AUC can be from 24+6 = 30 to as high as 106. That is the answer.
The tech is 80 years old and was used extensively in the last century and is in use today.
This analysis has shown that the costs associated with loss of life and or shutdown far outstrip the costs of upgrading the entire infrastructure using existing technology.
Is anyone doing this? Yes, facilities have already done this. These are some of the references from this research:
Margate condo first in state to install ultraviolet light sanitizing technology, they say, Press Of Atlantic City, September 09, 2020. webpage https://pressofatlanticcity.com/margate-condo-first-in-state-to-install-ultraviolet-light-sanitizing-technology-they-say/article_5c259798-7c35-5ad8-be85-e5b7a5838aa3.html, January 2021. Margate condo first in state to install ultraviolet light sanitizing technology, they say
Technology at the Forefront for Healthier High-Rise Buildings, The COVID-19 pandemic has real estate developers turning to new tech, like UV light treatments and touchless entrances, to create safer environments for residents, Mansion Global June 07, 2020. webpage https://www.mansionglobal.com/articles/technology-at-the-forefront-for-healthier-high-rise-buildings-216579, January 2021. Technology at the Forefront for Healthier High-Rise Buildings
UV lights, ozone cleaners, sanitizers help shelter keep homeless safe, Catholic News Service, June 16, 2020. webpage https://angelusnews.com/news/nation/uv-lights-ozone-cleaners-sanitizers-help-shelter-keep-homeless-safe/, January 2021. UV lights, ozone cleaners, sanitizers help shelter keep homeless safe
High school installs ultraviolet light system to keep students safe, WNNC, May 20, 2020. webpage https://www.wcnc.com/article/news/health/coronavirus/queens-grant-high-school-uv-light-system-coronavirus/275-c3e54672-905f-4fab-8e5f-8c58d5ca49f3, January 2021. High school installs ultraviolet light system to keep students safe
Some SC schools to use ultraviolet light to fight coronavirus. A few things to know. The Herald November 10, 2020. webpage https://www.heraldonline.com/news/coronavirus/article247021112.html, January 2021. Some SC schools to use ultraviolet light to fight coronavirus. A few things to know
Meanwhile this research disclosed that Philadelphia Schools are proposing cheap fans mounted on wooden boards to be placed in windows and it is very sad. Make no mistake about it, they were contacted by at least a dozen HVAC /UV facilities vendors and 2 or 3 presented their proper engineering solutions, but management selected this approach.
You have to dig deep and protect yourself, family, friends, and community.
Don't think that the new administration will remove all the toxic self interest players that led to this disaster.
Leaders are still documenting and stating vague untestable requirements like increase ventilation.
The proper documentation and statements must disclose the proper performance requirements using numbers and then tell the public the costs.
This research is not going to try to get the leaders to educate the public and disclose the numbers.
If policy makers don't do the right thing there is nothing that can be done from a technical engineering perspective. It becomes a social problem.
Meanwhile a book will be published of this research sometime in early to mid 2021 and future generations will assess and judge.
Technical Systems Engineering Findings
The following is a quick summary of the rest of this system engineering analysis. The findings are out of sequence with the report content. All findings are of equal importance.
This systems analysis suggests that there is no single solution that will stop this virus, instead the virus mitigation system must include multiple complex and highly effective subsystems
Now that we have a deadly airborne virus we have to address HVAC systems standards and designs
The systems analysis suggests that classrooms and small spaces like restaurants must have effective ventilation and exhaust mechanisms [spreadsheet]
The system boundary is too narrow.
The stakeholder needs are significant, grave, and must not be silenced with management talking points.
The root cause technical analysis is important when developing a return to life system. The technical root cause findings are unexpected.
There are many decontamination approaches.
The potential system solutions include decontamination tools used in broader architecture(s) solutions. [spreadsheet]
The return to life systems were started the very first day of the virus outbreak. [spreadsheet]
As the data from different countries is examined patterns need to be identified. [spreadsheet]
This analysis does offer engineering based solutions to mitigate the spread of the virus. [spreadsheet]
This analysis suggests that the indoor ventilation rates in terms of Air Updates Per Hour (AUC) must be increased: [spreadsheet]
This analysis suggests that a Test and Evaluation effort be established to test various engineering based virus mitigation approaches.
This analysis suggests that the US fails to perform effective contact tracing. Effective contact tracing must:
Key requirements to fix the system.
There is a broader root cause analysis that includes analysis of the US government and its transformation as part of privatization
There is a harsh and unfortunate finding.
We are in bigger trouble than we realize because we have a fundamental structural problem in our system that surfaced with privatization of government beginning in the 1980's.
Special note see section Second Wave Accountability.
All systems analysis begins with identifying the system stakeholders and their needs. The following stakeholders and their perspectives are offered to begin to understand the COVID-19 disaster return to life needs.
When it became clear that they were dealing with a serious epidemic China did the following things [1]:
1. Hospitals were separated into COVID and non-COVID hospitals.
2. In areas where separate hospitals were not possible, existing hospitals were modified to have COVID and non-COVID areas with complete physical separation to ensure no cross contamination.
3. As a healthcare worker entered and exited a COVID area, there was a physical transition boundary with a third party watching the staff person put on and remove the protective gear.
4. Healthcare workers were separated into COVID and non-COVID staff with NO mixing between the 2 groups.
5. COVID positive children were separated from their parents and placed into recovery centers.
5. During the shelter in place time the streets were constantly being sprayed with disinfecting agents. (see note 1)
This is not new or exotic knowledge. This is a failsafe architecture that attempts to minimize failure propagation. This is standard procedure for highly infectious and dangerous diseases. The difference is that it was not isolated to a small lab or hospital with a single patient, it was established on a massive scale within a functioning society.
Why is this important for understanding a Return to Life system?
It clearly shows the extremely dangerous situation and the care that must be applied when establishing a Return to Life system. The same failsafe architecture that minimizes failure propagation also must be used for the Return to Life system.
Note 1: It appears that the virus eventually falls to the ground and is picked up by shoes and part of the protocol included the cleaning of shoes with disinfecting agents.
References:
[1] Handbook of COVID-19 Prevention and Treatment, Compiled According to Clinical Experience, The First Aliate Hospital, Zhejiang University School of Medicine, China, March 19, 2020, March 24, 2020. webpage https://asprtracie.hhs.gov/technical-resources/resource/7844/handbook-of-covid-19-prevention-and-treatment, March 2020; https://www.alsgbi.org/wp-content/uploads/2020/03/COVID-19-Prevention-and-Treatments-in-a-hospital.pdf, March 2020. U.S. Department of Health & Human Services . Handbook of COVID-19 Prevention and Treatment PDF from ALSGBI . local (PDF)
Eventually people will start to go back to work. So, what are their system needs going forward?
1. We now know the virus is partially airborne, what have you done to update the facility ventilation systems?
2. What is the facility ventilation air update rate per hour?
3. Have you installed UV-C ceiling lights?
4. Have you installed UV-C in the HVAC ducts and if so what are the specifications?
5. Which government authority certified that the HVAC system was properly upgraded to deal with the virus?
6. Will there be public view displays of the chemicals used, where they were used, and data sheets of all the chemicals?
7. Which areas were not sanitized and why to justify the inaction?
8. Which government authority(s) and independent labs certified that all the areas were properly sanitized, and all are now free of COVID-19?
9. How will government / company personal protection equipment be distributed to the employees as part of their legal responsibility to ensure a safe workplace?
10. What measures will be taken to ensure that no one entering the facility has COVD-19?
11. Will the population returning to work be phased into each physical location and what will be the phase in criteria?
12. Will the most vulnerable be the last to return to work after the physical space has shown that there are no COVID-19 cases?
13. What time frame will be used to show that a physical space is free from COVID-19 (2, 4, 6, 8 weeks) prior to the return of the most vulnerable?
14. How often will the staff be tested and how will the testing be accomplished?
The following is an example of the system complexity that cruise ships will face as they restart their operations. The same applies to airlines. These stakeholder requirements easily transfer to all workplace and public space settings.
1. Have you done anything to clean each of your ships?
2. Which products have you used to disinfect the Coronavirus from your ships' cabins, dining rooms, kitchens and common areas? Please, be specific by areas.
3. Can you provide me copies of the chemical data sheets of each of the products used?
4. Can you provide me a copy of the Government Authorization to use these products?
5. Can you provide scientific evidence conducted by one or more independent Labs with expertise in infectious diseases stating their effectiveness in eliminating the Coronavirus 100%? How long will the treatment last? Please explain.
7. Which Government Authorities certified the effectiveness of each product? Please be specific and indicate which countries approved each of the products.
7. Can you confirm that the products and process comply with the best health standards by: WHO, EPA, OSHA, CDC, and other health Authorities?
8. Have you implemented any health recognized protocol to assure ALL possible guests are free of Coronavirus before they enter the Port Terminal? Also as they enter the ship for check in? Be specific at each entrance. Please also answer this question on how you performed the same process for crew members and entertainment staff.
9. Have you implemented any process to improve you staff health practices to eliminate their contact with guests, to eliminate guest contamination?
10. Can you provide evidence of the Coronavirus tests performed on each crew member before they enter to the ship, and that all of them are 100% Coronavirus free before departing?
11. Can you explain which of the different options of Coronavirus test are you using?
12. Can you post those results in a public area to be available for inspection by any of the guests at any time?
13. Can you provide evidence of the certifications or approval to proceed by the Medical Labs that performed those tests?
14. Can you sign a Legal document, Sworn Statement, stating all the facilities are100% free of Coronavirus or any other infectious virus at the moment we enter for check in?
15. Can you sign a Legal document, Sworn Statement, stating each of the crew members and entertainment personnel are 100% free of Coronavirus?
16. Can you sign a Legal Document, Sworn Statement, stating each in transit guests and boarding guests are free of Coronavirus?
17. Can you provide evidence stating that each food and beverage provider is 100% free of Coronavirus?
18. If the ship enters ports, will they be free of reported Coronavirus a minimum of 6 months prior to arrival? Please, provide evidence verified by a neutral and recognized Government Authority.
19. The issue is not just the ship or airplane but broader and includes all social interaction while on travel.
Estimates as of June 2020 are that air travel will not return to previous levels for 2 years - the summer of 2022. The FAA in 2009 found that commercial aviation accounts for approximately 5% of U.S. gross domestic product and contributes 1.3 trillion in annual economic activity as well as helps generate and support 10 million jobs annually.
Any government that wants to start lifting restrictions must first meet six conditions:
1. Disease transmission is under control
2. Health systems are able to detect, test, isolate and treat every case and trace every contact
3. Hot spot risks are minimized in vulnerable places, such as nursing homes
4. Schools, workplaces and other essential places have established preventive measures
5. The risk of importing new cases can be managed
6. Communities are fully educated, engaged and empowered to live under a new normal
The stakeholder needs of students and teachers when returning back to school are grave. Unlike the other stakeholder needs, which were developed before this systems engineering analysis started during early April 2020, the students and teachers needs were developed starting on June 21, 2020. Much has been learned from an engineering perspective during that time period and it has been reflected in the Students and Teachers Returning Back to School needs.
As of June 2020 there are some countries that introduced the following elements to try and mitigate the risks of infection.
1. As elementary school children (grades 1-2) enter the school building there is a mat with liquid disinfectant. They jump up and down to disinfect their shoes. As they cross over into the school building they wipe their shoes on another dry mat.
2. Immediately to the left of the entry there is a row of sinks. The students are directed by 2 adults to the sinks to wash their hands.
3. While eating lunch the desks face the classroom wall and each desk has a partition to the left and right.
4. High school age children are seated 4 to a group. They are separated with clear plexiglass. The desk tables have their laptops, smartphones, and other school related items. The 4 group student pods are separated by more than 6 feet.
These mitigations are not based on a systems perspective, science, and or engineering. They are management actions designed to provide an image that the problem is being addressed. However, they provide a false sense of security and may even lead to more virus spread because the system still has massive hazards that are not addressed.
Upgraded and new infrastructure.
1. Provide hygiene infrastructure including upgraded restrooms for teachers and students and increased restroom capacity for teachers.
2. Provide massive new mechanical ventilation systems in restrooms, classrooms, and common rooms.
3. Provide UV-C ceiling lights and UV-C lights in HVAC systems along with appropriate air filters and associated daily inspection and immediate maintenance when needed.
4. Open the all the windows and doors to enable massive natural ventilation.
5. Provide new equipment and supplies directly related to the COVID-19 disaster including equipment for the school nurses, teachers, and administrators.
6. Provide new desks and equipment to maximize the effectiveness of social distancing.
7. Provide massive online in classroom live teaching computing infrastructure to support rotating student groups of 5 days in class and 10 days online classes until the infection rate significantly drops.
8. Change the school schedule including shutting down during seasons of high illness such as the Winter months.
9. Provide extremely healthy lunch menus to strengthen and maximize the immune systems of the students, teachers, and administrators. This may mean stopping all the outsourcing of food preparation and reopening the massive kitchen facilities that were once part of the schools from the last century.
10. Provide new course material to allow the students to understand how we may have arrived at this point, what is being done, and what they can do now and in the future when they become adults in hopefully a functioning high quality future society.
Masks and social distancing is not possible. The infrastructure must be modified.
1. Wearing a mask with no break for 7 to 8 hours is not possible.
2. Children and teenagers wearing a mask at bus stops unlikely, in bus unlikely, in cafeteria not possible, during gym not possible, during classroom changes unlikely, in classroom will destroy learning experience
3. Children and teenagers social distancing at bus stops unlikely, in bus unlikely, in cafeteria not possible, during gym not possible, during classroom changes unlikely, in classroom not possible
3. Special needs children and teenagers wearing a mask and social distancing is not possible.
4. Bullies will place students in grave risk by engaging in dangerous behavior (spiting, coughing, etc).
5. When possible move all classroom activity outside. (the stakeholders now know some of the engineering analysis and want these solutions)
6. Open all the windows and doors and help natural ventilation with fans everywhere. (the stakeholders now know some of the engineering analysis and want these solutions)
7. HVAC Infrastructure must be modified to allow for massive air exchanges. (the stakeholders now know some of the engineering analysis and want these solutions)
8. Add UV-C ceiling lights and update HVAC systems with UV-C lights. (the stakeholders now know some of the engineering analysis and want these solutions)
Observation: Pushing all the responsibility to the lowest level, the individual, is no longer a viable management strategy. Actual investment and work must happen or children, teachers, and others will get sick and die.
The politics and gaming of the system to siphon off taxpayer funds must be disclosed.
1. All funding gaps must be addressed by the Federal Government as part of the COVID-19 disaster. Many states are not permitted to carry a deficit unlike the Federal Government. This means they are completely incapable of dealing with this massive disaster.
2. Inform the students and parents about the school budgets and how tax money is spent on outsourcing and private schools by sending home quarterly reports much like companies produce. Incorporate this into new course material to allow the students to understand privatization and how it affects their education and the taxpayer resources. Call it a civics class.
3. All taxpayer education money must be immediately channeled back into extremely safe high quality public education that is fully transparent. Efforts to sabotage and dismantle public schools in hopes of monetizing the taxpayer dollars must stop immediately. There are not enough resources to deal with this disaster to be wasted on privatization schemes.
As a direct result of these stakeholder needs this analysis produced proposed legislation text: TITLE: COVID-19 Funding for Facility Ventilation Upgrade Recommendations and to Upgrade all Public Schools. For the full text see section Proposed Legislation. This proposed legislation was sent to multiple representatives and various media outlets starting in July 2020. There was no reply and there is no evidence of any movement in this area as of October 2020.
1. In the US, employers are required by law to provide a safe work environment.
2. In the US, employers are required by law to provide safety equipment to ensure the safety of people working in hazardous conditions.
3. Useless and confusing information must be removed from all official guidance provided by all official organizations everywhere. Focus on what must be done to stop sickness and death is critical.
4. The backup VA hospital system must be fixed immediately to allow for the massive spike in sick people overwhelming some hospitals in the US. (see note 1)
5. The US Federal Government is in a collapsed condition and it must be restarted and reinvigorate with competent people immediately (see note 2).
6. The US Federal Government must stop breaking the laws of the land while dealing with the COVID-19 disaster.
7. Restarting the US Federal Government will take a minimum of 1 year. The crisis assets locked in the Federal Government must begin to be transferred to the States immediately. This includes professional staff, equipment, and money. (see note 3)
Note 1: In accordance with the law, the US Veterans Administration (VA) hospital system is a backup to the civilian hospital system. It is clear that the system is broken, and the backup is not working properly.
Note 2: In mid-March 2020, multiple Federal Government organizations issued direction to civil servants and contractors that they should clean their workspaces using their own personal products. This is a clear violation of US law and shows that OSHA is compromised and cannot be depended upon to protect the people from dangerous incompetent management. It also shows that government is very large with many elements, some of which are very competent and effective but unfortunately other elements are in a collapsed condition. It is clearly having massive problems in meeting the needs of the people.
Note 3: The States have taken on the burden of dealing with this crisis. However, all the money and resources are centralized in the Federal Government because that has been the approach used since World War II. As each day passes where the US Federal Government is in a collapsed condition, more people get sick and die and the crisis becomes worse with massive unintended consequences that are gravely damaging the entire civilization.
Stakeholders List
|
|
|
Virus Defense System
The purpose of a defense system is to defend against a threat. There are many defense systems in our society like Air Defense and Missile Defense systems. These systems were developed and matured after World War II. They rely heavily on systems engineering practices because of their complexity and potential massive loss of life should something go wrong. There are other defense systems, some are consciously developed and maintained and some just naturally evolve and exist as part of the civilization. Home security systems are an example of a simple defense system to defend against the threat of a home intruder and computer communications firewalls defend against computer viruses.
The threat in this case is a virus or other unknown contagion. The question then is do we have a Virus and or Contagion Defense System. The short answer is yes. It was consciously developed and matured through the decades. It is currently part of what we know as the Centers For Disease Control (CDC).
After World War II the US policy and tone was set by a major analysis that was requested by President Roosevelt called Science the Endless Frontier. This analysis identified many areas for the US Federal Government to address and many equate it with the founding of the National Science Foundation. However, its reach was far and wide and it can be easily pointed to as why the modern CDC exists. The CDC roots go back to the Office of National Defense Malaria Control Activities (1942). Its evolution goes from the Office of Malaria Control in War Areas (1942–46), Communicable Disease Center (1946–67), National Communicable Disease Center (1967–70), Center for Disease Control (1970–80), and currently Centers for Disease Control (1980–92). The US took the domestic and international lead role in the international Contagion Defense System beginning in 1942. These are some of the key CDC events representing their activities and role:
1940s
1950s
1960s
1970s
1980s
1990s
2000s
2010s
In addition to the CDC there is the Department of Homeland Security (DHS), U.S. Department of Health & Human Services (HHS), Biomedical Advanced Research and Development Authority (BARDA) and National Center for Medical Intelligence (NCMI).
Unlike Air Defense or Missile Defense, the concept of a Virus Defense System or Contagion Defense System does not appear in simple Internet searches. The documents are probably stamped at some classification level [1]. It is unclear why that would be the case because we know from Air Defense and Missile Defense systems that it is important to disclose their existence and basic operations for the world to understand the implications and effectiveness of these systems. In Air Defense or Missile Defense the performance numbers tend to be classified. Crimson Contagion is an example why these systems need to be disclosed and studied [2].
Crimson Contagion was a joint exercise conducted January to August 2019, to test the capacity of the federal government and twelve states to respond to a severe pandemic of influenza originating in China. The simulation was conducted months prior to the start of the COVID-19 pandemic. The scenario was tourists returning from China spread a respiratory virus in the United States, beginning in Chicago. In less than two months the virus had infected 110 million Americans, killing more than half a million. The report issued at the conclusion of the exercise outlines the government's limited capacity to respond to a pandemic, with federal agencies lacking the funds, coordination, and resources to facilitate an effective response to the virus. [1]
This analysis does not examine existing Virus and or Contagion Defense Systems because there appears to be no public information. However, the virus defense system exists. It is either a consciously developed system or a system that naturally evolved, but it exits. This analysis draws from modern Air and Missile Defense systems public information to develop a conceptual virus defense system. It then provides an assessment of the performance of the system (circa December 2020).
Functional Analysis
A systems engineering analysis includes identification and understanding of the system functions. Typically similar systems are examined to provide guidance and inform the potential functions for the system under analysis. One of systems to consider is air defense because it shares many of the characteristics of a system that must deal with and eliminate a virus contagion. These characteristics will become self-evident once the air defense functions are listed and briefly described. The following are the key functions and descriptions in a typical air defense system and the resulting virus defense functions.
Air Defense Functions |
Air Defense Description | Virus Defense Functions |
Virus Defense Description |
| Surveillance | The system is constantly watching the skies to determine if there are unusual target flight patterns. | Surveillance | The system is constantly watching the planet to determine if there are unusual contagion patterns. |
| Identification | When an unusual target flight pattern is detected there is an attempt to identify the target as known, unknown, or a threat. | Identification | When an unusual contagion pattern is detected there is an attempt to identify the contagion as known, unknown, or a threat. |
| Threat Assessment | If the target is unknown it is assessed to determine if it is a threat. This may include making visual contact to assess the situation. | Threat Assessment | If the unusual contagion pattern is unknown it is assessed to determine if it is a threat. This may include making physical contact to assess the situation. |
| Weapons Assignment | Based on an assessment of the target threat a weapon or weapons are assigned to deal with the threat. | Resources Assignment | Based on an assessment of the contagion threat appropriate resources are assigned to deal with the threat. The resources include tools, techniques, methods, processes, money, medications, infrastructure and other items available in the arsenal to fight the contagion. |
| Intercept | The weapon or weapons are sent to intercept the threat as quickly as possible. | Deployment | The tool or tools are sent to intercept the unusual contagion pattern as quickly as possible. |
| Assessment | Once the intercept is complete an assessment is performed to determine the success of the encounter. The first encounter is a visual confirmation and reassessment to a known target is typically all that is needed. In the case of war the intercept that follows is meant to remove the threat and an assessment of the event is performed. | Assessment | Once the deployment is complete an assessment is performed to determine the success of the encounter. The first encounter of a visual confirmation and reassessment to a known contagion is typically all that is needed. In the case of a new contagion threat the deployment that follows is meant to remove the threat and an assessment of the event is performed. |
What the above table describes is a typical Situational Awareness Command and Control System. This system concept based on doctrine, computers, communications, and massive technology started during World War II, was heavily matured during the 1950's with the Semi-Automatic Ground Environment (SAGE) system and now exists everywhere from civilian air traffic control systems to emergency response systems. The following figure is a potential virus defense system functional block diagram.
Virus Defense System Functional Block Diagram |
The epidemic or pandemic functional decomposition is:
| 1.0 Surveillance
2.0 Identification
3.0 Threat Assessment
4.0 Resources Assignment |
5.0 Deployment 5.1 Containment 5.2 Exposure Elimination 5.3 Treatment 5.4 Eradication
6.0 Assessment |
The functions are implemented in one or more subsystems. The subsystems can be automated using machines, manual performed by people, or both automated and manual. Placing the functions in one or more subsystems is called a functional allocation. Once a functional allocation is performed a conceptual architecture surfaces and performance can be determined. Different allocations result in different conceptual architectures each with their own performance characteristics. The potential subsystems for this system are:
As in all complex systems there are primary subsystems and secondary subsystems that are used as backup should the primary subsystem fail. Many do not realize that there is always a system regardless if there was a conscious effort to establish a system. The system can be very effective or poor. The contagion defense system evolved probably for the most part unconsciously over decades. The system basically started after World War II.
The following table shows the epidemic or pandemic system functions and subsystems that implement the functions with an assessment of the system performance in 2020. We see that prior to the pandemic the world viewed certain subsystems as having a primary role in implementing certain functions. We also see there were many primary subsystem failures and the secondary subsystems needed to perform the function.
Functions / Subsystems |
US Gov |
WHO |
Non US Nation |
Academic |
Business |
US |
Comment |
Surveillance |
Primary |
Secondary |
Secondary |
Secondary |
Secondary |
Secondary |
China performed this function. |
Identification |
Primary |
Secondary |
Secondary |
Secondary |
Secondary |
Secondary |
China performed this function. |
Threat Assessment |
Primary |
Secondary |
Secondary |
Secondary |
- |
Primary |
China performed this function. |
Resources Assignment |
Primary |
Secondary |
Primary |
- |
- |
- |
US government failed to perform this function. |
Deployment |
Primary |
- |
Primary |
- |
Secondary |
- |
US government failed to perform this function. |
Assessment |
Primary |
Primary |
Primary |
Primary |
- |
Primary |
US government failed to perform this function. |
The above conceptual architecture shows that either the primary functional allocations must change, resulting in a different conceptual architecture, or the US Gov and US Press Subsystems must be fixed and quickly.
The following table shows the epidemic or pandemic functions, a functional decomposition, and resources that have been implemented by date. It is a more detailed assessment of the system functional performance for the current conceptual architecture where the US Gov Subsystem has the primary role in performing the system functions.
| Functions | Lower Level Functions & Resources | March 2020 | October 2020 | December 2020 | Comment |
| Surveillance | Surveillance - US CDC - US Press |
Completed |
- |
- |
This was performed by China. |
| Identification | Identification - Genetic Sequencing - Transmission Method |
|
|
|
This was performed by China. The US knew that the transmission method was airborne in January 2020 but did not disclose the information and engaged in disinformation and propaganda to deflect away from the issue. |
| Threat Assessment | Threat Modeling Analysis - Small indoor space - Large indoor space - Outside venues - Transportation Systems |
|
|
|
The performance numbers were not published and distributed by the US government. Only analysis from independent research like this report developed, published and distributed the findings. The findings did not match any of the management talking points from all the US institutions. Management engaged in damage control and only provided vague guidance that reflected the findings of the performance numbers in some instances and in other instance like airplane risks were counter to the findings. This left the population with no real guidance on how to proceed. |
| Threat Assessment | Threat Data & Analysis - Small indoor pace - Large indoor space - Outside venues - Transportation Systems |
|
|
|
The data is not being provided by the US to the people. The only data that is available is from international research reports. The CDC and NIH typically have those research reports on their websites suggesting there is no capability within the US to capture this data and perform the analysis. The US research appears to be irrelevant or just duplicates of small elements of existing research. |
| Resource Assignment
Deployment |
Containment - Testing - Contact Trace & Quarantine - Travel Restrictions - Public Indoor Space Shutdown - Schools Shutdown - Surface Decontamination - Masks - Social Distance - Open Air UV Systems - HVAC Systems - Open Air Ventilation …………………………………… |
|
|
|
The US failed to contain the virus. A large portion of the US population rejected masks and social distance recommendations because the US Government turned the guidance into a political issue. There was no proper existing HVAC settings guidance. Contact tracing and quarantine only worked in Hawaii. Because the virus transmission is also airborne all the surface cleaning and plastic shields was ineffective at stopping the virus. There was no proper engineering science based reopening plan, only massive pressure to reopen. There was no desire to roll out airborne infrastructure mitigation solutions like Open Air UV and HVAC system upgrades. |
| Resource Assignment
Deployment |
Exposure Elimination - Surface Decontamination - Masks - Social Distance - Open Air UV Systems - HVAC Systems - Open Air Ventilation |
|
|
|
In October 2020 it was admitted that the virus spread is airborne. This was known by the US Government in January of 2020 but the information was suppressed and denied. Between January and October schools and many small indoor spaces could have been upgraded with proper UV and HVAC systems. |
| Resource Assignment
Deployment |
Treatment - Drugs - Blood Plasma - Physical Placement - Oxygen Delivery - Intubation |
|
|
|
Many treatments were pioneered in China and Italy. Eventually treatments were developed from around the world. Healthcare professionals networked on their own to share treatments and results. |
| Resource Assignment
Deployment |
Eradication - Vaccines - Open Air UV Systems - Proper HVAC Systems |
|
|
|
As of December 2020 many falsely think this virus will be quickly eradicated with vaccines. Management damage control talking points are still in control of the mass message. History and this systems analysis shows that this is an incorrect assumption. To reduce the time to eradicate this virus and protect against future virus attacks this analysis suggests that the infrastructure must be modified. |
| Assessment | Performance Monitoring - Infections - Deaths - Long Term Health Damage |
|
|
|
As of December 2020 the only system performance numbers provided to the public are infections and deaths. Numbers associated with long term health by damaged body subsystems are not being provided. |
| Assessment | Presentation & Visualization - Infections - Deaths - Long Term Health Damage |
|
|
|
As of December 2020 the only system performance numbers presented to the public are infections and deaths. Numbers associated with long term health by damaged body subsystems are not being provided. |
Note: Yes = Resources deployed, No = Resources not deployed, Rejected = rejected by many because of US Government leadership.
What this functional analysis shows is the massive breakdown in the US Virus Defense System. The lessons learned and technologies to deal with the virus are almost 100 years old and they were not used. The biggest issues from this analysis are:
Nature abhors a vacuum. Because the US failed to disclose real performance numbers the Internet has been filled with disinformation and propaganda. A civilization is not sustainable with carefully crafted management talking points aimed at damage control and protecting narrow interests like airline revenues especially in times of massive disaster. For example, the analysis clearly shows that a social distance of 1 foot as found when seated on an airplane will lead to infection. The airlines are clearly on record stating that the goal is to book all seats on a flight. A reasonable approach would be to book seats that provide 6 or more feet of social distancing. This translates to 1 person every other row or every third row. Given that the original infection spread was accelerated via air travel, to allow that condition to reappear by October 2020 is outrageous behavior. This is a triple failure. The first failure is with the airline companies, the second failure is with the FAA that failed to roll out emergency regulations because of deregulation dogma, and the third failure is with the people who refuse to follow their common sense. Estimates are that 9.4 million people traveled by air for the Thanksgiving Holiday [3].
There are suggestions that in 2021 there will be renewed emphasis on US research and a return to respecting the findings of scientists, engineers, and common sense. Basic research occurs in academia and science directed research at solving societal problems occurs in federal laboratories [4].
This is an unusual functional analysis. When it was started this final path was not the intent. The goal was to just disclose the functions and show the relationship between the functions. Instead, once the system became visible via the functional analysis, it was natural to begin to assess the performance of each function performed by the various subsystems. The subsystems for this system are social subsystems and so the result is a social assessment of the situation.
After this analysis made its first pass there was an intense effort to try and find the actual Virus Defense System. Instead what was found was the critical role of the CDC in bio-defense beginning in the 1950's and the Crimson Contagion national level exercise performed from January to August 2019 [1] [2].
References:
[1] Before Virus Outbreak, a Cascade of Warnings Went Unheeded, New York Times, March 22, 2020. webpage https://www.nytimes.com/2020/03/19/us/politics/trump-coronavirus-outbreak.html, December 2020. Before Virus Outbreak, a Cascade of Warnings Went Unheeded
[2] Crimson_Contagion https://en.wikipedia.org/wiki/Crimson_Contagion, December 2020.
[3] Sunday was the busiest day for US air travel since the pandemic began, CNN www.cnn.com, November 30, 2020. webpage https://www.cnn.com/travel/article/thanksgiving-travel-volume-2020-pandemic/index.html, December 2020. Sunday was the busiest day for US air travel since the pandemic began
[4] Memo for President Biden: Five steps to getting more from science, Going back to normal is not enough. A revamp is required. Nature, November 8, 2020. webpage https://www.nature.com/articles/d41586-020-03148-w, December 2020. Memo for President Biden: Five steps to getting more from science, Going back to normal is not enough
On March 11, 2020 the WHO declared the coronavirus outbreak a pandemic. US Total confirmed Infections and Deaths from the US Center for Disease Control are below [1]
The table shows total reported cases and deaths. It also includes a projection for different herd immunity levels. When the herd immunity levels are compared with the death rates we see the number of years for herd immunity to take effect. Either the herd immunity percentages are too high (50%-75%), the affected population is too high (328 million), the infection rate is too slow, or the infection will be with us for a very long time (8-31 years).
These numbers do not reflect innate immunity. Innate immunity also called native immunity is the ability of an organism to resist infection because of its genetic makeup [2]. Native immunity to COVID-19 is being studied and the numbers are 12% to 21%. This would reduce the potential affected population and reduce all the numbers in the table by the same factor. Also the case fatality rates is a big factor. Changing the number from 3.5% to 3.02% is an additional 15% reduction. These two assumptions would reduce the numbers by 35%.
The numbers are very bad. Virus mutation could change all these numbers. A virus can mutate to a less dangerous form as it tries to survive in the eco system. It is unclear if that will happen in this case. Virus containment could also change these numbers. Currently virus containment in the US is based on masks, social distancing, and limited tracking. Based on the numbers from the US, it appears that the virus will not be contained. The big question is at what point will virus containment become impossible.
Date |
Total Cases |
Daily Cases |
Total Deaths |
Case fatality rates (%) |
Daily Deaths |
50% |
60% |
75% |
% into pandemic |
Comments |
March 11, 2020 |
1000 |
1000 |
29 |
2.9 |
- |
- |
- |
- |
|
CDC [1]. TV news is reporting the US COVID-19 cases and death rates. |
April 01, 2020 |
184,770 |
8,751 |
3,746 |
2.0 |
177 |
89 |
107 |
133 |
0.06 |
CDC [1]. TV news is displaying the US COVID-19 cases and death rates. |
May 01, 2020 |
1,062,446 |
29,256 |
62,406 |
5.9 |
1955 |
8 |
10 |
12 |
0.32 |
CDC [1]. TV news is displaying the US COVID-19 cases and death
rates.
Deaths exceed World War I Battle Deaths 53,402 [7] |
June 01, 2020 |
1,761,503 |
22,550 |
103,700 |
5.9 |
1332 |
12 |
14 |
18 |
0.54 |
CDC [1]. TV news STOPPED displaying and reporting the US COVID-19 cases
and death rates
Instead the news is dominated by protests that erupted by May 29, 2020 over the murder of an American citizen by police in Minneapolis, Minnesota on May 25, 2020. The TV images of the murder were broadcast around the world. [3] Deaths exceed Korean + Vietnam Wars Battle Deaths [7] |
June 10, 2020 |
1,956,421 |
21,658 |
110,925 |
5.7 |
803 |
20 |
24 |
29 |
0.60 |
CDC [1]. After 2 weeks of demonstrations over the murder of an American
citizen by police in Minneapolis, Minnesota. The second line is data from Johns Hopkins University & Medicine Cases [4]. |
| July 01, 2020 |
2,581,229 |
29,753 |
126,739 |
4.9 |
753 |
21 |
25 |
31 |
0.79 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. |
| August 01, 2020 |
4,473,974 |
61,056 |
151,499 |
3.4 |
799 |
20 |
24 |
30 |
1.36 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War I + Korean + Vietnam Wars Battle Deaths [7] |
| September 01, 2020 |
6,004,443 |
49,370 |
183,050 |
3.0 |
1018 |
15 |
19 |
23 |
1.83 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War I + Korean + Vietnam Wars Battle Deaths [7] |
| October 01, 2020 |
7,213,419 |
40,299 |
206,402 |
2.9 |
778 |
20 |
24 |
30 |
2.20 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War I + Korean + Vietnam Wars Battle Deaths [7] |
| November 01, 2020 |
9,105,230 |
61,026 |
229,932 |
2.5 |
759 |
21 |
25 |
31 |
2.78 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War I + Korean + Vietnam Wars Battle Deaths [7] |
| December 01, 2020 |
13,447,627 |
144,747 |
267,302 |
2.0 |
1246 |
13 |
15 |
19 |
4.10 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War I + Korean + Vietnam Wars Battle Deaths [7] 0 vaccinations |
| January 01, 2021 |
19,663,976 |
199,655 |
341,199 |
2.5 |
2384 |
7 |
8 |
10 |
6.00 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War II [7] Deaths exceed World War I + Korean + Vietnam Wars [7] 2.8 million sinlge dose vaccinations [8] |
| February 01, 2021 |
25,921,703
|
201,862 |
438,035 |
3.3 |
3124 |
5 |
6 |
8 |
7.90 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War II [7] Deaths exceed World War I + Korean + Vietnam Wars [7] 31 million single dose vaccinations [8] |
| March 01, 2021 |
28,405,925 |
88,722 |
511,839 |
2.6 |
2636 |
6 |
7 |
9 |
8.66 |
CDC [1]. The second line is data from Johns Hopkins University & Medicine Cases [4]. Deaths exceed World War II [7] Deaths exceed World War I + Korean + Vietnam Wars [7] 75 million single dose vaccinations [8] |
| April 01, 2021 |
30,213,759 |
58,317 |
548,162 |
2.1 |
1172 |
11 |
13 |
17 |
25.86% |
CDC [1]. Second line is Johns Hopkins University & Medicine Cases
[4].
Deaths exceed World War II [7] Vaccinations impact remaining years
CDC
Cases . Johns Hopkins
University & Medicine Cases |
|
Projections Let us hope and pray that something happens to stop this massive disaster
|
|||||||||
| 2+ years | 164,000,000 | 5,740,000 |
3.5 |
50% herd immunity 328 million people | ||||||
| 2+ years | 196,800,000 | 6,888,000 |
3.5 |
60% herd immunity 328 million people | ||||||
| 2+ years | 246,000,000 | 8,610,000 |
3.5 |
75% herd immunity 328 million people | ||||||
see video |
see video |
see video |
see video |
COVID19 Trend Analysis Case Study Other projections: [5] |
The following data is as of April 2020. Notice the US data has not been updated since March 2020. It is interesting to see that the old traditional retirement age of 55 appears to be a point of inflection. [6]
| Age | 0-9 | 10-19 | 20-29 | 30-39 | 40-49 | 50-59 | 60-69 | 70-79 | 80-89 | 90+ |
|---|---|---|---|---|---|---|---|---|---|---|
| Canada as of 25 April | 0.0 | 0.1 | 0.5 | 5.2 | 16.2 | |||||
| China as of 11 February | 0.0 | 0.2 | 0.2 | 0.2 | 0.4 | 1.3 | 3.6 | 8.0 | 14.8 | |
| Denmark as of 26 April | 0.2 | 4.4 | 15.4 | 24.8 | 41.0 | |||||
| Israel as of 26 April | 0.0 | 0.0 | 0.0 | 1.0 | 0.5 | 1.5 | 8.6 | 24.8 | 34.3 | 29.3 |
| Italy as of 23 April | 0.2 | 0.0 | 0.1 | 0.4 | 0.9 | 2.6 | 10.0 | 24.9 | 30.8 | 26.1 |
| Netherlands as of 25 April | 0.0 | 0.3 | 0.1 | 0.2 | 0.5 | 1.5 | 7.6 | 23.2 | 30.0 | 29.3 |
| Portugal as of 24 April | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 0.6 | 2.8 | 8.5 | 16.5 | |
| S. Korea as of 30 April | 0.0 | 0.0 | 0.0 | 0.2 | 0.2 | 0.8 | 2.6 | 10.4 | 24.3 | |
| Spain as of 25 April | 0.3 | 0.4 | 0.3 | 0.3 | 0.5 | 1.3 | 4.4 | 13.2 | 20.3 | 20.2 |
| Sweden as of 26 April | 0.0 | 0.0 | 0.4 | 0.4 | 1.0 | 2.3 | 6.9 | 21.2 | 30.0 | 34.0 |
| Switzerland as of 25 April | 0.9 | 0.0 | 0.0 | 0.1 | 0.0 | 0.5 | 2.7 | 10.1 | 24.0 | |
| WA state as of 25 April | 0.0 | 0.2 | 1.3 | 8.9 | 29.9 | |||||
| Age | 0-19 | 20-44 | 45-54 | 55-64 | 65-74 | 75-84 | 85+ |
|---|---|---|---|---|---|---|---|
| United States as of 16 March | 0.0 | 0.1-0.2 | 0.5-0.8 | 1.4-2.6 | 2.7-4.9 | 4.3-10.5 | 10.4-27.3 |
| Note: The lower bound includes all cases. The upper bound excludes cases that were missing data. | |||||||
| 0-9 | 10-19 | 20-29 | 30-39 | 40-49 | 50-59 | 60-69 | 70-79 | 80+ | |
|---|---|---|---|---|---|---|---|---|---|
| Severe disease | 0.0 (0.0-0.0) |
0.04 (0.02-0.08) |
1.0 (0.62-2.1) |
3.4 (2.0-7.0) |
4.3 (2.5-8.7) |
8.2 (4.9-17) |
11 (7.0-24) |
17 (9.9-34) |
18 (11-38) |
| Death | 0.0016 (0.00016-0.025) |
0.0070 (0.0015-0.050) |
0.031 (0.014-0.092) |
0.084 (0.041-0.19) |
0.16 (0.076-0.32) |
0.60 (0.34-1.3) |
1.9 (1.1-3.9) |
4.3 (2.5-8.4) |
7.8 (3.8-13) |
| Total infection fatality rate is estimated to be 0.66%
(0.39-1.3). Infection fatality rate is fatality per all infected individuals, regardless of whether they were diagnosed or had any symptoms. Numbers in parentheses are 95% credible intervals for the estimates. |
|||||||||
The following table has the battle deaths of US wars. [7] It is provided to offer a systems perspective of the situation.
| US Wars | Battle Deaths | US Wars | Battle Deaths |
| American Revolution (1775-1783) | 4,435 |
World War I (1917-1918) | 53,402 |
| War of 1812 (1812-1815) | 2,260 |
World War II (1941 –1945) | 291,557 |
| Indian Wars (approx. 1817-1898) | 1,000 |
Korean War (1950-1953) | 33,739 |
| Mexican War (1846-1848) | 1,733 |
Vietnam War (1964-1975) | 47,434 |
| Civil War (1861-1865) Union | 140,414 |
Desert Shield/Desert Storm (1990-1991) | 148 |
| Civil War (1861-1865) Confederate | 74,524 |
||
| Spanish-American War (1898-1902) | 385 |
America’s Wars Total (1775 -1991) | 651,031 |
References:
[1] CDC Cases, webpage https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/cases-in-us.html, various dates.
[2] Immunity, webpage https://en.wikipedia.org/wiki/Immunity_(medical), May 2020.
[3] Murder by Police Sparked World Wide Demonstrations During COVID-19 Disaster, webpage https://en.wikipedia.org/wiki/Killing_of_George_Floyd, June 2020.
[4] Johns Hopkins University & Medicine Cases, webpage https://coronavirus.jhu.edu/map.html, various dates.
[5] COVID19 Trend Analysis Case Study, COVID19 Trend Analysis Case Study, Richard Grandrino, Drexel University, June 2020.
[6] Coronavirus_disease_2019, webpage https://en.wikipedia.org/wiki/Coronavirus_disease_2019, April 2020.
[7] America’s Wars, Department of Veterans Affairs, November 2019. webpage https://www.va.gov/opa/publications/factsheets/fs_americas_wars.pdf, August 2020. America’s Wars . local
[8] Coronavirus (COVID-19) Vaccinations, Our World In Data, https://ourworldindata.org/covid-vaccinations, various dates
The reality is that the return to life systems were started the very first day of the virus outbreak. Life continued as the virus spread. Various systems were developed across the planet and by May 2020 there may be sufficient data to determine which return to life systems are more effective. These systems are embedded in different countries and in some cases different states and provinces within various countries.
Two views of this data are offered. The first is a Performance Scale and the other is an attempt to understand it by including additional data so that patterns might be detected.
Excess mortality is the number of deaths occurring in each crisis above and beyond normal conditions. The is accomplished by comparing data from previous years. Data is available from Our World In Data [1] and The Human Mortality Database [2] . local [spreadsheet].
The following data is not based on Excess Mortality, instead it is based on COVID-19 death records.
Data May 25, 2020 AM Johns Hopkins University & Medicine [3]
Global Deaths 355,629
More than 1,000,000
More than 100,000
US 100,411 . 153,320 (8/1/2020)
More than 10,000
United Kingdom 37,542 . Italy 33,072 . France 28,599 . Spain 27,117 . Brazil 25,598 .
More than 1,000
Belgium 9,364 . Mexico 8,597 . Germany 8,428 . Iran 7,564 . Canada 6,876 . Netherlands 5,890 . China 4,638 . India 4,534 . Turkey 4,431 . Sweden 4,220 . Peru 3,983 . Russia 3,968 . Ecuador 3,275 . Switzerland 1,917 . Ireland 1,631 . Indonesia 1,473 . Portugal 1,356 . Romania 1,227 . Pakistan 1,225 . Poland 1,028 .
More than 100
Philippines 904 . Japan 858 . Chile 841 . Egypt 816 . Colombia 803 . Ukraine 658 . Austria 645 . Algeria 623 . Denmark 565 . South Africa 552 . Bangladesh 544 . Hungary 505 . Argentina 500 . Dominican Republic 474 . Saudi Arabia 425 . Czechia 317 . Panama 315 . Finland 313 . Israel 281 . Bolivia 274 . Moldova 274 . Korea, South 269 . United Arab Emirates 255 . Nigeria 254 . Serbia 240 . Norway 235 . Afghanistan 227 . Belarus 214 . Morocco 202 . Sudan 195 . Honduras 194 . Cameroon 175 . Iraq 175 . Kuwait 175 . Greece 173 . Bosnia and Herzegovina 151 . Bulgaria 133 . North Macedonia 119 . Malaysia 115 . Luxembourg 110 . Slovenia 108 . Australia 103 . Croatia 101 .
More than 10
Armenia 98 . Cuba 82 . Mali 70 . Congo (Kinshasa) 68 . Guatemala 68 . Somalia 67 . Estonia 66 . Lithuania 66 . Chad 64 . Niger 63 . Thailand 57 . Kenya 55 . Azerbaijan 54 . Burkina Faso 53 . Yemen 53 . Andorra 51 . Tunisia 48 . Tajikistan 47 . Sierra Leone 45 . San Marino 42 . El Salvador 39 . Oman 39 . Senegal 38 . Kazakhstan 37 . Nicaragua 35 . Ghana 34 . Albania 33 . Haiti 33 . Cote d'Ivoire 31 . Kosovo 30 . Qatar 30 . Slovakia 28 . Liberia 27 . Lebanon 26 . Latvia 23 . Singapore 23 . New Zealand 22 . Uruguay 22 . Tanzania 21 . Guinea 20 . Congo (Brazzaville) 19 . Djibouti 18 . Cyprus 17 . Kyrgyzstan 16 . Mauritania 16 . Bahrain 15 . Gabon 14 . Uzbekistan 14 . Diamond Princess 13 . Togo 13 . Equatorial Guinea 12 . Georgia 12 . Sao Tome and Principe 12 . Bahamas 11 . Guyana 11 . Paraguay 11 . Venezuela 11 . Iceland 10 . Costa Rica 10 . Mauritius 10 . South Sudan 10 . Sri Lanka 10 .
Less than 10
Jamaica 9 . Jordan 9 . Montenegro 9 . Trinidad and Tobago 8 . Barbados 7 . Guinea-Bissau 7 . Malta 7 . Taiwan* 7 . Zambia 7 . Burma 6 . Ethiopia 6 . Maldives 5 . Angola 4 . Cabo Verde 4 . Libya 4 . Malawi 4 . Monaco 4 . Nepal 4 . Syria 4 . Zimbabwe 4 . Antigua and Barbuda 3 . Benin 3 . West Bank and Gaza 3 . Belize 2 . Brunei 2 . Comoros 2 . Eswatini 2 . MS Zaandam 2 . Madagascar 2 . Botswana 1 . Burundi 1 . Central African Republic 1 . Gambia 1 . Liechtenstein 1 . Mozambique 1 . Suriname 1 . Western Sahara 1 .
May 26, 2020 PM Worldmeters [4]
As the data is examined patterns need to be identified. It is easy to dismiss the data as being inaccurate. However, in a systems analysis we must assume the data has the same level of accuracy across all the data points. Instead there is a search for a pattern. The difference may be due to environment, genes, food, culture, virus mitigation action plan, or another element. We know that the environment is not a factor, temperature and humidity are not relevant. Some suggest genes may be the source however there are examples suggesting that is not the case when adjacent countries are examined. Food like genes can be discounted for the same reason, adjacent countries have significant differences. The remaining variables are culture and virus mitigation action plans. [spreadsheet]
| # | Country | Deaths (Sorted by) |
Cases/1M | Deaths/1M | Population | Observations |
| World | 351,601 | 728 | 45.1 | 7,750,747,910 | ||
| 1 | USA | 100,545 | 5,215 | 304 | 330,811,717 | The US is geographically very diverse. Examining the numbers by state may offer some insights. For example, Hawaii always has trade winds and perhaps people tend to live outside rather than in enclosed office buildings. As an island(s) state the culture may be more sensitive to pandemics and they may have a very effective virus mitigation plan. |
| 2 | UK | 37,048 | 3,909 | 546 | 67,851,047 | |
| 3 | Italy | 32,955 | 3,813 | 545 | 60,470,230 | |
| 4 | France | 28,530 | 2,800 | 437 | 65,259,581 | |
| 5 | Spain | 27,117 | 6,060 | 580 | 46,753,049 | |
| 6 | Brazil | 24,512 | 1,842 | 115 | 212,409,786 | |
| 7 | Belgium | 9,334 | 4,960 | 806 | 11,584,702 | |
| 8 | Germany | 8,498 | 2,164 | 101 | 83,757,965 | |
| 9 | Mexico | 7,633 | 552 | 59 | 128,796,145 | |
| 10 | Iran | 7,508 | 1,663 | 90 | 83,883,203 | |
| 11 | Canada | 6,639 | 2,298 | 176 | 37,709,091 | |
| 12 | Netherlands | 5,856 | 2,661 | 342 | 17,131,215 | |
| 13 | China | 4,634 | 58 | 3 | 1,439,323,776 | |
| 14 | Turkey | 4,397 | 1,884 | 52 | 84,247,422 | |
| 15 | India | 4,349 | 109 | 3 | 1,378,641,054 | |
| 16 | Sweden | 4,125 | 3,412 | 409 | 10,093,058 | |
| 17 | Russia | 3,807 | 2,483 | 26 | 145,928,485 | It is possible that the HVAC systems in Russia are different. There is more emphasis on heat rather than air conditioning. Also the buildings might be older based on natural ventilation concepts. |
| 18 | Peru | 3,788 | 3,941 | 115 | 32,924,686 | |
| 19 | Ecuador | 3,203 | 2,121 | 182 | 17,615,358 | |
| 20 | Switzerland | 1,915 | 3,557 | 221 | 8,648,347 | |
| 21 | Ireland | 1,615 | 5,015 | 327 | 4,932,204 | |
| 22 | Indonesia | 1,418 | 85 | 5 | 273,231,828 | |
| 23 | Portugal | 1,342 | 3,040 | 132 | 10,199,497 | |
| 24 | Romania | 1,216 | 957 | 63 | 19,249,480 | |
| 25 | Pakistan | 1,197 | 262 | 5 | 220,438,956 | |
| 26 | Poland | 1,024 | 583 | 27 | 37,850,537 | |
| 27 | Philippines | 886 | 134 | 8 | 109,431,787 | |
| 28 | Japan | 846 | 131 | 7 | 126,512,743 | It is possible that as an extremely high technology society they may have a very effective virus mitigation action plan. |
| 29 | Chile | 806 | 4,082 | 42 | 19,099,822 | |
| 30 | Egypt | 797 | 184 | 8 | 102,130,974 | Personal Observation circa 1995: The people in Egypt live outside. The car windows are always rolled down and the high rise apartments have no windows. |
| 31 | Colombia | 776 | 453 | 15 | 50,828,154 | |
| 32 | Ukraine | 644 | 493 | 15 | 43,757,987 | |
| 33 | Austria | 643 | 1,839 | 71 | 9,001,347 | |
| 34 | Algeria | 617 | 199 | 14 | 43,767,938 | |
| 35 | Denmark | 563 | 1,974 | 97 | 5,790,221 | |
| 36 | South Africa | 524 | 410 | 9 | 59,232,433 | |
| 37 | Bangladesh | 522 | 223 | 3 | 164,524,398 | |
| 38 | Hungary | 499 | 390 | 52 | 9,662,656 | |
| 39 | Argentina | 490 | 293 | 11 | 45,154,246 | |
| 40 | Dominican Republic | 468 | 1,409 | 43 | 10,836,968 | |
| 41 | Saudi Arabia | 411 | 2,207 | 12 | 34,757,706 | |
| 42 | Czechia | 317 | 845 | 30 | 10,707,069 | |
| 43 | Panama | 313 | 2,657 | 73 | 4,307,725 | |
| 44 | Finland | 312 | 1,196 | 56 | 5,539,893 | |
| 45 | Israel | 281 | 1,822 | 31 | 9,197,590 | |
| 46 | S. Korea | 269 | 219 | 5 | 51,264,961 | It is unclear if people live outside in S. Korea. It is possible that as an extremely high technology society they may have a very effective virus mitigation action plan. |
| 47 | Moldova | 267 | 1,810 | 66 | 4,034,845 | |
| 48 | Bolivia | 261 | 571 | 22 | 11,656,694 | |
| 49 | UAE | 253 | 3,147 | 26 | 9,878,250 | |
| 50 | Nigeria | 249 | 41 | 1 | 205,584,173 | |
| 51 | Serbia | 239 | 1,284 | 27 | 8,740,651 | |
| 52 | Norway | 235 | 1,548 | 43 | 5,417,027 | |
| 53 | Afghanistan | 220 | 305 | 6 | 38,834,157 | |
| 54 | Belarus | 208 | 4,028 | 22 | 9,449,619 | |
| 55 | Morocco | 202 | 206 | 5 | 36,866,123 | |
| 56 | Honduras | 182 | 424 | 18 | 9,888,260 | |
| 57 | Cameroon | 175 | 205 | 7 | 26,473,989 | |
| 58 | Greece | 173 | 277 | 17 | 10,427,777 | Greece takes great pride in the virus mitigation action plan that they enacted very early in the COVID-19 outbreak. One news report showed that they even spray their outdoor beach lounges with disinfectant. |
| 59 | Kuwait | 172 | 5,294 | 40 | 4,264,055 | |
| 60 | Sudan | 170 | 91 | 4 | 43,738,792 | |
| 61 | Iraq | 169 | 121 | 4 | 40,125,564 | |
| 62 | Bosnia and Herzegovina | 149 | 736 | 45 | 3,282,698 | |
| 63 | Bulgaria | 130 | 351 | 19 | 6,953,227 | |
| 64 | North Macedonia | 116 | 967 | 56 | 2,083,382 | |
| 65 | Malaysia | 115 | 235 | 4 | 32,323,664 | |
| 66 | Luxembourg | 110 | 6,393 | 176 | 624,919 | |
| 67 | Slovenia | 108 | 707 | 52 | 2,078,911 | |
| 68 | Australia | 102 | 280 | 4 | 25,469,872 | |
| 69 | Croatia | 101 | 546 | 25 | 4,107,599 | |
| 70 | Armenia | 91 | 2,498 | 31 | 2,962,710 | |
| 71 | Cuba | 82 | 173 | 7 | 11,327,273 | |
| 72 | Mali | 70 | 53 | 3 | 20,186,088 | |
| 73 | DRC | 68 | 27 | 0.8 | 89,256,655 | |
| 74 | Somalia | 67 | 108 | 4 | 15,844,234 | |
| 75 | Estonia | 65 | 1,383 | 49 | 1,326,450 | |
| 76 | Lithuania | 65 | 601 | 24 | 2,725,640 | |
| 77 | Niger | 63 | 39 | 3 | 24,105,596 | |
| 78 | Chad | 62 | 43 | 4 | 16,373,575 | |
| 79 | Guatemala | 59 | 210 | 3 | 17,880,705 | |
| 80 | Thailand | 57 | 44 | 0.8 | 69,783,058 | |
| 81 | Azerbaijan | 52 | 435 | 5 | 10,130,034 | |
| 82 | Kenya | 52 | 25 | 1.0 | 53,644,375 | |
| 83 | Burkina Faso | 52 | 40 | 2 | 20,840,103 | |
| 84 | Andorra | 51 | 9,877 | 660 | 77,253 | |
| 85 | Yemen | 49 | 8 | 2 | 29,755,574 | |
| 86 | Tunisia | 48 | 89 | 4 | 11,806,151 | |
| 87 | Tajikistan | 47 | 343 | 5 | 9,514,637 | |
| 88 | Channel Islands | 45 | 3,218 | 259 | 173,702 | |
| 89 | Sierra Leone | 44 | 95 | 6 | 7,959,753 | |
| 90 | San Marino | 42 | 19,632 | 1,238 | 33,924 | |
| 91 | Kazakhstan | 37 | 478 | 2 | 18,753,881 | |
| 92 | Oman | 37 | 1,594 | 7 | 5,092,460 | |
| 93 | Senegal | 36 | 189 | 2 | 16,695,568 | |
| 94 | El Salvador | 36 | 315 | 6 | 6,483,000 | |
| 95 | Nicaragua | 35 | 115 | 5 | 6,616,547 | |
| 96 | Ghana | 34 | 230 | 1 | 31,003,853 | |
| 97 | Albania | 33 | 358 | 11 | 2,878,095 | |
| 98 | Haiti | 31 | 93 | 3 | 11,388,384 | |
| 99 | Ivory Coast | 30 | 94 | 1 | 26,307,273 | |
| 100 | Qatar | 28 | 16,414 | 10 | 2,875,978 | |
| 101 | Slovakia | 28 | 277 | 5 | 5,459,389 | |
| 102 | Lebanon | 26 | 167 | 4 | 6,828,287 | |
| 103 | Liberia | 26 | 53 | 5 | 5,044,844 | |
| 104 | Isle of Man | 24 | 3,953 | 282 | 84,989 | |
| 105 | Singapore | 23 | 5,533 | 4 | 5,845,767 | |
| 106 | Latvia | 22 | 558 | 12 | 1,888,068 | |
| 107 | Uruguay | 22 | 227 | 6 | 3,472,561 | |
| 108 | New Zealand | 21 | 312 | 4 | 4,818,333 | |
| 109 | Tanzania | 21 | 9 | 0.4 | 59,545,671 | |
| 110 | Guinea | 20 | 250 | 2 | 13,093,597 | |
| 111 | Mayotte | 20 | 6,005 | 74 | 272,102 | |
| 112 | Cyprus | 17 | 778 | 14 | 1,206,488 | |
| 113 | Kyrgyzstan | 16 | 225 | 2 | 6,512,990 | |
| 114 | Congo | 16 | 88 | 3 | 5,503,335 | |
| 115 | Sint Maarten | 15 | 1,798 | 350 | 42,827 | |
| 116 | Bahrain | 14 | 5,526 | 8 | 1,694,805 | |
| 117 | Uzbekistan | 14 | 98 | 0.4 | 33,419,241 | |
| 118 | Djibouti | 14 | 2,502 | 14 | 986,520 | |
| 119 | Gabon | 14 | 1,008 | 6 | 2,220,060 | |
| 120 | Martinique | 14 | 525 | 37 | 375,293 | |
| 121 | Guadeloupe | 14 | 402 | 35 | 400,117 | |
| 122 | Diamond Princess | 13 | 0 | |||
| 123 | Togo | 13 | 47 | 2 | 8,257,779 | |
| 124 | Mauritania | 13 | 58 | 3 | 4,636,268 | |
| 125 | Equatorial Guinea | 12 | 746 | 9 | 1,397,760 | |
| 126 | Georgia | 12 | 183 | 3 | 3,989,889 | |
| 127 | Sao Tome and Principe | 12 | 2,016 | 55 | 218,731 | |
| 128 | Venezuela | 11 | 43 | 0.4 | 28,443,500 | |
| 129 | Paraguay | 11 | 123 | 2 | 7,123,619 | |
| 130 | Guyana | 11 | 177 | 14 | 786,181 | |
| 131 | Bahamas | 11 | 255 | 28 | 392,867 | |
| 132 | Iceland | 10 | 5,290 | 29 | 341,024 | |
| 133 | Sri Lanka | 10 | 62 | 0.5 | 21,404,496 | |
| 134 | Costa Rica | 10 | 188 | 2 | 5,089,461 | |
| 135 | Mauritius | 10 | 263 | 8 | 1,271,565 | |
| 136 | Jordan | 9 | 70 | 0.9 | 10,192,951 | |
| 137 | Jamaica | 9 | 188 | 3 | 2,959,906 | |
| 138 | Montenegro | 9 | 516 | 14 | 628,058 | |
| 139 | Bermuda | 9 | 2,231 | 144 | 62,299 | |
| 140 | South Sudan | 8 | 72 | 0.7 | 11,180,404 | |
| 141 | Trinidad and Tobago | 8 | 83 | 6 | 1,399,048 | |
| 142 | Guinea-Bissau | 7 | 600 | 4 | 1,962,975 | |
| 143 | Zambia | 7 | 50 | 0.4 | 18,327,041 | |
| 144 | Taiwan | 7 | 19 | 0.3 | 23,812,627 | |
| 145 | Barbados | 7 | 320 | 24 | 287,341 | |
| 146 | Ethiopia | 6 | 6 | 0.05 | 114,654,045 | |
| 147 | Malta | 6 | 1,384 | 14 | 441,429 | |
| 148 | Myanmar | 6 | 4 | 0.1 | 54,373,757 | |
| 149 | Maldives | 5 | 2,665 | 9 | 539,547 | |
| 150 | Hong Kong | 4 | 142 | 0.5 | 7,490,925 | |
| 151 | Nepal | 4 | 27 | 0.1 | 29,081,827 | |
| 152 | Cabo Verde | 4 | 702 | 7 | 555,377 | |
| 153 | Syria | 4 | 7 | 0.2 | 17,454,561 | |
| 154 | Malawi | 4 | 5 | 0.2 | 19,075,919 | |
| 155 | Monaco | 4 | 2,499 | 102 | 39,214 | |
| 156 | Angola | 4 | 2 | 0.1 | 32,751,429 | |
| 157 | Zimbabwe | 4 | 4 | 0.3 | 14,840,631 | |
| 158 | Palestine | 3 | 84 | 0.6 | 5,088,625 | |
| 159 | Benin | 3 | 17 | 0.2 | 12,088,427 | |
| 160 | Aruba | 3 | 946 | 28 | 106,722 | |
| 161 | Libya | 3 | 11 | 0.4 | 6,861,713 | |
| 162 | Saint Martin | 3 | 1,036 | 78 | 38,597 | |
| 163 | Antigua and Barbuda | 3 | 255 | 31 | 97,848 | |
| 164 | Madagascar | 2 | 21 | 0.07 | 27,613,258 | |
| 165 | Eswatini | 2 | 225 | 2 | 1,158,954 | |
| 166 | Belize | 2 | 45 | 5 | 396,870 | |
| 167 | MS Zaandam | 2 | 0 | |||
| 168 | CAR | 1 | 139 | 0.2 | 4,820,985 | |
| 169 | Reunion | 1 | 513 | 1 | 894,679 | |
| 170 | French Guiana | 1 | 1,289 | 3 | 297,835 | |
| 171 | Mozambique | 1 | 7 | 0.03 | 31,158,631 | |
| 172 | Brunei | 1 | 323 | 2 | 437,059 | |
| 173 | Cayman Islands | 1 | 2,041 | 15 | 65,644 | |
| 174 | Comoros | 1 | 100 | 1 | 867,624 | |
| 175 | Liechtenstein | 1 | 2,151 | 26 | 38,117 | |
| 176 | Burundi | 1 | 4 | 0.08 | 11,851,274 | |
| 177 | Botswana | 1 | 15 | 0.4 | 2,346,588 | |
| 178 | Gambia | 1 | 10 | 0.4 | 2,409,159 | |
| 179 | Curaçao | 1 | 110 | 6 | 164,028 | |
| 180 | Turks and Caicos | 1 | 310 | 26 | 38,663 | |
| 181 | Montserrat | 1 | 2,204 | 200 | 4,992 | |
| 182 | Suriname | 1 | 19 | 2 | 586,106 | |
| 183 | Western Sahara | 1 | 15 | 2 | 595,744 | |
| 184 | British Virgin Islands | 1 | 265 | 33 | 30,211 | |
| 185 | Rwanda | 26 | 12,917,314 | |||
| 186 | Vietnam | 3 | 97,250,965 | |||
| 187 | Uganda | 6 | 45,578,341 | |||
| 188 | Faeroe Islands | 3,828 | 48,845 | |||
| 189 | Gibraltar | 4,571 | 33,692 | |||
| 190 | Mongolia | 43 | 3,272,806 | |||
| 191 | Cambodia | 7 | 16,695,214 | |||
| 192 | French Polynesia | 214 | 280,748 | |||
| 193 | Macao | 69 | 648,427 | |||
| 194 | Eritrea | 11 | 3,541,383 | |||
| 195 | Bhutan | 35 | 770,749 | |||
| 196 | Timor-Leste | 18 | 1,315,796 | |||
| 197 | Grenada | 204 | 112,472 | |||
| 198 | Namibia | 8 | 2,536,074 | |||
| 199 | Laos | 3 | 7,264,685 | |||
| 200 | Fiji | 20 | 895,801 | |||
| 201 | New Caledonia | 63 | 285,223 | |||
| 202 | Saint Lucia | 98 | 183,545 | |||
| 203 | St. Vincent Grenadines | 162 | 110,906 | |||
| 204 | Dominica | 222 | 71,969 | |||
| 205 | Saint Kitts and Nevis | 282 | 53,162 | |||
| 206 | Falkland Islands | 3,747 | 3,469 | |||
| 207 | Greenland | 211 | 56,761 | |||
| 208 | Vatican City | 14,981 | 801 | |||
| 209 | Seychelles | 112 | 98,287 | |||
| 210 | Papua New Guinea | 0.9 | 8,929,153 | |||
| 211 | Caribbean Netherlands | 229 | 26,199 | |||
| 212 | St. Barth | 608 | 9,874 | |||
| 213 | Anguilla | 200 | 14,990 | |||
| 214 | Lesotho | 0.9 | 2,140,560 | |||
| 215 | Saint Pierre Miquelon | 173 | 5,797 | |||
| Total: | 351,601 | 728.3 | 45.1 | 7,750,747,910 |
References:
[1] Our World In Data, webpage https://ourworldindata.org/excess-mortality-covid, various dates.
[2] The Human Mortality Database, webpage https://www.mortality.org, various dates.
[3] Johns Hopkins University & Medicine, webpage https://coronavirus.jhu.edu/map.html, May 25, 2020.
[4] Worldmeters, webpage https://www.worldometers.info/coronavirus, May 26, 2020.
US Failure to Contain the Virus
As of July 2020 the US failed to contain the virus.
Many states following political dogma from zealots rather than medical advice are seeing massive increases in the virus spread. Hospitals are starting to be overwhelmed in these states. They did not follow reopening guidance where disease transmission is under control, specifically that they have a 14 day decline in the infection rate. The Governors ignored the daily infection data provided by their medical professionals. Instead they engaged in catastrophically flawed management practices of just pushing an agenda regardless of the harm and the harm in this case is grave harm [1]. The people were not wearing masks in public settings, they were not social distancing, and they consciously decided to attended venues with large crowds inside close indoor spaces.
It should be noted that as the summer months approached people in the sunbelt tend to move from outdoor into air conditioned indoor venues. The combination of the indoor venues and disregard for guidance from the medical professions is what led to the sudden increase in the infection rates.
On January 9, 2020 the Chinese Center for Disease Control and Prevention reported that a new coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2), had been identified as the cause of COVID-19, and the genomic sequence was made public. In early December 2019 the Chinese Government identified a cluster of people infected with pneumonia and no clear causes. Chinese scientists linked what they thought was a pneumonia like illness to a new strain of coronavirus that was given the initial designation 2019 Novel Coronavirus (2019-nCoV). Some of the first symptoms appeared on December 10, 2019. The initial 24 cases were traced to the Huanan Seafood Wholesale Market in Wuhan. On January 10, 2020 the first death and 41 clinically confirmed infections caused by the coronavirus were reported [2].
Lock down in China:
Italy was the first European nation to be affected by COVID-19 [3]. The virus was first confirmed to have spread to Italy on January 31, 2020 when two Chinese tourists in Rome tested positive for the virus. On January 31, 2020 the Italian government suspended all flights to and from China and declared a state of emergency [4].
Quarantine
On June 24, 2020 the Governors from the states of New Jersey, New York and Connecticut implemented a 14-day quarantine program for travelers coming from coronavirus hotspot states. Anyone arriving in New York, New Jersey and Connecticut from any of the states listed, regardless of the amount of time spent in that state starting June 25, 2020 should self-quarantine for 14 days. This includes travel by train, bus, car, plane and any other method of transportation. The state of New York established fines for people who enter from certain states and don’t voluntarily quarantine for 14 days will be subject to fines and a mandatory quarantine. The fines will be 2,000 for the first violation, 5,000 for the second and up to 10,000 if they cause harm. [5].
The state of Hawaii had this policy in place for months. All tourists in Hawaii are required to quarantine for 14 days in designated locations. If they violate their quarantine they are escorted to the airport and put on the next flight out of Hawaii [6]. A press release was issued on March 21, 2020.
Press Release Mar 21, 2020
HONOLULU – Gov. David Y. Ige issued a second supplemental emergency proclamation ordering all individuals, both residents and visitors, arriving or returning to the State of Hawaii to a mandatory 14-day self-quarantine. The mandate — the first such action in the nation — applies to all arrivals at state airports from the continental U.S. and international destinations and extends to other private and commercial aircrafts.
“With the majority of Hawaii’s COVID-19 cases linked to travel, it is critical that we further mitigate the spread of the virus by both residents and visitors who are coming from out-of-state,” said Gov. Ige. “This plan was developed in collaboration with our county mayors and Hawaii’s business, community and visitor industry leaders.”
All visitors and residents arriving through Hawaii’s airports will be required to complete a Hawaii Department of Agriculture form that will be distributed onboard their flight. They will retain the form when disembarking the aircraft. Upon arrival, they will go through a checkpoint and present the completed form with a valid identification. Checkpoint staff will validate the form and issue documentation that certifies they cleared the checkpoint. The form also includes information on the mandatory requirements for the 14-day quarantine along with penalties.
The mandatory 14-day self-quarantine orders are:
- Proceed directly from the airport to your designated quarantine location, which is the location identified and affirmed by you on the mandatory State of Hawaii Department of Agriculture Plants and Animals Declaration Form.
- Remain in your designated quarantine location for a period of 14 days or the duration of your stay in the State of Hawaii, whichever is shorter.
- If you are a resident, your designated quarantine location is your place of residence.
- If you are a visitor, your designated quarantine location is your hotel room or rented lodging.
- You can only leave your designated quarantine location for medical emergencies or to seek medical care.
- Do not visit any public spaces, including but not limited to pools, meeting rooms, fitness centers or restaurants.
- Do not allow visitors in or out of your designated quarantine location other than a physician, healthcare provider, or individual authorized to enter the designated quarantine location by the Director of HIEMA.
- Comply with any and all rules or protocols related to your quarantine as set forth by your hotel or rented lodging.
- If you become ill with a fever or cough:
- Continue to stay in designated quarantine location, avoid contact with others and contact a healthcare provider for further instructions on treatment or testing.
- If you are older or have any medical conditions (e.g., immune compromise, diabetes, asthma), consult your regular healthcare provider.
- If you feel you need medical care, contact healthcare provider and inform them of your travel history.
- If you need urgent medical care (e.g., have difficulty breathing), call 9-1-1 and let the dispatcher know your travel history).
Failure to follow this order is a misdemeanor and punishable by a maximum fine of 5,000, or imprisonment of not more than one year, or both. Enforcement will be handled by each of Hawaii’s four counties.
The mandate will go into effect at 12:01 a.m. on Thursday, March 26, 2020.
“These actions are extreme, but they will help flatten the curve and lay the groundwork for a quicker recovery. We need everyone to comply with these quarantine orders to help protect Hawaii’s residents,” added Ige.
# # #
On March 11, 2020 the number of cases in US was 29. On April 1, 2020 the number of cases was 3,746. Both these numbers are manageable using contact tracing where all the people that may have been exposed to the virus could have been contacted and quarantined. [7]
The Canadian response is a whole Government response as evidenced by their citizen friendly website [8]. Early in the outbreak citizens that traveled by air were able to enter their flight numbers and they would be provided information if they were at risk of virus infection. A Canadian Quarantine Act was passed on March 24, 2020. Compliance and enforcement is as as follows: [9]
Compliance and enforcement of the Quarantine Act
The Government of Canada is working with federal and provincial partners to promote and verify compliance of the emergency order with active communication and spot checks.
If you are permitted to enter Canada, you will be:
- asked if you have a cough, fever or difficulty breathing
- required to acknowledge that you must:
- isolate for 14 days if you have symptoms of COVID-19 or
- quarantine (self-isolate) for 14 days if you do not have symptoms
- asked if you have a suitable place to isolate or quarantine (self-isolate)
- a suitable place is one where you will have basic necessities, such as food and medication, and where you will not have contact with vulnerable people
given instructions about your obligations under the emergency order
Violating any instructions provided to you when you entered Canada is an offence under the Quarantine Act and could lead to up to:
- 6 months in prison and/or
- 750,000 in fines
Further, a person who causes a risk of imminent death or serious bodily harm to another person while wilfully or recklessly contravening this act or the regulations could be liable for:
- a fine of up to 1,000,000 or
- imprisonment of up to 3 years or
- both
The Contraventions Act has been changed to give police (including RCMP, provincial and local police) more power to enforce the Quarantine Act. They can now issue tickets to people who do not comply with the act. Fines range from 275 to 1000.
Surveillance Systems
The CDC manages a very large number of health surveillance systems that includes collecting data from local and state health officials through the National Notifiable Diseases Surveillance System (NNDSS). The CDC also gathers information from medical facilities and public health departments on potentially dangerous health symptoms before they have been diagnosed by medical experts in the National Syndromic Surveillance Program (NSSP). The CDC US epidemiologist embedded in China's public-health system position was eliminated just months before the coronavirus outbreak began. As a result, the CDC could only get information from Chinese authorities, who covered up the severity of the crisis. Chinese police reprimanded a doctor who warned of the outbreak. He later died of the virus [12].
By mid-January, the US intelligence community started briefing the President on the outbreak. The Director of National Intelligence Dan Coats told Congress in January 2019 that a large-scale outbreak could lead to massive rates of death and disability, severely affect the world economy, strain international resources, and increase calls on the United States for support [12] [13].
Pandemic detection within the intelligence community is performed by agencies like the National Center for Medical Intelligence (NCMI). It is part of the Department of Defense and it tracks emerging diseases, bioterrorist threats and the medical capabilities of other countries. The NCMI has access to information that is not available to the CDC, WHO, or anyone else outside of the intelligence community. Its staff includes virologists, epidemiologists, toxicologists, medical doctors, veterinarians and other experts with medical experience from the military services. In normal times NCMI serves the US military and uses the information to monitor potential health threats to US military stationed abroad [14] [15].
US Response:
The WHO has been warning for years about the possibility of a new pandemic. In 2018 the group published a list of disease threats, including one called Disease X, where a serious international epidemic could be caused by an unknown pathogen [12].
Data is starting to suggest that the US performance to the pandemic is very poor. The issue is that the virus has spread and containment must still be a top priority. This is based on many elements in the system and one of the key elements is contact tracing, however the US is performing poorly on contact tracing [10] [11].
Contact Tracing
In Florida 5 out of 27 COVID-19 positive cases received a call from health authorities asking for their contacts [10]. In New York City 3,000 contact tracers only had close contact information from 42% of people who tested positive for Covid-19. San Francisco has been able to reach an average of 83% of Covid-19 cases and their contacts [11].
The following are key contact tracing system requirements:
As of February 2021 this is how organizations are handling COVID-19 events detected in their facilities.
Major University known for its Engineering program in Philadelphia, PA
February 01, 2021
Dear Faculty Colleagues,
As we increase variety and amount of activities on-campus and with the establishment of our own COVID-19 testing regiment, we wish to remind you of some key do’s and don’ts that the University has put into place to ensure that our community remains safe.
If you believe you have been in contact with someone who has tested positive for infection with COVID-19…
Do’s:
- Notify your immediate supervisor (do not reveal names) of the potential exposure.
- Remove yourself from the workplace.
- Determine if this is a true exposure:
- Students should contact the Student Health Center by phone or through the University Health Tracker app
- Faculty and staff should notify their primary care physician and then immediately after calling your provider contact covid19health contact email
- While waiting for guidance, quarantine.
- If deemed a true exposure you will be asked to quarantine for 14 days regardless of negative COVID-19 test, unless advised differently by the university COVID-19 team.
- Monitor symptoms via University Health Tracker app.
- Faculty and staff will receive further guidance regarding FMLA and the return-to-work process following notification to covid19health contact email.
Don’ts:
- Don’t discuss health conditions or share name(s) or contact info of positive case(s).
- Don’t attempt to contact trace.
- Don’t provide any medical advice or impose any quarantine(s) unless directed by a health care professional.
- Don’t return to work until cleared by University’s Occupational Health Provider.
If you have been in contact with someone else who was in contact with a positive or presumed positive case…
Do’s:
- Continue to work as normal following all established protocols ("contact of a contact" does not trigger investigation nor quarantine).
- Monitor symptoms via University Health Tracker app.
- Students who develop symptoms must call student health
- Employees who develop symptoms must contact their primary care provider and then notify covid19health contact email.
Don’ts:
- Don’t discuss health conditions or share name(s) or contact info of positive case(s).
- Don’t attempt to contact trace
If you learn that a student or employee has tested positive or had a potential exposure…
Do’s
- Advise the student to contact Student Health (phone) and/or the employee to contact covid19health contact email.
- Recognize that some students or employees may need to quarantine for 14 days since last exposure.
- Understand that contract tracing will be handled by the Student Health Center and trained contact tracers.
Don’ts
- Don’t discuss/share health conditions or contact info of positive cases.
- Do not start or forward any communications that may have names or medical information included.
- Don’t attempt to contact trace.
- Don’t provide any medical advice or impose any quarantine(s) unless directed by a medical professional.
- Don’t tell employee/student to return to work/class until cleared by University’s Occupational Health provider or Student Health, respectively.
On-campus COVID-19 Testing
- Student COVID-19 testing requirements
- All students that meet ANY of the following criterion MUST undergo weekly surveillance testing which started January 25th:
- Live in University-affiliated housing or buildings connected to campus properties regardless of the operator,
- Have been approved to participate in on-campus research and scholarly activities
- Take face-to-face classes, including simulation labs.
- Students living in off-campus housing who are only taking remote classes are strongly recommended to regularly participate in COVID-19 testing even if they are without any symptoms and feel well. This is especially encouraged for students with three or more roommates.
- COVID-19 testing is available on campus Monday through Friday via the Health Check app. , even if they are without any symptoms and feel well. Additional information regarding testing, including when and how to schedule a test, can be found on University’s Covid-19 Testing, Reporting and Contact-Tracing webpage.
- Please remember that if you test positive for COVID-19, a representative from Student Health- in conjunction with the Philadelphia Department of Public Health- will contact you to gain further information in order to identify exposure location and to properly and confidentially identify and contact any individuals who may have been exposed. Please note that contact tracers will never reveal your identity and diagnosis.
- If you have been in contact with a University community member who has tested positive for COVID-19, a member of the University’s contact tracing team will call you and provide instructions. Should you receive a call from (phone number), please answer the phone. Failure to participate in contact tracing may result in disciplinary action by the University.
Please continue to adhere to these protocols. It is your responsibility and obligation to yourself, your family, and your fellow University Community member to be ever vigilant to ensure we are collectively doing all that we can to keep our community safe.
On behalf of Universities’ Return Oversight Committee,
This system does not satisfy the key contact tracing requirements of:
Age 55 Home Owners Association
January 28, 2021
The Board of Trustees has extended the Clubhouse hours from 7am to 8pm.
Face coverings are required while in the Clubhouse and social distancing measures must be employed.
Please make sure you sign in and out and have a fully executed COVID-19 waiver on file with the office.
Thank you and be well!
February 02, 2021
Good Morning Everyone,
The Clubhouse is CLOSED until further notice. Unfortunately, one of our neighbors has tested positive for COVID-19. For contact tracing purposes, this resident was in the Clubhouse on the 27th, 28th, 29th and 30th. To protect the privacy of this individual, I can not divulge any more information. I'm sure you all join me in wishing our neighbor and friend a speedy recovery. Thank you for your patience and cooperation.
Notice that the system relies 100% on previous contact tracing history and does not anticipate if the individual ignores quarantine and comes in contact with other residents in the community. This system does not satisfy the key contact tracing requirements of:
Both systems, the Age 55 Community and the University, are based on the shutdown of any normal external human communications. This normal human communications existed in 1918 and exists in many other countries in 2020 and 2021. This system relies entirely on the official contact tracing mechanisms and the contact tracing mechanisms only track previous contacts. Further it relies on the trust of the individuals to first get tested and then to maintain quarantine. This is a broken system and the evidence is the US COVID-19 disaster. The virus was not stopped it was only managed at some catastrophic level.
Within the age 55 community during 2020 residents requested the board to investigate installing UV systems in the clubhouse HVAC system and in the rooms. The response was short and swift, the board rejected the request. The reason was these systems cause cancer. There was no discussion or attempt to follow up on the request. In 2021 the residents requested the board to again investigate these systems by contacting companies and the response was these systems cost too much money, no details were given. Once again no follow up or discussion. Like everyone else in the society the system that they are using is based on legal assessments and management damage control [1]. Attempts to solve the problem are not even on the table. In this case there are infection specialists, doctors, engineers, and scientists in the community and all were ignored, just like in the rest of the society.
References:
[1] On Bullshit Hardcover, Harry G. Frankfurt, Princeton University Press, ISBN: 978-0691122946, January 30, 2005.
[2] COVID-19 Pandemic Lockdown in Hubei, webpage https://en.wikipedia.org/wiki/COVID-19_pandemic_lockdown_in_Hubei, July 2020.
[3] The Outbreak of COVID-19 in Italy Fighting the Pandemic, Ciro Indolfi, MD, Carmen Spaccarotella, MD, JACC: Case Reports, April 2020 DOI: 10.1016/j.jaccas.2020.03.012. webpage https://casereports.onlinejacc.org/content/early/2020/04/22/j.jaccas.2020.03.012 The Outbreak of COVID-19 in Italy Fighting the Pandemic . local
[4] COVID-19 pandemic in Italy, https://en.wikipedia.org/wiki/COVID-19_pandemic_in_Italy, July 2020.
[5] New York, New Jersey and Connecticut impose 14-day quarantine on travelers from coronavirus hot-spot states, CNBC, Jun 24 2020. webpage https://www.cnbc.com/2020/06/24/new-york-new-jersey-and-connecticut-impose-14-day-quarantine-on-travelers-from-coronavirus-hotspot-states.html. New York, New Jersey and Connecticut impose 14-day quarantine on travelers from coronavirus hot-spot states
[6] Governor’s Office - News Release - Gov. Ige orders mandatory 14-day quarantine for all individuals arriving or returning to the State of Hawaii, March 21, 2020.
[7] See section Death Rates
[8] webpage https://www.canada.ca/en/public-health/services/diseases/coronavirus-disease-covid-19.html, July 2020. Government of Canada Response
[9] webpage https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/latest-travel-health-advice.html, July 2020. Government of Canada Quarantine
[10] Florida Health Authorities Often Fail To Do Contact Tracing, CBS/Miami/CNN TV, July 6, 2020. webpage https://miami.cbslocal.com/2020/07/06/florida-health-authorities-often-fail-to-do-contact-tracing, July 2020. Florida Health Authorities Often Fail To Do Contact Tracing
[11] Hey America, What Happened to Contact Tracing, elemental, Keren Landman, MD, June 29, 2020. webpage https://elemental.medium.com/hey-america-what-happened-to-contact-tracing-47a2dbccc020, July 2020. Hey America, What Happened to Contact Tracing
[12] U.S. intelligence agencies quick to detect Covid-19 and implications, Erik J. Dahl - The Conversation, 15th June 2020. webpage https://www.bignewsnetwork.com/news/265456931/us-intelligence-agencies-quick-to-detect-covid-19-and-implications, July 2020. U.S. intelligence agencies quick to detect Covid-19 and implications
[13] Worldwide Threat Assessment of the US Intelligence Community, 29 January 2019, Senate Select Committee on Intelligence, Office of The Director National Intelligence USA. webpage https://www.dni.gov/files/ODNI/documents/2019-ATA-SFR---SSCI.pdf, July 2020. Worldwide Threat Assessment of the US Intelligence Community
[14] Spying on coronavirus: A little-known U.S. intel outfit has its most important mission yet, NBC News, Ken Delanian, March 13, 2020. webpage https://www.nbcnews.com/health/health-news/spying-coronavirus-little-known-u-s-intel-outfit-has-its-n1157296, July 2020. Spying on coronavirus: A little-known U.S. intel outfit has its most important mission yet
[15] National Center for Medical Intelligence, webpage: https://en.wikipedia.org/wiki/National_Center_for_Medical_Intelligence, July 2020.
Any return to work system needs to include a root cause analysis from a technical perspective. There is a separate root cause analysis that is beyond the technical perspective.These are some considerations when trying to find the root cause from a technical perspective:
The COVID-19's global spread happening among the relatively rich was offered by multiple popular media circa March 2020 [1]. As time moves on this will disappear from the historical records but it is critical information. This suggests that the mechanism associated with the spread may have been airplanes and cruise ship. They both have ventilation systems and conditions where people are tightly packed together. On a cruise ship the 1 foot social distancing in voluntary while on an airplane the 1 foot social distancing is involuntary. Transmission of influenza, tuberculosis, and severe acute respiratory syndrome (SARS) have been observed on commercial airliners [2] [3]. Airplanes have dense seating but cruise ships are open air settings with internal settings similar to what is found in any city with hotel sleeping arrangements. This includes shopping, restaurants, swimming pools, open air and theater entertainment. The common elements between these two transportation systems are the material used in physical structure and the Heating Ventilation and Cooling (HVAC) systems. In September 2020 two studies were release that showed COVID-19 can spread on airline flights [4] [5] [6].
Observations:
When developing systems in the previous century knowing the system environment was critical. One of the environments was fungus and salt fog. The systems had special conformal coating and or used special materials. Otherwise the systems would be overcome by the environment and stop functioning. Moving forward, should a back to work system include:
References:
[1] COVID-19's Global Spread Among The Relatively Rich Has Been Remarkable, National Public Radio (NPR), March 14, 2020 10:09 AM ET, Transcript, interviewer: Garcia-Navarro guest: Jason Beaubien. webpage https://www.npr.org/2020/03/15/815828858/coronavirus-and-the-rich-beaubien, March 2020. COVID-19's Global Spread Among The Relatively Rich Has Been Remarkable
[2] Transmission of the severe acute respiratory syndrome on aircraft. The New England Journal of Medicine, December 18, 2003. webpage https://www.nejm.org/doi/pdf/10.1056/NEJMoa031349, March 2020. Transmission of the severe acute respiratory syndrome on aircraft
[3] Evaluating the Commercial Airliner Cabin Environment with Different Air Distribution Systems, Indoor Air 29:840–853, 2019. webpage https://engineering.purdue.edu/~yanchen/paper/2019-9.pdf, March 2020. Evaluating the Commercial Airliner Cabin Environment with Different Air Distribution Systems
[4] Coronavirus can spread on airline flights, two studies show, CNN www.cnn.com, September 18, 2020. webpage https://www.cnn.com/2020/09/18/health/coronavirus-airline-transmission-studies/index.html, September 2020. Coronavirus can spread on airline flights, two studies show
[5] Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 During Long Flight, CDC Volume 26, Number 11—November 2020, webpage https://wwwnc.cdc.gov/eid/article/26/11/20-3299_article, September 2020. Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 During Long Flight . PDF . local
[6] In-Flight Transmission of Severe Acute Respiratory Syndrome Coronavirus 2, CDC Volume 26, Number 11—November 2020, webpage https://wwwnc.cdc.gov/eid/article/26/11/20-3254_article, September 2020. In-Flight Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 . PDF . local
Return To Life Systems Performance
As of December 28, 2020 it is possible to examine the different Return To Life Systems that have been established around the world.
It appears that New Zealand may have the most successful system but it required that it closed its borders to all out of country travelers. Initially they stopped the virus internally. They then opened their borders. When the virus entered their country they shut down their borders again with no new cases since that final outbreak. New Zealand’s response to the virus has been among the most successful, together with actions taken by China, Taiwan and Thailand early on in the pandemic. The country of 5 million had 25 deaths and managed to stamp out the spread of COVID-19, allowing people to return to workplaces, schools and packed sports stadiums without restrictions [1].
Prime Minister Jacinda Ardern in interviews stated that the only two options countries were considering were (1) herd immunity or (2) flattening the curve. Initially the Prime Minister opted for the latter because the prevailing view was that elimination was impossible. Elimination was the third option that no one was considering. Her thinking quickly changed after the chief science adviser showed a graph of what flattening the curve would look like and the healthcare capacity for New Zealand. The curve wasn’t sitting under the hospital and health capacity line. The Prime Minister knew that flattening the curve wasn’t sufficient and the third option of elimination must be attempted. Prime Minister Ardern said she didn’t worry that elimination might be impossible, because even if New Zealand didn’t get there, the approach would still save lives [1].
The bottom line is that New Zealand went beyond flattening the curve. The choice was to save the most lives as quickly as possible and in the process the virus was eliminated. As always be careful what choice you pick. She and New Zealand picked well.
As of December 28, 2020, the following is a snapshot of various country Return To Life Systems performance. It is based on the number of deaths per 1 million people [2]. [spreadsheet Per Dec 28]
The following table shows selected countries doing better than the world average. They are tagged as G for Green. The full list of countries in this category is provided further in this section.
Country |
Total |
New |
Total |
New |
Total |
Active |
Serious, |
Tot Cases / |
Deaths / |
Total |
Tests / |
Population |
Tot Test |
P |
Taiwan |
793 |
8 |
7 |
|
654 |
132 |
|
33 |
0.3 |
124,021 |
5,203 |
23,837,991 |
0.5% |
G |
Vietnam |
1,451 |
10 |
35 |
|
1,303 |
113 |
|
15 |
0.4 |
1,431,631 |
14,643 |
97,767,309 |
1.5% |
G |
Thailand |
6,285 |
144 |
60 |
|
4,180 |
2,045 |
1 |
90 |
0.9 |
1,217,873 |
17,427 |
69,886,134 |
1.7% |
G |
China |
86,976 |
21 |
4,634 |
|
82,003 |
339 |
5 |
60 |
3 |
160,000,000 |
111,163 |
1,439,323,776 |
11.1% |
G |
Singapore |
58,529 |
5 |
29 |
|
58,386 |
114 |
|
9,966 |
5 |
5,236,487 |
891,638 |
5,872,885 |
89.2% |
G |
New Zealand |
2,144 |
|
25 |
|
2,069 |
50 |
|
429 |
5 |
1,394,812 |
278,845 |
5,002,100 |
27.9% |
G |
Sri Lanka |
41,603 |
549 |
194 |
3 |
33,221 |
8,188 |
|
1,939 |
9 |
1,204,350 |
56,128 |
21,457,360 |
5.6% |
G |
Ghana |
54,401 |
|
333 |
|
53,180 |
888 |
13 |
1,733 |
11 |
656,754 |
20,924 |
31,387,415 |
2.1% |
G |
S. Korea |
57,680 |
808 |
819 |
11 |
39,268 |
17,593 |
295 |
1,125 |
16 |
4,038,307 |
78,733 |
51,290,915 |
7.9% |
G |
Hong Kong |
8,672 |
61 |
139 |
2 |
7,526 |
1,007 |
51 |
1,152 |
18 |
4,943,667 |
656,811 |
7,526,775 |
65.7% |
G |
Japan |
220,236 |
2,924 |
3,252 |
39 |
184,662 |
32,322 |
661 |
1,744 |
26 |
4,725,966 |
37,423 |
126,285,250 |
3.7% |
G |
Australia |
28,337 |
25 |
909 |
1 |
25,733 |
1,695 |
|
1,105 |
35 |
11,126,082 |
433,860 |
25,644,423 |
43.4% |
G |
UAE |
202,863 |
1,027 |
660 |
3 |
179,925 |
22,278 |
|
20,391 |
66 |
20,440,219 |
2,054,550 |
9,948,758 |
205.5% |
G |
Norway |
47,276 |
217 |
429 |
8 |
37,658 |
9,189 |
27 |
8,687 |
79 |
2,754,609 |
506,175 |
5,442,011 |
50.6% |
G |
Philippines |
470,650 |
766 |
9,124 |
15 |
438,780 |
22,746 |
708 |
4,267 |
83 |
6,679,776 |
60,564 |
110,292,627 |
6.1% |
G |
India |
10,224,271 |
15,546 |
148,180 |
240 |
9,805,908 |
270,183 |
8,944 |
7,373 |
107 |
168,818,054 |
121,746 |
1,386,641,760 |
12.2% |
G |
Denmark |
155,826 |
2,479 |
1,204 |
30 |
114,841 |
39,781 |
113 |
26,856 |
208 |
10,264,912 |
1,769,133 |
5,802,228 |
176.9% |
G |
Kuwait |
149,653 |
|
931 |
|
145,579 |
3,143 |
36 |
34,792 |
216 |
1,243,422 |
289,077 |
4,301,347 |
28.9% |
G |
The following table shows selected countries doing worse than the world average. They are tagged as Y for Yellow. The full list of countries in this category is provided further in this section.
Country |
Total |
New |
Total |
New |
Total |
Active |
Serious, |
Tot Cases / |
Deaths / |
Total |
Tests / |
Population |
Tot Test |
P |
World |
81,370,893 |
237,043 |
1,776,284 |
4,761 |
57,484,045 |
22,110,564 |
105,289 |
10,439 |
227.9 |
|
|
|
|
Y |
Turkey |
2,162,775 |
15,197 |
20,135 |
257 |
2,037,433 |
105,207 |
4,251 |
25,510 |
237 |
23,958,818 |
282,591 |
84,782,714 |
28.3% |
Y |
Germany |
1,665,534 |
10,212 |
30,838 |
336 |
1,255,700 |
378,996 |
5,535 |
19,848 |
367 |
33,708,381 |
401,694 |
83,915,659 |
40.2% |
Y |
Russia |
3,078,035 |
27,787 |
55,265 |
487 |
2,471,309 |
551,461 |
2,300 |
21,087 |
379 |
89,516,176 |
613,270 |
145,965,290 |
61.3% |
Y |
Canada |
554,295 |
2,275 |
14,970 |
7 |
459,096 |
80,229 |
715 |
14,624 |
395 |
13,438,585 |
354,541 |
37,904,174 |
35.5% |
Y |
Ukraine |
1,030,374 |
4,385 |
17,849 |
75 |
665,729 |
346,796 |
177 |
23,630 |
409 |
5,472,989 |
125,516 |
43,603,742 |
12.6% |
Y |
South Africa |
1,004,413 |
|
26,735 |
|
844,874 |
132,804 |
546 |
16,832 |
448 |
6,445,318 |
108,009 |
59,673,704 |
10.8% |
Y |
Greece |
135,931 |
475 |
4,672 |
66 |
9,989 |
121,270 |
467 |
13,073 |
449 |
3,283,621 |
315,797 |
10,397,879 |
31.6% |
Y |
The following table shows selected countries doing significantly worse than the world average. They are tagged as O for Orange. The full list of countries in this category is provided further in this section.
Country |
Total |
New |
Total |
New |
Total |
Active |
Serious, |
Tot Cases / |
Deaths / |
Total |
Tests / |
Population |
Tot Test |
P |
Netherlands |
770,400 |
7,415 |
11,042 |
44 |
N/A |
N/A |
651 |
44,912 |
644 |
5,770,408 |
336,398 |
17,153,526 |
33.6% |
O |
Poland |
1,261,010 |
3,211 |
27,147 |
29 |
1,005,376 |
228,487 |
1,599 |
33,337 |
718 |
7,078,555 |
187,134 |
37,826,168 |
18.7% |
O |
Sweden |
396,048 |
|
8,279 |
|
N/A |
N/A |
302 |
39,096 |
817 |
4,272,532 |
421,764 |
10,130,157 |
42.2% |
O |
Switzerland |
438,284 |
10,087 |
7,361 |
151 |
317,600 |
113,323 |
432 |
50,461 |
847 |
3,559,277 |
409,788 |
8,685,645 |
41.0% |
O |
Brazil |
7,486,094 |
1,809 |
191,207 |
61 |
6,515,370 |
779,517 |
8,318 |
35,097 |
896 |
28,600,000 |
134,083 |
213,300,138 |
13.4% |
O |
Argentina |
1,583,297 |
|
42,650 |
|
1,407,926 |
132,721 |
3,313 |
34,875 |
939 |
4,683,310 |
103,159 |
45,398,764 |
10.3% |
O |
Mexico |
1,383,434 |
6,217 |
122,426 |
400 |
1,038,766 |
222,242 |
3,913 |
10,675 |
945 |
3,511,534 |
27,096 |
129,595,093 |
2.7% |
O |
France |
2,559,686 |
|
62,746 |
|
189,941 |
2,306,999 |
2,659 |
39,172 |
960 |
34,273,124 |
524,498 |
65,344,575 |
52.4% |
O |
The following table shows selected countries doing massively worse than the world average. They are tagged as R for Red. The full list of countries in this category is provided further in this section.
Country |
Total |
New |
Total |
New |
Total |
Active |
Serious, |
Tot Cases / |
Deaths / |
Total |
Tests / |
Population |
Tot Test |
P |
USA |
19,589,952 |
16,105 |
341,332 |
194 |
11,501,001 |
7,747,619 |
28,689 |
59,014 |
1,028 |
246,804,411 |
743,487 |
331,955,077 |
74.3% |
R |
UK |
2,329,730 |
41,385 |
71,109 |
357 |
N/A |
N/A |
1,529 |
34,230 |
1,045 |
52,257,588 |
767,804 |
68,061,074 |
76.8% |
R |
Spain |
1,869,610 |
|
49,824 |
|
N/A |
N/A |
1,907 |
39,980 |
1,065 |
27,016,086 |
577,715 |
46,763,700 |
57.8% |
R |
Peru |
1,007,657 |
|
37,474 |
|
945,603 |
24,580 |
1,144 |
30,355 |
1,129 |
5,463,577 |
164,586 |
33,195,820 |
16.5% |
R |
Italy |
2,056,277 |
8,585 |
72,370 |
445 |
1,408,686 |
575,221 |
2,565 |
34,034 |
1,198 |
26,114,818 |
432,236 |
60,417,968 |
43.2% |
R |
Belgium |
638,877 |
847 |
19,200 |
42 |
43,873 |
575,804 |
492 |
55,007 |
1,653 |
6,816,200 |
586,875 |
11,614,401 |
58.7% |
R |
This shows that there are other countries that have also been successful at containing the virus and they should also be part of the study efforts. These are the shown above countries that performed better than the world average:
Burundi Eritrea Taiwan Tanzania Vietnam Thailand Papua New Guinea Fiji Western Sahara China Burkina Faso Benin Niger Singapore Uganda Ivory Coast Mozambique New Zealand Nigeria DRC Guinea Rwanda South Sudan Chad Brunei Somalia Togo Comoros Mauritius Sri Lanka Madagascar Tajikistan Sierra Leone Malawi Ghana Angola Mali Cuba CAR Malaysia Ethiopia S. Korea Liberia Cameroon Botswana Uzbekistan Hong Kong Congo Haiti Yemen Zambia Senegal Zimbabwe Guinea-Bissau Lesotho Barbados Nicaragua Japan Saint Lucia Gabon Cayman Islands Kenya Sudan British Virgin Islands Australia Venezuela Syria Bangladesh Pakistan Uruguay Réunion Myanmar Gambia Antigua and Barbuda Afghanistan Equatorial Guinea Djibouti Nepal Algeria UAE Mauritania Egypt Namibia Monaco Sao Tome and Principe Indonesia Norway Iceland Philippines Curaçao Qatar Maldives Trinidad and Tobago Cyprus Finland Jamaica St. Barth India Martinique Caribbean Netherlands Kazakhstan Eswatini Belarus Turks and Caicos Estonia Bermuda Saudi Arabia Gibraltar Morocco Mayotte Cabo Verde Montserrat El Salvador Suriname Bahrain Kyrgyzstan Lebanon Denmark Libya Guyana Kuwait Dominican Republic
Many of these countries have populations that tend to live outside, have small populations, and or are island nations. However, some share many social and economic characteristics of the worst performing countries like the United States and they are industrialized with daily life engaged inside buildings. This data suggests that the following Return to Life Systems need to be closely studied:
It is clear that their buildings and air travel characteristics need to be studied. It is not just about the social aspect of respecting the virus and practicing virus mitigation approaches like social distancing, masks, and quarantine. It is possible that the virus mitigation practices will only work when there is first safe air travel and second safe indoor living spaces. This analysis and empirical data shows that air travel is a massive source of virus spread and the countries with the worst return to life systems performance, like the US, do engage in massive air travel. The R0 while on an airplane can be as high as 22, which is massive [3].
The other countries performance are as follows:
Green: 122 (better than world average)
Burundi Eritrea Taiwan Tanzania Vietnam Thailand Papua New Guinea Fiji Western Sahara China Burkina Faso Benin Niger Singapore Uganda Ivory Coast Mozambique New Zealand Nigeria DRC Guinea Rwanda South Sudan Chad Brunei Somalia Togo Comoros Mauritius Sri Lanka Madagascar Tajikistan Sierra Leone Malawi Ghana Angola Mali Cuba CAR Malaysia Ethiopia S. Korea Liberia Cameroon Botswana Uzbekistan Hong Kong Congo Haiti Yemen Zambia Senegal Zimbabwe Guinea-Bissau Lesotho Barbados Nicaragua Japan Saint Lucia Gabon Cayman Islands Kenya Sudan British Virgin Islands Australia Venezuela Syria Bangladesh Pakistan Uruguay Réunion Myanmar Gambia Antigua and Barbuda Afghanistan Equatorial Guinea Djibouti Nepal Algeria UAE Mauritania Egypt Namibia Monaco Sao Tome and Principe Indonesia Norway Iceland Philippines Curaçao Qatar Maldives Trinidad and Tobago Cyprus Finland Jamaica St. Barth India Martinique Caribbean Netherlands Kazakhstan Eswatini Belarus Turks and Caicos Estonia Bermuda Saudi Arabia Gibraltar Morocco Mayotte Cabo Verde Montserrat El Salvador Suriname Bahrain Kyrgyzstan Lebanon Denmark Libya Guyana Kuwait Dominican Republic
Yelllow: 36
French Guiana Turkey Azerbaijan Palestine Guatemala Oman Isle of Man Paraguay Honduras Latvia Saint Martin Iraq Channel Islands Slovakia Serbia Israel Germany Jordan Tunisia Russia French Polynesia Guadeloupe Canada Albania Costa Rica Ukraine Bahamas Ireland South Africa Greece Aruba Lithuania Malta Belize Sint Maarten Georgia
Orange: 23
Netherlands Iran Portugal Austria Poland Moldova Luxembourg Bolivia Ecuador Romania Sweden Colombia Switzerland Chile Panama Brazil Croatia Liechtenstein Armenia Argentina Mexico Hungary France
Red: 14
USA Bulgaria Czechia UK Spain Andorra Montenegro Peru North Macedonia Italy Bosnia and Herzegovina Slovenia Belgium San Marino
No Data: 25
Mongolia Diamond Princess Bhutan Faeroe Islands Cambodia Seychelles Grenada St. Vincent Grenadines Dominica Macao Timor-Leste Laos New Caledonia Saint Kitts and Nevis Falkland Islands Vatican City Greenland Solomon Islands Saint Pierre Miquelon Anguilla MS Zaandam Marshall Islands Wallis and Futuna Samoa Vanuatu
References:
[1] There’s a job to be done': New Zealand's leader explains success against Covid-19, Associated Press, Politico, December 16, 2020. webpage https://www.politico.com/news/2020/12/16/new-zealand-coronavirus-success-446192, December 2020. There’s a job to be done': New Zealand's leader explains success against Covid-19
[2] Worldmeters, webpage https://www.worldometers.info/coronavirus, December 28, 2020.
[3] See section Airplanes and Airports.
Life Expectancy
There is data available now to start to make predictions about impacts on life expectancy if the virus is not stopped and treatments do not reduce death rates. The implications are significant. Those that are 20, 30, 40, and 50 will eventually transition into the higher death rate categories. However, even before that transition the probability of death from COVID-19 is very high for the young with significant impact.
The following analysis shows the US Life Expectancy for 2017 [1]. It has been augmented to include the effects of COVD-19. The COVID-19 death probability numbers selected are based on the numbers provided in the Death Rates section of this document. The best way to understand the data is to pick the number of lives and then look at the age. For example, before COVID-19 at male age 80 there are 50,344 male lives remaining and with COVID-19 when we look at male lives remaining 50,363 the age is 68. That is a loss of 12 years because of COVID-19 if nothing works to stem the pandemic. This is similar to the 1918 Influenza pandemic where the life expectancy was reduced by 12 years. [spreadsheet Life Expect]
Exact |
Male |
Male |
Male |
Female |
Female |
Female |
Male |
Male |
Male |
0 |
0.006569 |
100,000 |
76.18 |
0.0055130 |
100,000 |
80.95 |
|
|
|
1 |
0.000444 |
99,343 |
75.69 |
0.0003820 |
99,449 |
80.39 |
0 |
100,000 |
100,000 |
2 |
0.000291 |
99,299 |
74.72 |
0.0002180 |
99,411 |
79.42 |
0 |
99,343 |
98,686 |
3 |
0.000226 |
99,270 |
73.74 |
0.0001660 |
99,389 |
78.44 |
0 |
99,299 |
98,598 |
4 |
0.000173 |
99,248 |
72.76 |
0.0001430 |
99,373 |
77.45 |
0 |
99,270 |
98,540 |
5 |
0.000158 |
99,230 |
71.77 |
0.0001270 |
99,358 |
76.47 |
0 |
99,248 |
98,496 |
6 |
0.000147 |
99,215 |
70.78 |
0.0001160 |
99,346 |
75.48 |
0 |
99,230 |
98,460 |
7 |
0.000136 |
99,200 |
69.79 |
0.0001060 |
99,334 |
74.48 |
0 |
99,215 |
98,430 |
8 |
0.000121 |
99,187 |
68.80 |
0.0000980 |
99,324 |
73.49 |
0 |
99,200 |
98,400 |
9 |
0.000104 |
99,175 |
67.81 |
0.0000910 |
99,314 |
72.50 |
0.003 |
99,187 |
98,374 |
10 |
0.000092 |
99,164 |
66.82 |
0.0000860 |
99,305 |
71.51 |
0.003 |
98,877 |
98,052 |
11 |
0.000097 |
99,155 |
65.82 |
0.0000890 |
99,296 |
70.51 |
0.003 |
98,867 |
98,031 |
12 |
0.000134 |
99,146 |
64.83 |
0.0001020 |
99,288 |
69.52 |
0.003 |
98,858 |
98,013 |
13 |
0.000210 |
99,132 |
63.84 |
0.0001280 |
99,277 |
68.52 |
0.003 |
98,849 |
97,995 |
14 |
0.000317 |
99,112 |
62.85 |
0.0001640 |
99,265 |
67.53 |
0.003 |
98,835 |
97,967 |
15 |
0.000433 |
99,080 |
61.87 |
0.0002050 |
99,248 |
66.54 |
0.003 |
98,815 |
97,927 |
16 |
0.000547 |
99,037 |
60.90 |
0.0002460 |
99,228 |
65.56 |
0.003 |
98,783 |
97,863 |
17 |
0.000672 |
98,983 |
59.93 |
0.0002850 |
99,204 |
64.57 |
0.003 |
98,740 |
97,777 |
18 |
0.000805 |
98,917 |
58.97 |
0.0003190 |
99,175 |
63.59 |
0.003 |
98,686 |
97,669 |
19 |
0.000941 |
98,837 |
58.02 |
0.0003500 |
99,144 |
62.61 |
0.003 |
98,620 |
97,537 |
20 |
0.001084 |
98,744 |
57.07 |
0.0003830 |
99,109 |
61.63 |
0.001 |
98,540 |
97,377 |
21 |
0.001219 |
98,637 |
56.13 |
0.0004170 |
99,071 |
60.66 |
0.001 |
98,645 |
97,389 |
22 |
0.001314 |
98,517 |
55.20 |
0.0004460 |
99,030 |
59.68 |
0.001 |
98,538 |
97,175 |
23 |
0.001357 |
98,387 |
54.27 |
0.0004690 |
98,986 |
58.71 |
0.001 |
98,418 |
96,935 |
24 |
0.001362 |
98,254 |
53.35 |
0.0004870 |
98,939 |
57.74 |
0.001 |
98,289 |
96,676 |
25 |
0.001353 |
98,120 |
52.42 |
0.0005050 |
98,891 |
56.76 |
0.001 |
98,156 |
96,410 |
26 |
0.001350 |
97,987 |
51.49 |
0.0005250 |
98,841 |
55.79 |
0.001 |
98,022 |
96,142 |
27 |
0.001353 |
97,855 |
50.56 |
0.0005510 |
98,789 |
54.82 |
0.001 |
97,889 |
95,876 |
28 |
0.001371 |
97,722 |
49.63 |
0.0005850 |
98,735 |
53.85 |
0.001 |
97,757 |
95,612 |
29 |
0.001399 |
97,588 |
48.69 |
0.0006260 |
98,677 |
52.88 |
0.001 |
97,624 |
95,346 |
30 |
0.001432 |
97,452 |
47.76 |
0.0006720 |
98,615 |
51.92 |
0.002 |
97,490 |
95,078 |
31 |
0.001464 |
97,312 |
46.83 |
0.0007200 |
98,549 |
50.95 |
0.002 |
97,257 |
94,709 |
32 |
0.001497 |
97,170 |
45.90 |
0.0007660 |
98,478 |
49.99 |
0.002 |
97,117 |
94,429 |
33 |
0.00153 |
97,024 |
44.96 |
0.0008060 |
98,403 |
49.02 |
0.002 |
96,976 |
94,146 |
34 |
0.001568 |
96,876 |
44.03 |
0.0008460 |
98,323 |
48.06 |
0.002 |
96,830 |
93,854 |
35 |
0.001617 |
96,724 |
43.10 |
0.0008910 |
98,240 |
47.10 |
0.002 |
96,682 |
93,558 |
36 |
0.001682 |
96,568 |
42.17 |
0.0009460 |
98,153 |
46.15 |
0.002 |
96,531 |
93,255 |
37 |
0.001759 |
96,405 |
41.24 |
0.0010130 |
98,060 |
45.19 |
0.002 |
96,375 |
92,943 |
38 |
0.001852 |
96,236 |
40.31 |
0.0010940 |
97,960 |
44.23 |
0.002 |
96,212 |
92,617 |
39 |
0.001963 |
96,057 |
39.39 |
0.0011900 |
97,853 |
43.28 |
0.002 |
96,044 |
92,280 |
40 |
0.002092 |
95,869 |
38.46 |
0.0012960 |
97,737 |
42.33 |
0.005 |
95,865 |
91,922 |
41 |
0.002246 |
95,668 |
37.54 |
0.0014130 |
97,610 |
41.39 |
0.005 |
95,390 |
91,259 |
42 |
0.002436 |
95,453 |
36.62 |
0.0015490 |
97,472 |
40.45 |
0.005 |
95,190 |
90,858 |
43 |
0.002669 |
95,221 |
35.71 |
0.0017060 |
97,321 |
39.51 |
0.005 |
94,976 |
90,429 |
44 |
0.002942 |
94,967 |
34.81 |
0.0018810 |
97,155 |
38.57 |
0.005 |
94,745 |
89,966 |
45 |
0.003244 |
94,687 |
33.91 |
0.0020690 |
96,972 |
37.65 |
0.005 |
94,492 |
89,459 |
46 |
0.003571 |
94,380 |
33.02 |
0.0022700 |
96,772 |
36.72 |
0.005 |
94,214 |
88,901 |
47 |
0.003926 |
94,043 |
32.13 |
0.0024860 |
96,552 |
35.81 |
0.005 |
93,908 |
88,288 |
48 |
0.004309 |
93,674 |
31.26 |
0.0027160 |
96,312 |
34.89 |
0.005 |
93,573 |
87,616 |
49 |
0.004719 |
93,270 |
30.39 |
0.0029600 |
96,050 |
33.99 |
0.005 |
93,206 |
86,880 |
50 |
0.005156 |
92,830 |
29.53 |
0.0032260 |
95,766 |
33.09 |
0.015 |
92,804 |
86,074 |
51 |
0.005622 |
92,352 |
28.68 |
0.0035050 |
95,457 |
32.19 |
0.015 |
91,438 |
84,268 |
52 |
0.006121 |
91,832 |
27.84 |
0.0037790 |
95,123 |
31.30 |
0.015 |
90,967 |
83,319 |
53 |
0.006656 |
91,270 |
27.01 |
0.0040400 |
94,763 |
30.42 |
0.015 |
90,455 |
82,287 |
54 |
0.007222 |
90,663 |
26.19 |
0.0043010 |
94,380 |
29.54 |
0.015 |
89,901 |
81,171 |
55 |
0.007844 |
90,008 |
25.38 |
0.0045920 |
93,974 |
28.67 |
0.015 |
89,303 |
79,966 |
56 |
0.008493 |
89,302 |
24.57 |
0.0049200 |
93,543 |
27.80 |
0.015 |
88,658 |
78,666 |
57 |
0.009116 |
88,544 |
23.78 |
0.0052660 |
93,083 |
26.93 |
0.015 |
87,962 |
77,264 |
58 |
0.00969 |
87,736 |
22.99 |
0.0056300 |
92,592 |
26.07 |
0.015 |
87,216 |
75,760 |
59 |
0.010253 |
86,886 |
22.21 |
0.0060280 |
92,071 |
25.22 |
0.015 |
86,420 |
74,156 |
60 |
0.010872 |
85,995 |
21.44 |
0.0064790 |
91,516 |
24.37 |
0.076 |
85,583 |
72,469 |
61 |
0.011591 |
85,060 |
20.67 |
0.0070010 |
90,923 |
23.52 |
0.076 |
79,459 |
65,454 |
62 |
0.012403 |
84,075 |
19.90 |
0.0076020 |
90,287 |
22.68 |
0.076 |
78,595 |
63,655 |
63 |
0.013325 |
83,032 |
19.15 |
0.0082940 |
89,600 |
21.85 |
0.076 |
77,685 |
61,760 |
64 |
0.01437 |
81,925 |
18.40 |
0.0090820 |
88,857 |
21.03 |
0.076 |
76,722 |
59,754 |
65 |
0.015553 |
80,748 |
17.66 |
0.0099900 |
88,050 |
20.22 |
0.076 |
75,699 |
57,624 |
66 |
0.016878 |
79,492 |
16.93 |
0.0110050 |
87,171 |
19.42 |
0.076 |
74,611 |
55,359 |
67 |
0.018348 |
78,151 |
16.21 |
0.0120970 |
86,211 |
18.63 |
0.076 |
73,451 |
52,943 |
68 |
0.019969 |
76,717 |
15.51 |
0.0132610 |
85,168 |
17.85 |
0.076 |
72,212 |
50,363 |
69 |
0.021766 |
75,185 |
14.81 |
0.0145290 |
84,039 |
17.09 |
0.076 |
70,887 |
47,604 |
70 |
0.02384 |
73,548 |
14.13 |
0.0159910 |
82,818 |
16.33 |
0.232 |
69,471 |
44,656 |
71 |
0.026162 |
71,795 |
13.47 |
0.0176620 |
81,494 |
15.59 |
0.232 |
56,485 |
30,033 |
72 |
0.028625 |
69,917 |
12.81 |
0.0194860 |
80,054 |
14.86 |
0.232 |
55,139 |
26,934 |
73 |
0.031204 |
67,915 |
12.18 |
0.0214670 |
78,494 |
14.14 |
0.232 |
53,696 |
23,613 |
74 |
0.033997 |
65,796 |
11.55 |
0.0236580 |
76,809 |
13.44 |
0.232 |
52,159 |
20,074 |
75 |
0.0372 |
63,559 |
10.94 |
0.0262230 |
74,992 |
12.76 |
0.232 |
50,531 |
16,327 |
76 |
0.040898 |
61,195 |
10.34 |
0.0291590 |
73,026 |
12.09 |
0.232 |
48,813 |
12,372 |
77 |
0.04504 |
58,692 |
9.76 |
0.0323310 |
70,896 |
11.44 |
0.232 |
46,998 |
8,193 |
78 |
0.049664 |
56,048 |
9.20 |
0.0357250 |
68,604 |
10.80 |
0.232 |
45,075 |
3,767 |
79 |
0.054844 |
53,265 |
8.66 |
0.0394690 |
66,153 |
10.18 |
0.232 |
43,045 |
-907 |
80 |
0.060801 |
50,344 |
8.13 |
0.0438280 |
63,542 |
9.58 |
0.3 |
40,908 |
|
81 |
0.067509 |
47,283 |
7.62 |
0.0488960 |
60,757 |
9.00 |
0.3 |
35,241 |
|
82 |
0.074779 |
44,091 |
7.14 |
0.0545770 |
57,786 |
8.43 |
0.3 |
33,098 |
|
83 |
0.082589 |
40,794 |
6.68 |
0.0609090 |
54,633 |
7.89 |
0.3 |
30,864 |
|
84 |
0.091135 |
37,424 |
6.23 |
0.0680190 |
51,305 |
7.37 |
0.3 |
28,556 |
|
85 |
0.10068 |
34,014 |
5.81 |
0.0760540 |
47,815 |
6.87 |
0.3 |
26,197 |
|
86 |
0.111444 |
30,589 |
5.40 |
0.0851480 |
44,179 |
6.40 |
0.3 |
23,810 |
|
87 |
0.123571 |
27,180 |
5.02 |
0.0953950 |
40,417 |
5.94 |
0.3 |
21,412 |
|
88 |
0.137126 |
23,822 |
4.65 |
0.1068570 |
36,561 |
5.52 |
0.3 |
19,026 |
|
89 |
0.152092 |
20,555 |
4.31 |
0.1195570 |
32,655 |
5.12 |
0.3 |
16,675 |
|
90 |
0.168426 |
17,429 |
4.00 |
0.1335020 |
28,751 |
4.75 |
0.293 |
14,389 |
|
91 |
0.186063 |
14,493 |
3.70 |
0.1486850 |
24,912 |
4.40 |
0.293 |
12,322 |
|
92 |
0.204925 |
11,797 |
3.44 |
0.1650880 |
21,208 |
4.08 |
0.293 |
10,247 |
|
93 |
0.224931 |
9,379 |
3.19 |
0.1826850 |
17,707 |
3.79 |
0.293 |
8,340 |
|
94 |
0.245995 |
7,270 |
2.97 |
0.2014420 |
14,472 |
3.53 |
0.293 |
6,631 |
|
95 |
0.266884 |
5,481 |
2.78 |
0.2204060 |
11,557 |
3.29 |
0.293 |
5,140 |
|
96 |
0.287218 |
4,018 |
2.61 |
0.2392730 |
9,010 |
3.08 |
0.293 |
3,875 |
|
97 |
0.306593 |
2,864 |
2.46 |
0.2577140 |
6,854 |
2.89 |
0.293 |
2,841 |
|
98 |
0.324599 |
1,986 |
2.33 |
0.2753760 |
5,088 |
2.72 |
0.293 |
2,025 |
|
99 |
0.340829 |
1,341 |
2.21 |
0.2918990 |
3,687 |
2.56 |
0.293 |
1,404 |
|
100 |
0.35787 |
884 |
2.09 |
0.3094130 |
2,610 |
2.41 |
0.293 |
948 |
|
101 |
0.375764 |
568 |
1.98 |
0.3279780 |
1,803 |
2.27 |
0.293 |
625 |
|
102 |
0.394552 |
354 |
1.88 |
0.3476560 |
1,211 |
2.13 |
0.293 |
402 |
|
103 |
0.41428 |
215 |
1.77 |
0.3685160 |
790 |
2.00 |
0.293 |
250 |
|
104 |
0.434993 |
126 |
1.68 |
0.3906270 |
499 |
1.87 |
0.293 |
152 |
|
105 |
0.456743 |
71 |
1.58 |
0.4140640 |
304 |
1.75 |
0.293 |
89 |
|
106 |
0.47958 |
39 |
1.49 |
0.4389080 |
178 |
1.64 |
0.293 |
50 |
|
107 |
0.503559 |
20 |
1.40 |
0.4652430 |
100 |
1.53 |
0.293 |
28 |
|
108 |
0.528737 |
10 |
1.32 |
0.4931570 |
53 |
1.43 |
0.293 |
14 |
|
109 |
0.555174 |
5 |
1.24 |
0.5227470 |
27 |
1.33 |
0.293 |
7 |
|
110 |
0.582933 |
2 |
1.16 |
0.5541110 |
13 |
1.23 |
0.293 |
4 |
|
111 |
0.61208 |
1 |
1.09 |
0.5873580 |
6 |
1.14 |
0.293 |
1 |
|
112 |
0.642683 |
0 |
1.02 |
0.6225990 |
2 |
1.06 |
0.293 |
1 |
|
113 |
0.674818 |
0 |
0.95 |
0.6599550 |
1 |
0.98 |
0.293 |
0 |
|
114 |
0.708559 |
0 |
0.89 |
0.6995530 |
0 |
0.90 |
0.293 |
0 |
|
115 |
0.743986 |
0 |
0.82 |
0.7415260 |
0 |
0.83 |
0.293 |
0 |
|
116 |
0.781186 |
0 |
0.76 |
0.7811860 |
0 |
0.76 |
0.293 |
0 |
|
117 |
0.820245 |
0 |
0.71 |
0.8202450 |
0 |
0.71 |
0.293 |
0 |
|
118 |
0.861257 |
0 |
0.65 |
0.8612570 |
0 |
0.65 |
0.293 |
0 |
|
119 |
0.90432 |
0 |
0.60 |
0.9043200 |
0 |
0.60 |
0.293 |
0 |
|
a. Probability of dying within one year.
b. Number of survivors out of 100,000 born alive.
Note: The period life expectancy at a given age for 2017 represents the average
number of years of life remaining if a group of persons at that age were
to experience the mortality rates for 2017 over the course of their remaining
life.
A picture is worth a thousand words. The following graph shows the remaining lives per year before and after COVID-19 using the previous data. We don't know what multiple infections over a life time will do to further reduce life expectancy. We also do not know the types and levels of health loss due to this infection. There will be people that will be partially and permanently disabled. Others will suffer with loss of health and reduced life quality.
The political management talking points in 2020 by the current US administration in power were that the virus impacts only the old and sick. This was offered to the masses. Some accepted it blindly and some knew better. This was a gross misrepresentation and massive social injustice to future generations. [2]
This is a wakeup call that massive resources need to be applied to stop this pandemic. This systems analysis suggests that there is no single solution that will stop this virus. Instead the virus mitigation system must include multiple complex and highly effective subsystems and upgrades that need to start immediately.
Waiting for a vaccine and treatments is irresponsible. The vaccine analysis shows that it may take decades to remove the virus from the population unless we somehow change previous history where the vaccine approaches 90% effectiveness and we approach 90% vaccination levels. Both of which are individually unlikely and in combination impossible. It is an incomplete system solution.
The infrastructure modifications must begin immediately. In the previous century we used new forced air ventilation systems and UV-C systems that were properly designed and managed to minimize infection. That generation lived through measles, polio, 1918, and general illness and infections from many viruses and bacteria. As an elementary school child I learned about this struggle from the previous generation. It began with basic hygiene and clean running water and sewage management. They built a modern world that led to a very healthy population by the 1960s and 1970s [3].
The following table shows the effects of a vaccine, then the effects with the addition of UV, and finally the effects with the addition of ventilation. We have the technology, the projected decline in life expectancy shown in this analysis does not need to happen. [4]
Population |
Naturally |
Vaccine |
Vaccinated |
Exposed |
Deaths |
Deaths |
Deaths |
UV-C or |
Deaths |
Ventilation |
Deaths |
Comment |
328,000,000 |
10% |
70% |
70% |
150,552,000 |
3,011,040 |
4,516,560 |
5,269,320 |
90% |
526,932 |
28% |
379,391 |
Likely vaccine result with some natural immunity |
328,000,000 |
10% |
90% |
90% |
56,088,000 |
1,121,760 |
1,682,640 |
1,963,080 |
90% |
196,308 |
28% |
141,342 |
Unlikely vaccine result with some natural immunity |
328,000,000 |
0% |
70% |
70% |
167,280,000 |
3,345,600 |
5,018,400 |
5,854,800 |
90% |
585,480 |
28% |
421,546 |
Likely vaccine result with no natural immunity |
328,000,000 |
0% |
90% |
90% |
62,320,000 |
1,246,400 |
1,869,600 |
2,181,200 |
90% |
218,120 |
28% |
157,046 |
Unlikely vaccine result with no natural immunity |
. |
|
|
|
|
|
|
|
|
|
|
||
328,000,000 |
0% |
0% |
0% |
328,000,000 |
6,560,000 |
9,840,000 |
11,480,000 |
90% |
1,148,000 |
28% |
826,560 |
No vaccine, natural herd immunity |
328,000,000 |
10% |
0% |
0% |
295,200,000 |
5,904,000 |
8,856,000 |
10,332,000 |
90% |
1,033,200 |
28% |
743,904 |
No vaccine, natural herd immunity |
Note: Ventilation works only when it is turned on. The HVAC fan(s) must run 1 hour before and 1 hour after the facility opens to the public.
Things have changed in the 21st century. In the previous century they did not know what to do, they had to study and learn and it was hard. In this century we have the technology but we have a massive social problem where we refuse to do what needs to be done because of self-interest. If this does not stop and the system perspective is not adopted our children and grandchildren will curse this generation for cutting their lives short. That is assuming that this does not lead to social unrest as the virus keeps resurfacing. For those that view this as a good thing to reduce the stress of over population - understand that it is no fun living through revolutions and war as the natural system tries to correct itself. Make no mistake about it, this pandemic left unchecked will destabilize the world.
References:
[1] US SSA Actuarial Life Table - 2017 period life table, US Social Security Administration. webpage https://www.ssa.gov/OACT/STATS/table4c6.html, November 2020. US SSA Actuarial Life Table - 2017 period life table
[2] See section System Collapse.
[3] Science The Endless Frontier, US Government Office of Scientific Research and Development, United States Government Printing Office, Washington: 1945. webpage https://www.nsf.gov/od/lpa/nsf50/vbush1945.htm, November 2020. Science The Endless Frontier . local
[4] See section Vaccine Systems Perspective.
COVID-19 disease severity and lingering symptoms [1]:
Lingering symptoms reported by participants of a multi-state phone study in the USA [1] [2]:
What we know about people who feel they do not fully recover from COVID-19 [1] [2]:
Studies of long term health effects Severe Acute Respiratory Syndrome (SARS) infections from 2003 suggested [1] [3]:
COVID-19 can result in prolonged illness and persistent symptoms in young adults and persons with no underlying medical conditions who were not hospitalized. COVID-19 may increase the risk of long-term health problems [1]:
The virus can damage the Lungs, Heart, Brain, and Kidneys. The most common signs and symptoms that linger over time include: Fatigue, Cough, Shortness of breath, Headache, Joint pain. Heart imaging tests taken months after recovery from COVID-19 show lasting damage to the heart muscle, even in people who experienced only mild COVID-19 symptoms. This may increase the risk of heart failure or other heart complications in the future. In the Lungs pneumonia often associated with COVID-19 can cause long term damage to the tiny air sacs (alveoli) in the lungs. The resulting scar tissue can lead to long term breathing problems. In the Brain even in young people, COVID-19 can cause strokes, seizures and Guillain-Barre syndrome, a condition that causes temporary paralysis. COVID-19 may also increase the risk of developing Parkinson's disease and Alzheimer's disease. COVID-19 can weaken blood vessels, which contributes to potentially long term problems with the liver and kidneys. COVID-19 can make blood cells more likely to clump up and form clots. While large clots can cause heart attacks and strokes, much of the heart damage caused by COVID-19 is believed to come from very small clots that block tiny blood vessels (capillaries) in the heart muscle [4].
People who have severe symptoms of COVID-19 often have to be treated in a hospital's intensive care unit, with mechanical assistance such as ventilators to breathe. Simply surviving this experience can make a person more likely to later develop post-traumatic stress syndrome, depression and anxiety. Many who have recovered from SARS have gone on to develop chronic fatigue syndrome, a complex disorder characterized by extreme fatigue that worsens with physical or mental activity, but doesn't improve with rest. The same may be true for people who have had COVID-19 [4].
What is missing are the numbers and this is a very serious issue because we do not have a handle on the damage being cause by this disaster without the long term health effects numbers.
| Damage |
1 yr |
2 yr |
Permanent |
1 yr |
1 yr |
Permanent |
| Lungs | ? |
? |
? |
? |
? |
? |
| Heart | ||||||
| Brain | ||||||
| Kidneys | ||||||
| Musculoskeletal | ||||||
| Other Physical | ||||||
| Post-traumatic stress syndrome | ||||||
| Depression | ||||||
| Anxiety |
This is yet another indication of the failures of the systems that everyone assumed were in place. However, they are either not in place or have been made ineffective [5].
References:
[Library/Long-Term-Health-Effects]
[1] What we know about Long-term effects of COVID-19, THE LATEST ON THE COVID-19 GLOBAL SITUATION & LONG-TERM SEQUELAE, The World Health Organization (WHO), September 09, 2020. https://www.who.int/docs/default-source/coronaviruse/risk-comms-updates/update-36-long-term-symptoms.pdf, October 2020. What we know about Long-term effects of COVID-19 . PDF. local
[2] Symptom Duration and Risk Factors for Delayed Return to Usual Health Among Outpatients with COVID-19 in a Multistate Health Care Systems Network - United States, Morbidity and Mortality Weekly Report MMWR/July 31, 2020/Vol. 69/No. 30993 US Department of Health and Human Services/Centers for Disease Control and Prevention Symptom, March–June 2020. webpage https://www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6930e1-H.pdf, October 2020. Symptom Duration and Risk Factors for Delayed Return to Usual Health Among Outpatients with COVID-19 in a Multistate Health Care Systems Network - United States . PDF . local
[3] The long-term impact of severe acute respiratory syndrome on pulmonary function, exercise capacity and health status, Respirology (2010)15, 543–550. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7192220/pdf/RESP-15-543.pdf, October 2020. The long-term impact of severe acute respiratory syndrome on pulmonary function, exercise capacity and health status
[4] COVID-19 (coronavirus): Long-term effects, Mao Clinic, October 7. 2020. webpage https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-long-term-effects/art-20490351, October 2020. COVID-19 (coronavirus): Long-term effects
[5] See section Government Failure.
The ventilation discussion includes both indoor and outdoor ventilation. A key finding is that an outdoor venue can behave like a poor indoor venue under certain conditions.
One of the major differences between the 1918 Flu Pandemic and the COVID-19 Pandemic of 2020 is the design of our buildings. The heating ventilation and cooling systems (HVAC) in use today did not exist in 1918. This begs the question, what can be done from an engineering perspective to reduce the level of airborne viruses in all buildings especially public space buildings. As of October 2020 we now know that the virus is transmitted in poorly ventilated buildings. This analysis has the details and the results are summarized as fllows:
This analysis suggests that the indoor ventilation rates in terms of Air Updates Per Hour (AUC) must be increased: [spreadsheet]
Consumer and small public building recommendations:
This analysis states that the government should have immediately started a test and evaluation program using the national labs to develop specifications for modifications to all HVAC systems for all types of spaces [1]. Proposed legislation text is offered in the analysis [2].
References:
[1] See section Ventilation Test and Evaluation
[2] See section Proposed Legislation
HVAC Background
A literature search reveals the following documents of interest. The titles of the documents reveal some of the key issues.
References:
[1] Chemical/Biological/Radiation (CBR) Safety of the Building Envelope, Rob Bolin, PE, Syska Hennessy Group, Whole Building Design Guide, January 2017. webpage https://www.wbdg.org/resources/chemicalbiologicalradiation-cbr-safety-building-envelope, April 2020. Whole Building Design Grade (.org)
[2] Simplifying the assessment of building vulnerability to chemical, biological and radiological releases, U.S. Department of Energy Office of Scientific and Technical Information, LBNL-56780, January 2005. webpage https://www.osti.gov/servlets/purl/929080, April 2020. LBNL-56780
[3] BIPS 06 / FEMA 426 Reference Manual to Mitigate Potential Terrorist Attacks Against Buildings, U.S. Department of Homeland Security (DHS), October 2011. webpage https://www.wbdg.org/ffc/dhs/criteria/bips-06, April 2020. IPS 06 / FEMA 426 Reference Manual
[4] Protecting Buildings against Airborne Contamination, MIT, March 2008. webpage https://www.ll.mit.edu/sites/default/files/page/doc/2019-02/17_1_7Cousins.pdf, April 2020. Protecting Buildings against Airborne Contamination (MIT Lincoln Labs)
[5] Chemical/Biological/Radiological Incident Handbook, CIA, October 1998. webpage https://www.cia.gov/library/reports/general-reports-1/cbr_handbook/cbrbook.htm, April 2020. Chemical/Biological/Radiological Incident Handbook October 1998
[6] NIOSH 2003-136 Guidance for Filtration and Air Cleaning Systems to Protect Building Environments from Airborne Chemical, Biological, or Radiological Attacks, Whole Building Design Guide, April 2003. webpage https://www.wbdg.org/ffc/hhs/niosh-criteria/2003-136, April 2020. NIOSH 2003-136 Guidance for Filtration and Air Cleaning Systems
[7] Guidance for Filtration and Air-Cleaning Systems to Protect Building Environments from Airborne Chemical, Biological, or Radiological Attacks, CDC, April 2003. webpage https://www.cdc.gov/niosh/docs/2003-136/pdfs/2003-136.pdf, April 2020. Guidance for filtration and Air-Cleaning Systems to Protect Building Environments from Airborne Chemical, Biological, or Radiological Attacks (CDC)
[8] Protecting Building Occupants from Exposure to Biological Threats, Johns Hopkins University. webpage https://www.centerforhealthsecurity.org/resources/interactives/protecting_building_occupants/faq.html, April 2020. Protecting Building Occupants from Exposure to Biological Threats
[9] Building Retrofits for Increased Protection Against Airborne Chemical and Biological Releases, NIST, NISTIR 7379, March 2007. webpage https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=861035, April 2020. NISTIR 7379 Building Retrofits for Increased Protection Against Airborne Chemical and Biological Releases
[10] Biological Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Systems, U.S. Environmental Protection Agency, American Ultraviolet Corporation ACP-24/HO-4, EPA 600/R-06/054, May 2006. webpage https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=459522, April 2020. Biological Inactivation Efficiency By HVAC In-Duct Ultraviolet Light Systems . local
Building Retrofit Technologies Including UV
A number of technologies have the potential to increase building protection against chembio agent releases. Most of these are in the particle filtration and gaseous air cleaning categories. Other technologies for building protection include systems for use in mail rooms, and other spaces that may be more vulnerable to agent releases, to capture and remove the agents before they are able to migrate to other portions of the building. [1]
There are also technologies that clean the air of viruses. These fall into the categories of destroying the virus in the air or filtering the virus from the air. Now that we know the virus is airborne (as of November 2020) these are critical technologies that must be understood and applied.
Enhanced particle filtration
Particle filtration is currently employed in most commercial and institutional buildings, primarily to limit dirt buildup on cooling coils and other wetted surfaces in order to reduce the potential for microbial growth and to maintain good heat transfer between the air and the coil surfaces. However, typical levels of filtration are not always very effective in removing particles of the sizes associated with many biological agents, i.e., on the order of 1 µm. Nevertheless, dramatic increases in removal rates can still be achieved through enhanced filtration without the use of very high levels of efficiency (NIOSH 2003). Particle removal efficiencies are fairly well established based on the use of ASHRAE Standard 52.2 (ASHRAE 1999), which provides a rating method referred to as Minimum Efficiency Reporting Value (MERV). The implementation of enhanced filtration involves a number of important issues. First, the particle size of interest must be considered. Biological agents vary in size, but the bacteria and spores of most interest are generally on the order of 1 µm to 10 µm. In addition, the installation of more efficient filters will generally result in an increase in the pressure drop across the filter. Depending on the increase in filter efficiency and the type of filter installed, the increase in pressure drop may or may not be particularly large. In some cases, the air handling equipment will need to be modified due to the increased pressure drop. [1]
Sorption based gaseous air cleaning
Sorption based gaseous air cleaning is currently employed in a number of applications to control odorous, corrosive or otherwise undesirable gases generated within or outside of buildings. A variety of sorbents are employed including activated carbon, alumina and sorbents impregnated with compounds to enhance their ability to remove specific contaminants (NIOSH 2003, ASHRAE 2003). These sorbents have varying degrees of removal effectiveness depending on the particular sorbent-contaminant combination, and they capture contaminants through either physical adsorption or chemisorption. Some sorbents employing the former mechanism can be regenerated through heating or other processes. Adsorbents using a chemisorption process generally rely on catalytic (continuously self-regenerating) reactions that chemically decompose the threat gases into less toxic or non-toxic gases. The effectiveness of sorbent-based air cleaners also depends on temperature, humidity, the concentrations of the contaminant of interest as well as other contaminants, and the residence time of the airstream in the air cleaning unit. Gaseous air cleaning devices are not typically employed in commercial and institutional buildings but are seeing increasing use in a number of applications. There are no standard test methods for determining the contaminant removal efficiency of gaseous air cleaning equipment for use in selecting and sizing these systems. Manufacturers have performance data and experience that can be useful, but efforts to develop the equivalent of a MERV rating for gaseous air cleaning are still being pursued.
In general, gaseous air cleaning systems are associated with a more significant pressure drop than particle filtration devices and require more space than typical filtration equipment. These increased pressure drops can in turn affect system airflow rates and may require significant system modifications. These devices must be changed at intervals that depend on their capacity, the concentrations to which they are exposed, and the degree of temperature and humidity control in the system. [1]
Ultraviolet germicidal irradiation (UVGI)
UVGI systems have been used for many years to kill airborne infectious agents in healthcare facilities and other venues, primarily to control the transmission of tuberculosis. These devices use ultraviolet irradiation in the 250 nm to 260 nm wavelength range and are generally installed in the upper portions of a room with shielding to protect the occupants or in ductwork where such shielding is not required. This application is distinct from the use of UVGI to kill biological contamination on exposed cooling coils resulting from dirt accumulation and condensation.
The effectiveness of these devices is primarily a function of device geometry, intensity of the light source, microbial resistance and residence time of the agents of concern. Inactivation or “kill” rates can be predicted with a fair level of reliability based on these parameters (VanOsdell and Foarde 2002). However, there is no standard test method for determining the effectiveness of these devices and they are not generally supplied with the performance data to determine kill rates. These devices are associated with electrical energy consumption and require some level of maintenance to keep them operating effectively. EPA Test Results: [2]
Photocatalytic oxidation air cleaning (PCO)
PCO is an air cleaning approach in which titanium dioxide (TiO2) acts as a photocatalyst when irradiated by UV light, removing organic chemicals including both chemical and biological agents. If the photocatalytic reaction is 100 % complete, the byproducts include water and carbon dioxide, but complete conversion is difficult to achieve in practice. Various PCO devices are available as either portable, stand-alone units or in-duct devices. However, the lack of test methods for gas or biological removal limits the availability of performance data.
PCO systems generally have low pressure drops in comparison to particle filters and sorption based gaseous air cleaning. However, questions exist as to the useful life of the catalysts in practice and the production of undesirable byproducts associated with incomplete photochemical reactions. [1]
Work area treatment
A variety of devices are available for capturing and removing particulates from work areas, e.g. mail opening stations. These devices are essentially air capture hoods combined with high-efficiency filtration systems. Some of these devices also incorporate anti-microbial elements, gaseous air cleaning components and UVGI. The performance of these devices is generally expressed as a filter efficiency at a specific particle size and an airflow rate. Units with anti-microbial or gaseous air cleaning capabilities are impacted by the lack of standard test methods noted earlier. Another important parameter is the contaminant capture effectiveness, but this is not generally covered in the product specifications. [1]
References:
[1] Building Retrofits for Increased Protection Against Airborne Chemical and Biological Releases, NIST, NISTIR 7379, March 2007. webpage https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=861035, April 2020. NISTIR 7379Building Retrofits for Increased Protection Against Airborne Chemical and Biological Releases
[2] Biological Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Systems, U.S. Environmental Protection Agency, American Ultraviolet Corporation ACP-24/HO-4, EPA 600/R-06/054, May 2006. webpage https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=459522, April 2020. Biological Inactivation Efficiency By HVAC In-Duct Ultraviolet Light Systems (EPA 600/R-06/054) local
Ultraviolet Germicidal Irradiation (UVGI) - Open Air
This section addresses the use of Ultraviolet radiation in the open air rather than within an HVAC system or other enclosed system meant to disinfect the air or a surface. There are two broad categories to consider. The first is UV-C Ceiling Level lights and the second is FAR UV-222 full room lights. The UV-C application has a long history dating back into 1943. The FAR UV-222 full room lights are new technology with few applications.
This is the analysis. See sections for Design Solutions UV-C Ventilation Design Solutions . FAR UV-222 Design Solutions. See section for UV Infrastructure Cost Estimates.
UV-C Ceiling Level Lights
A 6 year study in 1943 performed in Philadelphia on the effects of the use of UV-C ceiling level lights concluded that the use of UV-C lights lowered infection levels. The study begins with: the prevalence of respiratory infection during the season of indoor congregation suggests a natural relationship between ventilation and communicable disease and concludes that the level of infection was much lower in the irradiated classroom compared to the unirradiated classroom despite the fact that there were more susceptibles in the irradiated classroom than the unirradiated classroom [1]. UV-C light when placed at the ceiling level is a ventilation approach. As the air is mixed through convection or via mechanical mechanisms and finds its way to the ceiling it is subjected to the UV-C light and bacteria or virus are destroyed. [2] [9]
This is the analysis. See section for Design Solutions UV-C Ventilation Design Solutions. See section for UV Infrastructure Cost Estimates.
Swarthmore Public School Classroom circa 1937 - 1943 |
According to CDC guidelines there is upwards of 90 percent effectiveness when applying UV-C lights and they effectively boost the air changes per hour where there can be 17 additional air changes per hour. During a study in a simulated healthcare room aerosolized M. parafortuitum was used in decay-method experiments that were conducted at mechanical ventilation rates of 0, 3, and 6 ACH, with a mixing fan to ensure a well-mixed room. The upper-room UVGI system (216 W) provided (42 ± 19) ìW/cm2 in the irradiated zone as measured by chemical actinometry. Inactivation rates (eACH) provided by the UVGI system were 17.5 ± 1.8 at 0 ACH, 20.0 ± 2.4 at 3 ACH, and 23.1 ± 0.78 at 6 ACH. [4] Note for this analysis eACH = AUC = ACH.
These are interesting numbers but they have no meaning. What matters is the percent of virus destroyed and the destruction rate. Without instantaneous 100% virus destruction we need to rely on test data. Regardless, the ceiling level UV-C systems need to be properly managed to ensure hot air is not trapped at the ceiling level, the air must circulate and yet allow sufficient time for the UV-C to destroy the virus. [2] [4]
UV-C radiation has been shown to destroy the outer protein coating of the SARS-Coronavirus [5] [7] [10]. The outer protein coating destruction leads to the inactivation of the virus. Although different from the current SARS-CoV-2 virus, it is a promising result. UV-C radiation also may be effective in inactivating the SARS-CoV-2 virus, which is the virus that causes the Coronavirus Disease 2019 (COVID-19) [5]. The effectiveness of UV-C lamps for inactivating the SARS-CoV-2 virus is based on the wavelength, exposure time, and radiation level. [8]
There are UVGI lamps that have been in use for over 80 years. [3] They are proven technology. The primary issue is that they have moved from the general consumer industrial base to the commercial industrial base with applications primarily at the industrial level in very narrow settings. This unfortunately has translated into relatively high cost driven by supply and demand where the demand numbers are low but an extreme necessity. For example, a hospital or meat packing plant will pay the high cost because it is needed. A school will not pay for these lamps because of the high cost. Every dollar counts in a school. The idea that this is a florescent light fixture available at the local hardware store for $29.95 requires an external agent to make that happen. These lamps were readily available at the consumer level in the 1960's and the previous generation knew of and understood their value. They were used everywhere in public spaces, restrooms, kitchens and even some home setting. As good health increased in the US during the 60's and 70's and the concept of infection and pandemics became an obsolete antiquated idea these lamps fell away from the consciousness of the population.
Low-pressure mercury lamp: This is the most common lamp used to produce UVC radiation. It is a low-pressure mercury lamp and more that 90% of the emission is at the 254 nm wavelength. Other specific narrow wavelengths are also available. There are other lamps that emit a broad range of UV wavelengths and also emit visible and infrared radiation. This is proven technology in use for decades.
Excimer lamp or Far-UVC lamp or FAR-UV 222: This is a new lamp being investigated to determine if humans can be directly exposed to this wavelength without any adverse health effects. This lamp produces a UV peak emission of approximately 222 nm. The concept is that the wavelength does affect the eyes or skin but will destroy the virus.
Pulsed xenon lamps: These lamps emit a short pulse of broad spectrum light (including UV, visible, and infrared) but have been filtered to emit mainly UV-C radiation. They are occasionally used in hospital settings to treat environmental surfaces in operating rooms or other spaces. They are normally used when no humans are occupying the space. This is proven technology in use for decades.
Light-emitting diodes (LEDs): Typically LEDs emit a very narrow wavelength band of radiation. Currently available UV LEDs have peak wavelengths at 214 nm, 265 nm, and 273 nm, and others. The small surface area and narrow beam width of LEDs may make them less effective for germicidal applications.
History
The germicidal effects of solar radiation was first identified in 1877 by Downes and Blunt who associated it the with actinic rays of the spectrum. The first large scale use of a UVGI system was for water purification in France in 1909 / 1910, when Marseilles authorities invited vendors of water purification equipment to participate in competitive tests. In 1936 UVGI was used to reduce postoperative infections. In 1937 UVGI was used in a school to reduce the incidence of measles, a highly contagious virus, the results were published in 1942 [9]. In the late 1950s and early 1960s a series of animal experiments showed that intense UVGI in air ducts kills or inactivates virulent M. tuberculosis in droplet nuclei. In addition to being used to control airborne viruses and microorganisms, UVGI systems have been used in wastewater treatment facilities, air handling unit cooling coils and filter assemblies, pharmaceuticals, biohazard control, medical equipment, and food. [4]
In healthcare facilities, three types of UVGI systems are used:
In duct irradiation systems, one or more UVGI lamps are positioned within a duct to irradiate air being exhausted from a room or area through the duct. In room air recirculation units containing ultraviolet (UV) lamps, a fan draws room air into the unit near lamps to disinfect the air before it is recirculated back into the room. These units may be either portable or permanently mounted. In upper room UVGI systems, UV lamps are installed into fixtures suspended from a ceiling or mounted on a wall. The UV lamps are positioned so that air in the upper part of the room is irradiated. The intent is to maximize the levels of UV radiation in the upper part of the room and to minimize the level in the lower part of the room where occupants are located. These systems depend on good air mixing to transport the air (and thereby the microorganisms) to the upper portion of the room. [4]
UV Radiation
UV radiation is a form of electromagnetic radiation with a wavelength between the blue region of the visible spectrum and the X-ray region. For convenient classification, the International Electrotechnical Commission [CIE 1987] has divided the wavelengths between 100 mn and 400 nm into three wavelength bands:
These spectral band designations are used to define approximate spectral regions and are shorthand notations that may vary between sources. Ozone in the atmosphere reacts with UV radiation below 290 nm and prevents UV-C radiation from reaching the earth's surface. UV-C radiation may be produced by a number of artificial sources (e.g. arc lamps, metal halide lamps). Germicidal lamps used in upper-room UVGI systems consist of low-pressure mercury vapor enclosed in special UV transmitting glass tubes. Approximately 95% of the energy from these lamps is radiated at 253.7 nm in the UV-C range [4].
The following table identifies other UV applications [11]:
Wavelength |
UV Applications |
13.5 |
Extreme Ultraviolet Lithography |
30-200 |
Photoionization, ultraviolet photoelectron spectroscopy |
230-365 |
UV-ID, label tracking, barcodes |
230-400 |
Optical sensors, various instrumentation |
240-280 |
Disinfection, decontamination of surfaces and water (DNA absorption has a peak at 265 nm) |
254 |
UV-C Low-pressure mercury lamp |
200-400 |
Forensic analysis, drug detection |
270-360 |
Protein analysis, DNA sequencing, drug discovery |
280-400 |
Medical imaging of cells |
300-320 |
Light therapy in medicine |
300-365 |
Curing of polymers an printer inks |
300-400 |
Solid state lighting |
350-370 |
Bug zappers (flies are most attracted to light at 365 nm) |
Cellular Effects and Health Issues
UVGI damages living cells by directly or indirectly affecting the molecular structure of nucleic acids such as deoxyribonucleic acid (DNA). Other studies have indicated that UVGI may also affect cytoplasmic and membrane structures. The photobiological reaction (e.g. the formation of covalent bonds between adjacent thymine bases in DNA) that may occur when a photon of UVGI (at 254 nm) strikes a cell translates into cellular or genetic damage that may lead to cell death or inability to successfully replicate. UVGI provides a significant germicidal effect since many biological polymers absorb energy in this bandwidth. [4]
UVGI is absorbed by the outer surfaces of the eyes and skin. Short-term overexposure may result in photokeratitis (inflammation of the cornea) and/or keratoconjunctivitis (inflammation of the conjunctiva). Keratoconjunctivitis may be debilitating for several days but is reversible. Because these effects usually manifest themselves in 6 to 12 hours after exposure, their relationship to UVGI exposure may be overlooked. Symptoms may include an abrupt sensation of sand in the eyes, tearing, and eye pain that may be severe. Skin overexposure is similar to sunburn but does not result in tanning. Several instances of healthcare workers overexposed to UVGI have been reported. Five workers in a hospital emergency room were reported to have developed dermatosis or photokeratitis after exposure to high UVGI levels from a germicidal lamp. An investigation of the incident determined that a UV lamp was unshielded. Additional reports of overexposure to UVGI from unshielded lamps have been reported in a hospital in Botswana and a morgue in the United States. [4]
UV-A and UV-B rays can damage skin [6] |
UV-C radiation has been shown to destroy the outer protein coating of the SARS-Coronavirus and the outer protein coating destruction leads to the inactivation of the virus. In 1947 during the Measles virus classroom study the UV levels were: average ultra-violet light intensity of 10 to 20 milliwatts per sq. ft. throughout the upper air; and 0.2 to 0.5 milliwatts per sq. ft. (or microwatts per sq. cm.) at face level of standing pupils [5] [9]. These numbers can be used as a reference for other analysis typically presented in microwatts per square centimeter:
The following table shows the disinfection time at 30,000 uW/cm2 or 30mJ/cm2 for bacteria, viruses, fungi and protozoa such as Cryptosporidium, Giardia, SARS, H5N 1 within one second. [11]
| Infection Source |
100% kill |
Infection Source |
100% kill |
Bacteria |
|||
| Anthraces | 0.30 | Tuberculosis | 0.41 |
| Diphtheria | 0.25 | Vibrio Cholera | 0.64 |
| Clostridium Botulism | 0.80 | Pseudo monas Bacteria | 0.37 |
| Tetanus | 0.33 | Salmonella | 0.51 |
| Dysentery Bacillus | 0.15 | Fever Bacteria | 0.41 |
| Colibacillus | 0.36 | Bacillus Typhi murium | 0.53 |
| Hook-side Pylon Bacillus | 0.20 | Shigella | 0.28 |
| Legion Ella | 0.20 | Staphylococcus | 1.23 |
| Micro co | 0.4-1.53 | Streptococcus | 0.45 |
Virus |
|||
| Adenovirus | 0.10 | Influenza Virus | 0.23 |
| Phagocyte Cell Virus | 0.20 | Polio Virus | 0.80 |
| Coxsackie Virus | 0.08 | Rota Virus | 0.52 |
| ECHO Virus | 0.73 | Tobacco Mosaic Virus | 16.00 |
| ECHO Virus 1 | 0.75 | Hepatitis B Virus | 0.73 |
Mold Spores |
|||
| Aspergillums Niger | 6.67 | Soft Spores | 0.33 |
| Aspergillums | 0.73-8.80 | Penicillium | 2.93-0.87 |
| Dung Fungi | 8.00 | Penicillium Chrysogenum | 2.00-3.33 |
| Mucor | 0.23-4.67 | Other Fungi Penicillium | 0.87 |
Water Algae |
|||
| Blue-green algae | 10-40 | Paramecium | 7.30 |
| Chlorella | 0.93 | Green Algae | 1.22 |
| Line Ovum | 3.40 | Protozoan | 4-6.7 |
Fish Disease |
|||
| Pang I Disuse | 1.6 | Infectious Pancreatic Necrosis | 4 |
| Leukodennia | 2.67 | Hemorrhagic | 1.6 |
The following analysis shows how long the virus needs to be exposed with lower power levels. It assumes 100% destruction and a linear time relationship. The original studies in 1937 - 1943 used power levels of 10-20 uW/cm2 with an unknown AUC, however an assumption of 2 AUC is reasonable.
100% destroyed |
uW/cm2 |
AUC |
kill |
Comment |
1 |
30000 |
3600 |
0.000277778 |
|
60 |
500 |
60 |
0.016666667 |
|
600 |
50 |
6 |
0.166666667 |
|
900 |
33 |
4 |
0.25 |
Design to criteria |
1800 |
17 |
2 |
0.5 |
|
3600 |
8 |
1 |
1 |
|
Guidelines Factors Influencing Effectiveness of Upper-Room UVGI Systems
The following is an extract from: Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings, Department of Health and Human Services Centers for Disease Control and Prevention National Institute for Occupational Safety and Health, DHHS (NIOSH). [4]
Extract Start
Note: This guidance is based on the control of M. Tuberculosis. References to M. Tuberculosis have been replaced with the generic term Virus. This will affect the level of recommended UV exposure, however the levels in the extract remain unchanged. Additional studies identify the proper level of UV exposure needed to destroy various viruses.
1. UVGI Irradiance and Dose
Factors that must be considered when evaluating the ability of an upper-room UVGI system to kill or inactivate airborne microorganisms include the sensitivity of the microorganisms to UVGI and the dose of UVGI received by a microorganism or population of microorganisms. UVGI dose is the ultraviolet (UV) irradiance multiplied by the time of exposure and is usually expressed as micro watts per square centimeter (uW/cm2). A well-designed upper-room UVGI system may be effective in killing or inactivating most airborne droplet nuclei containing mycobacteria if designed to provide an average UV fluence rate in the upper room in the range of 30 uW/cm2 to 50 uW/cm2 (for M. Tuberculosis), provided the other elements stipulated in these guidelines are met. In addition, the fixtures should be installed to provide as uniform a UVGI distribution in the upper room as possible. [4]
2. Upper-Room UVGI Systems and Mechanical Ventilation
As the mechanical ventilation rate in a room is increased, the total number of microorganisms removed from the room via this system is increased. However, when mechanical ventilation is increased in a room where an upper-room UVGI system has been deployed, the effectiveness of the UVGI system may be reduced because the residence time of the bacteria in the irradiated zone decreases. Under experimental laboratory conditions with mechanical ventilation rates up to six air changes per hour (ACH), the rate that microorganisms are killed or inactivated by UVGI systems appears to be additive with mechanical ventilation systems in well-mixed rooms. [4]
3. Air Mixing
Upper-room UVGI systems rely on air movement between the lower portion of the room where droplet nuclei are generated and the upper irradiated portion of the room. Once in the upper portion, droplet nuclei containing the Virus (original ref was M. Tuberculosis) may be exposed to a sufficient dose of UVGI to kill or inactivate them. When upper-room UVGI systems are installed, general ventilation systems should be designed to provide optimal airflow patterns within rooms and prevent air stagnation or short circuiting of air from the supply diffusers to the exhaust grills. Also, heating and cooling seasons should be considered and the system designed to provide for optimal convective air movement. Most rooms or areas with properly installed supply diffusers and exhaust grills should have adequate mixing. If areas of air stagnation are present, air mixing should be improved by adding a fan or repositioning the supply diffusers and/or exhaust grills. If there is any question about vertical air mixing between the lower and upper portions of the room due to environmental or other factors, a fan(s) should be used to continually mix the air. In a room without adequate air mixing under experimental laboratory conditions, the UVGI system effectiveness increased from 12% to 89% when a mixing fan was used. [4]
4. Humidity
A number of studies have indicated that the effectiveness of upper-room UVGI systems decreases as humidity increases. The reason for the decrease in UVGI effectiveness is not clearly understood. However, the effect needs to be considered in the general context of upper-room UVGI systems. For optimal efficiency, relative humidity (RH) should be controlled to 60% or less if upper room UVGI systems are installed. This is consistent with American Institute of Architects (AIA) and the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) recommendations that the RH affecting patient care areas in hospitals and outpatient facilities range from 30% RH to 60% RH. If high humidity conditions are normal, it may be necessary to install a system with greater than normal upper-room irradiance levels.
5. Temperature
Recommendations developed by ASHRAE and AIA stipulate that the design temperature for most areas affecting patient care in hospitals and outpatient facilities range from 68F to 75F (20C to 24C). This temperature range is consistent with the optimal use of low pressure mercury lamps that are used in upper-room UVGI systems. [4]
Extract End
Practical Guidelines for Installation of Upper-Room UVGI Systems
The following is an extract from: Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings, Department of Health and Human Services Centers for Disease Control and Prevention National Institute for Occupational Safety and Health, DHHS (NIOSH). [4]
Extract Start
Note: This guidance is based on the control of M. Tuberculosis. References to M. Tuberculosis have been replaced with the generic term Virus. This will affect the level of recommended UV exposure, however the levels in the extract remain unchanged. Additional studies identify the proper level of UV exposure needed to destroy various viruses.
1. UV Lamps
The most common way to generate germicidal UV radiation in lamps used in well-designed upper-room UVGI systems is to pass an electrical charge through low-pressure mercury vapor that has been enclosed in selected glass tubes that transmit only certain UV wavelengths. Care must be used in selecting the correct UVGI lamp for use in upper room UVGI systems. Typically, the optimal wavelength for UV germicidal radiation is 254 nanometers (nm) in the UV-C range. UV lamps are made for a variety of purposes that may have a negligible consequence in killing airborne microorganisms. Some UV lamps (such as those used for tanning) radiate energy in the UV-A and/or UV-B range and over extended periods may have adverse health consequences for exposed persons. Other UV lamps are designed to emit radiation at 184.9 nm and produce ozone, which is hazardous to humans even at low concentrations. Low-pressure mercury lamps should be rated for low or no ozone generation. Since all lamps must eventually be discarded, each lamp should contain only a relatively small quantity of mercury (i.e., 5 mg or less). [4]
2. UVGI Fixtures
In upper-room UV irradiation, fixtures containing UVGI lamps are suspended from the ceiling or installed on walls. The base of the lamp is shielded to direct the radiation upward and outward to create an intense zone of UVGI in the upper air while minimizing the level of UVGI in the lower (occupied) portion of the room or area. The height of the room must be considered to design an effective system. Only well-designed fixtures as noted in this document should be used. [4]
3. System Installation
Several rules of thumb for installation of the fixtures for upper-room UVGI systems have been developed over the last 50 to 60 years. In the CDC/NIOSH-funded study as indicated above, a well-designed upper-room UVGI system may be effective in killing or inactivating airborne Virus (original ref was M. tuberculosis) if designed to provide an average UV fluence rate in the upper irradiated zone in the range of 30 uW/cm2 to 50 uW/cm2 provided the other elements stipulated in these guidelines are met. Based on this, two additional rules of thumb (guidelines) are provided in the document for installing UVGI systems. To simplify the installation process, the new guidelines are based on the required UV lamp wattage for the system. Considering all parameters, the installation of UVGI fixtures in rooms with approximately 2.4 m (8 ft) ceilings that provide (1) a UV-C irradiance of 1.87 W/m2 (0.17 W/ft2) or (2) a UV-C power distribution of 6 W/m3 (0.18 W/ft3) in the upper UVGI zone should be effective in killing or inactivating airborne the virus (original ref was mycobacteria). A professional who is knowledgeable in upper-room UVGI systems and system installation should be consulted before procurement and installation of the system. The number of persons properly trained in the design of upper-room UVGI systems is currently limited. Persons who may be consulted include engineers, industrial hygienists, and radiation/ health physicists. A mechanism to provide training certification for system designers should be developed. [4]
4. Installation and Maintenance Considerations
Once the number and types of UVGI fixtures appropriate for the room or area have been determined, the fixtures need to be appropriately installed. Installation guidelines are provided in the document as well as problem areas that have been encountered during CDC/ NIOSH evaluations. Only qualified service technicians who have received training on the installation and placement of UVGI lamp fixtures should install the systems. Discussions are provided in the document on the required maintenance for the UVGI fixtures, UV lamps, and personal protective equipment (PPE) necessary during maintenance. Methods for UVGI measurements in the lower (occupied) level of a room or area and the upper irradiated area are discussed. [4]
Additional research needs for determining the most effective upper-room UVGI systems are provided in the document. These include UVGI measurements, air mixing, the effect of low humidity, microbial sensitivity, and testing and validating upper-room UVGI systems. Also, research needs to be done on the ability of UVGI systems to kill or inactivate microorganisms in (1) different size respirable droplet nuclei and (2) droplet nuclei coated with actual or simulated sputum. [4]
Extract End
See section for Design Solutions UV-C Ventilation Design Solutions. See section for UV Infrastructure Cost Estimates.
Continue to analysis section FAR UV-222 Full Illumination.
References:
[1] Air Disinfection in Day Schools, W.F. Wells Associate Professor in Research in Air-borne Infection, Laboratories for the Study of Air-borne Infection, the Department of Preventive Medicine and Public Health, University of Pennsylvania School of Medicine, Philadelphia, Pa. 1943. webpage https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.33.12.1436, November 2020. Air Disinfection in Day Schools . local
[2] How Can Airborne Transmission of COVID-19 Indoors be Minimized?, May 01, 2020. https://www.youtube.com/watch?v=jK6Cef5A8FQ. local transcript
[3] The History of Ultraviolet Germicidal Irradiation for Air Disinfection, Public Health Reports/January–February 2010/Volume 125. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789813 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789813/pdf/phr125000015.pdf, November 2020. The History of Ultraviolet Germicidal Irradiation for Air Disinfection . PDF . local
[4] Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings, Department of Health and Human Services Centers for Disease Control and Prevention National Institute for Occupational Safety and Health, DHHS (NIOSH), Publication No. 2009-105 March 2009. webpage https://www.cdc.gov/niosh/docs/2009-105/pdfs/2009-105.pdf, November 2020. Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings . local
[5] UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus, US Food and Drug Administration - FDA, August 19, 2020. webpage https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/uv-lights-and-lamps-ultraviolet-c-radiation-disinfection-and-coronavirus, November 2020. UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus . local
[6] Ultraviolet (UV) Radiation, US Food and Drug Administration - FDA, August 19, 2020. webpage https://www.fda.gov/radiation-emitting-products/tanning/ultraviolet-uv-radiation, November 2020. Ultraviolet (UV) Radiation . local
[7] Upper-Room-Disinfection, National Academies of Sciences, Engineering, and Medicine, September 17, 2020. webpage https://www.nationalacademies.org/event/09-16-2020/docs/D00062573057472031C5B95374B5C068AE9324D53EC4, November 2020. Upper-Room-Disinfection . local
[8] Upper-room ultraviolet air disinfection might help to reduce COVID-19 transmission in buildings: a feasibility study, PeerJ peerj.com, October 13, 2020. webpage https://peerj.com/articles/10196, November 2020. Upper-room ultraviolet air disinfection might help to reduce COVID-19 transmission in buildings: a feasibility study . local
[9] Effect of Ultra-violet Irradiation of Classrooms on Spread of Measles in Large Rural Central Schools, May 1947. New York State Department of Health, Albany, N.Y. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1623610/pdf/amjphnation01116-0034.pdf, November 2020. Effect of Ultra-violet Irradiation of Classrooms on Spread of Measles in Large Rural Central Schools . local
[10] Effect of Ultraviolet Germicidal Irradiation on Viral Aerosols, Environmental Science & Technology, vol. 41, no. 15, 2007. webpage https://pubs.acs.org/doi/pdf/10.1021/es070056u, November 2020. Effect of Ultraviolet Germicidal Irradiation on Viral Aerosols
[11] Lightbest Co, LTD, webpage https://www.light-best.com, November 2020.
FAR UV-222 Full Illumination
FAR-UV 222 also known as FAR UVC is new technology and may be a promising approach for continuous safe decontamination in public spaces. Its wavelength is such that it will destroy viruses but not damage the skin and eyes thus potentially avoiding the damage caused by UV-C direct light exposure [1] [2]. For the skin light at the 222 wavelength is absorbed by the Stratum corneum. This is the dead skin layer. For the eyes light at the 222 wavelength is absorbed in the outer surface of the cornea and is much less likely to cause cataracts. [A] [B] [C] There is an old study from 2014 suggesting that there may be issues associated with this technology. [D]
This is the analysis. See section for Design Solutions FAR UV-222 Design Solutions. See section for UV Infrastructure Cost Estimates.
The technology developed by Columbia University’s Center for Radiological Research uses lamps that emit continuous low doses of a particular wavelength of ultraviolet light known as far-UVC. It kills viruses and bacteria without harming human skin, eyes and other tissues. So it can be used directly in a public space for continuous decontamination without harm to occupants. Research shows far-UVC effective in eradicating two types of airborne seasonal coronaviruses. It is effective in inactivating the airborne H1N1 influenza virus and drug-resistant bacteria. The researchers are now testing the light against the SARS-CoV-2 virus. Multiple long-term studies on animals and humans have confirmed that exposure to far-UVC does not cause damage to the skin or eyes. [4]
|
When researchers develop a vaccine against the COVID-19 virus, it will not protect against the next novel virus. This new technology if used in occupied public places has the potential to check future epidemics and pandemics. It eradicates airborne viruses minutes after they are breathed, coughed or sneezed into the air. It has the potential to prevent the global spread of the virus that causes influenza, measles, and now COVID-19. This approach takes a different tactic in the war against infection. Traditional approaches focus on fighting the infection once it has entered body. This approach has the potential to prevent the spread of viruses before they enter the body. The technology uses existing light fixtures and can be quickly deployed in hospitals, schools, shelters, airports, airplanes, offices, stores, and any other public and private space. [4]
A system that uses UV-C light (around 254 nm) kills viruses and bacteria. Hospitals and laboratories use germicidal UV-C light to sterilize unoccupied rooms and equipment. However UV-C light cannot be used in the presence of people because it causes health problems with the skin and eyes. It needs to be managed such as placing it within HVAC ducts or using ceiling level installations. Ceiling level applications will only clean the air, not the surfaces, and will only work when there is a proper installation and management of the lights. [4]
A system that uses Far-UVC light has a very short wavelength (from 205 to 230 nm) and cannot reach or damage living human cells. Yet these wavelengths can still penetrate and kill viruses and bacteria floating in the air or on surfaces. Its advantage is that it can illuminate an entire space, including surfaces, and its installation and maintenance are simple. Far-UVC lamps are now in production. [4]
One of the technical issues with FAR UV-222 is a physics challenge where power density drops off with the square of the distance. A device that provides sufficient uW/CM2 within the distant regions of a room will have a very high uW/CM2 near the light. This is a design challenge. It suggests multiple low power lights rather than one or two large power lights.
The following table identifies other UV applications:
Wavelength |
UV Applications |
13.5 |
Extreme Ultraviolet Lithography |
30-200 |
Photoionization, ultraviolet photoelectron spectroscopy |
205-230 |
Far-UVC |
222 |
Far UV-222 |
230-365 |
UV-ID, label tracking, barcodes |
230-400 |
Optical sensors, various instrumentation |
240-280 |
Disinfection, decontamination of surfaces and water (DNA absorption has a peak at 265 nm) |
200-400 |
Forensic analysis, drug detection |
270-360 |
Protein analysis, DNA sequencing, drug discovery |
280-400 |
Medical imaging of cells |
300-320 |
Light therapy in medicine |
300-365 |
Curing of polymers an printer inks |
300-400 |
Solid state lighting |
350-370 |
Bug zappers (flies are most attracted to light at 365 nm) |
For the following discussion the following unit conversions are provided:
The current dose limit guideline for 222 nm light from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) is 23 mJ/cm2 per 8-hour exposure [5]. This as an intensity of ~3 mJ/cm2/hour or 3uW/cm2 in a 1 hour period. In the 1937 - 1946 study of UV-C the students were exposed to 0.2 uW/cm2 to 0.5 uW/cm2 and the decontamination zone at the ceiling level was 10 uW/cm2 to 20 uW/cm2. The power density is less than the ceiling level system, however the advantage is that all of the volume in the space is exposed to a higher UV power density. Also air mixing and air management becomes irrelevant and will not negatively impact the system. If we assume a 10 foot ceiling with a 1 foot irradiation zone we see that covers about 10% of the volume. This translates broadly to 1-2 uW/cm2 across the entire volume with the UV-C approach. This simple relationship suggests that the FAR UV-222 level of 3uW/cm2 should be equivalent to a UV-C based system unless the UV-C based system increases the power density at the ceiling level, manages the lower UV-C exposure via careful reflective structure, and manages the air exchange. Previous studies have suggested that a UV-C system could offer an AUC of up to 17 per hour [6].
FAR-UVC is being studied at Columbia University and they have disclosed some of the data. The following table shows the virus inactivation in a test chamber where the virus was exposed for 20 minutes. [5]
Virus & Inactivation % |
90% |
99% |
99.9% |
HCov-229E |
0.56 |
1.10 |
1.70 |
HCov-OC43 |
0.39 |
0.78 |
1.20 |
Influenza A (H1N1) |
1.30 |
2.60 |
1.80 |
The units need to be converted to uW/cm2 so that we have a common performance number to compare with other systems and analysis. For example, the recommended exposure intensity is ~ 3mJ/hr/cm2. This is 0.833 uj/cm2/sec = uW. The following table shows that 90% of HCov-229E or HCov-OC43 is inactivated in 20 minutes and is within safe limits for an 8 hour exposure.
Virus & Inactivation % |
90% |
99% |
99.9% |
90% |
99% |
99.9% |
90% |
99% |
99.9% |
HCov-229E |
0.56 |
1.10 |
1.70 |
560 |
1100 |
1700 |
0.47 |
0.92 |
1.42 |
HCov-OC43 |
0.39 |
0.78 |
1.20 |
390 |
780 |
1200 |
0.33 |
0.65 |
1.00 |
Influenza A (H1N1) |
1.30 |
2.60 |
1.80 |
1300 |
2600 |
1800 |
1.08 |
2.17 |
1.50 |
Given that FAR-UVC or FAR UV-222 does not penetrate the skin or eye cornea, it is unclear what the recommended exposure intensity of ~ 3mJ/hr/cm2 means in terms of future applications. The following are selected extracts from the Columbia University research on FAR-UVC [5]:
Extract Start
Beta results for the HCoV-OC43 coronavirus, continuous far-UVC exposure at this intensity would result in 90% viral inactivation in approximately 8 minutes, 95% viral inactivation in approximately 11 minutes, 99% inactivation in approximately 16 minutes and 99.9% inactivation in approximately 25 minutes. Low doses of far-UVC, 1.7 and 1.2 mJ/cm2, can inactivate 99.9% of aerosolized alpha and beta coronavirus. The beta coronavirus results indicate that continuous far-UVC exposure in public locations at the currently recommended exposure limit (3 mJ/cm2/hour) would result in 99.9% viral inactivation in ~25 minutes. As all human coronaviruses have similar genomic size, a key determinant of radiation sensitivity, it is realistic to expect that far-UVC will show comparable inactivation efficiency against other human coronaviruses, including SAR-CoV-2.
Extract End
There are real world projects being implemented based on this technology. It is not theoretical. The following are examples of real world projects implementing FAR-UVC or FAR UV-222. It is not an endorsement of the technology or the companies involved. It is provided for reference and further research. The research is going live and perhaps is similar to the very first UV-C study that was started in 1937.
September 9, 2020 (Margate
City, NJ) - 9600 Condominium, a premier, award-winning New Jersey Shore living
destination, today announced that it will become the first Garden State facility
to install Far-UVC 222nm light technology to help protect its staff, residents
and guests against the spread of harmful viruses and pathogens. Developed
by Melbourne, Fla. based Healthe, Inc., three state-of-the-art sanitization
products will be installed at key touch and travel points throughout 9600
Condominium’s facility, including the building’s lobby, gym and
bathrooms. This state-of-the art sanitization technology was developed by
Melbourne, Fla. based Healthe, Inc. [3]
September 30, 2020 (New
York, NY) - Australian-inspired coffee and hospitality brand Bluestone Lane
announced today that it will become the first nationwide café chain
to install Far-UVC 222 light technology to increase protections for locals
and employees against the spread of harmful pathogens and viruses like COVID-19.
Bluestone Lane is first deploying Healthe’s suite of light solutions
in its “Collective Café” (55 Greenwich Ave.) and “Bowery
Café” (19 Kenmare Street), with plans for a nationwide rollout.
[3]
October 13, 2020 (Kohler,
WI) - The Blind Horse Restaurant & Winery is the first restaurant in
the United States to install Far-UVC 222 light technology to provide real-time
mitigation of harmful pathogens and viruses. State-of-the-art sanitization
solutions, developed by Melbourne, Fla. based Healthe, Inc., will be installed
at key locations throughout the restaurant in mid-October. Far-UVC 222 light
technology provides an additional layer of critical protection for staff
and guests–along with the other safety initiatives already in place
throughout the property. [3]
October 22, 2020 (Summit,
NJ) - Boll & Branch (the “Company”), the world’s leading
designer and retailer of sustainable home goods, is setting a new standard
for the future of retail space safety by becoming the first retail store
to install Far-UVC 222 light technology (Healthe Space™). This cutting-edge
sanitization solution will increase protections for customers and employees
against the spread of harmful pathogens and viruses. Boll & Branch has
installed Far-UVC downlights in its newly opened retail locations in Greenwich,
CT (169 Greenwich Ave) and Boca Raton, FL (Town Center at Boca Raton, 6000
Glades Road, Space 1034). This state-of-the art sanitization technology was
developed by Melbourne, Fla. based Healthe, Inc. [3]
This is the analysis. See section for Design Solutions FAR UV-222 Design Solutions. See section for UV Infrastructure Cost Estimates.
References:
[1] Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light, Radiat Res. 2017 April ; 187(4): 483–491. doi:10.1667/RR0010CC.1. webpage http://www.columbia.edu/~djb3/papers/Germicidal%20Efficacy%20and%20 Mammalian%20Skin%20Safety%20of%20222-nm%20UV%20Light.pdf, September 2020. Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light
[2] Far-UVC Light Safely Kills Airborne Coronaviruses, Nature www.nature.com, June 24, 2020. webpage https://www.nature.com/articles/s41598-020-67211-2, September 2020. Far-UVC Light Safely Kills Airborne Coronaviruses . PDF
[3] Healthe Inc. webpage https://healthelighting.com, September 2020. Healthe
[4] Could a New Ultraviolet Technology Fight the Spread of Coronavirus, Columbia University, June 30, 2020. webpage https://news.columbia.edu/ultraviolet-technology-virus-covid-19-UV-light, November 2020. Could a New Ultraviolet Technology Fight the Spread of Coronavirus
[5] Far-UVC light efficiently and safely inactivates airborne human coronaviruses, Center for Radiological Research, Columbia University Irving Medical Center, Under Review. webpage https://www.researchsquare.com/article/rs-25728, https://assets.researchsquare.com/files/rs-25728/v1/manuscript.pdf, November 2020. Far-UVC light efficiently and safely inactivates airborne human coronaviruses . PDF . local
[6] Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings, Department of Health and Human Services Centers for Disease Control and Prevention National Institute for Occupational Safety and Health, DHHS (NIOSH), Publication No. 2009-105 March 2009. webpage https://www.cdc.gov/niosh/docs/2009-105/pdfs/2009-105.pdf, November 2020. Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings . local
[7] Air Disinfection in Day Schools, W.F. Wells Associate Professor in Research in Air-borne Infection, Laboratories for the Study of Air-borne Infection, the Department of Preventive Medicine and Public Health, University of Pennsylvania School of Medicine, Philadelphia, Pa. 1943. webpage https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.33.12.1436, November 2020. Air Disinfection in Day Schools . local
[A] Filtered Far UV-C Excimer Lamp Module, Ushio America. webpage https://www.ushio.com/files/brochure/care222-filtered-far-uv-c-excimer-lamp-module.pdf, November 2020. Filtered Far UV-C Excimer Lamp Module . local
[B] Buonanno, Manuela; Ponnaiya, Brian; Welch, David; Stanislauskas, Milda; Randers-Pehrson, Gerhard; Smilenov, Lubomir; Lowy, Franklin D.; Owens, David M.; Brenner, David J.. Germicidal Efficacy and Mammalian Skin Safety of 222nm UV Light. Radiation Research. 2017 April; 187(4): 483-491.
[C] Kolozsvári, Lajos; Nógrádi, Antal; Hopp, Béla; Bor, Zsolt. UV Absorbance of the Human Cornea in the 240- to 400-nm Range. Investigative Ophthalmology & Visual Science July 2002, Vol.43, 2165-2168.
[D] The effect of 222-nm UVC photo testing on healthy volunteer skin: a pilot study, Photobiology Unit, Dermatology, Ninewells Hospital & Medical School, Dundee DD1 9SY, UK. December 7, 2014. webpage https://iuva.org/resources/covid-19/Woods%20et%20al%202015%20-%20UV222%20Pilot%20Study%20Testing%20on%20Volunteers%20Skin.pdf, November 2020.
Air Flow Rates And Natural Ventilation
This analysis was started because of the observations made while examining the infection and death rates in certain countries [1]. The key observations are:
The topics in this section are:
Air Update Rates CDC and Other Guidelines
There is a large body of guidelines recommending different building and room air flow rates from different organizations. Air flow is specified using the following units:
It is easy to convert to the different units. In some cases the room size is needed to make the conversions. As the different guidelines are accessed, the air update rates are significantly different. Note that the amount of fresh air is irrelevant to this issue. Any virus contaminated air must be cleaned before being expelled to the outside. Since it must be clean, it can be recycled and mixed with fresh air as part of the existing design to minimize the effects of gas and other contaminants in the building air.
The CDC air update rates for hospitals appear to be significantly lower than for other settings. However the CDC does not provide upper limits suggesting that each hospital can decide on the upper AUC limits. Also hospitals are designed to ensure staff are upwind of infected patients and the staff know and understand how to use personal protection equipment. Outside of a hospital setting people do not understand the importance of being upwind from an infected person and do not understand how to use personal protect equipment. Further outside of a hospital setting people are not able to control their locations relative to air movement and access different levels of personal protection equipment. For example an infected person sneezes 6 feet away from a uninfected person and does not protect the sneeze and it just goes everywhere.
The following is a sampling of air flow rates compiled from multiple sources [2], [3], [4], [5], [6], [7]. [spreadsheet]
| Area |
AUC |
AUC |
Source | Area |
AUC |
AUC max |
Source | |
| Hospital Trauma room | 15 | - | CDC | Malls | 6 | 10 | EPA | |
| Hospital rooms | 6 | 10 | EPA | Office | 8 | 30 | Greenheck | |
| Restaurants | 8 | 12 | EPA | Engine Room | 20 | 60 | Greenheck | |
| Restaurants | 8 | 20 | NCI | Kitchen | 12 | 60 | Greenheck | |
| Restaurants | 15 | 20 | wiki | Kitchen | 7 | 8 | NCI | |
| Bar | 15 | 30 | Greenheck | Kitchen | 14 | 18 | NCI | |
| Bar | 15 | 20 | NCI | Kitchens (commercial) | 15 | 30 | EPA | |
| Bar | 15 | 20 | wiki | Retail | 6 | 10 | NCI, wiki, EPA | |
| School Classroom | 4 | 12 | EPA | Laboratory | 12 | 30 | Greenheck | |
| Classroom (Art) | 16 | 20 | EPA | Laboratory | 6 | 12 | wiki |
The following table shows the lowest and highest ACH values from different guidelines. The range is significant and the guidelines vary significantly. A key issue is how were these values determined. Are they based on some engineering analysis, scientific findings, operational test findings from focus groups or other approaches. Now there is a need to determine the AUC or ACH because of the COVID-19 disaster. Is there an AUC or ÅCH that can be used to mitigate the effects of the virus inside buildings?
| ACH Min | ACH Max | Avg | Source |
| 3 | 60 | 11 | Greenheck |
| 3 | 20 | 9 | NCI |
| 4 | 30 | 8 | Fan App |
| 2 | 50 | 11 | EPA |
| 4 | 60 | 9 | Eng Tool Box |
| 3 | 30 | 8 | wiki |
| 2 to 15 | NA | 8 | CDC |
References:
[Library/Building-Ventilation]
[1] See section Death Rates By Country
[2] American Society of Heating and Air-Conditioning Engineers (ASHAE), webpage https://www.ashrae.org, May 2020.
[3] Greenheck, webpage https://www.greenheck.com, May 2020.
[4] Chartered Institution of Building Service Engineers, webpage https://www.cibse.org, May 2020.
[5] National Comfort Institute, https://www.nationalcomfortinstitute.com, webpage, May 2020.
[6] Appendix B. Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003). webpage https://www.cdc.gov/infectioncontrol/guidelines/environmental/appendix/air.html, May 2020. Appendix B. Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003)
[7] Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003) Updated July 2019. webpage https://www.cdc.gov/infectioncontrol/pdf/guidelines/environmental-guidelines-P.pdf, May 2020. Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003) . Library
World Health Organization Natural Ventilation
In 2009 The World Health Organization (WHO) released a document offering guidelines for building ventilation for infection control [1]. A team of engineers, architects, infection-control experts and microbiologists was assembled to provide a design and operation guide for hospital planners, engineers, architects and infection control personnel. There was a review of literature on ventilation and disease transmission and effective natural ventilation solutions for infection control. There are very few studies on natural ventilation for infection control in hospitals. The WHO guidelines for Natural Ventilation for Infection Control in Health-Care Settings should be reviewed by everyone addressing HVAC modifications to deal with the COVID-19 disaster.
Note: Natural ventilation is found in buildings without modern air conditioning systems. Mechanical ventilation is found in buildings with Heating Ventilation and Cooling (HVAC) systems. Natural ventilation is found in outdoor settings.
The higher the ventilation rate, the more rapid the decay of virus droplet nuclei in the room air. According to the Wells-Riley equation, the probability of infection via droplet nuclei is inversely related to the ventilation rate. The parameters used in the Wells-Riley equation include ventilation rate, generation of droplet nuclei from the source (quanta/minute) and duration of exposure.
P = D/S = 1 - exp ( - (Ipqt/Q) )
P = probability of infection for susceptibles
D = number of disease cases
S = number of susceptibles
I = number of infectors
p = breathing rate per person (m3/s)
q = quantum generation rate by an infected person (quanta/s)
t = total exposure time (s)
Q = outdoor air supply rate (m3/s)
quanta = virus
Based on this model, in situations of high virus production the estimated probability of infection with 15 minutes of exposure in a room with 12 ACH would be below 5%. However, this hospital scenario is not realistic while engaging in life such as going to school, working in an office, eating at a restaurant, shopping in a big box store, going to a beach or a park with a gentle wind, congregating outside with no wind, walking outside, and other scenarios. More realistic scenarios are developed further in this analysis that represent various living conditions [2].
Some key ACH numbers found in the WHO natural ventilation guidelines are:
| Openings | ACH | Ventilation rate (l/s) |
| Open window (100%) + open door | 37 |
1300 |
| Open window (50%) + open door | 28 |
975 |
| Open window (100%) + closed door | 4.2 |
150 |
Assumptions:
|
||
| Note: infection is more rapid and frequent in a ventilation lower than 2 ACH |
Ventilation reduces the concentration of airborne virus by removing or diluting airborne droplet nuclei. A higher ventilation rate provides a higher dilution of the virus and reduces the risk of airborne infections in a shared physical space. According to this WHO report The maximum ventilation rate above which there is no infection risk is unknown. Ventilation rate is driven by the need to reduce energy consumption because of costs. However, this analysis has attempted to address this critically missing information and numbers are provided further in this text.
When ACH is used to measure ventilation performance, the volume of the enclosed room is an important parameter. For a given ACH, a room with a larger volume can provide a larger airflow rate (m3/h or l/s) than a room with a smaller volume. For natural ventilation the WHO recommends the following minimum hourly average ventilation rates:
The CDC disclosed both the Droplet Evaporation curves from Wells (1934) and the Wells-Riley equation (1978) as part of their study on natural ventilation for infection control in health-care settings [1]. There is insufficient data to recommend a minimum ventilation rate for infection control against droplet nuclei. It is known that infection among clinical workers is more rapid and frequent in an average ventilation lower than 2 ACH. Once again, this analysis has attempted to address this critically missing information and numbers are provided further in this text.
Between 1934 and 1978 we went from a natural ventilation society to an enclosed air conditioned society with massive Heating Ventilation and Cooling (HVAC) Systems. Further, with the energy crisis in the 1970's all fresh air systems were converted to recycled air to save on energy costs. The question that needs to be answered is what happens in a work setting during the COVID-19 pandemic and what engineering needs to be performed to modify physical spaces to reduce the risk of virus infection.
References:
[Library/Building-Ventilation]
[1] WHO Publication/Guidelines Natural Ventilation for Infection Control in Health-Care Settings, World Health Organization (WHO), 2009. webpage https://www.ncbi.nlm.nih.gov/books/NBK143284/pdf/Bookshelf_NBK143284.pdf, May 2020. Natural Ventilation for Infection Control in Health-Care Settings, WHO, 2009 . local
[2] See section Wells Riley Probability of Infection.
What if Analysis
The following analysis is called a what if analysis [1], [2]. It was started before the WHO guidelines were reviewed and it is being updated after the WHO guidelines were reviewed.
It follows a path of least resistance to surface related information and the nature of the problem. It is based on various worst case scenarios, relationships, correlations and other elements to try and understand the problem. It is a disclosure of the nonlinear thinking paths taken when trying to solve a problem. The analysis may lead nowhere and it may just sit until the systems team revisits it and is able to move forward with the analysis and resulting system architecture changes.
The case studies, models, and certain country infection rates suggest that the infection rate is less outdoors than indoors. The question is what can be done to modify indoor environments to match more closely outdoor environments. In the late 1970's building HVAC systems were modified to reduce the amount of fresh air intake to reduce energy use. This is now an accepted norm. It is unclear if the old standards for fresh air exchange would be sufficient to mitigate the spread of bacterial, virus, or fungal agents.
There are many standards that exist for air exchange rates per hour and they are a function of the room use and the number of occupants. The ideal situation might be to just open all the windows and have massive cross flow of outside air as found in buildings in Egypt. However, that is not practical for all existing building architectures. The only alternative is to increase the HVAC systems air flow rates to exchange more air. This challenge exists not only for buildings but also public transportation systems. The ground based public transportation systems have been analyzed in this text. [3]
There are two engineering approaches that can be used. The first is old school brute force engineering. The second is new school engineering based on mathematics and modeling. In brute force engineering the solution is over engineered and it is intuitively obvious that it will work from a functional and performance perspective. In a mathematics and modeling based approach it is not intuitively obvious that the solution will work. Instead the numbers in the model suggest that the solution will work. This approach is used when it is not possible to brute force a solution because of cost or other issues including the ability to implement a viable solution.
The question is what the air flow rate should be to duplicate an outdoor environment in the indoor (building and transportation) settings.
An over engineered solution would be 1 cu-ft / sec per-person in a directed air flow setting. This is approximately equal to an outdoor wind speed of 1 mile per hour or a person walking and taking 1 step per second. The probability of any cross contamination in such an over engineered system is very low. The problem is that this translates into 60 cu-ft / min per-person in a building. Though possible, it is far beyond the current design guidelines for current buildings. For example, Hospital (Patient Rooms) are ventilated at 25 cu-ft per min. This scenario also translates to a personal air change rate of 1 per second or an AUC = 3600. That is beyond the limits of existing HVAC systems. Air exchanges in a room range from 1 to 30 per hour with the norm at 1 to 4 per hour. These are the various maximum AUC rates. [spreadsheet ACH]
Source |
AUC |
References |
|
| Various Standards | 60 |
[4], [5], [6], [7], [8] |
|
| CDC Hospital | 15 |
[4] |
|
| WHO Open Window | 37 |
[8] |
|
| Outside Walking at 1 mph | 3600 |
this analysis |
|
| Outside Sitting 1 mph breeze | 3600 |
this analysis |
Unfortunately, unless the building design is from the pre-air conditioning era it is unlikely that any HVAC systems will be modified to support a 1 mph breeze or an AUC of 3600. Further analysis is needed until someone can offer a technical solution to the massive artificial air flow rates needed to match outside conditions.
All the buildings would have to be modified with new massive air flow rates. It becomes problematic if the person is in a large room and the air is not directed over the person. This suggests the room air needs to be exchanged once per second. That is not possible. The solution needs to include directed air so that it is possible to implement the solution. The scenario is - The air gets sucked up at the rate of 1 cu-ft / sec per-person, enters the HVAC system, is subjected to massive UV-C and filtering, then is either fully exhausted to the outside environment or recycled back into the building with some percentage of fresh air and subjected to heating or cooling as needed.
Airplanes - Brute Force
It is relatively easy to retrofit an airplane cabin with floor or under seat vents and have massive airflow from the top vents to the floor because the plane is flying hundreds of miles per hour. The challenge is to provide massive air flow while the airplane is on the ground. Even with the ground challenge the solution is relatively easy and low cost because of the small space.
Computer Labs - Brute Force
Many computer labs are still fitted with false floors and chillers used to cool old mainframe computers. The tiles in these floors came in 2 styles, vented and unvented. The vented tiles can be moved to appropriate locations where people gather and walk to direct the massive airflow up and away. Everyone that works in these settings knows about the massive airflow coming from the vented tiles and either cover them with cardboard material or stay away from the floor vents. This is a simpler solution that can be implemented immediately in many computer labs or other false floor settings that use pressurized floor cooling systems.
Old Building Architectures - Engineered Solution
These are old buildings that were built before air conditioning. They have strategic placement of windows, very high ceilings, and maybe even ductwork for massive exhaust fans. These buildings can be opened up and new exhaust fans can be used to provide massive fresh air flow ranging for 1 to 5 miles per hour. The challenge is during the cold winter months. In this case these buildings will need changes to the heating systems to implement massive air flow, UV-C in the ducts, and filters. However, these buildings tend to be smaller and it will be less difficult to implement these massive air flow heating systems.
Case History
In the 1960's my family purchased a bar and restaurant in Philadelphia, PA. It was a small establishment consisting of 5 brownstones that were modified in the early 1900s to be a bar and restaurant. It had three Fedders window air conditioners, the largest that were available at the time. It also had two exhaust fans. One in front in the Bar area and one in back in the kitchen area open to an eating area. This was during a time when people smoked heavily. In this type of business customers arrived in droves at unexpected times. The air conditioners in the summer ran constantly and they would clean the air of cigarette smoke most of the time. However during sudden bursts of crowds the smoke would get so thick it would be difficult to see people in the establishment. The exhaust fans were manually controlled and they would be off during this sudden surge which might happen over 15 minutes - 75 people arrive - they are all smoking - no one can break away to turn on the exhaust fans. Eventually the exhaust fans would be turned on and within 30 seconds all the smoke would be cleared Yes they were loud and yes there was massive air movement. This is an example of brute force engineering. The AUC was easily 120.
New Building Architectures - Engineered Solution
These buildings tend to be large and are not designed to bring in the outside air when the temperature is moderate. They are designed to have conditioned air 100% of the time. This will require serious engineering to even get a working solution that will provide the needed air flow. There is no room for over engineering like in the case of the Old Buildings because of the cost of purchasing and operating the HVAC systems.
After this initial analysis, other analysis approaches were performed and the AUC rate can be less than this brute force approach.
References:
[Library/Building-Ventilation]
[1] Systems Practices As Common Sense, Walter Sobkiw, ISBN: 978-0983253082, first edition 2011, ISBN: 978-0983253051, second edition 2020. REF 1
[2] Systems Engineering Design Renaissance, Walter Sobkiw, ISBN: 978-0983253075, 2014. REF 2
[3] See section Public Transportation.
[4] Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003) Updated July 2019. webpage https://www.cdc.gov/infectioncontrol/pdf/guidelines/environmental-guidelines-P.pdf, May 2020. Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003) . Library
[5] Human Engineering, MIL-STD-1472F, Department of Defense, 23 August 1999, MIL-STD-1472D, 14 March 1989. MIL-STD-1472F . MIL-STD-1472D . local
[6] The Airliner Cabin Environment and the Health of Passengers and Crew, National Academy of Sciences, 2002. DTFA0100P100P10285, U.S. Department of Transportation. webpage https://pubmed.ncbi.nlm.nih.gov/25032286, May 2020. Library
[7] Strategies to Protect the Health of Deployed U.S. Forces: Force Protection and Decontamination Michael A. Wartell, Michael T. Kleinman, Beverly M. Huey, and Laura M. Duffy, Editors, Commission on Engineering and Technical Systems, National Research Council, ISBN: 0-309-66390-3, 262 pages, 6 x 9, (1999). NIH - Strategies to Protect the Health of Deployed U.S. Forces: Force Protection and Decontamination . local
[8] WHO Publication/GuidelinesNatural Ventilation for Infection Control in Health-Care Settings, World Health Organization (WHO), 2009. webpage https://www.ncbi.nlm.nih.gov/books/NBK143284/pdf/Bookshelf_NBK143284.pdf, May 2020. Natural Ventilation for Infection Control in Health-Care Settings, WHO, 2009 . local
Models
Various models were developed to try and understand the air update rates needed to mitigate the risks of infection inside a building [1] [2]. [spreadsheet Droplet Dispersion]
References
[1] For references to the various numbers in the models see section Virus Transmission.
[2] Additional models are developed in other sections.
Sneeze Analysis Model
When a contaminated person sneezes, they expel 200 million droplets and some percentage of those droplets contain the virus. Currently the models and analysis suggest that the droplets eventually fall to the floor. The question is how long the droplets are airborne. One analysis that can be performed is to determine the room size needed if the droplets were uniformly distributed where the virus load reaches the 1000 count threshold. This suggests that a person would inhale 1000 viruses with a single breath. If the room has a 12-foot ceiling the room dimensions are 59 feet X 59 feet. Further the sneeze is traveling at 50-200 miles per hour. The question then becomes how fast the air needs to be exchanged to protect a person from the infected sneeze. [spreadsheet Droplet Dispersion]
| Droplet Density Analysis | Male | Female | Assumptions & Comments |
| Total lung capacity (Liters) | 6 |
4.2 |
Assumption |
| Total lung capacity (cu in) | 366.12 |
256.284 |
|
| Total lung capacity (cu ft) | 0.211875 |
0.1483125 |
|
| Infected Sneeze (droplets) | 200,000,000 |
200,000,000 |
Assumption |
| Infection Level (droplets) | 1,000 |
1,000 |
Assumption |
| Infected Sneeze/cu ft (droplets) | 42,375,000 |
29,662,500 |
|
| Volume needed for infection level (cu ft) | 42,375 |
29,663 |
Uniform droplet dispersion |
| Room Ceiling Level (ft) | 12 |
12 |
Assumption |
| Room size needed (ft X ft) | 59 |
50 |
|
| Square feet | 3600 |
2500 |
This less than a grocery store, or big box store This is similar to a retail store or restaurant |
The equation is:
C1*V1 = C2*V2
C1 = infection event (breathing, cough, sneeze)
V1 = lung capacity volume
C2 = infection level (dose needed)
V2 = physical space volumeV1 = TL = Total lung capacity (cu ft) = assumption
C1 = IE = Infection event = Infected Sneeze (droplets) = assumption
C2 = IL = Infection Level (droplets) = assumption
IS = Infected Sneeze/cu ft (droplets) = IE * TL
V2 = VIL = volume needed for infection level (cu ft) = IS/IL
Idb = Infected Dose Received (breaths) = IL/1000
Ids = Infected Dose Received (seconds) = Idb
AUC = Required Air Exchanges (per hour) = 3600/Ids
An interesting analysis but it does not yield any insights that might help in the design of an updated HVAC system in a building. However it forced a new set of perspectives and analysis as follows.
Virus Load Air Exchanges Needed Model
The next analysis performed is given a virus load what should the air exchange be to mitigate infection risk. The analysis started with breathing, it continued with coughing, and finally with sneezing.
| Analysis 2 - Virus Load Based Air Exchanges Needed | Any Person | Assumptions & Comments |
| Infected Single Breath (virus load) | 20 |
Assumption |
| Breaths / Second | 1 |
Assumption |
| Infected Droplets / Hour | 72,000 |
|
| Infection Level (droplets) | 1,000 |
Assumption |
| Seconds Needed to Reach Virus Load | 50 |
|
| Required Air Exchanges (per hour) | 72 |
Possible but very high |
|
||
| Cough (droplets) | 3,000 |
Assumption |
| Infection percentage | 0.8 |
Assumption |
| Virus Load | 2,400 |
|
| Coughs / Event | 3 |
Assumption |
| Cough Events / Hour | 6 |
Assumption |
| Total Coughs / Hour | 18 |
|
| Infected Droplets / Hour | 43,200 |
|
| Infection Level (droplets) | 1,000 |
Assumption |
| Required Air Exchanges / Hour | 43 |
Possible but still high |
| Sneeze (droplets) | 200,000,000 |
Assumption |
| Infection percentage | 0.8 |
Assumption |
| Virus Load | 160,000,000 |
|
| Sneeze / Event | 1 |
Assumption |
| Sneeze Events / Hour | 1 |
Assumption |
| Total Sneeze / Hour | 1 |
|
| Infected Droplets / Hour | 160,000,000 |
|
| Infection Level (droplets) | 1,000 |
Assumption |
| Required Air Exchanges / Hour | 160,000 |
Not possible |
AUC = Idh / IL = Isb * Bs *3600 / IL
Isb = Infected Single Breath (virus load) = assumption
Bs = Breaths / Second = assumption
Idh = Infected Droplets / Hour = Isb * Bs * 3600
IL = Infection Level (droplets) = assumption
Svl = Seconds Needed to Reach Virus Load = IL / (Isb * Bs)
AUC = Required Air Exchanges (per hour) = Idh / IL
AUC = Idh/IL = Ed * Ip * Epe * Eph / IL
Ed = Event - Cough (droplets) = assumption
Ip = Infection percentage = assumption
VL = Virus Load = Ed * Ip
Epe = Event - Coughs / Event = assumption
Eph = Event - Cough Events / Hour = assumption
Eth = Event - Total Coughs / Hour = Epe * Eph
Idh = Infected Droplets / Hour = VL * Eth
IL = Infection Level (droplets) = assumption
AUC = Required Air Exchanges / Hour = Idh / IL
AUC = Idh / IL = Ed * Ip * Epe * Eph / IL
Ed = Event Sneeze (droplets) = assumption
Ip = Infection percentage = assumption
VL = Virus Load = Ed * Ip
Epe = Event - Sneeze / Event = assumption
Eph = Event - Sneeze Events / Hour = assumption
Eth = Event - Total Sneeze / Hour = Epe * Eph
Idh = Infected Droplets / Hour = VL * Eth
IL = Infection Level (droplets) = assumption
AUC = Required Air Exchanges / Hour = Idh / IL
It is very difficult to protect against a sneeze event with an AUC of 160,000. Breathing is cyclic and predictable. Coughing is usually controlled. Sneezing is usually an uncontrolled event. As a result people do not cover their sneeze and the droplets are fully released into the environment. This led to an analysis based on events.
This led to an interesting result however it soon became obvious that there is an exposure time window where there is risk of infection.
| Analysis 3 - Event Based Air Exchanges Needed | Any Person | Assumptions & Comments |
| Coughs or Sneeze / Event | 3 |
Assumption |
| Coughs or Sneeze Events / Hour | 6 |
Assumption |
| Total Coughs or Sneeze / Hour | 18 |
|
| Number of People | 3 |
Assumption |
| Required Air Exchanges / Hour | 54 |
Possible but still high |
| Potential Infection Exposure (min) | 6 |
Time before air is exchanged |
| Probability of Infection | 0.1 |
Decreases with air exchange |
AUC = Eth * N
Epe = Event - Sneeze / Event = assumption
Eph = Event - Events / Hour = assumption
Eth = Event - Total Sneeze / Hour = Epe * Eph
N = Number of People = assumption
AUC = Required Air Exchanges / Hour = Eth * N
Pie = Potential Infection Exposure (min) = 60 - AUC
Pi = Probability of Infection = Pie / 60
This led to an analysis based on probability of exposure.
This led to an interesting result because it is clear that near a certain threshold the probability of infection drops significantly with a doubling of the air exchange rate.
| Analysis 4 Probability of Exposure Air Exchanges Needed | Any Person | Assumptions & Comments | Observations |
| Breaths / Second | 60 |
Assumption | |
| Breaths / Hour | 3600 |
||
| Breaths / Infection Threshold | 50 |
||
| Seconds / Infection Threshold | 50 |
||
| Infection Virus Load | 1000 |
Assumption | |
| Virus Load / Breath | 20 |
Assumption | |
| Scenarios | Exchanges / Hour |
Probability of Exposure |
|
| 1 | 3600 |
~0 |
No infection |
| 2 | 1800 |
~0 |
No infection |
| 3 | 900 |
~0 |
No infection |
| 4 | 450 |
~0 |
No infection |
| 5 | 225 |
~0 |
No infection |
| 6 | 113 |
~0 |
No infection |
| 7 | 56 |
0.21875 |
Significant infection risk |
| 8 | 28 |
0.609375 |
Ventilation is pointless |
| 9 | 14 |
0.8046875 |
Ventilation is pointless |
| 10 | 7 |
0.90234375 |
Ventilation is pointless |
The CDC has a similar study.
CDC Airborne Contaminant Removal Model
The following is the CDC guideline: Table B.1. Air changes/hour (ACH) and time required for airborne-contaminant removal by efficiency *
ACH |
Time (mins.) |
Time (mins.) |
Comments |
2 |
138 |
207 |
|
4 |
69 |
104 |
|
6+ |
46 |
69 |
|
8 |
35 |
52 |
|
10+ |
28 |
41 |
frequently cited ACH for patient-care areas |
12+ |
23 |
35 |
frequently cited ACH for patient-care areas |
15+ |
18 |
28 |
frequently cited ACH for patient-care areas |
20 |
14 |
21 |
|
50 |
6 |
8 |
ACH Values were derived from the formula:
t2 - t1 = - [ln (C2 / C1) / (Q / V)] X 60, with t1 = 0
where:
t1 = initial timepoint in minutes
t2 = final timepoint in minutes
C1 = initial concentration of contaminant
C2 = final concentration of contaminant
C2 / C1 = 1 - (removal efficiency / 100)
Q = air flow rate in cubic feet/hour
V = room volume in cubic feet
Q / V = ACH
Values apply to an empty room with no aerosol-generating source. With a person present and generating aerosol, this table would not apply. Other equations are available that include a constant generating source. However, certain diseases (e.g., infectious tuberculosis) are not likely to be aerosolized at a constant rate. The times given assume perfect mixing of the air within the space (i.e., mixing factor = 1). However, perfect mixing usually does not occur. Removal times will be longer in rooms or areas with imperfect mixing or air stagnation.
It took a while to get to this analysis. This is a static model and it is based on computer static timing and sizing analysis. I wanted to perform this analysis first, but my fear was that something would be missed from other perspectives. It appears that this analysis might be the most useful from a users perspective. It shows the required air update change per hour (AUC) and the point at which a person is exposed to the virus infection load.
AUC/ |
Breaths/ |
Exposure |
Breaths/ |
Exposure |
Virus |
Infection |
Virus |
Virus |
Virus |
Hours before |
3600 |
1 |
1 |
1 |
0.02 |
20 |
1000 |
20 |
40 |
60 |
50.00 |
1800 |
1 |
2 |
2 |
0.03 |
20 |
1000 |
40 |
80 |
120 |
25.00 |
900 |
1 |
4 |
4 |
0.07 |
20 |
1000 |
80 |
160 |
240 |
12.50 |
450 |
1 |
8 |
8 |
0.13 |
20 |
1000 |
160 |
320 |
480 |
6.25 |
225 |
1 |
16 |
16 |
0.27 |
20 |
1000 |
320 |
640 |
960 |
3.13 |
113 |
1 |
32 |
32 |
0.53 |
20 |
1000 |
640 |
1280 |
1920 |
1.56 |
56 |
1 |
64 |
64 |
1.07 |
20 |
1000 |
1280 |
2560 |
3840 |
0.78 |
28 |
1 |
128 |
128 |
2.13 |
20 |
1000 |
2560 |
5120 |
7680 |
0.39 |
14 |
1 |
256 |
256 |
4.27 |
20 |
1000 |
5120 |
10240 |
15360 |
0.20 |
7 |
1 |
512 |
512 |
8.53 |
20 |
1000 |
10240 |
20480 |
30720 |
0.10 |
4 |
1 |
900 |
900 |
15.00 |
20 |
1000 |
18000 |
36000 |
54000 |
0.06 |
2 |
1 |
1800 |
1800 |
30.00 |
20 |
1000 |
36000 |
72000 |
108000 |
0.03 |
1 |
1 |
3600 |
3600 |
60.00 |
20 |
1000 |
72000 |
144000 |
216000 |
0.01 |
TBIL = IL/(Bs * (3600/AUC) * VL)
TBIL = IL/Vi1
TBIL = IL/(Bae * VL)
TBIL = IL/(Bae * VL)
TBIL = IL/(Bs * Es * VL)
TBIL = IL/(Bs * (3600/AUC) * VL)
AUC = AUC/Hour = Assumptions
Bs = Breaths/Sec = Assumptions
Es = Exposure/Sec = 3600/AUC
Bae = Breaths/Air Exchange = Bs * Es (needed for when the Breaths/sec changes
e.g. 0.5 or 2.0)
Em = Exposure Min = (Exposure/Sec)/60 (to get a feel for exposure time)
VL= Virus load = Assumption
IL = Infection load = Assumption
Vi1 = Virus inhaled (1 hr) = Bae * VL (any value above the Infection Load
will lead to infection)
Vi2 = Virus inhaled (2 hr) = Vi1 * 2
Vi3 = Virus inhaled (3 hr) = Vi2 * 3
TBIL = hr before infected load = IL/Vi1
The magic number appears to be between 50 and 100 air exchanges per hour. Another important consideration is the amount of time before the infection level is reached. Even though an air exchange rate of 113 may exist the infection level will still be reached in 1.56 hours. This is a significant finding because it suggests that the best mitigation is to leave any enclosed spaces as soon as possible. Further an enclosed space is not just a building but it is also a large crowd in a outdoor space with no ventilation into the crowd center.
Natural and Mechanical Ventilation Designs
A picture is worth a thousand words. Examining the design of hospital rooms and natural ventilation structures can provide insights into how to prepare different public spaces. It is all about air movement. Just because people are at an outdoor cafe it does not mean the air exchange is sufficient or in the directions that are needed to minimize the potential spread of disease.
|
Natural Ventilation Restroom (Hawaii, California) |
Careful placement of people and mechanical ventilation is needed and can only happen with a drawing or sketch of the outdoor venue. Simple ceiling fans, wall fans, exhaust fans in strategic locations will keep the outdoor air moving but it must not be trapped in circulating zones. After some thought and a simple paper design, a smoke test can be used to tune the final placement of the fans.
|
Hospital Room Negative Pressure |
Observations
We know that fresh air movement is key. We know that when we walk we move into a space of fresh air once per second. We also know that is approximately 1 mile per hour. This should be easy to duplicate with outdoor venues. It is problematic with modern office buildings. The modern office buildings will need serious HVAC upgrades. Some of the office buildings have outdoor spaces. People should be encouraged to spend time in these outdoor spaces.
Hospitals are designed to mitigate the spread of infection. Further the hospital staff uses different levels of professional protection equipment based on the circumstances. The issue is what can people do as they return back to life during a pandemic with a highly infectious disease. Some buildings are able to immediately take advantage of natural ventilation and bring the outside air indoors with relatively large AUC levels. Other buildings are closed and use HVAC systems that are designed for energy efficiency and not minimizing the spread of disease. It is these buildings that must be updated with massive new AUC levels. The analysis suggests that the:
AUC levels must be: 50 - 100 AUC to minimize the spread of disease inside tight buildings with no external ventilation alternatives
This is very interesting because the case history of a small bar and restaurant in the 1960's and 1970's had a brute force engineering approach where the AUC was easily 120. [1]
With such a high AUC level it is obvious that any virus would be quickly diluted and then expelled from the environment. It would be nice if formal lab testing could be immediately initiated to determine if this recommended AUC level is sufficient or if it can be reduced.
References:
[1] See section What if Analysis, Old Building Architectures - Engineered Solution.
Design Solutions
HVAC and Open Ventilation Design Solutions
This analysis has attempted to identify the AUC levels that must be achieved to mitigate virus infection. The next step is to determine if a design is possible and what are the issues associated with the design. A product search was initiated to locate large commercial fans for potential mechanically assisted natural ventilation in small buildings like a Home Owners Association Clubhouse. The following analysis was performed for a house using a whole house fan, a house using its current HVAC system and then a public clubhouse modified with commercial attic based ventilation fans.
The following analysis is for a house. It is provided to get a feel for the design considerations and possibility of very high AUC levels. [spreadsheet Design]
| Whole House Fan System | House HVAC System | |||
| 30 inch whole house fan cu-ft/min | 5,700 |
Home HVAC cu-ft/min | 1,600 |
|
| 30 inch whole house fan cu-ft/hr | 342,000 |
Home HVAC cu-ft/hr | 96,000 |
|
| Ceiling | 10 |
Same | Same |
|
| square feet | 2,400 |
Same | Same |
|
| Space cu-ft | 24,000 |
Same | Same |
|
| AUC | 14.25 |
AUC | 4.00 |
|
| Minutes to change air | 4.21 |
Minutes to change air | 15.00 |
The following analysis is for a public club house.
HOA Club House |
Alternative 1 |
Alternative 2 |
Alternative 3 |
Alternative 4 |
Comments |
fan system cu-ft/min |
53,900 |
53,900 |
53,900 |
53,900 |
Note 1 |
Number of fans |
1 |
2 |
3 |
4 |
Note 2 |
cu-ft/min |
53,900 |
107,800 |
161,700 |
215,600 |
|
cu-ft/hr |
3,234,000 |
6,468,000 |
9,702,000 |
12,936,000 |
|
Ceiling |
10 |
10 |
10 |
10 |
|
square feet |
12,000 |
12,000 |
12,000 |
12,000 |
|
Space cu-ft |
120,000 |
120,000 |
120,000 |
120,000 |
|
AUC |
26.95 |
53.90 |
80.85 |
107.80 |
Note 3 |
Minutes to change air |
2.23 |
1.11 |
0.74 |
0.56 |
Note 1: Direct Drive Wall Fan 48 inches.
Vendor.
Note 2: More smaller fans may be better. For example 1 per room.
Note 3. This systems engineering analysis suggests an AUC of 50-100 to minimize
the risk of infection Air
Flow Rates And Natural Ventilation
It appears that 2 to 3 commercial grade exhaust/attic fans can provide the suggested AUC levels in this analysis. That is 1 to 2 times the CDC recommended AUC levels from Table B.1. Air changes/hour (ACH) and time required for airborne-contaminant removal by efficiency or 1 to 2 times the recommended level for a commercial kitchen. The issue is that the open windows and doors will be bringing outside air into the building. This includes pollen. Also, depending on the window and door opening sizes the drafts may be significant while also creating dead air zones. This requires careful management of openings to ensure consistent and full air flow throughout the building. The exhaust/attic fan based solution is only viable when the temperatures are moderate.
Modifying the HVAC system to have AUC levels approaching the recommended levels may require additional duct work. One possibility is to use the attic/exhaust fans and HVAC system at the same time when temperatures are extreme. This is not a new operational setting. Many small bars and restaurants in the major cities operated in this mode throughout the 1960's and 1970's. They had to deal with massive cigarette smoke and provide for comfortable temperature and humidity conditions. As movement happened into the suburbs the new structures used centralized HVAC systems and so there was less of a dependence on exhaust fans to freshen the air and remove cigarette smoke from these settings. The final change happened when cigarette smoking was banned in many public spaces. So there was no longer a need to run the HVAC and exhaust fans at the same time. With the COVID-19 disaster, running the HVAC systems in parallel with the fans exhaust systems once again should be considered in the designs and used in operational settings.
This is a challenge that no one will touch with a 10 foot pole. There are great engineering companies that have attempted to go down this path but they stop short of claiming to have the answer [1]. However these companies can be helped with a massive government sponsored Ventilation Test and Evaluation program.
The JASON group from MITRE performed analysis for restarting university research programs that were impact because of the inability to physically access workspaces because of the COVID-19 disaster. These are some of the findings. From the executive summary they suggest labs ensure at least 4 air changes per hour (ACH) and to increase the flow rate if the lab has more than a single occupant. Within the report more detail is provided - more than half the benefit is achieved at 4 ACH, which is on the lower end of typical commercial spaces; and 90% of the benefit is achieved at 15 ACH, which is on the high end of what one might be found in a laboratory space. Aerosols are an important means of transmission in laboratories and other enclosed spaces. In addition to wearing masks, minimizing double occupancy, and maintaining distance, buildings HVAC systems can play a role in mitigating transmission [2].
References:
[Library/Building-Ventilation]
[1] COVID-19 White Paper, Taylor Engineering, Updated: May 28, 2020. webpage https://taylorengineers.com/taylor-engineering-covid-19-whitepaper, July 2020. COVID-19 White Paper . local
[2] Managing the Risk from COVID-19 During a Return to On-Site University Research, JASON The MITRE Corporation, JSR-20-NS1, July 2, 2020. https://fas.org/irp/agency/dod/jason/covid-19.pdf, July 2020. Managing the Risk from COVID-19 During a Return to On-Site University Research . local
UV-C Ventilation Design Solutions
UV-C when placed at the ceiling level is a ventilation approach. As the air is mixed through convection or via mechanical mechanisms and finds its way to the ceiling it is subjected to the UV-C light and the virus is destroyed. This addition to a room can translate into 17, 20, 23 additional eAUC per hour for mechanical ventilation rates of 0, 3, and 6 ACH. The performance of these systems is base on the time the air spends at the ceiling levels and the power density of the UV design. [2] [4] Note that for this analysis eAUC = ACH = AUC.
This is the Design section. For the Analysis see section UV-C Ceiling Level Lights. See section for UV Infrastructure Cost Estimates.
There are no shrink wrapped products that allow the average consumer to buy and install a ceiling level UV-C solution without external support from professionals. Unique design needs to be performed to determine the maximum UV-C effectiveness that can be achieved for different room sizes and ceiling heights. Some of the considerations include the existing ventilation system. The ventilation must be tuned so that the virus is subjected to the ceiling level UV-C for a sufficient amount of time to destroy the virus and yet maximize the virus destruction rate (the UV-C based AUC). For rooms that use radiant heat in the winter this may require the introduction of fans. For rooms that use forced hot air systems this may require modifications of airflow from the vents. The same applies to air conditioned environments during the hot weather months [5] [6].
In spite of the lack of shrink wrapped products, UV-C ceiling level applications exist in hospitals, schools, homeless shelters, etc. The industrial base does need to be expanded to address the home market because of high cost and systems that may be too large for the typical home. The market is basically an industrial market. Design guidance is provided by the CDC and FDA.
The first proven design appeared in 1937 as part of a study performed in Philadelphia by W.F. Wells. He was an Associate Professor in Research in Air-borne Infection at the Laboratories for the Study of Air-borne Infection in the Department of Preventive Medicine and Public Health at University of Pennsylvania School of Medicine, Philadelphia, PA. The findings were presented in part before the Engineering Section of the American Public Health Association at the Seventy-first Annual Meeting at St. Louis, Mo., October 30,1942. It was supported by a grant from the Common wealth Fund to the University of Pennsylvania for the study of the mechanics of air-borne infection and control. The design was based on science and engineering using numbers to understand the system and its level of performance [1].
Swarthmore Public School Classroom circa 1937 - 1943 |
The effectiveness of UVGI is typically expressed in terms of deactivation rate, which is a function of device geometry, intensity of the light source, resistance of the bioagent of interest, and residence time of the agent in the field of irradiation. Inactivation or kill rates can be predicted based on these parameters. However, there is no standard test method for determining the effectiveness of these devices and they are not generally supplied with the performance data to determine kill rates. There is a proposed UVGI Rating Value (URV) from 8 to 15 that corresponds to an average light intensity expressed in units of mW/cm2 [10]. Based on the exposure time and the susceptibility of a particular organism, the URV value can then be converted to a kill rate for that organism. However, the URV concept has not yet been adopted in an industry standard. At this point, UVGI systems are described in terms of the lamp specifications, including the light intensity expressed uW/m2. [11]
The design solution needs to be verified. This is accomplished using measurement equipment that measures the ceiling level UV concentration where the virus is expected to be destroyed and the lower room level UV concentration where people are expected to be present to ensure that safe levels are present. Ideally the measurements should be continuous 24/7 or when the space is open to the public. The power levels are a function of the power density. There are studies being performed to determine the power density needed to destroy this virus. There is data SAR-Cov-1 that can be used as a starting point.
Various product brochures are in the Library [Lib/UV-Systems/Products]. The potential vendors and organizations are shown below (there is no for or against endorsement).
| Company / Organization | Links | Products & Markets | Comment |
| Lightbest Co, LTD * | https://www.light-best.com | All products all markets | International manufacturing company |
| Coospider | https://coospider.com | Light Fixtures and bulbs | International manufacturing company |
| . | |||
| Atlantic Ultraviolet Corporation * | https://www.buyultraviolet.com | All products all markets | Manufacturing company |
| EvergreenUV / Lumalier | https://www.lumalier.com | All products all markets | Manufacturing company |
| American Air and Water | https://www.americanairandwater.com | All products all markets | Manufacturing company |
| American Ultraviolet | https://www.americanultraviolet.com | All products all markets | Manufacturing company |
| Larson Electronics | https://www.larsonelectronics.com | UV-C & FAR UV-222 | Manufacturing company |
| ProLampSales | https://www.prolampsales.com/collections/g13-base-uvc-bulbs
https://www.prolampsales.com/collections/uvc-indirect-upper-air-sanitizers |
UV-C Lights | Distributer |
| Phillips | https://www.lighting.philips.com/main/products/uv-disinfection | All products all markets | International manufacturing company |
| . | |||
| International Ultraviolet Association | http://www.iuva.org | All products all markets | Professional organization |
| UVSolutions | https://uvsolutionsmag.com | All products all markets | The Official Publication of the International Ultraviolet Association |
| UV Solutions Buyers Guide | https://uvsolutionsmag.com/buyersguide/services/MAIN_COVID19 | All products all markets | The Official Publication of the International Ultraviolet Association |
* vendors use in conceptual design solution
Vendor: Lightbest
Instant Start (Slimline) Germicidal Lamps-T5 SP_DE Instant start lamps-Ozone
free
Model |
Diameter |
Length |
Arc Length |
Power |
Current |
voltage |
UV output |
Watts |
Rated Life |
G10T5l |
15 |
14 |
277 |
17 |
425 |
51 |
54 |
5.7 |
9000 |
G36T5l |
15 |
33 |
763 |
41 |
425 |
120 |
130 |
13 |
9000 |
G48T5l |
15 |
45 |
1068 |
55 |
425 |
165 |
170 |
18 |
9000 |
G64T5l |
15 |
61 |
1474 |
75 |
425 |
220 |
225 |
24 |
9000 |
Vendor: Atlantic Ultraviolet Corporation [Lib/Products]
| Model Number | Length (inches) |
Watts |
| LIND24-EVO 40-0125B | 24 |
8.5 |
| LIND24-EVO-2PM 40-0126C | 24 |
17 |
The following table shows a potential design for a house. The solution is based on components that are assembled by the installer. This approach is the lowest cost approach. Until there is a commercial consumer market this is the only reasonable option because of cost. [Spreadsheet UV Design]
Whole House UV-C |
Lamp Type |
Number |
Length |
Watts / Light |
Living room |
G36T5l |
2 |
33 |
13 |
Dining Room |
G36T5l |
1 |
33 |
13 |
Kitchen |
G36T5l |
1 |
33 |
13 |
Rec Room |
G36T5l |
2 |
33 |
13 |
Bedroom |
G36T5l |
1 |
33 |
13 |
Bedroom |
G36T5l |
1 |
33 |
13 |
Bedroom |
G36T5l |
1 |
33 |
13 |
Bedroom |
G36T5l |
1 |
33 |
13 |
Bathroom |
G10T5l |
1 |
14 |
5.7 |
Bathroom |
G10T5l |
1 |
14 |
5.7 |
Powder Room |
G10T5l |
1 |
14 |
5.7 |
UV Measurement Tool |
- |
1 |
- |
- |
It is unclear if the house installation benefits outweigh the risk. For example homeowners and children tampering with the UV lights while they are on is a risk while the benefit is just limited to a small number of people in extreme close contact. However, if there is an infected person in the house there may be a benefit to the infected person where the free virus load in the air is significantly reduced allowing the body to fight off a diminished total virus load that includes external and internal body virus exposure.
The following table shows a potential design for a Home Owners Association (HOA) club house. It uses industrial products. This is currently a high cost approach. The analysis shows that this approach costs 15 times more than sourcing the individual components and assembling the components onsite. [Spreadsheet UV Design]
HOA Club House |
# Units |
Unit Type |
Length |
Watts / Unit |
Ballroom |
4 |
LIND24-EVO-2PM 40-0126C |
24 |
17 |
Library |
1 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Sitting Area |
1 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Conference Room |
1 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Office |
1 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Craft Room |
1 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Billiards Room |
1 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Game Room |
1 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Exercise Room |
2 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Indoor Pool |
2 |
LIND24-EVO-2PM 40-0126C |
24 |
17 |
Locker Room 1 |
2 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Locker Room 2 |
2 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Powder Room 1 |
2 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Powder Room 2 |
2 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Reception Area |
2 |
LIND24-EVO 40-0125B |
24 |
8.5 |
Hallway |
2 |
LIND24-EVO 40-0125B |
24 |
8.5 |
UV Measurement Tool |
1 |
- |
- |
|
In all cases the UV installation needs to be tested for UV levels where the infection is to be destroyed and for the worst case living levels. This is to ensure that maximum benefit is achieved and there is minimal UV exposure to humans. Permissible Exposure Times (PET) can be calculated for various irradiance levels as follows:
PET (seconds) = REL (6000 uJ/cm2 at 254 nm) / Measured irradiance level at 254 nm (uW/cm2)
where: At 254 nm, the CDC/NIOSH REL is 6 mJ/cm2 (6000 uJ/cm2)
The following table shows the PET values for different scenarios. [4]
PET |
PET |
Effective Irradiance |
8 h |
28,800 |
0.2 |
4 h |
14,400 |
0.4 |
2 h |
7,200 |
0.8 |
1 h |
3,600 |
1.7 |
30 min |
1,800 |
3.3 |
15 min |
900 |
6.7 |
10 min |
600 |
10 |
5 min |
300 |
20 |
1 min |
60 |
100 |
30 sec |
30 |
200 |
10 sec |
10 |
600 |
1 sec |
1 |
6,000 |
0.5 sec |
0.5 |
12,000 |
0.1 sec |
0.1 |
60,000 |
In the original 1937 - 1943 Air Disinfection in Day Schools study, the exposure was 0.2 to 0.5 milliwatts per sq. ft. (or microwatts per sq. cm.) at face level of standing pupils. Those taller than the students, such as adults would have been exposed to a higher level. To destroy the virus, the upper air level was 10 to 20 milliwatts per sq. ft (or microwatts per sq. cm.). [1] The CDC recommends 30 uW/cm2 to 50 uW/cm2 but the number as of November 2020 for the COVID-19 virus is unknown. We can only look at data from previous MERS and SARS outbreaks. [12]
Public School UV Light Installation circa 2020 |
Case History
In the 1960's my family purchased a bar and restaurant in Philadelphia, PA. It was a small establishment consisting of 5 brownstones that were modified in the early 1900s to be a bar and restaurant. Around the perimeter of the main bar area at the ceiling level there were UV-C lights. They were controlled via a standalone switch behind the bar. The UV-C light tubes were mounted inside a stained wooden box that matched the rest of the bar trim and wood architecture. The box was approximately 12 inches deep, 12 inches high, and continuously spanned across all 4 walls. The trim was angled away toward the interior perhaps 15 degrees. The UV-C lights were mounted inside this structure. The perimeter box top was perhaps 18-24 inches below the ceiling allowing the UV-C to irradiate the ceiling. This was obviously a custom installation but it illustrates the point that existing architectural materials are used to house the electrical components.
Public School UV Light Installation circa 1937 - 1943 |
Author Comment: As far as UV risks - management and wavelength is very important. As of November 2020 we have dangerous products and products that do not work being sold to the public. In the previous century it was called snake oil and that is why the US established the FDA.
This is the Design section. For the Analysis see section UV-C Ceiling Level Lights. See section for UV Infrastructure Cost Estimates.
Continue to design section FAR UV-222 Design Solutions.
References:
[1] Air Disinfection in Day Schools, W.F. Wells Associate Professor in Research in Air-borne Infection, Laboratories for the Study of Air-borne Infection, the Department of Preventive Medicine and Public Health, University of Pennsylvania School of Medicine, Philadelphia, Pa. 1943. webpage https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.33.12.1436, November 2020. Air Disinfection in Day Schools . local
[2] How Can Airborne Transmission of COVID-19 Indoors be Minimized?, May 01, 2020. https://www.youtube.com/watch?v=jK6Cef5A8FQ. local transcript
[3] The History of Ultraviolet Germicidal Irradiation for Air Disinfection, Public Health Reports/January–February 2010/Volume 125. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789813 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789813/pdf/phr125000015.pdf, November 2020. The History of Ultraviolet Germicidal Irradiation for Air Disinfection . PDF . local
[4] Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings, Department of Health and Human Services Centers for Disease Control and Prevention National Institute for Occupational Safety and Health, DHHS (NIOSH), Publication No. 2009-105 March 2009. webpage https://www.cdc.gov/niosh/docs/2009-105/pdfs/2009-105.pdf, November 2020. Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings . local
[5] UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus, US Food and Drug Administration - FDA, August 19, 2020. webpage https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/uv-lights-and-lamps-ultraviolet-c-radiation-disinfection-and-coronavirus, November 2020. UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus . local
[6] Ultraviolet (UV) Radiation, US Food and Drug Administration - FDA, August 19, 2020. webpage https://www.fda.gov/radiation-emitting-products/tanning/ultraviolet-uv-radiation, November 2020. Ultraviolet (UV) Radiation . local
[7] Upper-Room-Disinfection, National Academies of Sciences, Engineering, and Medicine, September 17, 2020. webpage https://www.nationalacademies.org/event/09-16-2020/docs/D00062573057472031C5B95374B5C068AE9324D53EC4, November 2020. Upper-Room-Disinfection . local
[8] Upper-room ultraviolet air disinfection might help to reduce COVID-19 transmission in buildings: a feasibility study, PeerJ peerj.com, October 13, 2020. webpage https://peerj.com/articles/10196, November 2020. Upper-room ultraviolet air disinfection might help to reduce COVID-19 transmission in buildings: a feasibility study . local
[9] Effect of Ultra-violet Irradiation of Classrooms on Spread of Measles in Large Rural Central Schools, New York State Department of Health, Albany, N.Y. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1623610/pdf/amjphnation01116-0034.pdf, November 2020. Effect of Ultra-violet Irradiation of Classrooms on Spread of Measles in Large Rural Central Schools . local
[10] Proposed Standards and Guidelines for UVGI Air Disinfection, The Indoor Environment Center Department of Architectural Engineering The Pennsylvania State University, August 20, 2007. local
[11] Building Retrofits for Increased Protection Against Airborne Chemical and Biological Releases, U.S. Environmental Protection Agency, EPA 600/R-06/157 NIST IR7379, February 2007. webpage https://nepis.epa.gov/Exe/ZyPDF.cgi/P1005UD2.PDF?Dockey=P1005UD2.PDF, November 2020. Building Retrofits for Increased Protection Against Airborne Chemical and Biological Releases . local
[12] See section UV-C Ceiling Level Lights.
FAR UV-222 Design Solutions
Unlike the UV-C approach, FAR UV-222 also known as FAR UVC may not need special engineering to perform a design. Guidance in terms of light selection and placement may be sufficient to ensure a safe and yet effective system. Existing UV-C companies also offer FAR UV-222 solutions and there appears to be one or more companies focusing on FAR UV-222 solutions. [1]
This is the Design section. For the Analysis see FAR UV-222 Full Illumination. See section for UV Infrastructure Cost Estimates.
|
The light is typically produced from Excimer lamps (excilamps). They are a special type of gas discharge lamps generating ultraviolet light. They can generate quasi-monochromatic UV light with particularly short wavelengths, are fairly efficient, and can have long lifetimes. Typical applications are printing, photolithography, UV curing of adhesives, surface cleaning and surface modification, ozone generation and sterilization.
Various product brochures are in the Library [Lib/UV-Systems/Products]. The potential vendors and organizations are shown below (there is no for or against endorsement).
| Company / Organization | Links | Products & Markets | Comment |
| Healthe | https://healthelighting.com | FAR UV-222 all markets | Provides total system installation |
| Ushio America | https://www.ushio.com | FAR UV-222 | International manufacturing company |
| Larson Electronics | https://www.larsonelectronics.com | 222 nm UVC Excimer Lamp | Distributor |
| . | |||
| Columbia University Center for Radiological Research (CRR) |
https://www.crr.columbia.edu | Research | Columbia University is performing FAR UV-222 research |
| . | |||
| RP Photonics Consulting GMBH | https://www.rp-photonics.com/bg/buy_excimer_lamps.html | Excimer lamps | Excimer Lamps buyers guide |
| International Ultraviolet Association | http://www.iuva.org | Traditional UV-C | Professional organization |
| UVSolutions | https://uvsolutionsmag.com | Traditional UV-C | The Official Publication of the International Ultraviolet Association |
| UV Solutions Buyers Guide | https://uvsolutionsmag.com/buyersguide/services/MAIN_COVID19 | Traditional UV-C | The Official Publication of the International Ultraviolet Association |
As of November 2020, there appears to be a great deal of confusion about UV light disinfection. There are many uncertified products with questionable effectiveness. Industry must step up to the challenges and nation state governments from around the world also must step up to begin proper regulation and certification of products. Otherwise critical technology and important companies will be lost in the noise of snake oil sales and products that do not work and can cause harm.
One of the technical issues with FAR UV-222 is a physics challenge where power density drops off with the square of the distance. A device that provides sufficient uW/CM2 within the distant regions of a room will have a very high uW/CM2 near the light. This is a design challenge. It suggests multiple low power lights rather than one or two large power lights.
The following table shows a potential design for a house. Because of the high cost the suggestion is to use a portable moveable fixture and move the fixture into the space occupied by people. [Spreadsheet UV Design]
Whole House UV-C |
Lamp Type |
Number |
Watts / Light |
Comment |
Living room |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
1 |
10 |
Portable moveable fixture |
Dining Room |
|
|
|
Use portable moveable fixture |
Kitchen |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
1 |
10 |
Portable moveable fixture |
Rec Room |
|
|
|
Use portable moveable fixture |
Bedroom |
|
|
|
Use portable moveable fixture |
Bedroom |
|
|
|
Use portable moveable fixture |
Bedroom |
|
|
|
Use portable moveable fixture |
Bedroom |
|
|
|
Use portable moveable fixture |
Bathroom |
|
|
|
Use portable moveable fixture |
Bathroom |
|
|
|
Use portable moveable fixture |
Powder Room |
None |
0 |
0 |
Not covered |
UV Measurement Tool |
- |
1 |
- |
- |
It is unclear if the house installation benefits outweigh the risk. For example homeowners and children tampering with the UV-222 lights while they are on is a risk while the benefit is just limited to a small number of people in extreme close contact. However, if there is an infected person in the house there may be a benefit to the infected person where the free virus load in the air is significantly reduced allowing the body to fight off a diminished total virus load that includes external and internal body virus exposure.
The following table shows a potential design for a Home Owners Association (HOA) club house. The analysis shows that this UV-222 approach costs approximately the same as the UV-C approach. [Spreadsheet UV Design]
HOA Club House |
# Units |
Unit Type |
Watts / Unit |
Ballroom |
4 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Library |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Sitting Area |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Conference Room |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Office |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Craft Room |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Billiards Room |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Game Room |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Exercise Room |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Indoor Pool |
2 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Locker Room 1 |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Locker Room 2 |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Powder Room 1 |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Powder Room 2 |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Reception Area |
1 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
Hallway |
2 |
IND-CDL-RD-8-FUVC-MP-1L-V1 Far-UV Sanitation Light |
10 |
UV Measurement Tool |
1 |
- |
|
In all cases the UV-222 installation needs to be tested for UV-222 levels where the infection is to be destroyed and for the worst case living levels. This is to ensure that maximum benefit is achieved and there is minimal UV exposure to humans. This is new technology and the system performance numbers are still being studied. [2]
Author Comment: As far as UV risks - management and wavelength is very important. As of November 2020 we have dangerous products and products that do not work being sold to the public. In the previous century it was called snake oil and that is why the US established the FDA.
This is the Design section. For the Analysis see FAR UV-222 Full Illumination. See section for UV Infrastructure Cost Estimates.
References:
[1] Could a New Ultraviolet Technology Fight the Spread of Coronavirus, Columbia University, June 30, 2020. webpage https://news.columbia.edu/ultraviolet-technology-virus-covid-19-UV-light, November 2020. Could a New Ultraviolet Technology Fight the Spread of Coronavirus
[2] See section FAR UV-222 Full Illumination.
UV Infrastructure Cost Estimates
The following is a cost estimate to roll out UV into the entire US infrastructure. It does not consider that there are already UV systems in operation in hospitals, some homeless shelters, some work settings like meat packing plants, some restaurant kitchens, and elite facilities. The production ramp up is considered only a small challenge because UV-C lights are basically florescent lights without internal coating to produce the desired visible light. FAR UV-222 costs are similar but currently there is limited production capacity.
[Spreadsheet UV Design]
UV Space |
sq-ft [1] |
Cost/sq-ft |
Cost |
Comment |
Schools |
1,698,000,000 |
$1.76 |
$2,996,470,588 |
Public and private |
| Commercial Office Space | 4,000,000,000 |
$1.76 |
$7,058,823,529 |
Manhattan skyscrapers to lawyer's office |
| Retail | 9,500,000,000 |
$1.76 |
$16,764,705,882 |
Indoor & strip malls, big box retailers, grocery stores, restaurants, shopping center space |
| Industrial property | 13,000,000,000 |
$1.76 |
$22,941,176,471 |
Manufacture, distribute, warehouse |
The cost per sq-ft is derived from using an average cost of $1,588 in a 900 sq-ft school classroom. The cost of the components to make a UV-C light fixture is approximately 10-20 percent the cost of current fixtures. If these devices were to become ubiquitous it is anticipated that the costs would significantly drop. There are also operational and maintenance costs which are considered to be negligible at this time. The roll out strategy should follow some type of priority such as:
The benefit from this investment is provided in Section Current and Future Virus Eradication Findings.
The analysis showing the history and effectiveness of UV is in Section Ultraviolet Germicidal Irradiation (UVGI) - Open Air.
References:
[1] Commercial Real Estate and the Economy, The Balance, February 28, 2019. webpage https://www.thebalance.com/what-is-commercial-real-estate-3305914, November 2020. Commercial Real Estate and the Economy
Ventilation Test and Evaluation
Industry has looked at this challenge and they have done some great work [1] [2] . However this is beyond the capability of a single company or even a group of companies. The issues are vast and even include legal liability. The bottom line is that the US Government must establish a massive Ventilation Test and Evaluation program using National Labs and the Industrial base from around the world. This is the largest and most important test and evaluation program in history. The government must then certify the findings so that we know that the best science and engineering has been used to address this challenge. This certification will clear the issues associated with legal liability. Once the specifications are known then they can be rolled out to the community, building checks can be performed, and if needed certificates issued.
It is possible to establish a test and evaluation strategy to determine if the proposed analysis and resulting design can mitigate the risk of virus infection. The approach is to use smoke generators to simulate the volumes of air that contain the virus and track the path and dispersion characteristics of the smoke. Alternatives include various gases and gas detectors.
We know that a male exhales 6 liters of air because that is the typical lung capacity. The 6 liters of puffing smoke from one or more emitters can be tracked visually using cameras and a time stamp on the images. We also know that the virus load in the 6 liters of smoke can range from 20 (single breath) to some factor of 200,000,000 (sneeze). As the smoke is dispersed the volume is increase and it can be measured. This measurement will provide an estimate of the dispersed virus load. The next step is to determine the real world scenarios. The final step is to perform the tests, gather the data, and reduce the data to potential results. These results can then be provided as specifications for all ventilation modifications.
The scenarios are based on physical space, number of emitters with different infection loads (breathing, coughing, sneezing), and different air exchange rates (2 to 100 or more if needed). The physical spaces are:
Test different ideas:
The following diagrams are offered to suggest the various test scenarios and different test ideas.
Airplane Passenger Compartment |
Enclosed Space |
Airplanes have positive pressure vents above each passenger. There are also other positive and negative pressure vents. The test involves mapping the current air circulation to understand potential infection paths. It is anticipated that there are multiple infection paths and one approach is to install negative pressure vents at the floor of each seat position or under the chair and study the changed airflow paths. At some air flow level and placement of negative pressure vents the paths can be modified to mitigate exposure to the virus.
Enclosed spaces have a room size, existing ventilation, and a maximum person capacity. This test involves changing the airflow rates, percentage of infected people, and number of people in the enclosed spaced. This systems engineering analysis suggests that the AUC needs to be 50 to 100, but as with all models and analysis reasonable testing needs to be performed. It is possible the rate can be lower or it needs to be higher. We will not understand the situation until testing is performed.
Outdoor Space Tent |
Outdoor Open Space |
Many have suggested that outdoor venues can be held because the setting is outside. There is a big difference walking outside exchanging the air 3600 times per hour and sitting in an open space surrounded by people when there is no air movement. Testing needs to be performed to understand various outdoor venues. Simple placement of a few fans will significant change the air exchange rate in the open space.
Student Desk Negative Pressure Vents |
Workstation Negative Pressure Vents |
Students at a desk and people at work are personal space situations similar to what is found on an airplane. It is expected that many buildings will not be able to increase the air update rates. One approach is to introduce personal negative pressure vents. Negative pressure is established at the student desk or workstation and it is routed via low cost tubing to a fan, UV-C lights, filter, and then released back into the environment. In a centralized system the release can be near the negative pressure vents of the existing HVAC system and exhaust fans. In a decentralized system the release can be into the floor or into the ceiling.
Restaurant Table Negative Pressure Vents |
Crowd Negative Pressure Vents |
Negative Pressure Floor, Walkway, Pad |
People will gather to engage in life. In a restaurant situation tables and bars can be modified to introduce negative pressure vents. In crowd situations there are always crowd control border mechanisms using a pole and a soft cloth or hard barrier. They can be replaced or updated with negative pressure poles connected by flexible hoses that can also serve as a soft barrier or PVC tubes can be used for hard barrier settings. Negative pressure walkways, standing pads, floors especially in areas like TSA checks and healthcare examination rooms can be added.
Initial Virus Mitigation Test and Evaluation Program
The following is a suggestion for starting an engineering based virus mitigation test and evaluation effort. It can be expanded to cover all the aspects described in this section plus all the suggestions that will come from such an effort.
Airplane Passenger Compartment
Testing. Determine the effectiveness of different air flow modifications
in an airplane passenger compartment.
Enclosed Space Testing. Determine
the required HVAC airflow rates needed in buildings. Include HVAC the UV-C
light levels and filter recommendations.
Outdoor Space Tent Testing.
Simple placement of a few fans will significantly change the air exchange
rate.
Outdoor Open Space Testing.
Simple placement of a few fans will significantly change the air exchange
rate.
Negative Pressure Vents Testing.
Students at a desk and people at work are personal space situations similar
to what is found on an airplane. The same applies to restaurant tables and
people waiting in a line with traditional physical walking boundaries.
National Lab Testing. The
FAA Technical Center performed similar tests related to fire mitigation in
the late 1970's. They have the facilities and capability to immediately ramp
up to perform the world class engineering testing needed to mitigate the
spread of the virus.
Other Engineering Testing.
Ideas will come. Everyone should be encouraged to perform their own engineering
tests and publish their results.
References:
[Library/Building-Ventilation]
[1] COVID-19 White Paper, Taylor Engineering, Updated: May 28, 2020. webpage https://taylorengineers.com/taylor-engineering-covid-19-whitepaper, July 2020. COVID-19 White Paper . local
[2] Managing the Risk from COVID-19 During a Return to On-Site University Research, JASON The MITRE Corporation, JSR-20-NS1, July 2, 2020. https://fas.org/irp/agency/dod/jason/covid-19.pdf, July 2020. Managing the Risk from COVID-19 During a Return to On-Site University Research . local
Others have started to try to understand ventilation but the next step is needed where effective engineering is performed to solve the virus transmission problem within enclosed and semi enclosed spaces. It is time to apply the massive US Federal Government resources needed to solve this massive problem of bring people safely back to life. A picture is worth a thousand words. Here are some pictures from various groups doing great work. They should be used as a starting point for this massive Ventilation Test and Evaluation program. How big is the program? Your guess is as good as mine. Let's start with 1 billion dollars over the next 6 months engaging every national lab in the US. Redirect existing national lab resources immediately.
Larger droplets with viral content fall to the ground (droplet transmission), while smaller droplets travel long distances in the air (aerosol transmission) [1]
Trajectories of droplets and aerosols from an infected patient (a) event of sneezing with droplets travelled for 6 m at a speed of 50 m/s within 0.12 s (b) event of coughing with droplets travelled for 2 m at a speed of 10 m/s within 0.2 s (c) event of exhaling with droplets travelled for 1 m at a speed of 1 m/s within 1 s. [2]
Trajectories of droplets and aerosols from an infected patient in the event of coughing with different masks and respirators worn (a) without any mask or respirator (b) with surgical mask (c) with N95 respirator (d) with reusable elastomeric respirator. [2]
Trajectories of droplets and aerosols from an infected patient in the event of coughing in an aircraft (a) airflow pattern of the cabin without any cough-jet expiration (b) without any mask (c) with surgical mask (d) with N95 respirator. [2]
Trajectories of droplets and aerosols from an infected patient in the event of coughing in a car with air-conditioner switched on (a) airflow pattern inside the car without any cough-jet expiration (b) without any mask (c) with surgical mask (d) with N95 respirator. [2]
Trajectories of droplets and aerosols from an infected patient in the event of coughing in a car with windows opened (a) airflow pattern inside the car without any cough-jet expiration (b) without any mask (c) with surgical mask (d) with N95 respirator. [2]
Trajectories of droplets and aerosols from an infected patient in the event of coughing in a healthcare center with ventilation provided by an air conditioner (a) airflow pattern inside the healthcare center without any cough-jet expiration (b) without any mask (c) with surgical mask (d) with N95 respirator. [2]
Trajectories of droplets and aerosols from an infected patient in the event of coughing in a healthcare center with ventilation provided by ceiling fans (a) airflow pattern inside the healthcare center without any cough-jet expiration (b) without any mask (c) with surgical mask (d) with N95 respirator. [2]
Sample Literature Search
Evaluating Virus Containment Efficiency Of Air-Handling Systems: Air-handling systems serving an infected space can transfer an infection agent through the ductwork. This article presents a mathematical model of virus-laden aerosol propagation through air-handling systems. It also recommends simple engineered measures that can improve the system’s virus containment efficiency [3].Makeshift Negative Pressure Patient Rooms In Response to COVID-19: Recommendations and Lessons Learned: You don’t have much time to create negative pressure hospital patient rooms during a pandemic. You can create these rooms quickly using appliances such as portable HEPA exhaust fan units, along with guidance from relevant codes and standards and hospital requirements [4].
References:
[1] Airborne transmission of SARS-CoV-2: The world should face the reality, Lidia Morawskaa, Junji Caob, International Laboratory for Air Quality and Health (ILAQH), School of Earth of Atmospheric Sciences, Queensland University of Technology, Brisbane, Queensland 4001, Australia, Key Lab of Aerosol Chemistry & Physics (KLACP), Chinese Academy of Sciences, Beijing, China, Environment International 139 (2020) 105730, June 2020, 105730. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7151430, July 2020. Airborne transmission of SARS-CoV-2: The world should face the reality . local
[2] Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy, Mahesh Jayaweeraa,., Hasini Pererab, Buddhika Gunawardanaa, Jagath Manatungea, Department of Civil Engineering, University of Moratuwa, Sri Lanka, Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Sri Lanka, Environmental Research 188 (2020) 109819, June 2020. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495, June 2020. Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy . local
[3] Evaluating Virus Containment Efficiency of Air-Handling Systems, ASHRAE Journal, vol. 62, no. 7, July 2020, Renat Manassypov, Ph.D., P.Eng., ASHRAE, July 2020.
[4] Makeshift Negative Pressure Patient Rooms In Response to COVID-19, ASHRAE Journal, vol. 62, no. 7, July 2020, Frank Shadpour, P.E.; Stefanie Johnson, ASHRAE, July 2020.
Real Time Monitoring of Air Flow Conditions
The ventilation test and evaluation program suggests that there may be approaches to perform real time monitoring of the airflow. This may be especially useful for outdoor venues where everyone assumes the airflow is safe. However we know that the air can stagnate in these settings without the use of fans especially on hot summer days. Simple elegant smoke emitters can provide immediate feedback to the staff who can turn on / off different fans as needed. This also can be effective indoors when the HVAC system is being tuned to the new needs to mitigate the risk of infection. It can also show if something has changed with the HVAC system.
There needs to be multiple Virus Mitigation Solution-Base-Programs legislation actions to allow for a reasonable return to life scenario. This is the first proposed legislation.
TITLE
COVID-19 Funding for Facility Ventilation Upgrade Recommendations and to Upgrade all Public Schools
DATE
July 3, 2020
BACKGROUND
The current system for containing the COVID-19 virus is based on wearing masks, practicing social distancing, quarantine of infected individuals, and waiting for a potential vaccine. During this time the country has been shutdown and only essential workers have been going to work.
Research is suggesting that the risk of virus infection is significantly higher within enclosed buildings than in outdoor settings. Further it appears that the virus has not been contained, it continues to spread.
The purpose of this legislation is to provide the funding to develop existing and new engineering based ventilation approaches and perform a ventilation test and evaluation effort using the best science and engineering available to determine what must be done to facilities to ensure that they are safe and the potential virus infection is fully mitigated. It is anticipated that the engineering solutions are off the shelf and the primary effort will be in ventilation test and evaluation so that government certified specifications can be developed and then offered to the industrial base for implementations. The government certification will ensure that the best science and engineering has been used and that all legal liability issues are fully addressed so that industry can provide the safe solutions.
Unfortunately it is anticipated that this engineering based effort to provide safe indoor and outside venues and environments will continue for multiple years until the virus is fully mitigated. Sadly, during this time people will get sick and die but without a cure there is no other alternative.
May our children and God forgive us for waiting so long to take this reasonable and appropriate action.
RESOURCES
1. All national labs shall be redirected to support an engineering based Ventilation Test and Evaluation effort.
2. The FAA William J. Hughes Technical Center in Atlantic City, NJ shall take the lead role in this massive Ventilation Test and Evaluation effort.
They are selected because of their role in ensuring the safety of airplane passenger compartments (they have performed similar studies in the past), they maintain hundreds of facilities across the country that must be free from virus infection risk, they are located in close proximity to the finest Universities in the world, they have an onsite airport that can accommodate military and civilian aircraft, they are located in an area with massive numbers of small businesses that also must have their needs addressed, they have the contracting expertise to roll out the massive amount of funding that is anticipated for this effort, and they have the physical space to build the anticipated structures that will be needed for proper testing and evaluation.
3. The FAA shall engage the MITRE corporation to help them establish and manage the Ventilation Test and Evaluation effort.
4. The CDC shall take on an equal and parallel role and use the engineering resources of the FAA Technical Center in Atlantic City to more fully understand how the virus spread can be mitigated using engineering approaches.
It is recognized that the CDC is primarily focused on disease control and that this has been viewed primarily from a healthcare perspective. Until now there was no need to examine our infrastructure from a disease spread and mitigation perspective. This is a new development in the 21st century. This requires an engineering perspective.
RESULTS (Ventilation Test and Evaluation) AND TIME TABLE
1. Within 6 months the Ventilation Test and Evaluation effort shall provide recommendations for the minimum amount of air exchanges per hour based on multiple tests in multiple scenarios that represent all the reasonable anticipated living scenarios. This includes both indoor and outside venues and environments.
2. Within 6 months the Ventilation Test and Evaluation effort shall provide recommendations for the proper use of UV-C lights and filters based on multiple tests in multiple scenarios that represent all the reasonable anticipated living scenarios. This includes both indoor and outside venues and environments.
3. Within 6 months the Ventilation Test and Evaluation effort shall provide recommendations for various engineering based solutions that stop the spread of the virus based on multiple tests in multiple scenarios that represent all the reasonable anticipated living scenarios. This includes both indoor and outside venues and environments.
4. All the results shall be updated monthly and made available via a public access website so that the industrial base can implement these results as quickly as possible.
5. Within 1 year the Ventilation Test and Evaluation effort shall provide status on the success of the program based on industry acceptance, facilities upgraded, and estimates of potential lives saved.
6. After 1 year this program shall be assessed to determine the work that must be performed in the next year.
RESULTS (Materials) AND TIME TABLE
1. As we have focused on environmentally friendly materials we may have the unintended consequences of developing infrastructure that promotes the spread the virus, bacteria, and fungi within our physical structures.
2. Within 6 months an Infrastructure Materials and Disease Effects study shall be produced identifying how our infrastructure materials have changed in the past 50 years and if that change has resulted in the potential spread of disease.
3. Within 6 months an Infrastructure Materials and Disease Effects study shall identify environmentally friendly materials that also do not allow virus, bacteria, and fungi to survive.
The study shall search for various materials, propose new materials, and quantify the potential mitigation effects. For example copper, brass, and nickel are known to have these characteristics.
4. Within 6 months an Infrastructure Materials and Disease Effects study shall identify where virus mitigation materials should be immediately applied, applied in the midterm, and applied in the long term.
5. During the Infrastructure Materials and Disease Effects study, the findings and recommendations shall be subjected to a Materials Test and Evaluation effort to ensure that the study findings are valid.
6. Within 1 year the Infrastructure Materials and Disease Effects effort shall provide status on the success of the program based on industry acceptance, facilities upgraded, and estimates of potential lives saved.
7. After 1 year this program shall be assessed to determine the work that must be performed in the next year.
FUNDING
1. The initial funding for the Ventilation Test and Evaluation effort shall be a minimum of 1 billion dollars.
2. In order to allow schools to safely open as soon as possible, a minimum of 110 billion dollars shall be initially allocated to fund the upgrade of all public schools using the results of this effort. [spreadsheet Schools]
3. The funding shall be increased as needed to support any short falls in the Ventilation Test and Evaluation effort but not to exceed 10 billion dollars with this legislation.
4. The funding shall be increased as needed to support any short falls in the upgrade of all public schools but not to exceed 428 billion dollars with this legislation. [spreadsheet Schools]
CLOSING REMARKS
This is the worst disaster in modern history. There is something very wrong with our systems and they must be corrected. It is possible that our modern enclosed buildings and transportation systems might have led to this massive disaster. This program will help to determine if that is the case and it will then develop the solutions that are needed moving forward. As a result of this program we will have healthier facilities and this will lead to reduced healthcare costs in general. The initial 1 billion dollar investment to perform massive Ventilation Test and Evaluation is irrelevant once compared with the massive costs already incurred from this disaster. Based on existing analysis we will need to upgrade our buildings. We should begin with our schools.
STUDENTS AND TEACHERS RETURNING BACK TO WORK
These are the stakeholder needs of the students and teachers. As these needs are reviewed it becomes very clear that this legislation is critical and must be passed or the consequences will be horrific.
Masks and social distancing is not possible. The infrastructure must be modified.
1. Wearing a mask with no break for 7 to 8 hours is not possible.
2. Children and teenagers wearing a mask at bus stops unlikely, in bus unlikely, in cafeteria not possible, during gym not possible, during classroom changes unlikely, in classroom will destroy learning experience
3. Children and teenagers social distancing at bus stops unlikely, in bus unlikely, in cafeteria not possible, during gym not possible, during classroom changes unlikely, in classroom not possible
3. Special needs children and teenagers wearing a mask and social distancing is not possible.
4. Bullies will place students in grave risk by engaging in dangerous behavior (spiting, coughing, etc).
5. When possible move all classroom activity outside. (the stakeholders now know some of the engineering analysis and want these solutions)
6. Open all the windows and doors and help natural ventilation with fans everywhere. (the stakeholders now know some of the engineering analysis and want these solutions)
7. HVAC Infrastructure must be modified to allow for massive air exchanges. (the stakeholders now know some of the engineering analysis and want these solutions)
8. Add UV-C ceiling lights and update HVAC systems with UV-C lights. (the stakeholders now know some of the engineering analysis and want these solutions)
9. All funding gaps must be addressed by the Federal Government as part of the COVID-19 disaster. Many states are not permitted to carry a deficit unlike the Federal Government. This means they are completely incapable of dealing with this massive disaster.
CAPABILITY
This legislation will establish a national level capability to answer key questions and certify safe systems such as:
1. I need to know the air update changes needed for a certified safe building, is it 5, 10, 15, 25, 50, or 100 AUC.
2. I have a negative pressure restaurant table and I want to have it tested and certified.
3. I want to augment student desks with negative pressure using low cost PVC, will this work.
4. I have people standing in long lines and I want to test negative pressure crowd control poles and barriers.
5. I have negative pressure office cubical separators and I want it tested to see if it will work.
6. I have a positive / negative pressure open face mask and I want to have it tested for virus containment.
7. I just put up a tent for an event and I need to know what must be done to make it safe.
The scenarios include: Classroom, School Cafeteria, Cubical in a Cube Farm, Single Multi Person Office, Restaurant Large Room, Multiple Small Rooms, Movie Theater, Outdoor Venues (e.g. restaurants) Under a Tent, Umbrellas, Open Air, At the Beach, Park, Lake under various wind conditions, Public Community Center, Library, Rehabilitation Facilities, Assisted Living Facilities, Airport Security Check, Public Demonstrations, Airplane Passenger Cabin, Cruise Ship, Public Transportation (bus, train, subway, taxi), Generic Spaces 1-n to be defined as more is learned.
This section needs to be reviewed with great care. No one should come away with the thoughts that COVID-19 is not contagious. We know that it is extremely contagious. We know that it will spread until there is a herd immunity or there is a cure. We also know that if we do not control the infection rate it will spread so quickly that all our systems will be massively overwhelmed - our civilization will collapse, period. However, that does not mean that we should not try to understand how this virus is spread. From a systems analysis perspective a reasonable starting point is to identify different scenarios and use data to gain insight into the virus mechanical transmission characteristics.
This model attempts to understand the virus behavior from different biological event scenarios. Each scenario has a potential virus load and distance traveled based on the droplets produced [1] [2]. The scenarios considered are:
Current data suggests that most people get infected in their own home. A household member gets the virus in the community and brings it into the physical house. In that structure there is sustained contact between household members. This close constant contact appears to be an element in the virus transmission characteristics. However, the virus is originating outside the house in the community.
A key question is what amount of virus exposure leads to infection. This can be viewed as a dosage amount. Infection dosage studies were performed on the MERS [3] and SARS [4] outbreaks. Based on these studies it is estimated that 1000 COVID-19 viral particles are needed for infection and illness. This begs the next question - does the virus dosage amount affect the severity of the resulting illness [5].
Bio Event |
Droplets |
Virus Load |
Speed |
Distance |
Comment |
Cough |
3,000 |
none |
50 |
12 |
Most droplets are large, and fall quickly (gravity), but many do stay in the air and can travel across a room in a few seconds. [6] |
Sneeze |
30,000 |
none |
200 |
18 |
Most droplets are small and travel great distances (easily across a room). [6] [7] |
Infected Cough or Sneeze |
200,000,000 |
some % of 200 million |
50 - 200 |
12 |
Dispersed into the environment. Cough and sneeze droplets have huge concentrations of viral material. [6] [7] |
Single Breath |
50 - 5000 |
none |
Low |
- |
Most droplets are low velocity and quickly fall to the ground. There are even fewer droplets released through nose-breathing. Viral particles from the lower respiratory areas are not likely to be expelled because of small of the small force with a breath. [8] |
Infected Single Breath |
- |
20 |
Low |
6 |
Respiratory droplets released from breathing have a low concentration of virus. Influenza can be used as a starting point until the COVID-19 studies are complete. A person infected with influenza releases about 3 - 20 virus RNA copies per minute of breathing. [9] COVID-19 patients exhale 1,000 to 100,000 virus particles per minute, with the highest rate seen during the early stages of COVID-19. [13] [14] |
Speaking |
- |
200 |
Low |
6 |
Increases the release of respiratory droplets about 10 times over breathing. [10] |
Bathroom |
- |
High |
- |
- |
Bathrooms have many high touch surfaces, door handles, faucets, stall doors. Fomite transfer risk in this environment is high. [11] We still do not know whether a person releases infectious material in feces or just fragmented virus, but we do know that toilet flushing does aerosolize many droplets. Environmental biologists at the University of Stirling have warned that the potential spread of COVID-19 via sewage "must not be neglected" in the battle to protect human health [11]. We know from studies in China that the virus is found in feces and raw sewage. From the report [12]:
SARS-CoV-2 may have the potential to be transmitted through aerosols. Room ventilation, open space, sanitization of protective apparel, and proper use and disinfection of toilet areas can limit the concentration of SARS-CoV-2 RNA in aerosols. Future work should explore the infectivity of aerosolized virus [13]. |
A mental model can be developed using the MERS and SARS studies suggesting 1000 virus particles. The mental model can show how infection happens under different scenarios. In the model assume infection occurs with 1000 viral particles received in one breath or from one eye-rub. Alternatively assume 100 viral particles inhaled with each breath over 10 breaths, or 10 viral particles with 100 breaths. In the model each of these situations can lead to an infection. Now run the different scenarios.
There is a relationship between exposure to the virus and time: Infection Prediction = Virus Load * Time where virus load is associated with the number of droplets released by an infected person.
If an infected person coughs or sneezes 200,000,000 droplets go everywhere and most of the droplets have the virus. Some viruses hang in the air, some falls onto surfaces, most fall to the ground within a few hours unless there is some mechanical air movement and displacement.
Model Run Scenario 1 Cough or Sneeze in Room: If an infected person coughs or sneezes, some infected droplets can hang in the air for a few minutes filling every corner of a room. A 20 x 20 x 10 foot room is 4000 cubic feet. This results in 50,000 droplets per cubic foot. When someone enters the room, it's easy to see how it is possible to inhale 1,000 virus particles and become infected.
Model Run Scenario 2 Cough or Sneeze in Face: During a face-to-face a conversation, if an infected person sneezes or coughs, it's easy to see how it is possible to inhale 1,000 virus particles and become infected.
Model Run Scenario 3 Breathing: With general breathing 20 viruses per minute into a room would require 50 minutes to be exposed to 1000 viruses.
Model Run Scenario 4 Speaking: Assuming every virus is inhaled, it would take 5 minutes of speaking face-to-face to receive the required dose for infection.
Model Run Scenario 5 Bathroom: Treat public bathrooms with extra caution (surface and air).
Model Results
The formula Infection
Prediction = Virus Load * Time is the basis of contact tracing.
Anyone that spends greater
than 10 minutes with an infected person in a face-to-face setting is likely
to get infected.
Anyone that shares a space
(office) with an infected person for an extended period is likely to get
infected.
It is critical for people
who are symptomatic to stay home.
Sneezes and coughs expel
so much virus that they can infect a whole room of people.
The next step is to try and find case histories to see if this mental model is reasonable.
References:
[1] The Risks - Know Them - Avoid Them, www.erinbromage.com, by Erin S. Bromage, Ph.D., is an Associate Professor of Biology at the University of Massachusetts Dartmouth, May 20, 2020. webpage https://www.erinbromage.com/post/the-risks-know-them-avoid-them, May 2020. The Risks - Know Them - Avoid Them
[2] COVID-19 Superspreader Events in 28 Countries: Critical Patterns and Lessons, Quillete www.quillette.com, Jonathan Kay, April 23, 2020. webpage https://quillette.com/2020/04/23/covid-19-superspreader-events-in-28-countries-critical-patterns-and-lessons/, May 2020. COVID-19 Superspreader Events in 28 Countries: Critical Patterns and Lessons.
[3] Middle East respiratory syndrome coronavirus (MERS-CoV) causes transient lower respiratory tract infectionin rhesus macaques, Proceedings of the National Academy of Sciences (PNAS), www.pnas.org. August 26, 2013 (received for review June 6, 2013). webpage https://www.pnas.org/content/pnas/110/41/16598.full.pdf, May 2020. Middle East respiratory syndrome coronavirus (MERS-CoV) causes transient lower respiratory tract infectionin rhesus macaques . local
[4] SARS virus infection of cats and ferrets, Nature Research www.nature.com, October 30, 2003.webpage https://www.nature.com/articles/425915a, May 2020. SARS virus infection of cats and ferrets . PDF
[5] Expert reaction to questions about COVID-19 and viral load, Science Media Centre, www.sciencemediacentre.org, March 24, 2020. webpage https://www.sciencemediacentre.org/expert-reaction-to-questions-about-covid-19-and-viral-load/, May 2020. Expert reaction to questions about COVID-19 and viral load
[6] Natural Ventilation for Infection Control in Health-Care Settings, World Health Organization 2009. webpage https://www.ncbi.nlm.nih.gov/books/NBK143281, March 2020. NIH. webpage https://www.ncbi.nlm.nih.gov/books/NBK143284/pdf/Bookshelf_NBK143284.pdf, March 2020. Natural Ventilation for Infection Control in Health-Care Settings PDF . local
[7] The Gross Science of a Cough and a Sneeze, Live Science www.livescience.com, May 12, 2009. webpage https://www.livescience.com/3686-gross-science-cough-sneeze.html, May 2020. The Gross Science of a Cough and a Sneeze
[8] Factors involved in the aerosol transmission of infection and control of ventilation in healthcare premises, Journal Of Hospital Infection www.journalofhospitalinfection.com, October 01, 2006. webpage https://www.journalofhospitalinfection.com/article/S0195-6701(06)00286-6/fulltext, May 2020. Factors involved in the aerosol transmission of infection and control of ventilation in healthcare premises
[9] Influenza Virus in Human Exhaled Breath: An Observational Study, .PloS ONE www.plosone.org, July 16, 2008. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2442192 March 2020. Influenza Virus in Human Exhaled Breath: An Observational Study . PDF
[10] Aerosol emission and superemission during human speech increase with voice loudness, Nature www.nature.com, February 19, 2019. webpage https://pubmed.ncbi.nlm.nih.gov/30787335, March 2020. Aerosol emission and superemission during human speech increase with voice loudness . PDF
[11] Sewage poses potential COVID-19 transmission risk, experts warn, Science Daily www.sciencedaily.com, May 6, 2020. webpage https://www.sciencedaily.com/releases/2020/05/200506133603.htm, March 2020. Sewage poses potential COVID-19 transmission risk, experts warn
[12] Handbook of COVID-19 Prevention and Treatment, Compiled According to Clinical Experience, The First Aliate Hospital, Zhejiang University School of Medicine, China, March 19, 2020, March 24, 2020. webpage https://asprtracie.hhs.gov/technical-resources/resource/7844/handbook-of-covid-19-prevention-and-treatment, March 2020; https://www.alsgbi.org/wp-content/uploads/2020/03/COVID-19-Prevention-and-Treatments-in-a-hospital.pdf, March 2020. U.S. Department of Health & Human Services . Handbook of COVID-19 Prevention and Treatment PDF from ALSGBI . local (PDF)
[13] Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals, Nature www.nature.com, April 27, 2020. webpage https://www.nature.com/articles/s41586-020-2271-3, Marh 2020. Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals
[14] COVID-19 patients exhale millions of viral particles per hour, News Medical www.news-medical.net, June 3, 2020. webpage https://www.news-medical.net/news/20200603/COVID-19-patients-exhale-millions-of-viral-particles-per-hour.aspx June 2020, COVID-19 patients exhale millions of viral particles per hour
[15] Exhaled breath is a significant source of SARS-CoV-2 emission, medRxiv www.medrxiv.org, June 2, 2020. webpage https://www.medrxiv.org/content/10.1101/2020.05.31.20115154v1.full.pdf, June 2020. Exhaled breath is a significant source of SARS-CoV-2 emission
From January 26 to February 10, 2020, an outbreak of 2019 COVD-19 affected 10 persons from 3 families (families A–C) who had eaten at the same air-conditioned restaurant in Guangzhou, China. One of the families just traveled from Wuhan, Hubei Province, China. [1]
The infected person (A1) sat at a table and had dinner with 9 people. During this meal, the asymptomatic carrier released low levels of virus into the air from breathing. Airflow from the restaurant's various airflow vents was from right to left. Approximately 50% of the people at the infected person's table became sick over the next 7 days. 75% of the people on the adjacent downwind table B became infected. And even 2 of the 7 people on the upwind table C were infected (turbulent airflow). No one at tables E or F became infected, they were out of the main airflow from the air conditioner on the right to the exhaust fan on the left of the room.
The only known source of exposure for the affected persons in families B and C was patient A1 at the restaurant. We determined that virus had been transmitted to more than 1 member of family B and more than 1 member of family C at the restaurant and that further infections in families B and C came from within-family transmission.
The Restaurant is air-conditioned, in a 5-floor building without windows. The third-floor dining area occupies 145 m2; each floor has its own air conditioner. The distance between each table is about 1 m. Families A and B were each seated for an overlapping period of 53 minutes and families A and C for an overlapping period of 73 minutes. The air outlet and the return air inlet for the central air conditioner were located above table C.
On January 24, a total of 91 persons (83 customers, 8 staff members) were in the restaurant. Of these, a total of 83 had eaten lunch at 15 tables. Among the 83 customers, 10 became ill with COVID-19; the other 73 were identified as close contacts and quarantined for 14 days. During that period, no symptoms developed, and throat swab samples from the contacts and 6 smear samples from the air conditioner (3 from the air outlet and 3 from the air inlet) were negative for severe acute respiratory syndrome COVID-19 by reverse transcription PCR.
From the examination of the potential routes of transmission, it was concluded that the most likely cause of this outbreak was droplet transmission. Although the index patient (patient A1) was asymptomatic during the lunch, presymptomatic transmission has been reported. Given the incubation periods for family B, the most likely scenario is that all 3 family B members were directly infected by patient A1. However, we cannot not exclude the possibility that patients B2 and B3 were infected by patient B1, the first family B member to become ill. For family C, a possible scenario is that both patients C1 and C2 were infected by patient A1; another scenario is that the patient C1 acquired the infection while caring for patient C2, beginning on January 27.
Virus transmission in this outbreak cannot be explained by droplet transmission alone. Larger respiratory droplets (>5 µm) remain in the air for only a short time and travel only short distances, generally <1 m. The distances between patient A1 and persons at other tables, especially those at table C, were all >1 m. However, strong airflow from the air conditioner could have propagated droplets from table C to table A, then to table B, and then back to table C.
Virus-laden small (<5 µm) aerosolized droplets can remain in the air and travel long distances, >1 m. Potential aerosol transmission of severe acute respiratory syndrome and Middle East respiratory syndrome viruses has been reported. However, none of the staff or other diners in the restaurant were infected. The smear samples from the air conditioner were all nucleotide negative. This finding is less consistent with aerosol transmission. However, aerosols would tend to follow the airflow, and the lower concentrations of aerosols at greater distances might have been insufficient to cause infection in other parts of the restaurant.
The conclusion is that this outbreak is caused by droplet transmission was prompted by air-conditioned ventilation. The key factor for infection was the direction of the airflow. Of note, patient B3 was afebrile and 1% of the patients in this outbreak were asymptomatic, providing a potential source of outbreaks among the public. To prevent spread of COVID-19 in restaurants, the recommendation was to strengthen temperature-monitoring surveillance, increasing the distance between tables, and improving ventilation.
A single infected employee came to work on the 11th floor of a building with 216 employees. Over the period of a week, 94 people become infected (43.5%: the blue chairs), 92 of those 94 people became sick, and 2 remained asymptomatic. One side of the office is primarily infected, while there are very few people infected on the other side. While exact the number of people infected by respiratory droplets / respiratory exposure verse fomite transmission (door handles, shared water coolers, elevator buttons etc) is unknown. This suggests that being in an enclosed space, sharing the same air for a prolonged period increases the chances infection. Another 3 people on other floors of the building were infected, but the study was unable to trace the infection to the primary cluster on the 11th floor. Even though there were interaction between workers on different floors of the building in elevators and the lobby, the outbreak was mostly limited to a single floor. [2]
A choir Washington State decided to go ahead with rehearsal and dozens of members were infected with COVID-19 and two died. The people were aware of the virus and took steps to minimize transfer: they avoided handshakes and hugs, brought their own music to avoid sharing, and socially distanced themselves during practice. A single asymptomatic carrier infected most of the people in attendance. The choir sang for 2 1/2 hours, inside an enclosed church which was roughly the size of a volleyball court. [3]
Singing unlike talking significantly aerosolizes respiratory droplets. Deep breathing while singing facilitated the respiratory droplets getting deep into the lungs. Two and half hours of exposure time subjected people to enough virus over a long enough period of time for infection to take place. Over a period of 4 days, 45 of the 60 choir members developed symptoms, 2 died. The youngest infected was 31.
A curling event in Canada with 72 attendees became a hotspot for COVID-19 transmission. Curling brings contestants and teammates in close contact in a cool indoor environment, with heavy breathing for an extended period. This tournament resulted in 24 of the 72 people becoming infected. [4]
This report describes the cluster of 16 cases of confirmed or probable COVID-19, including three deaths, likely resulting from transmission of COVID-19 at two family gatherings (a funeral and a birthday party) and other activities. [5]
In February 2020, a funeral was held for a decedent with a non-COVID-19, nonrespiratory cause of death. A close friend of the bereaved family (patient A1.1) attended the funeral. Patient A1.1 had recently traveled out of state and was experiencing mild respiratory symptoms. He was tested later as part of the epidemiologic investigation and received a diagnosis of confirmed COVID-19. The evening before the funeral, patient A1.1 shared a takeout meal, eaten from common serving dishes, with two family members of the decedent (patients B2.1 and B2.2) at their home. At the meal, which lasted approximately 3 hours, and the funeral, which lasted about 2 hours and involved a shared “potluck-style” meal, patient A1.1 also reported embracing family members of the decedent, including patients B2.1, B2.2, B2.3, and B3.1, to express condolences.
Patients B2.1 and B2.2 subsequently developed confirmed COVID-19 with onset of symptoms 2 and 4 days, respectively, after the funeral. Patient B2.3 developed probable COVID-19 with symptom onset 6 days after the funeral. Patient B2.1 was hospitalized, required endotracheal intubation and mechanical ventilation for acute respiratory failure, and died. Patients B2.2 and B2.3 were managed as outpatients, and both recovered.
Another family member who had close physical contact with patient A1.1 at the funeral (patient B3.1) visited patient B2.1 in the acute medical inpatient ward, embraced patient B2.1, and provided limited personal care, while wearing no personal protective equipment (PPE). Patient B3.1 developed signs and symptoms consistent with COVID-19, including a fever and cough after last visiting B2.1. Patient B3.1 had also attended the funeral but described more extensive exposure while visiting patient B2.1 in the hospital.
Three days after the funeral, patient A1.1, who was still experiencing mild respiratory symptoms, attended a birthday party attended by nine other family members, hosted in the home of patient A2.1. Close contact between patient A1.1 and all other attendees occurred. Patient A1.1 embraced others and shared food at the 3-hour party. Seven party attendees subsequently developed COVID-19, including three with confirmed cases (patients A2.1, A2.2, and A2.3) and four with probable cases (patients A2.4, A2.5, A2.6, and A2.7). Two patients with confirmed COVID-19 (A2.1 and A2.2) were hospitalized. Both required endotracheal intubation and mechanical ventilation, and both died. One patient with a confirmed case (A2.3) experienced mild symptoms of cough and subjective low-grade fever, as did the four others who received diagnoses of probable COVID-19. Two attendees did not develop symptoms within 14 days of the birthday party.
Two persons who provided personal care for patient A2.1 without using PPE, including one family member (patient A3.1) and a home care professional (patient C3.1), both developed probable COVID-19. It is likely that patient A3.1 subsequently transmitted COVID-19 to a household contact (patient A4.1), who did not attend the birthday party, but developed a new onset cough 3 days following unprotected, close contact with patient A3.1 while patient A3.1 was symptomatic.
Three symptomatic birthday party attendees with probable COVID-19 (patients A2.5, A2.6, and A2.7) attended church 6 days after developing their first symptoms (investigation day 17). Another church attendee (patient D3.1, a health care professional) developed confirmed COVID-19 following close contact with patients A2.5, A2.6, and A2.7, including direct conversations, sitting within one row for 90 minutes, and passing the offering plate.
The patients described in this report ranged in age from 5 to 86 years. Three patients died (patients A2.1, B2.1 and A2.2).
This is a case study from China that identified various living venues and tracked the COVID-19 outbreaks. They concluded that all identified outbreaks of three or more cases occurred in an indoor environment, which confirms that sharing indoor space is a major COVID-19 infection risk. They identified only a single outbreak in an outdoor environment, which involved two cases. [6]
You would think that companies dealing with food would know how to deal with virus and bacterial contamination. Apparently, there are extremely stupid people in charge of these operations. It is also outrageous that the US Federal Government did not step in to secure the nation's food supply. This case study is not one of infection spread and control. Instead it is one of a collapsed system that has become completely incompetent and dangerous with severe grave consequences. The COVID-19 virus cannot be blamed for this mess. [7]
In Hawaii, an assisted living facility went into shelter in place mode on December 1, 2019 to deal with the COVID-19 outbreak based on news from around the world. They screen all visitors prior to entry and have instituted other policies and procedures. As of May 2020, there are no reported COVID-19 cases. [personal ref]
This contrasts with what is happening on the mainland in the US and around the world. [8]
References:
[1] COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020. Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 26, No. 7, July 2020, webpage https://wwwnc.cdc.gov/eid/article/26/7/20-0764_article, https://wwwnc.cdc.gov/eid/article/26/7/pdfs/20-0764.pdf, May, 2020. CDC-Ref . PDF . local
[2] Coronavirus Disease Outbreak in Call Center, South Korea, Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 26, No. 8, August 2020. webpage https://wwwnc.cdc.gov/eid/article/26/8/20-1274_article, https://wwwnc.cdc.gov/eid/article/26/8/pdfs/20-1274.pdf, May 2020. CDC-ref . PDF . local
[3] A choir decided to go ahead with rehearsal. Now dozens of members have COVID-19 and two are dead, LA Times, March 29, 2020. webpage https://www.latimes.com/world-nation/story/2020-03-29/coronavirus-choir-outbreak, May 2020 LA Times-ref
[4] How an Edmonton curling tournament became a hotspot for the COVID-19 outbreak in Canada, National Post, March 27, 2020. webapge https://nationalpost.com/news/how-an-edmonton-curling-tournament-became-a-hotspot-for-the-covid-19-outbreak-in-canada, May 2020. National Post-ref - US
[5] Community Transmission of SARS-CoV-2 at Two Family Gatherings - Chicago, Illinois, February-March 2020, MMWR US Department of Health and Human Services/Centers for Disease Control and Prevention, Vol. 69/No. 15, April 17, 2020. webpage https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e1.htm?s_cid=mm6915e1_w, https://www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6915e1-H.pdf, May 2020. CDC-ref . PDF . local
[6] Indoor transmission of SARS-Cov-2, medRxiv, April 7, 2020. webpage https://www.medrxiv.org/content/10.1101/2020.04.04.20053058v1, https://www.medrxiv.org/content/10.1101/2020.04.04.20053058v1.full.pdf, May 2020. medRxiv . PDF
[7] Impact of the COVID-19 pandemic on the meat industry in the United States, webpage https://en.wikipedia.org/wiki/Impact_of_the_COVID-19_pandemic_on_the_meat_industry_in_the_United_States, May 2020.
[8] Impact of the COVID-19 pandemic on long-term care facilities, webpage https://en.wikipedia.org/wiki/Impact_of_the_COVID-19_pandemic_on_long-term_care_facilities, May, 2020.
Indoor spaces, with limited air exchange or recycled air and lots of people, are high risk settings:
Long time exposure to low density virus counts is high risk:
Social distancing rules are to protect a person with brief exposures or outdoor exposures:
When assessing the risk of infection (via respiration) at the grocery store or mall consider:
The Federal Government is not working:
Personal Assessments:
Droplets Versus Aerosols
To determine if a virus is airborne the reproductive number R is examined. The reproductive number R describes the average number of individuals that a infected person infects. It depends on how that virus is transmitted as well as how often people come into contact. The factors that could vary depending on the virus strain and on the time and location of an outbreak. The R0 is the basic reproductive number that describes disease transmission at the very beginning of an outbreak in a fully susceptible population. The Re is the effective reproductive number that describes transmission once measures such as social distancing or vaccination have been introduced. Re is typically much lower than R0. [1]
| Disease | R0 (log scale) |
| 2020 COVID-19 early in Wuhan [1] | 1.4 - 5.7 |
| 2014 MERS Saudi Arabia [1] | 0.45 - 3.9 |
| 2014 Ebola [1] | 1.5 - 2.5 |
| 2003 SARS Hong Kong [1] | 1.7 - 3.6 |
| 1918 Influenza US & Europe [1] | 2.2 - 2.9 |
| 20th century Measles in UK and US [1] | 12 - 18 |
| SARS 2003 Airplane [19] | 22 |
| SARS 2018 Airplane Movement Study [19] | 13.4 - 18 |
| COVID-19 2020 Airplane [19] | 15 |
An R0 value of 6.5 was observed for New York early in the COVID-19 disaster. A key observation is that the world quickly implemented social distancing and masks making it difficult to predict the traditional R0.
This study has performed an analysis to determine the R0 on an airplane. The results are R0 ranging from 13.4 to 22. This is significant because it suggests that the R0 for COVID-19 approaches that of Measles [19].
As of June 2020 many focus on the Droplet Evaporation curves from Wells (1934) ignoring the Wells-Riley equation first published in 1978. The CDC disclosed both of these findings as part of their study on natural ventilation for infection control in health-care settings [2]. Between 1934 and 1978 we went from a natural ventilation society to an enclosed air conditioned society with massive Heating Ventilation and Cooling (HVAC) Systems. Further, with the energy crisis in the 1970's all fresh air systems were converted to recycled air to save on energy costs. The world has been focused on droplets versus aerosols [3]. Unfortunately the reality is that it is not an either or condition. Instead it is a numbers game where the concentration of the aerosols is what matters. There is now sufficient empirical data to suggest that aerosol transmission within enclosed environments cannot be ignored [4] [5] [6] [7] [8] [15] [16].
As of July 2020 Governments are starting to change policies because of concerns that tiny droplets can carry SARS-CoV-2 [9]. In May 2020 the German Department of Health changed its guidance:
In taped interviews with journalist Bob Woodward on Feb. 7, 2020, President Trump said that the virus was more dangerous than the flu, even as he told the country otherwise [10]. It is clear that it was known from the beginning that the virus is spread through the air. President Trump stated the following in the audio interview.
It is obvious that the US Government and media knew that the virus was airborne but they did not inform the public or take action to mitigate the virus spread from the airborne element. This information was made public on September 09, 2020.
The U.S. Centers for Disease Control and Prevention (CDC) has been subjected to massive political pressure from the Trump Administration and Republican party members including elected and unelected officials and citizens undermining the science. In July 2020 the CDC added guidelines language stressing the importance of children returning to schools and saying Covid-19 poses lower risks for children than for adults. In August 2020, the CDC reduced testing recommendations, stating that close contacts of confirmed cases did not need to undergo testing.
A change occurred on October 5, 2020 when the CDC said tiny particles lingering in the air can spread the coronavirus. This is the second announcement after an initial release in September 2020 that was pulled a few days later from public view [11] [12]. This October 5 release of CDC guidance acknowledged:
We also know that Airborne transmission is happening in normal situations such as in a restaurant, on a school bus, at a camp. The virus spreads by air in certain environments, such as crowded indoor and poorly ventilated spaces.
There is epidemiological data showing an association between indoor humidity above 40% and reduced healthcare associated infections. The ideal humidity levels are between 40% and 60%. Infection control protocols focus on hand, instrument and surface hygiene, as well as on cough etiquette and facial masks. These approaches interrupt transmission through contact and short distance large droplet spray. Except for masks they do not stop tiny aerosolized droplets which spread infectious microorganisms across significant distances and for extended periods through the air. Droplet nuclei with diameters less than 5 µm are easily inhaled and can go into deep layers of the respiratory tract. Studies indicate that 10 to 33 percent of all healthcare associated infections move through the air at some point between the infected person and the non-infected person. Until transmission of these tiny infectious aerosols are controlled, even excellent compliance with contact hygiene protocols will not stop a healthcare associated infection epidemic in a facility. Humidity control as a prevention strategy is a critical virus spread mitigation strategy and is equally applicable to all public buildings like hospitals, offices, classroom, stores, bars and residential buildings. [13] [14]
There is also evidence to suggest that a low humidity level inside a room may lead to the mucus drying out and lowering the ability of the innate immune system to deal with an infection source. This is typically why many homes have humidifiers that are used during the winter months.
The implications are that all indoor ventilation systems must be examined. However, there are no COVID-19 building ventilation standards based on solid engineering with associated test and evaluation activities that can be provided except for the preliminary findings in this report. Most indoor ventilation systems will probably need modifications. It is critical that building ventilation test and evaluation begin immediately using our best tools and facilities to find the answers and minimize the spread of the virus. Read this full report. [17] [18]
References:
[1] Why R0 Is Problematic for Predicting COVID-19 Spread, The Scientist, July 13, 2020. webpage https://www.the-scientist.com/features/why-r0-is-problematic-for-predicting-covid-19-spread-67690, September 2020. Why R0 Is Problematic for Predicting COVID-19 Spread
[2] WHO Publication/Guidelines Natural Ventilation for Infection Control in Health-Care Settings, World Health Organization (WHO), 2009. webpage https://www.ncbi.nlm.nih.gov/books/NBK143284/pdf/Bookshelf_NBK143284.pdf, May 2020. Natural Ventilation for Infection Control in Health-Care Settings, WHO, 2009 . local
[3] Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy, June 2020. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495, June 2020. Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy . local
[4] Airborne transmission of SARS-CoV-2: The world should face the reality, Lidia Morawskaa, Junji Caob, Environment International Volume 139, June 2020, 105730. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7151430, July 2020. Airborne transmission of SARS-CoV-2: The world should face the reality . local
[5] Transmission of SARS-CoV-2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event, Indoor Air, 15 June 2020. webpage https://www.medrxiv.org/content/10.1101/2020.06.15.20132027v1.full.pdf, July 2020. Transmission of SARS-CoV-2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event . local
[6] Scientists say WHO ignores the risk that coronavirus floats in air as aerosol, Richard Read, LA Times, July 4, 2020, webpage https://news.yahoo.com/scientists-ignores-risk-coronavirus-floats-120014485.html?soc_src=newsroom&soc_trk=com.apple.UIKit.activity.Mail&.tsrc=newsroom, Scientists say WHO ignores the risk that coronavirus floats in air as aerosol
[7] Coronavirus drifts through the air in microscopic droplets – here’s the science of infectious aerosols, Shelly Miller Professor of Mechanical and Environmental Engineering, University of Colorado Boulder, The Conversation US, April 24, 2020. webpage Coronavirus drifts through the air in microscopic droplets – here’s the science of infectious aerosols
[8] Identifying airborne transmission as the dominant route for the spread of COVID-19, PNAS June 30, 2020 117 (26) 14857-14863; first published June 11, 2020, webpage https://www.pnas.org/content/117/26/14857, October 2020. Identifying airborne transmission as the dominant route for the spread of COVID-19 . PDF
[9] Mounting evidence suggests coronavirus is airborne - but health advice has not caught up, Nature Research www.nature.com, 08 July 2020, Update 23 July 2020. webpage https://www.nature.com/articles/d41586-020-02058-1, July 2020. Mounting evidence suggests coronavirus is airborne - but health advice has not caught up
[10] Trump Admits Downplaying the Virus Knowing It Was Deadly Stuff, New York Times, September 09, 2020. webpage https://www.nytimes.com/2020/09/09/us/politics/woodward-trump-book-virus.html, September 10, 2020. Trump Admits Downplaying the Virus Knowing It Was Deadly Stuff
[11] CDC Acknowledges Covid-19 Can Spread Via Tiny Air Particles, Wall Street Journal, October 5, 2020. webpage https://www.wsj.com/articles/cdc-updates-covid-19-guidelines-acknowledging-virus-can-spread-via-tiny-air-particles-11601921416, October 2020. CDC Acknowledges Covid-19 Can Spread Via Tiny Air Particles
[12] CDC revises coronavirus guidance to acknowledge that it spreads through airborne transmission, CNBC October 5, 2020. website https://www.cnbc.com/2020/10/05/cdc-revises-coronavirus-guidance-to-acknowledge-that-it-spreads-through-airborne-transmission.html, October 2020. CDC revises coronavirus guidance to acknowledge that it spreads through airborne transmission
[13] This Inexpensive Action Lowers Hospital Infections And Protects Against Flu Season, Forbes, October 17, 2019. webpage https://www.forbes.com/sites/leahbinder/2019/10/17/harvard-researcher-says-this-inexpensive-action-will-lower-hospital-infection-rates-and-protect-us-for-the-flu-season, November 2020. This Inexpensive Action Lowers Hospital Infections And Protects Against Flu Season
[14] Is low indoor humidity a driver for healthcare-associated infections? Stephanie Taylor, MD, M Arch, CIC, FRSPH(UK), CABE, Walter Hugentobler, MD Harvard Medical School, Boston, Massachusetts, United States, Institut für Hausarztmedizin, Universität und Universitätsspital Zürich, Switzerland, May 26, 2016. webpage https://www.isiaq.org/docs/Papers/Paper340.pdf, November 2020. Is low indoor humidity a driver for healthcare-associated infections? . local
[15] Airborne Transmission of COVID-19, Interview with Professor Morawska, https://www.youtube.com/watch?v=wdE3NNPeIWI, August 10, 2020. local transcript
[16] How Can Airborne Transmission of COVID 19 Indoors be Minimized? What We Know Now final, https://www.youtube.com/watch?v=DpWNnNuxFYE, September 15, 2020. local transcript
[17] See section Proposed Legislation.
[18] See section Indoor Outdoor Ventilation.
[19] See section Airplanes and Airports.
The whole argument about the nature of the virus airborne element provided to the public centered on the size of the virus and the size of airborne droplets and aerosols. The US Government knew in January of 2020 that the virus was airborne [9]. They allowed disinformation to proceed without closure in the public dialog knowing that it was wrong and that people would be infected, some would lose their health, and others would die.
The marginalized scientists and engineers performing the analysis that were not sworn to secrecy by the US government performed their research and published their results in open forums. They were ignored by the general public. It was not until the research started publishing numbers that the press started to report on the findings and the US government was forced to disclose what they knew in January 2020. Meanwhile a member of the press sat on this grave information for months, until his book was released, as people got sick and died.
Here are some of the sizes associated with various viruses. Bacteria and Virus sizes:
| Virus / Bacteria | Size | Ref |
| Respiratory Droplets | 5-10 um | [1] [7] [8] |
| Bacterium | 2 um | [1] |
| Pitovirus | 1.5 um | [1] |
| Mimivirus | 400 nm | [1] |
| T4 Bacteriophage | 225 nm | [1] |
| HIV | 120 nm | [1] |
| Measles | 100 to 300 nm | [3] |
| Murine Hepatitis MHV | 80-90 nm | [5] |
| SARS-CoV-1 | 78 nm | [6] |
| SARS-CoV-2 | 70–90 nm | [2] |
| SARS-CoV-2 | 60-140 nm | [1] |
| Zika | 45 nm | [1] |
| Parovirus | 18-28 nm | [1] |
1 micron = 1 um = 1000 nm
As a result of this analysis and other analysis produced between March 2020 and October 2020 the COVID-19 virus is now acknowledged as an airborne transmission virus. This is the guidance offered by the state of New Jersey [4]:
Is the coronavirus airborne?Yes, COVID-19 can spread via airborne transmission.
When people with the COVID-19 infection breathe out, clear their throats, cough, sneeze, speak, or otherwise move air out through their nose or mouth, droplets of all different sizes, which can contain the virus, are ejected into the air. A substantial portion of people infected with SARS-CoV-2 - around 40 percent - wouldn't even know they are ejecting virus-laden droplets, as they may not exhibit symptoms.
Droplets suspended in the air are called an aerosol. Droplets that are large can remain in the air for seconds to minutes before falling to the ground. Smaller droplets stay in the air longer – minutes to even hours.
Outside, the circulation of fresh air disperses the drifting droplets quickly, and so the combination of wearing cloth face coverings and maintaining physical distance (6 feet or more) is very effective at impeding the spread of COVID-19 in outdoor spaces where air moves. However, in indoor spaces, especially those with poor ventilation, coronavirus-laden droplets can build up to a level that is risky.
To the extent possible, we should all be minimizing the amount of time we spend in any one place, especially if others are nearby, or if you are indoors with other people. This limits the time a person is potentially exposed to the virus.
It is also very important to stay as far away from one another as possible, minimum 6 feet. The farther, the better. Some experts recommend staying at least 25 feet away from others, even when outdoors. And it's a good idea to avoid crowded indoor spaces.
The traditional definition of airborne transmission is that small droplets containing a pathogen remaining viable over long time periods travel long distances in the air and infect other people when the pathogen is breathed in. Measles and tuberculosis are examples of respiratory diseases that remain infectious in the air for long time periods. The measles virus can live for up to two hours in the air where an infected person coughs or sneezes. Tuberculosis can live in the air for up to six hours.
Under experimental conditions, researchers found that the COVID-19 virus stayed viable in the air for three hours. The researchers estimate that in most real-world situations, the virus would remain suspended in the air for about 30 minutes, before settling onto surfaces. This is similar to what was found for SARS and MERS, which some researchers consider likely to be spread via airborne transmission. One study estimates that a person infected with the COVID-19 virus who speaks loudly for one minute produces at least 1,000 virus-containing droplets that remain airborne for more than 8 minutes. Furthermore, the Centers for Disease Control and Prevention recommend airborne precautions for the care of COVID-19 suspected or confirmed patients.
Many unknowns remain about SARS-CoV-2, such as how many virus particles need to be breathed in for an infection to begin. However, active COVID-19 virus travels through the air when ejected by infected people, and can infect cells in the petri dish. By staying as far away from one another as possible, keeping on the move, avoiding touching our faces, frequently washing our hands well with soap and water, coughing or sneezing into the crook of our elbows, wearing cloth face coverings (masks), and staying home when sick, we can protect ourselves and others.
Drafted 14 September 2020
References:
[1] The Size of SARS-CoV-2 Compared to Other Things, News-Medical.Net Jul 16, 2020. webpage https://www.news-medical.net/health/The-Size-of-SARS-CoV-2-Compared-to-Other-Things.aspx, December 2020. The Size of SARS-CoV-2 Compared to Other Things
[2] Identification of Coronavirus Isolated from a Patient in Korea with COVID-19, NIH US Government, February 2020. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7045880/#:~:text=Virus%20particle%20size%20ranges%20from,70%E2%80%9390%20nm., December 2020. PDF . local
[3] Manual for the Laboratory-based Surveillance of Measles, Rubella, and Congenital Rubella Syndrome, World Health Organization (WHO), Third edition, June 2018. webpage https://www.who.int/immunization/monitoring_surveillance/burden/laboratory/manual_section1.1/en/, December 2020. Manual for the Laboratory-based Surveillance of Measles
[4] Is the coronavirus airborne? Yes, COVID-19 can spread via airborne transmission. New Jersey Department Of Health, September 14 ,2020. webpage https://covid19.nj.gov/faqs/coronavirus-information/about-the-virus/is-the-coronavirus-airborne, December 2020. Is the coronavirus airborne? Yes, COVID-19 can spread via airborne transmission . local
[5] Electron microscopy studies of the coronavirus ribonucleoprotein complex, NIH US Government, April 18, 2012. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5326623/pdf/13238_2016_Article_352.pdf, December 2020. PDF . local
[6] Ultrastructural Characterization of SARS Coronavirus, Emerging Infectious Diseases, Centers for Disease Control and Prevention, CDC, US Government, February 2004. webpage https://wwwnc.cdc.gov/eid/article/10/2/03-0913_article, https://wwwnc.cdc.gov/eid/article/10/2/pdfs/03-0913.pdf, December 2020. PDF . local
[7] Size And Duration Of Air Carriage Of Respiratory Droplets, Department of Bacteriology, Edinburgh University, US National Institute of Health, webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2234804/pdf/jhyg00188-0053.pdf, December 2020. PDF . local
[8] Coronavirus drifts through the air in microscopic droplets – here’s the science of infectious aerosols, Shelly Miller Professor of Mechanical and Environmental Engineering, University of Colorado Boulder, The Conversation US, April 24, 2020. webpage Coronavirus drifts through the air in microscopic droplets – here’s the science of infectious aerosols
[9] Trump Admits Downplaying the Virus Knowing It Was Deadly Stuff, New York Times, September 09, 2020. webpage https://www.nytimes.com/2020/09/09/us/politics/woodward-trump-book-virus.html, September 10, 2020. Trump Admits Downplaying the Virus Knowing It Was Deadly Stuff
Virus Mutations & Architecture Solutions
For those reading this report for the first time, this section normally would be at the end of the report after all the analysis and data have been reviewed. It is found in the middle of the report because it logically fits in this section for those that are reading these findings in real time as they are reported. In many ways this section is the culmination of months of research and it is a vision for moving forward in January 2021.
The original title for this analysis was Virus Mutations and now it is Virus Mutations & Architecture Solutions. When the virus mutation systems analysis started there was no intent to identify architecture solutions and perform an architecture tradeoff. Like many systems analysis efforts things tend to self-disclose and it is logical to follow the path of least resistance. In this case it was obvious and easy to identify and compare architecture approaches in the setting of a future that will obviously have virus mutations. Also, this analysis moved into relating the social to the technical aspect as per the definition of systems engineering from Simon Ramo in the introduction. I also shifted the discussion and inserted a meeting format to provide a feel for what might happen during a systems meeting on this topic. This is a systems engineering perspective on virus mutations.
The COVID-19 virus has been mutating since it has entered the human population. The larger the virus population the larger the mutation rates. Currently a large number of people have been infected and so multiple mutations are being detected and studied to determine their impacts.
On December 01, 2020 a new COVID-19 virus mutation, the SARS-CoV-2 lineage B.1.1.7, now designated Variant of Concern 202012/01 (VOC) by Public Health England, originated in the UK in the late Summer to early Autumn 2020. It has been found to be more contagious than the original virus and other mutations. Evidence in the United Kingdom suggests that infection is growing more rapidly in areas where the B.1.1.7 variant is found. A study from The Centre for the Mathematical Modelling of Infectious Diseases in London shows this particular strain is 56% more transmissible [1] [2]. For the COVID-19 virus to enter a cell it needs to bind to a receptor. The new B.1.1.7 mutation binds tighter and more easily to ACE2 and enters the cell easier than the current COVID-19 virus. [2] [3]
The B.1.1.7 variant was detected in August 2020, officially claimed on December 01, 2020 and as of January 7, 2021 there has been no unique action for mitigation. That is 5 months. It is also unclear how long the B.1.1.7 variant was circulating before being detected.
Given that the COVID B.1.1.7 mutation is 56% more transmissible, the implications are that all the findings in this study relative to COVID-19 probability of infection and associated recommendations need to be adjusted by 56%. For example, if the time before infection in a particular scenario is 2.27 hours then the time before infection for the B.1.1.7 mutation is 1 hour. If the probability of infection is 1% then with the B.1.1.7 mutation the probability of infection is 1.56%. However the situation may not be that simple. The mutant viral particle binds to the ACE2 receptor for a longer period of time than the less-infectious viral particle. The implications are that during the early exposure to the virus equal amounts of the virus will be bound to the ACE2 receptors, but as time moves on the mutant virus level bound to the ACE2 receptors will exceed the level of the original virus.
The South African variant known as 501.V2 has been replacing other strains of the coronavirus as early as November 2020 South African officials reported on December 18, 2020. It appears that it may obviate some of the medical countermeasures, particularly the antibody drugs. As of January 2021 the strain is prevalent in South America and Brazil. The 501.V2 partially escapes prior immunity suggesting that some of the antibodies people produce when they get infected with COVID-19, as well as the antibody drugs, may not be as effective. The 501.V2 variant has mutated a part of the spike protein that antibodies bind to, to try to clear the virus [4].
The 501.V2 variant carries a mutation in the spike protein called E484K, which is not present in the UK strain. The E484K mutation has been shown to reduce antibody recognition which may help the virus bypass immune protection provided by prior infection or vaccination. However, the mutation is not sufficient for the variant to bypass the protection provided by vaccines in general. Current estimates are that it would take 4 to 6 weeks to develop a modified vaccine, if needed [6].
The 501.V2 variant was detected in November 2020, officially claimed on December 18, 2020 and as of January 7, 2021 there has been no unique action for mitigation. That is 2 months. It is also unclear how long the 501.V2 variant was circulating before being detected.
The following analysis summary is presented in a non-prose form using a VU-Graph approach that is typically provided in a systems meeting. One of the advantages of this form of presentation is that the logic and analysis chain is easily followed. The supporting data typically includes dozens if not hundreds of studies, analysis, design artifacts, papers and other information products capturing the work and findings behind the systems effort (e.g. this full report).
From a systems perspective the key issues are:
From a systems perspective the observations are:
The system approach to mitigate the current and future virus infection is a complex system solution involving multiple subsystems. The subsystems are:
The most effective subsystems in this system are the subsystems that immediately work with no lead time for detection and then roll out of the solution. These subsystems are:
Final observation:
The following backup slide would probably be presented at this systems meeting:
Naturally |
Vaccine |
Vaccinated |
Exposed |
Deaths |
Deaths |
Deaths |
UV-C or |
Deaths |
Ventilation |
Deaths |
10% |
70% |
70% |
150,552,000 |
3,011,040 |
4,516,560 |
5,269,320 |
90% |
526,932 |
28% |
379,391 |
10% |
90% |
90% |
56,088,000 |
1,121,760 |
1,682,640 |
1,963,080 |
90% |
196,308 |
28% |
141,342 |
0% |
70% |
70% |
167,280,000 |
3,345,600 |
5,018,400 |
5,854,800 |
90% |
585,480 |
28% |
421,546 |
0% |
90% |
90% |
62,320,000 |
1,246,400 |
1,869,600 |
2,181,200 |
90% |
218,120 |
28% |
157,046 |
. |
|
|
|
|
|
|
|
|
||
0% |
0% |
0% |
328,000,000 |
6,560,000 |
9,840,000 |
11,480,000 |
90% |
1,148,000 |
28% |
826,560 |
10% |
0% |
0% |
295,200,000 |
5,904,000 |
8,856,000 |
10,332,000 |
90% |
1,033,200 |
28% |
743,904 |
Note: This table shows that all three approaches of Vaccine, UV, and Ventilation are needed to eradicate the virus.
The systems discussion would then revolve around virus mutation rate and the expectations for future virus outbreaks.
Infrastructure costs would not even be part of the discussion. The discussion would be on developing the most effective system. The system must work and it will cost what it will cost. Once the system implementation begins, then it must be implemented as efficiently as possible. There is a difference between efficient and cheap. Cheap is a poor solution that will not meet the system requirements. Efficient ensures that all costs are properly monitored and there is no waist.
The reason the cost discussion was added is because of push back from some stakeholders that will use cost as an excuse to prevent an effective system from being established. In this case the costs to implement this system are actually very low [7] [8]. The reasons for one or more stakeholders to use cost as an excuse to prevent a proper system from being developed is simple - they are trying to game the system in their favor. In the process they enlist others that are not aware that they are being used and they just blindly state costs without any logic, justification, or even data. All systems efforts include cost estimates but the costs are never used to invalidate a system. Instead costs are used to determine the effectiveness of each system approach.
As of January 2021 there is sufficient information in this systems engineering analysis effort to perform a tradeoff analysis of different architecture approaches. The architecture approaches are:
The Coronavirus Aid, Relief, and Economic Security (CARES) Act is a $2.2 trillion dollar economic stimulus bill signed into law on March 27, 2020. As of October 5, 2020 the COVID-19 disaster cost $4 trillion dollars. [9] The $4 trillion dollar figure establishes the cost associated with Architecture A. If there is a vaccine infrastructure in place it will still take 6 months before the virus is detected to the full rollout of the updated vaccine. The $2.2 trillion dollar figure establishes the cost associated with Architecture B. Both architectures A and B have large loss of life and they each have a cost associated with those sad figures. Architecture C has infrastructure costs.
With this information it is now possible to perform a systems engineering tradeoff using the Measure Of Effectiveness (MOE). The MOE is the unit of goodness in each architecture for each dollar spent. The MOE is calculated by dividing the total tradeoff criteria rating of each architecture by its total costs. [10] [11]
MOE = total tradeoff criteria rating / total costs
The following table contains the tradeoff for Architectures A, B and C.
[spreadsheet Arch Trade]
Tradeoff Criteria |
Arch A | Arch B | Arch C | Comments |
Ability to prevent future epidemic |
1 |
3 |
5 |
Sensitivity analysis shows that the 5 rating for Arch C is irrelevant |
Ability to stop Pandemic |
1 |
3 |
5 |
Sensitivity analysis shows that the 5 rating for Arch C is irrelevant |
Total Rating |
2 |
6 |
10 |
|
. |
||||
Shutdown Costs ($ billions) |
$4,400 |
$0 |
$0 |
|
Future Potential Shutdown Costs ($ billions) |
$0 |
$2,200 |
$0 |
It will take 6 months for an updated vaccine This is similar to the CARES act level of costs |
Lives Lost Costs ($ billions) |
$7,852 |
$2,100 |
$151 |
$7 million per life |
Infrastructure Costs ($ billions) |
$0 |
$10 |
$150 |
Vaccine for Arch B UV + HVAC upgrades for Arch C |
Total Costs ($ billions) |
$12,252 |
$4,310 |
$301 |
|
. |
||||
MOE (Rating / Total Costs) |
0.00016 |
0.00139 |
0.03322 |
|
. |
||||
MOE Normalized Result |
1 |
9 |
204 |
Arch C is as shown times better than Arch A |
Note: Rating Scale: 1 = worst, 5 = best
This analysis suggests that Architecture C is 204 times more effective than Architecture A and 24 times more effective than Architecture B.
After this initial tradeoff analysis is performed it is subjected to a sensitivity analysis where the tradeoff criteria is arbitrarily changed to maximum and lower level ratings. In the case of Architecture C the ratings can never drop below the ratings of Architecture B because Architecture C includes Architecture B as part of the solution. This would mean that the addition of UV + HVAC upgrades would have zero effect on mitigating the virus. In that case the rating would still be the same as Architecture B. The reason is because the infrastructure costs are so low once compared to the lives lost and future potential shutdown costs. In other words there is nothing to lose by just upgrading the infrastructure. Also we know from empirical data, scientific analysis, and engineering data going back into the 1940's that there will be significant virus mitigation benefit and lives will be saved [12].
This is a preliminary tradeoff. As more is learned during the weeks, months, and perhaps years, the tradeoff criteria and ratings will change. The costs of each architecture approach will change. The big question is will the most effective architecture change. The reality is the answer is no because the cost of shut down and massive loss of life far outstrips any costs of the technologies we currently have to solve this problem of future virus mitigation.
It is important to note that policy makers really selected Architecture A in 2020. Placing an order for some vaccination doses is not a commitment to Architecture B. Everyone must understand that Architecture B exists by January 2021 only because of the scientists from around the world and the commitment by a handful of companies. They pulled off a miracle and we have Architecture B available as an alternative.
Architecture C is not even on the table. There are engineers and scientists pushing for Architecture C but unless there is a massive commitment from the US Federal Government, it will not happen. There are no massive companies able to make the case that everyone should start installing UV systems and upgrading HVAC systems. Further the critical importance of these systems is not clear in the public mind. The general public does not know that Architecture C is needed to bring this pandemic fully under control in the least amount of time and that it is needed for virus events that will now be part of the future because of COVID-19. Making this case with the public is a massive education challenge.
In November 2019 US intelligence reported that something serious was happening in China. The intelligence was in the form of communications intercepts and overhead images showing increased activity at health facilities. The intelligence was distributed to some federal public health officials in the form of a situation report in late November 2019. Current and former officials say there was no formal assessment in November 2019 but that there was raw intelligence data that was part of formal assessments in December 2019 [13]. In late December, doctors in Wuhan were puzzled by many pneumonia cases of unknown cause. On December 30, 2019 the Wuhan CDC sent out an internal memo to all Wuhan hospitals to be alerted and started an investigation into the exact cause of the pneumonia.
So here is what should have happened:
November 2019, A small
systems staff would have been aware of the intelligence data. They would
have alerted others to prepare for something significant.
December 2019 a small
systems team should have formally formed from the informal team that started
in November 2019. The team would be about 10 systems engineers where one
would be the technical director. There might be a shared program manager.
They would have reviewed all the informal analysis.
December 2019, the systems
team would have started the formal analysis on topics similar to what is
found in this analysis.
January 2020, the small
systems team would have been augmented with perhaps 50 others representing
different specialty areas. In 2 months they would have produced all the findings
in this report which took 11 months to produce (March 2020 and January 2021).
February 2020, systems
staff would be flying around the world to examine UV production facilities
and to Washington DC to brief the systems findings. They would be presenting
analysis similar to this analysis. Architecture alternatives and tradeoffs
would be presented. Legislators, based on the briefings would be drafting
legislation such as tax incentives and direct grants for HVAC upgrades and
UV installations. It would have been part of the Coronavirus Aid, Relief,
and Economic Security (CARES) act.
March 2020, they would
have started to coordinate with the industrial base to develop strategies
to roll out upgraded HVAC systems and UV systems. The organizations ILS group
that includes facilities experts would be working with the systems team that
now might number between 50-75 systems engineers. The project team might
now number 200 people.
April 2020, there would
be new HVAC and UV standards with testable requirements that include specific
performance numbers for roll out to the country in preparation for massive
infrastructure upgrades. This would be augmented with a massive education
program.
May 2020, small space
public building owners and managers would know the importance of managing
and upgrading their HVAC systems. They would be introduced to UV systems.
Because of tax incentives and direct credits they would start to upgrade
their facilities with appropriate UV and HVAC systems.
June - August 2020, there
are massive HVAC infrastructure upgrades and new UV systems.
August 2020, metrics might
show that 50% of the needed commercial infrastructure and 90% of the public
space (airports, etc.) has been upgraded.
September 2020, there
would be perhaps 1500 people on the project team. All schools would have
been upgraded with appropriate HVAC and UV systems. The reason this would
happen is because there would be massive analysis and data to support this
policy coming from the most qualified organizations in the US with the systems
team driving the systems perspective.
September 2020, the undisputed
solid findings from the respected organization and a functioning US Federal
Government would have rolled out proper airplane and airport guidance along
with appropriate UV and HVAC systems so that the expected Holiday Travel
would not lead to disaster.
The above scenario represents what should have been.
Before this topic is closed out the previous architectures need to be addressed. These architectures and their effectiveness are in the following table. Notice that the architecture and tradeoff criteria have exchanged rows and columns. It is easier to capture the comments for each architecture alternative.
Previous |
Prevent |
Stop |
Cost |
MOE for |
MOE for |
MOE for |
MOE for |
Comments |
1. Masks + Social Distance |
0-3 |
0-3 |
Infrastructure |
0 |
3 |
2 |
3 |
Probably explains Japan Unable to implement in US |
2. Total Quarantine |
0-5 |
0-5 |
Shutdown |
0 |
5 |
NA |
NA |
Worked in New Zealand Unable to implement in US |
3. Partial Quarantine |
0-3 |
0-3 |
Shutdown |
0 |
3 |
3 |
3 |
Somewhat successful in Hawaii Unable to implement in US |
Note: Rating Scale: 1 = worst, 5 = best
The costs for the above architectures are considered a wash. In this case the MOE becomes the tradeoff criteria ratings. The above table shows that the key to a successful architecture is to consider the people in the system. We can argue about the ratings but the results documented in the comments are now part of history. They are irrefutable empirical data.
Meanwhile the work continues. SEPTA and Drexel Team up to Battle COVID-19 in December of 2020. The partnership will focus on understanding the role of masks, ventilation, air treatment and surface cleaning in preventing transmission of the virus, developing strategies that SEPTA can deploy in the near future and guiding the agency in communicating these new safety protocols [14].
This analysis has gone from virus mutation, to a tradeoff for the most effective architecture, to a potential vision of how that architecture might be realized. It is never too late to make corrections and 2021 is the start of a new year for a new path.
References:
[1] Estimated transmissibility and severity of novel SARS-CoV-2 Variant of Concern 202012/01 in England, Centre for Mathematical Modelling of Infectious Diseases, December 31,2020. webpage https://cmmid.github.io/topics/covid19/uk-novel-variant.html, January 2021. Estimated transmissibility and severity of novel SARS-CoV-2 Variant of Concern 202012/01 in England.
[2] Transmission of SARS-CoV-2 Lineage B.1.1.7 in England: Insights from linking epidemiological and genetic data, Imperial College London, December 31, 2020. webpage https://www.imperial.ac.uk/mrc-global-infectious-disease-analysis/covid-19/report-42-sars-cov-2-variant, https://www.medrxiv.org/content/10.1101/2020.12.30.20249034v2.full.pdf, January 2021. PDF . local
[3] Even more contagious? Here’s what you need to know about the mutating virus now in California, January 4, 2021. webpage https://calmatters.org/health/coronavirus/2021/01/new-covid-strain-california, January 2021. Even more contagious? Here’s what you need to know about the mutating virus now in California.
[4] South African Covid variant appears to ‘obviate’ antibody drugs, Dr. Scott Gottlieb says, CNBC www.cnbc.com, January 6, 2021. webpage https://www.cnbc.com/2021/01/05/south-africa-covid-variant-appears-to-obviate-antibody-drugs-dr-scott-gottlieb-says.html, January 2021. South African Covid variant appears to ‘obviate’ antibody drugs, Dr. Scott Gottlieb says.
[5] Covid-19 501.V2: New variant of coronavirus dey for South Africa, BBC December 22, 2020. webpage https://www.bbc.com/pidgin/world-55415013, January 2021. Covid-19 501.V2: New variant of coronavirus dey for South Africa.
[6] South African SARS-CoV-2 Variant Alarms Scientists, The Scientist www.the-scientist.com, January 5, 2021. webpage https://www.the-scientist.com/news-opinion/south-african-sars-cov-2-variant-alarms-scientists-68317, January 2021. South African SARS-CoV-2 Variant Alarms Scientists.
[7] See section UV Infrastructure Cost Estimates.
[8] See section Proposed Legislation.
[9] Doomed to fail’: Why a $4 trillion bailout couldn’t revive the American economy, The Washington Post, October 5.2020. webpage https://www.washingtonpost.com/graphics/2020/business/coronavirus-bailout-spending, January 2021. Doomed to fail’: Why a $4 trillion bailout couldn’t revive the American economy.
[10] Systems Practices As Common Sense, Walter Sobkiw, ISBN: 978-0983253082, first edition 2011, ISBN: 978-0983253051, second edition 2020. REF 1
[11] Systems Engineering Design Renaissance, Walter Sobkiw, ISBN: 978-0983253075, 2014. REF 2
[12] This full report and its references.
[13] U.S. spy agencies collected raw intelligence hinting at public health crisis in Wuhan, China, in November. NBC News, April 9, 2020. webpage, https://www.nbcnews.com/politics/national-security/u-s-spy-agencies-collected-raw-intel-hinting-public-health-n1180646, January 2021. U.S. spy agencies collected raw intelligence hinting at public health crisis in Wuhan, China
[14] SEPTA and Drexel Team up to Battle COVID-19, Drexel Now December 15, 2020. webpage https://drexel.edu/now/archive/2020/December/SEPTA-COVID-19-research-partnership January 2021. SEPTA and Drexel Team up to Battle COVID-19
Virus Diffusion
Understanding how the virus will diffuse in an environment is critical to understanding how to mitigate the risk of exposure. In this analysis there are multiple approaches that were used to understand virus diffusion. Some of the analysis approaches are based on analogies of how the virus might behave and they come from other unrelated engineering areas. They are used to compare the results with analysis that more closely matches a diffusion analysis approach.
The following analysis was considered and the analysis that was developed have tables that show different scenarios and results. They use the simple particle dispersion and the density models:
Virus Density by Distance (Electrical Engineering)
This analysis is based on electrical engineering and comes from trying to understand the radiation exposure from a transmitter antenna. There are IEEE standards that identify limits of safe exposure based on milli-watts per square centimeter. The equation eventually boils down to the power density being inversely proportional to the square of the distance.
Pd=Ps/d^2
Pd = Power density at the target surface
Ps = Power at the source
d = distance
Even though it comes from electrical engineering it is a generic equation that uses distance to determine the density of an emitter at a distance. The equation applies to any emitter including the virus. It is a volume geometry equation. In the case of the virus we can easily translate the parameters that apply to virus diffusion:
Virus Load Destination = Pd
Virus Load Source = Ps
Distance = d
The following analysis is based on electrical engineering power density. The parameters were replaced with the relevant virus parameters. This model does not include wind speed. [spreadsheet Diffusion]
Ps |
d |
Pd |
|
Source |
Distance |
Destination |
Time to Reach Ps |
1200 |
6 |
33.3333 |
36 |
1200 |
16 |
4.6875 |
256 |
1200 |
26 |
1.7751 |
676 |
1200 |
36 |
0.9259 |
1296 |
1200 |
46 |
0.5671 |
2116 |
1200 |
56 |
0.3827 |
3136 |
1200 |
66 |
0.2755 |
4356 |
1200 |
76 |
0.2078 |
5776 |
Virus Diffusion by Distance and Windspeed (Nuclear Engineering)
The third analysis comes from nuclear engineering and is based on trying to understand the spread of radiation in the event of a release [1]. This is a more useful model because it considers wind speed along with the distance from a source. The equation is:
Ca= B*Qi / (u*x^2)
Ca = concentration at the point of interest (Bq/m3)
Qi = released concentration per unit of time (Bq/s)
x = distance between release vent and point of interest [m]
u = speed of the wind [m/s]
B = Unitless constant accounts for increase in air concentration along vertical wall because of air stagnation created by wakes.
B = 30 against wall, B = 1 open air
Radionuclides Atmospheric Dispersion, Source and Receptor on same building surface
If x is greater than three times the diameter of the stack or vent below to calculate the air concentration with B = 30
Even though it comes from nuclear engineering it is a generic equation that uses distance, wind speed, and an emitter with some rate of emission. The equation applies to any emitter including the virus. It is a particle dispersion model that uses a volume geometry equation with the additional factor of a wind speed that is used to consider a continuous emitter. The constant B is arbitrary to deal with the situation of dead air in settings like being up against a wall. In the case of the virus we can easily translate the parameters that apply to virus diffusion:
Virus Load Destination = Ca
Virus Load Source = Qi
Distance = x
Wind Speed = u
Open Air = B = 1
Against a Wall = B =30
This analysis is based on nuclear engineering and it shows the spread of radiation in the event of a release. The equation parameters have been replaced with relevant virus parameters. [spreadsheet Diffusion]
B |
Qi |
u |
u |
x |
Ca |
|
B |
Source |
Wind |
Wind |
Distance |
Destination |
Time to Reach Qi |
30 |
1200 |
1 |
88 |
6 |
11.3636 |
106 |
30 |
1200 |
1 |
88 |
16 |
1.5980 |
751 |
30 |
1200 |
1 |
88 |
26 |
0.6052 |
1983 |
30 |
1200 |
1 |
88 |
36 |
0.3157 |
3802 |
30 |
1200 |
1 |
88 |
46 |
0.1933 |
6207 |
30 |
1200 |
1 |
88 |
56 |
0.1304 |
9199 |
30 |
1200 |
1 |
88 |
66 |
0.0939 |
12778 |
30 |
1200 |
1 |
88 |
76 |
0.0708 |
16943 |
This is a worst case analysis where the uninfected person is up against a wall where B = 30. The level of virus exposure is a function of distance and wind speed.
This analysis is based on the nuclear engineering model. It has been augmented
to reflect Risk, Locations, and Scenarios.
[spreadsheet Diffusion]
B |
Qi |
u |
u |
x |
Ca |
|
|
|
|
B |
Source Virus/min |
Wind Miles/Hr |
Wind Feet/Min |
Distance Feet |
Destination Virus/min |
Time to Reach Qi Min |
Risk |
Location |
Scenarios |
30 |
1200 |
1 |
88 |
1 |
409.09 |
3 |
Unacceptable |
Outside wall |
Up against wall |
30 |
1200 |
1 |
88 |
6 |
11.36 |
106 |
High |
Outside wall |
Up against wall |
30 |
1200 |
1 |
88 |
16 |
1.60 |
751 |
Low to Unacceptable |
Outside wall |
Up against wall, common sense needs to apply, if infection source is downwind then Risk = Unacceptable |
. |
|
|
|
|
|
|
|
|
|
30 |
1200 |
0.01136 |
1 |
1 |
36000.00 |
0 |
Unacceptable |
Inside |
Up against wall No air movement, this is after a period of time (B becomes T) to build up against the wall |
30 |
1200 |
0.01136 |
1 |
6 |
1000.00 |
1 |
Unacceptable |
Inside |
Up against wall No air movement |
30 |
1200 |
0.01136 |
1 |
16 |
140.63 |
9 |
Unacceptable |
Inside |
Up against wall No air movement |
. |
|
|
|
|
|
|
|
|
|
1 |
1200 |
1 |
88 |
1 |
13.64 |
88 |
High |
Outside, Beach, Park |
Free space air movement, at 1 foot this is really up against a wall and you are the wall |
1 |
1200 |
1 * |
88 |
6 |
0.38 |
3168 * |
Low |
Outside, Beach, Park |
Free space air movement |
1 |
1200 |
1 |
88 |
16 |
0.05 |
22528 |
Low |
Outside, Beach, Park |
Free space air movement |
. |
|
|
|
|
|
|
|
|
|
1 |
1200 |
0.01136 |
1 |
1 |
1200.00 |
1 |
Unacceptable |
Outside No Wind, Tent |
Free space no air movement, Equation check |
1 |
1200 |
0.01136 |
1 |
6 |
33.33 |
36 |
Unacceptable |
Outside No Wind, Tent |
Free space no air movement |
1 |
1200 |
0.01136 |
1 |
16 |
4.69 |
256 |
High |
Outside No Wind |
Free space no air movement |
* Wind speed used in the design of a classroom
This analysis shows that Inside Locations are Unacceptable. This is obvious to engineers that are used to dealing with relationships like power density and air friction. It is not obvious to others and that is a serious issue. The relationship is clear, because there is no wind and no place for the virus to diffuse, the virus will settle in the environment. This analysis also shows that certain outdoor scenarios and locations are just as dangerous as indoor settings. This table has 12 scenarios and only 2 scenarios have Low Risk. There are 6 scenarios out of 12 that are Unacceptable.
Virus Density by Volume and Air Mixing (Engineering)
The next analysis shows the effects of mixing the virus in the indoor space and then exchanging the air. This strategy significantly changes the results and shows a path towards establishing safe indoor spaces. In this analysis there is a mechanism that is able to distribute the virus evenly throughout the room before anyone next to the infected person can get a whiff of the virus load. For example, fans are used to distribute the virus fully every minute. The next step is to determine how long it will take for the entire room to reach the virus load. So an infected person breathing 20 viruses per breath, taking 1 breath per second will produce 1200 virus particles around their head (about 1 cu-ft) in one minute. If the room is 10,800 cu-ft, it will take 9,000 minutes for the entire room space to be filled with 1000 virus particles for each cu-ft in the room. If the room is able to constantly distribute the virus and then change the room air with clean air then infection will be prevented. In the case of breathing and a cough the analysis suggests that even a very small AUC will have very low risk of infection. In the case of a sneeze the air must be fully exchanged with an AUC of 14.81. The challenge with this model is to ensure that the air in the room is constantly moving and random so that the virus is evenly diluted before being expelled from the room. Although this analysis is deterministic and based on simple math the real world scenario and results will be less optimistic. An alternative analysis based on the Well-Riley equation is more representative of what is observed in real world settings.
This metal model of an infection cloud building up around an infected person is important and should be considered in all analysis checks. In 1 minute the cloud is relatively small. A male exhales 6 liters per breath or about .21 cu-ft per breath. In 5 seconds that is about 1 cu-ft. In 50 seconds that is about 10 cu-ft. Some of the virus particles will fall to the ground and some will stay in the air. As time moves on the virus cloud grows first placing individuals near the infected person at risk and then eventually those farther away from the infected person are at risk as time moves on. This is common sense and intuitive. [spreadsheet Diffusion]
Source |
L |
W |
H |
Cubic-Ft |
Virus/Cubic-ft |
Time to Reach |
Req'd ACH |
Risk |
Location |
Scenarios |
1,200 |
30 |
30 |
12 |
10,800 |
0.11 |
9,000 |
0.01 |
Virtually none * |
Classroom, restaurant, office, small shop |
Breathing |
720 |
30 |
30 |
12 |
10,800 |
0.07 |
15,000 |
0.00 |
Virtually none * |
Classroom, restaurant, office, small shop |
Cough 6/hr 80% Droplet Infection |
2,666,667 ** |
30 |
30 |
12 |
10,800 |
246.91 |
4 |
14.81 ** |
Low * |
Classroom, restaurant, office, small shop |
Sneeze 1/hr 80% Droplet Infection |
. |
|
|
|
|
|
|
|
|
|
|
1,200 |
100 |
100 |
40 |
400,000 |
0.00 |
333,333 |
0.00 |
Virtually none |
Grocery store, big box store, garage, warehouse |
Breathing |
720 |
100 |
100 |
40 |
400,000 |
0.00 |
555,556 |
0.00 |
Virtually none |
Grocery store, big box store, garage, warehouse |
Cough 6/hr 80% Droplet Infection |
2,666,667 |
100 |
100 |
40 |
400,000 |
6.67 |
150 |
0.40 |
Virtually none |
Grocery store, big box store, garage, warehouse |
Sneeze 1/hr 80% Droplet Infection |
* Note that the Wells-Riley equation suggests that the risks are very high.
This analysis is provided further in the document.
** AUC used in the design of a classroom
To not lose the perspective of the effects of air mixing the following table shows the results when there is no air mixing. The size of the space becomes irrelevant. What matters is the distance between the infected and uninfected people. The table shows that all the scenarios become unacceptable because of the massive AUC levels that are needed to mitigate the virus exposure. [spreadsheet Diffusion]
Source |
L |
W |
H |
Cubic-Ft |
Virus/Cubic-ft |
Time to Reach |
Req'd ACH |
Risk |
Location |
Scenarios |
1,200 |
30 |
30 |
12 |
10,800 |
1,200 |
0.83 |
72 |
Unacceptable |
Classroom, restaurant, office, small shop |
Breathing |
720 |
30 |
30 |
12 |
10,800 |
720 |
1.39 |
43 |
Unacceptable |
Classroom, restaurant, office, small shop |
Cough 6/hr 80% Droplet Infection |
2,666,667 |
30 |
30 |
12 |
10,800 |
2,666,667 |
0.00 |
160,000 |
Unacceptable |
Classroom, restaurant, office, small shop |
Sneeze 1/hr 80% Droplet Infection |
. |
|
|
|
|
|
|
|
|
|
|
1,200 |
100 |
100 |
40 |
400,000 |
1,200 |
0.83 |
72 |
Unacceptable |
Grocery store, big box store, garage, warehouse |
Breathing |
720 |
100 |
100 |
40 |
400,000 |
720 |
1.39 |
43 |
Unacceptable |
Grocery store, big box store, garage, warehouse |
Cough 6/hr 80% Droplet Infection |
2,666,667 |
100 |
100 |
40 |
400,000 |
2,666,667 |
0.00 |
160,000 |
Unacceptable |
Grocery store, big box store, garage, warehouse |
Sneeze 1/hr 80% Droplet Infection |
Virus Density by Mask Filtering Levels (Engineering)
The following analysis shows that masks provide significant reduction in the virus counts but they must be coupled with social distancing and indoor settings that condition the air to minimize the amount of the virus.
This table shows the mask with No social distancing scenarios. [spreadsheet Diffusion]
Source |
Mask |
Mask |
Filter |
Virus/Cubic-ft |
Time to Reach |
Risk * |
Scenarios |
1200 |
0.25 |
1 |
0.25 |
300 |
3 |
Unacceptable |
1 Mask filter effectiveness 75% |
1200 |
0.25 |
0.25 |
0.0625 |
75 |
13 |
Unacceptable |
2 Masks filter effectiveness 75% |
1200 |
0.1 |
1 |
0.1 |
120 |
8 |
Unacceptable |
1 Mask filter effectiveness 90% |
1200 |
0.1 |
0.1 |
0.01 |
12 |
83 |
Unacceptable |
2 Masks filter effectiveness 90% |
1200 |
0.01 |
1 |
0.01 |
12 |
83 |
Unacceptable |
1 Mask filter effectiveness 99% |
1200 |
0.01 |
0.1 |
0.001 |
1.2 |
833 |
Low |
2 Masks filter effectiveness 99% |
* Does not include the effects of social distancing. Social distancing effects are found in the particle dispersion model and the density model.
Virus Density by Distance and Mask Filtering Levels (Engineering)
This analysis shows the mask with indoor social distancing scenarios. The virus density model is used because it is indoors with no natural wind and unknown ventilation characteristics. The ventilation is assumed to be off. Distance is the only variable that is considered. In this analysis we see that distance reduces the virus density more than the masks in Virus Density by Mask Filtering Levels analysis. Even when masks are worn it is critical to maintain social distance. [spreadsheet Diffusion]
Source |
Indoor |
Destination |
Mask Filter |
Destination |
Time to Reach |
Risk |
Scenarios |
1200 |
6 |
33.33 |
0.25 |
8.33 |
120 |
This is why outdoors is good |
Indoor, 1 Mask filter effectiveness 75% |
1200 |
6 |
33.33 |
0.0625 |
2.08 |
480 |
Med |
Indoor, 2 Masks filter effectiveness 75% |
1200 |
6 |
33.33 |
0.1 |
3.33 |
300 |
This is why outdoors is good |
Indoor, 1 Mask filter effectiveness 90% |
1200 |
6 |
33.33 |
0.01 |
0.33 |
3000 |
Low |
Indoor, 2 Masks filter effectiveness 90% |
1200 |
6 |
33.33 |
0.01 |
0.33 |
3000 |
Low |
Indoor, 1 Mask filter effectiveness 99% |
1200 |
6 |
33.33 |
0.001 |
0.03 |
30000 |
Virtually None |
Indoor, 2 Masks filter effectiveness 99% |
Unfortunately this table suggests that indoor ventilation must be properly engineered to reduce the virus exposure rate.
Just like the masks reduce the level of virus exposure, the design of the ventilation also reduces the level of virus exposure. The amount of virus exposure reduction is significant:
The use of a mask is for scenarios where the ventilation in an indoor space is not working and is unsafe or is unable to keep up with the virus load and provide a safe environment.
To summarize the results of this analysis:
NIST FaTIMA
This analysis is based on a modeling tool available from the National Institute Of Standards (NIST) - A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA). The tool allows the determination of the fate of indoor microbiological aerosols associated with ventilation, filtration, deposition, and inactivation mechanisms. It provides a representation of a single, well-mixed zone that is served by a mechanical ventilation system and uses source and removal mechanisms for an aerosol with a single, user-defined representative particle size. The simple mechanical ventilation system model allows specification of supply, return, and outdoor air intake rates to represent either a positive, negative or balanced ventilation system. Aerosol sources are provided to enable any combination of continuous, e.g., breathing-related emissions, or intermittent, e.g., coughing-related emissions. Aerosol removal mechanisms include filters within the ventilation system, room air cleaners, and deposition onto floors, walls, and ceilings. Simulations can be run for a 24-h period, with the results including the time history of the airborne concentration and surface loading, as well as integrated exposure of an occupant. Exposure is based on a uniform aerosol concentration within the zone and does not account for spatial differences in aerosol concentrations such as those due to momentum effects of respiratory emissions [2]. The equation is:
(1) V(dCz/dt) = PQinfCoa(t) + QsCs(t) + G(t) - (Qr + Qix + MacQac)Cz(t) - Sum [(i=1 to Ns) VdiAsiCz(t)]
(2) Asi(dLsi/dt) = VdiAsiCz(t)
C = particle concentration in air [kg/m3], subscripts: zone, outdoor air, and supply
Q = volumetric airflow rate [m3/s], subscripts: supply, return, infiltration, air cleaner, and local exhaust
Lsi = surface loading for surface i [kg/m2]
V = zone volume [m3]
Asi = deposition surface area for surface i [m2]
Vdi = particle deposition velocity for surface i [m/s] (Vdi = kd V /As)
Ns = number of surfaces (floor, walls, and ceiling)
Mac = particle filtration efficiency of air cleaner [-]
kd = particle deposition rate [1/s]
G = particle generation rate [kg/s]
P = particle penetration factor [-]
t = time [s]
This model is available online at: https://pages.nist.gov/CONTAM-apps/webapps/FaTIMA/index.html, July 2020. FaTIMA. This analysis was not expanded because it uses specific design parameters. As building ventilation is checked and modified, this and similar models should be used to understand the virus behavior.
Wells-Riley Equation
This model is based on the Wells-Riley equation which provides a probability of infection. The Wells–Riley equation provides the probability of airborne infection risk as a function of ventilation rate. The key concept is that the higher the ventilation rate, the more rapid the decay of particles (droplet nuclei) in the room air. According to the Wells–Riley equation, the probability of infection from droplet nuclei is inversely related to the ventilation rate. The parameters used in the Wells–Riley equation include ventilation rate, generation of infection droplet nuclei from the source, and the duration of exposure. This model is expanded to show the resulting AUC level in the modeled space, the actual affected US population counts, categories of ventilation, the role of masks, and scenarios.
Wells-Riley Summary
The following is a summary of the Wells-Riley equation applied to different living scenarios. We see that small indoor spaces have extremely high levels of probability of infection. We also see that it is unrealistic for someone to wear a mask constantly and that there will be times when the mask must come off to deal with real world life situations. During these times, when in small indoor spaces, there will be infection. We also see that living outside shows very low probability of infection. [spreadsheet Probability]
In the school scenario when the children are infected they bring it home. Basically when they go to school everyone goes to school. The same applies for any of the other scenarios.
Low income populations are affected more by COVID-19 and the suggestions are high risk working conditions and more underlying health issues [3]. However there also may be connections to the huge risks of small indoor spaces at work and at home. In the home, there may be more people living in the same house because of the high cost of housing. So when one person gets infected in a 3 person house the result is very different than in a house with 6, 7, 8, 9, 10 people where children, parents, grandparents, and even aunts, uncles, nieces and nephews may live. Expecting people at home to wear masks 100% of the time is unreasonable. Knowing how to reduce or eliminate the risk of infection in these settings with proper ventilation is critical. Opening the windows and installing attic fans seems like such a simple solution yet there is no detailed guidance other than to just open the windows.
The outside beach park scenarios show relatively low probability of infection. This assumes only 1 infection source. As the number of infected people increase over time the number in these settings will increase. One approach is to assume social distance practices and then assume a certain percentage of the population is infected. The square footage of the social distance divided into the scenario square footage will provide the number of people in the environment. The percentage of infected population will then provide the number of Infectors. The impact is approximately linear. With a 10% infected population the social distance will need to increase to 16 feet to keep the same levels of relatively low probability of infection for the outside beach park scenarios. It is also interesting to see that as the outside venue increases in size there is a larger impact on the number of infectors. This may not be appropriate because it is unlikely the virus will travel such long distances without be completely diluted.
time |
Masks |
P |
Chance of |
Space |
AUC |
Population |
Infected |
Deaths |
Ventilation |
Scenario |
1 |
Yes |
0.0449626 |
4% |
10,800 |
4.00 |
328,000,000 |
14,747,747 |
516,171 |
Expected |
Small indoor space |
1 |
No |
0.7194023 |
72% |
10,800 |
4.00 |
328,000,000 |
235,963,957 |
8,258,738 |
Expected |
Small indoor space |
8 |
Yes |
0.0624976 |
6% |
10,800 |
4.00 |
328,000,000 |
20,499,212 |
717,472 |
Expected |
Small indoor space |
1 |
Yes |
0.0021082 |
~ 0% |
400,000 |
4.00 |
328,000,000 |
691,475 |
24,202 |
Expected |
Large indoor space |
8 |
Yes |
0.0150030 |
2% |
400,000 |
4.00 |
328,000,000 |
4,920,984 |
172,234 |
Expected |
Large indoor space |
1 |
Yes but |
0.9938008 |
99% |
10,800 |
1.00 |
328,000,000 |
325,966,659 |
11,408,833 |
Poor |
Small indoor space |
1 |
Yes but |
0.7194023 |
72% |
10,800 |
4.00 |
328,000,000 |
235,963,957 |
8,258,738 |
Expected |
Small indoor space |
1 |
Yes but |
0.1193397 |
12% |
10,800 |
40.00 |
328,000,000 |
39,143,428 |
1,370,020 |
Massive Natural |
Small indoor space |
1 |
No |
0.0056322 |
1% |
10,800 |
3600 |
328,000,000 |
1,915,155 |
67,030 |
wind 1 mile / hr |
Outside small enclosed back yard |
1 |
No |
0.0011290 |
0.11% |
10,800 |
18000 |
328,000,000 |
370,309 |
12,961 |
wind 5 mile / hr |
Outside small enclosed back yard |
1 |
No |
0.0001525 |
0.02% |
400,000 |
3600 |
328,000,000 |
50,016 |
1,751 |
wind 1 mile / hr |
Outside beach park |
1 |
No |
0.0000305 |
0.00% |
400,000 |
18000 |
328,000,000 |
10,004 |
350 |
wind 5 mile / hr |
Outside beach park |
1 |
No |
0.0000152 |
0.00% |
4,000,000 |
3600 |
328,000,000 |
5,002 |
175 |
wind 1 mile / hr |
Outside large beach park |
1 |
No |
0.0000030 |
0.00% |
4,000,000 |
18000 |
328,000,000 |
1,000 |
35 |
wind 5 mile / hr |
Outside large beach park |
Wells-Riley equation:
|
Infection Load * Virus / Breath * Breaths / Sec * Sec to Infection =
q / sec 1000 * 20 * 1 * 50 = 0.0200 L x W x H = cu-ft:
30 X 30 X 12 = 10,800 |
Social Distance |
Space |
Parties |
Infected |
I |
6 |
900 |
25 |
10% |
3 |
6 |
10,000 |
278 |
10% |
28 |
6 |
100,000 |
2,778 |
10% |
278 |
. |
|
|
|
|
16 |
900 |
4 |
10% |
0.4 |
16 |
10,000 |
39 |
10% |
4 |
16 |
100,000 |
391 |
10% |
3 |
Wells-Riley Details Indoors
There has been evidence that our buildings have been spreading illness for decades after the energy crisis when the building ventilation systems reduced the ventilation rates to save on energy costs [4]. Fortunately there were few life threatening diseases that were partially airborne. People would get sick with the flu or the cold and just complain about the poor air in buildings. Now there is a virus that kills so it is now clear that the ventilation systems of small spaces must be modified to allow for a reasonable return to life. It is also clear the large indoor spaces should also have their ventilation systems modified even though the risk of infection is much lower. The following table shows various indoor scenarios and contrasts them with the outside scenarios. [spreadsheet Probability]
I |
p cu-in/sec |
q / sec |
time hour |
lpqt |
Q cu-in/sec |
2 Masks @ 75% |
Masks |
P |
Chance of Infection |
Q cu-ft/hr |
Space cu-ft |
AUC |
Population |
Infected |
death rate |
Deaths |
Ventilation |
Scenario |
2 |
366 |
0.0200 |
1 |
52,704 |
5,184 |
0.0625 |
Yes |
0.0624976 |
6% |
10,800 |
10,800 |
1 |
328,000,000 |
20,499,212 |
0.035 |
717,472 |
Poor |
Small indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
5,184 |
0.0625 |
Yes |
0.0621125 |
6% |
10,800 |
10,800 |
1 |
328,000,000 |
20,372,916 |
0.035 |
713,052 |
Poor |
Small indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
20,736 |
0.0625 |
Yes |
0.0449626 |
4% |
43,200 |
10,800 |
4 |
328,000,000 |
14,747,747 |
0.035 |
516,171 |
Expected |
Small indoor space Small Restaurant Not sure how to eat with a mask |
1 |
366 |
0.0200 |
1 |
26,352 |
20,736 |
no mask |
No |
0.7194023 |
72% |
43,200 |
10,800 |
4 |
328,000,000 |
235,963,957 |
0.035 |
8,258,738 |
Expected |
Small indoor space Small Restaurant Reality no mask while eating |
1 |
366 |
0.0200 |
1 |
26,352 |
51,840 |
0.0625 |
Yes |
0.0249064 |
2% |
108,000 |
10,800 |
10 |
328,000,000 |
8,169,307 |
0.035 |
285,926 |
Rare |
Small indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
207,360 |
0.0625 |
Yes |
0.0074587 |
1% |
432,000 |
10,800 |
40 |
328,000,000 |
2,446,464 |
0.035 |
85,626 |
Massive Natural |
Small indoor space |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2 |
366 |
0.0200 |
1 |
52,704 |
192,000 |
0.0625 |
Yes |
0.0150030 |
2% |
400,000 |
400,000 |
1 |
328,000,000 |
4,920,984 |
0.035 |
172,234 |
Poor |
Large indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
192,000 |
0.0625 |
Yes |
0.0080155 |
1% |
400,000 |
400,000 |
1 |
328,000,000 |
2,629,079 |
0.035 |
92,018 |
Poor |
Large indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
768,000 |
0.0625 |
Yes |
0.0021082 |
0% |
1,600,000 |
400,000 |
4 |
328,000,000 |
691,475 |
0.035 |
24,202 |
Expected |
Large indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
1,920,000 |
0.0625 |
Yes |
0.0008520 |
0% |
4,000,000 |
400,000 |
10 |
328,000,000 |
279,440 |
0.035 |
9,780 |
Rare |
Large indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
7,680,000 |
0.0625 |
Yes |
0.0002141 |
0% |
16,000,000 |
400,000 |
40 |
328,000,000 |
70,220 |
0.035 |
2,458 |
Massive Natural |
Large indoor space |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
366 |
0.0200 |
1 |
26,352 |
5,184 |
0.0625 |
Yes |
0.0621125 |
6% |
10,800 |
10,800 |
1 |
328,000,000 |
20,372,916 |
0.035 |
713,052 |
Poor |
Small indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
20,736 |
0.0625 |
Yes |
0.0449626 |
4% |
43,200 |
10,800 |
4 |
328,000,000 |
14,747,747 |
0.035 |
516,171 |
Expected |
Small indoor space |
1 |
366 |
0.0200 |
8 |
210,816 |
20,736 |
0.0625 |
Yes |
0.0624976 |
6% |
43,200 |
10,800 |
4 |
328,000,000 |
20,499,212 |
0.035 |
717,472 |
Expected |
Small indoor space Best case school & work Setting |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
366 |
0.0200 |
1 |
26,352 |
192,000 |
0.0625 |
Yes |
0.0080155 |
1% |
400,000 |
400,000 |
1 |
328,000,000 |
2,629,079 |
0.035 |
92,018 |
Poor |
Large indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
768,000 |
0.0625 |
Yes |
0.0021082 |
0% |
1,600,000 |
400,000 |
4 |
328,000,000 |
691,475 |
0.035 |
24,202 |
Expected |
Large indoor space Shopping |
1 |
366 |
0.0200 |
8 |
210,816 |
768,000 |
0.0625 |
Yes |
0.0150030 |
2% |
1,600,000 |
400,000 |
4 |
328,000,000 |
4,920,984 |
0.035 |
172,234 |
Expected |
Large indoor space Retail Work |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
366 |
0.0200 |
1 |
26,352 |
5,184 |
mask failures in school |
Yes but 1 hour mask off |
0.9938008 |
99% |
10,800 |
10,800 |
1 |
328,000,000 |
325,966,659 |
0.035 |
11,408,833 |
Poor |
Small indoor space School Setting Small Restaurant |
1 |
366 |
0.0200 |
1 |
26,352 |
20,736 |
mask failures in school |
Yes but 1 hour mask off |
0.7194023 |
72% |
43,200 |
10,800 |
4 |
328,000,000 |
235,963,957 |
0.035 |
8,258,738 |
Expected |
Small indoor space School Setting |
1 |
366 |
0.0200 |
1 |
26,352 |
207,360 |
mask failures in school |
Yes but 1 hour mask off |
0.1193397 |
12% |
432,000 |
10,800 |
40 |
328,000,000 |
39,143,428 |
0.035 |
1,370,020 |
Massive Natural |
Small indoor space School Setting |
1 |
366 |
0.0200 |
8 |
210,816 |
20,736 |
no mask |
No |
0.9999616 |
100% |
43,200 |
10,800 |
4 |
328,000,000 |
327,987,395 |
0.035 |
11,479,559 |
Expected |
Small indoor space |
1 |
366 |
0.0200 |
8 |
210,816 |
207,360 |
no mask |
No |
0.6382011 |
64% |
432,000 |
10,800 |
40 |
328,000,000 |
209,329,951 |
0.035 |
7,326,548 |
Massive Natural |
Small indoor space |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
366 |
0.0200 |
1 |
26,352 |
192,000 |
no mask |
No |
0.1282477 |
13% |
400,000 |
400,000 |
1 |
328,000,000 |
42,065,258 |
0.035 |
1,472,284 |
Poor |
Large indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
768,000 |
no mask |
No |
0.0337305 |
3% |
1,600,000 |
400,000 |
4 |
328,000,000 |
11,063,605 |
0.035 |
387,226 |
Expected |
Large indoor space |
1 |
366 |
0.0200 |
1 |
26,352 |
7,680,000 |
no mask |
No |
0.0034254 |
0.34% |
16,000,000 |
400,000 |
40 |
328,000,000 |
1,123,521 |
0.035 |
39,323 |
Massive Natural |
Large indoor space |
1 |
366 |
0.0200 |
8 |
210,816 |
768,000 |
no mask |
No |
0.2400480 |
24% |
1,600,000 |
400,000 |
4 |
328,000,000 |
78,735,743 |
0.035 |
2,755,751 |
Expected |
Large indoor space |
1 |
366 |
0.0200 |
8 |
210,816 |
7,680,000 |
no mask |
No |
0.0270767 |
3% |
16,000,000 |
400,000 |
40 |
328,000,000 |
8,881,149 |
0.035 |
310,840 |
Massive Natural |
Large indoor space |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
366 |
0.0200 |
4 |
105,408 |
18,662,400 |
no mask |
No |
0.0056322 |
1% |
38,880,000 |
10,800 |
3600 |
328,000,000 |
1,847,371 |
0.035 |
64,658 |
wind 1 mile / hr |
Outside small enclosed back yard |
1 |
366 |
0.0200 |
4 |
105,408 |
93,312,000 |
no mask |
No |
0.0011290 |
0.11% |
194,400,000 |
10,800 |
18000 |
328,000,000 |
370,309 |
0.035 |
12,961 |
wind 5 mile / hr |
Outside small enclosed back yard |
1 |
366 |
0.0200 |
4 |
105,408 |
691,200,000 |
no mask |
No |
0.0001525 |
0.02% |
1,440,000,000 |
400,000 |
3600 |
328,000,000 |
50,016 |
0.035 |
1,751 |
wind 1 mile / hr |
Outside beach park |
1 |
366 |
0.0200 |
4 |
105,408 |
3,456,000,000 |
no mask |
No |
0.0000305 |
0.00% |
7,200,000,000 |
400,000 |
18000 |
328,000,000 |
10,004 |
0.035 |
350 |
wind 5 mile / hr |
Outside beach park |
1 |
366 |
0.0200 |
4 |
105,408 |
6,912,000,000 |
no mask |
No |
0.0000152 |
0.00% |
14,400,000,000 |
4,000,000 |
3600 |
328,000,000 |
5,002 |
0.035 |
175 |
wind 1 mile / hr |
Outside large beach park |
1 |
366 |
0.0200 |
4 |
105,408 |
34,560,000,000 |
no mask |
No |
0.0000030 |
0.00% |
72,000,000,000 |
4,000,000 |
18000 |
328,000,000 |
1,000 |
0.035 |
35 |
wind 5 mile / hr |
Outside large beach park |
Wells-Riley Details Outside
The following table shows the outside scenario with different levels of population infection and social distance. [spreadsheet Outside P]
Distance ft |
Infected % |
I |
p cu-in/sec |
q / sec |
time hour |
lpqt |
Q cu-in/sec |
2 Masks @ 75% |
P |
Chance of Infection |
Q cu-ft/hr |
Space cu-ft |
AUC |
Population |
Infected |
death rate |
Deaths |
Ventilation |
6 |
10% |
3 |
366 |
0.0200 |
4 |
263,520 |
18,662,400 |
no mask |
0.0140211 |
1% |
38,880,000 |
10,800 |
3600 |
328,000,000 |
4,598,936 |
0.035 |
160,963 |
wind 1 mile / hr |
6 |
10% |
3 |
366 |
0.0200 |
4 |
263,520 |
93,312,000 |
no mask |
0.0028201 |
0.28% |
194,400,000 |
10,800 |
18000 |
328,000,000 |
924,990 |
0.035 |
32,375 |
wind 5 mile / hr |
6 |
10% |
28 |
366 |
0.0200 |
4 |
2,928,000 |
691,200,000 |
no mask |
0.0042272 |
0.42% |
1,440,000,000 |
400,000 |
3600 |
328,000,000 |
1,386,506 |
0.035 |
48,528 |
wind 1 mile / hr |
6 |
10% |
28 |
366 |
0.0200 |
4 |
2,928,000 |
3,456,000,000 |
no mask |
0.0008469 |
0.08% |
7,200,000,000 |
400,000 |
18000 |
328,000,000 |
277,771 |
0.035 |
9,722 |
wind 5 mile / hr |
6 |
10% |
278 |
366 |
0.0200 |
4 |
29,280,000 |
6,912,000,000 |
no mask |
0.0042272 |
0.42% |
14,400,000,000 |
4,000,000 |
3600 |
328,000,000 |
1,386,506 |
0.035 |
48,528 |
wind 1 mile / hr |
6 |
10% |
278 |
366 |
0.0200 |
4 |
29,280,000 |
34,560,000,000 |
no mask |
0.0008469 |
0.08% |
72,000,000,000 |
4,000,000 |
18000 |
328,000,000 |
277,771 |
0.035 |
9,722 |
wind 5 mile / hr |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
12 |
10% |
1 |
366 |
0.0200 |
4 |
65,880 |
18,662,400 |
no mask |
0.0035239 |
0.35% |
38,880,000 |
10,800 |
3600 |
328,000,000 |
1,155,829 |
0.035 |
40,454 |
wind 1 mile / hr |
12 |
10% |
1 |
366 |
0.0200 |
4 |
65,880 |
93,312,000 |
no mask |
0.0007058 |
0.07% |
194,400,000 |
10,800 |
18000 |
328,000,000 |
231,492 |
0.035 |
8,102 |
wind 5 mile / hr |
12 |
10% |
7 |
366 |
0.0200 |
4 |
732,000 |
691,200,000 |
no mask |
0.0010585 |
0.11% |
1,440,000,000 |
400,000 |
3600 |
328,000,000 |
347,177 |
0.035 |
12,151 |
wind 1 mile / hr |
12 |
10% |
7 |
366 |
0.0200 |
4 |
732,000 |
3,456,000,000 |
no mask |
0.0002118 |
0.02% |
7,200,000,000 |
400,000 |
18000 |
328,000,000 |
69,465 |
0.035 |
2,431 |
wind 5 mile / hr |
12 |
10% |
69 |
366 |
0.0200 |
4 |
7,320,000 |
6,912,000,000 |
no mask |
0.0010585 |
0.11% |
14,400,000,000 |
4,000,000 |
3600 |
328,000,000 |
347,177 |
0.035 |
12,151 |
wind 1 mile / hr |
12 |
10% |
69 |
366 |
0.0200 |
4 |
7,320,000 |
34,560,000,000 |
no mask |
0.0002118 |
0.02% |
72,000,000,000 |
4,000,000 |
18000 |
328,000,000 |
69,465 |
0.035 |
2,431 |
wind 5 mile / hr |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
6 |
50% |
13 |
366 |
0.0200 |
4 |
1,317,600 |
18,662,400 |
no mask |
0.0681672 |
7% |
38,880,000 |
10,800 |
3600 |
328,000,000 |
22,358,833 |
0.035 |
782,559 |
wind 1 mile / hr |
6 |
50% |
13 |
366 |
0.0200 |
4 |
1,317,600 |
93,312,000 |
no mask |
0.0140211 |
1.40% |
194,400,000 |
10,800 |
18000 |
328,000,000 |
4,598,936 |
0.035 |
160,963 |
wind 5 mile / hr |
6 |
50% |
139 |
366 |
0.0200 |
4 |
14,640,000 |
691,200,000 |
no mask |
0.0209578 |
2.10% |
1,440,000,000 |
400,000 |
3600 |
328,000,000 |
6,874,166 |
0.035 |
240,596 |
wind 1 mile / hr |
6 |
50% |
139 |
366 |
0.0200 |
4 |
14,640,000 |
3,456,000,000 |
no mask |
0.0042272 |
0.42% |
7,200,000,000 |
400,000 |
18000 |
328,000,000 |
1,386,506 |
0.035 |
48,528 |
wind 5 mile / hr |
6 |
50% |
1389 |
366 |
0.0200 |
4 |
146,400,000 |
6,912,000,000 |
no mask |
0.0209578 |
2.10% |
14,400,000,000 |
4,000,000 |
3600 |
328,000,000 |
6,874,166 |
0.035 |
240,596 |
wind 1 mile / hr |
6 |
50% |
1389 |
366 |
0.0200 |
4 |
146,400,000 |
34,560,000,000 |
no mask |
0.0042272 |
0.42% |
72,000,000,000 |
4,000,000 |
18000 |
328,000,000 |
1,386,506 |
0.035 |
48,528 |
wind 5 mile / hr |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
12 |
50% |
3 |
366 |
0.0200 |
4 |
329,400 |
18,662,400 |
no mask |
0.0174956 |
1.75% |
38,880,000 |
10,800 |
3600 |
328,000,000 |
5,738,559 |
0.035 |
200,850 |
wind 1 mile / hr |
12 |
50% |
3 |
366 |
0.0200 |
4 |
329,400 |
93,312,000 |
no mask |
0.0035239 |
0.35% |
194,400,000 |
10,800 |
18000 |
328,000,000 |
1,155,829 |
0.035 |
40,454 |
wind 5 mile / hr |
12 |
50% |
35 |
366 |
0.0200 |
4 |
3,660,000 |
691,200,000 |
no mask |
0.0052811 |
0.53% |
1,440,000,000 |
400,000 |
3600 |
328,000,000 |
1,732,215 |
0.035 |
60,628 |
wind 1 mile / hr |
12 |
50% |
35 |
366 |
0.0200 |
4 |
3,660,000 |
3,456,000,000 |
no mask |
0.0010585 |
0.11% |
7,200,000,000 |
400,000 |
18000 |
328,000,000 |
347,177 |
0.035 |
12,151 |
wind 5 mile / hr |
12 |
50% |
347 |
366 |
0.0200 |
4 |
36,600,000 |
6,912,000,000 |
no mask |
0.0052811 |
0.53% |
14,400,000,000 |
4,000,000 |
3600 |
328,000,000 |
1,732,215 |
0.035 |
60,628 |
wind 1 mile / hr |
12 |
50% |
347 |
366 |
0.0200 |
4 |
36,600,000 |
34,560,000,000 |
no mask |
0.0010585 |
0.11% |
72,000,000,000 |
4,000,000 |
18000 |
328,000,000 |
347,177 |
0.035 |
12,151 |
wind 5 mile / hr |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
6 |
100% |
25 |
366 |
0.0200 |
4 |
2,635,200 |
18,662,400 |
no mask |
0.1316876 |
13% |
38,880,000 |
10,800 |
3600 |
328,000,000 |
43,193,528 |
0.035 |
1,511,773 |
wind 1 mile / hr |
6 |
100% |
25 |
366 |
0.0200 |
4 |
2,635,200 |
93,312,000 |
no mask |
0.0278457 |
2.78% |
194,400,000 |
10,800 |
18000 |
328,000,000 |
9,133,389 |
0.035 |
319,669 |
wind 5 mile / hr |
6 |
100% |
278 |
366 |
0.0200 |
4 |
29,280,000 |
691,200,000 |
no mask |
0.0414764 |
4.15% |
1,440,000,000 |
400,000 |
3600 |
328,000,000 |
13,604,264 |
0.035 |
476,149 |
wind 1 mile / hr |
6 |
100% |
278 |
366 |
0.0200 |
4 |
29,280,000 |
3,456,000,000 |
no mask |
0.0084364 |
0.84% |
7,200,000,000 |
400,000 |
18000 |
328,000,000 |
2,767,150 |
0.035 |
96,850 |
wind 5 mile / hr |
6 |
100% |
2778 |
366 |
0.0200 |
4 |
292,800,000 |
6,912,000,000 |
no mask |
0.0414764 |
4.15% |
14,400,000,000 |
4,000,000 |
3600 |
328,000,000 |
13,604,264 |
0.035 |
476,149 |
wind 1 mile / hr |
6 |
100% |
2778 |
366 |
0.0200 |
4 |
292,800,000 |
34,560,000,000 |
no mask |
0.0084364 |
0.84% |
72,000,000,000 |
4,000,000 |
18000 |
328,000,000 |
2,767,150 |
0.035 |
96,850 |
wind 5 mile / hr |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
12 |
100% |
6 |
366 |
0.0200 |
4 |
658,800 |
18,662,400 |
no mask |
0.0346851 |
3.47% |
38,880,000 |
10,800 |
3600 |
328,000,000 |
11,376,718 |
0.035 |
398,185 |
wind 1 mile / hr |
12 |
100% |
6 |
366 |
0.0200 |
4 |
658,800 |
93,312,000 |
no mask |
0.0070353 |
0.70% |
194,400,000 |
10,800 |
18000 |
328,000,000 |
2,307,585 |
0.035 |
80,765 |
wind 5 mile / hr |
12 |
100% |
69 |
366 |
0.0200 |
4 |
7,320,000 |
691,200,000 |
no mask |
0.0105344 |
1.05% |
1,440,000,000 |
400,000 |
3600 |
328,000,000 |
3,455,283 |
0.035 |
120,935 |
wind 1 mile / hr |
12 |
100% |
69 |
366 |
0.0200 |
4 |
7,320,000 |
3,456,000,000 |
no mask |
0.0021158 |
0.21% |
7,200,000,000 |
400,000 |
18000 |
328,000,000 |
693,987 |
0.035 |
24,290 |
wind 5 mile / hr |
12 |
100% |
694 |
366 |
0.0200 |
4 |
73,200,000 |
6,912,000,000 |
no mask |
0.0105344 |
1.05% |
14,400,000,000 |
4,000,000 |
3600 |
328,000,000 |
3,455,283 |
0.035 |
120,935 |
wind 1 mile / hr |
12 |
100% |
694 |
366 |
0.0200 |
4 |
73,200,000 |
34,560,000,000 |
no mask |
0.0021158 |
0.21% |
72,000,000,000 |
4,000,000 |
18000 |
328,000,000 |
693,987 |
0.035 |
24,290 |
wind 5 mile / hr |
With an infected population level of more than 10% the social distance will need to increase to 12 feet to keep the same levels of relatively low probability of infection for the outside beach park scenarios. As the outside venue increases in size there is a larger number of infectors. Using this increase in the number of infectors may not be appropriate because it is unlikely the virus will travel such long distances without being completely diluted.
The outside numbers are very low for population infection levels of 10%.
As the population infection level reaches 100% it is possible that this model starts to break down because the numbers are still very low and this conflicts with this analysts mental model of the situation. The nuclear engineering model based on wind speed and distance with the B factor may be a better predictor of the outcome. See section Virus Diffusion by Distance and Windspeed (Nuclear Engineering).
B |
Source Virus/min |
Wind Miles/Hr |
Wind Feet/Min |
Distance Feet |
Destination Virus/min |
Time to Reach Qi Min |
Risk |
Location |
Scenarios |
30 |
1200 |
1 |
88 |
1 |
409.09 |
3 |
Unacceptable |
Outside wall |
Up against wall |
30 |
1200 |
1 |
88 |
6 |
11.36 |
106 |
High |
Outside wall |
Up against wall |
30 |
1200 |
1 |
88 |
16 |
1.60 |
751 |
Low to Unacceptable |
Outside wall |
Up against wall, common sense needs to apply, if infection source is downwind then Risk = Unacceptable |
. |
|
|
|
|
|
|
|
|
|
1 |
1200 |
1 |
88 |
1 |
13.64 |
88 |
High |
Outside, Beach, Park |
Free space air movement, at 1 foot this is really up against a wall and you are the wall |
1 |
1200 |
1 |
88 |
6 |
0.38 |
3168 |
Low |
Outside, Beach, Park |
Free space air movement |
1 |
1200 |
1 |
88 |
16 |
0.05 |
22528 |
Low |
Outside, Beach, Park |
Free space air movement |
Distance and virus load as set by B are key factors in driving the potential of virus infection. The B factor multiplies the virus load by that amount. With it set to 30 it is equivalent to being subjected to 30 infection sources rather than 1 infection source. This may be a reasonable assumption in a large outdoor venue because the other infection sources will be subjected to dispersion by the wind and large outdoor space.
The Virus Diffusion by Distance and Windspeed (Nuclear Engineering) model also shows the impact of distance from a virus emitter. We see that for distances of less than 1 foot even though the venue is outside, people will be infected. A social distance of approximately 1 foot is found on college campuses as students gather for parties, airplanes, and cruise ships at various entertainment and pool side venues.
References:
[Library/Diffusion] . [Library/Building-Ventilation]
[1] Generic Models For Use In Assessing The Impact Of Discharges Of Radioactive Substances To The Environment, Safety Reports Series No.19, International Atomic Energy Agency (IAEA), Vienna, 2001. Printed by the IAEA in Austria September 2001, STI/PUB/1103. webpage https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1103_scr.pdf, July 2020. Generic Models For Use In Assessing The Impact Of Discharges Of Radioactive Substances To The Environment . local
[2] A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA), NIST Technical Note 2095, U.S. Department of Commerce, June 2020. webpage https://doi.org/10.6028/NIST.TN.2095 A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA) . local
[3] Webinar: Social Inequities and COVID-19 Community Response | COVID-19 Healthcare Coalition Response, c19hcc.org/insights August 26, 2020. webpage https://c19hcc.org/insights, August 2020. Webinar: Social Inequities and COVID-19 Community Response | COVID-19 Healthcare Coalition Response
[4] The Sick Building Syndrome, Indian Journal of Occupational and Environmental Medicine, August 12, 2008. webpage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2796751, August, 2020. The sick building syndrome
Current US Infrastructure Virus Concentration
This analysis uses the current US Infrastructure standards to determine the virus concentration in different settings. The settings and resulting scenarios are:
Virus Concentration (HVAC Industry Engineering)
This model calculates aerosol exposure based on Heating Ventilation and Cooling (HVAC) industry engineering using in-practice values for spatial volume, ventilation rate, filtration effectiveness, air recirculation rate, outside air rate, and normal at rest inhalation quantities for various settings including aircraft [1] [2]. The additional parameters are time and virus generation rate. For consistency the virus generation rate is the same as used in all the other models in this text. The model has been expanded with mask parameters so that stakeholders can see the conditions where an infection will occur given a set of different scenarios and typical HVAC systems that exist in the current infrastructure.
There are a few items to note in the model. The first is that the original parameters are using mixed units. The parameters all need to be converted to common units. The second is that some of the units are difficult for people to relate to - in the US people relate to Feet, Square Feet, Cubic Feet. They can visualize the space. It is difficult to visualize a space in terms of Liters. However when parameters are compared to a single breath and a single breath is provided in terms of Liters, suddenly people can relate to a parameter based on Liters. To allow for better visualization some of the parameters are shown in multiple units.
The model does not shed any new light on the situation. The results are basically the same. There is a deep understanding that surfaces once the model is examined and understood. All the previous analysis was based on a physical space, a room or outdoor area of some size. In this model the space moves from a macro level to the lowest common denominator, a single person. As the model results are examined that concept needs to be kept mind. [Spreadsheet Concentration]
The time dependence of airborne infectious disease (the virus) caused by occupant generated infectious aerosol concentration (the virus) in a uniformly mixed system, like any occupant bioeffluent concentration (e.g. human breath carbon dioxide, and perspiration, perfume, clothing and skin oil volatile organic compound emissions), is based on occupancy density (OD), air supply rate per person, the HVAC system effectiveness in getting that supply air to the breathing zone, and the quality of the supply air. The equations and parameters are:
C1 = [N/(V*Ve) * [1-exp(-V*Ve*t/v)]
C1 or C = Bioeffluent infectious aerosol concentration in the space at time
t, virus/L
N = Rate of bioeffluent infectious aerosol generation/person, virus/s per
person, based on this analysis
t = Duration of infectious aerosol generation, sec
v = OD = Spatial volume/person, L/person
V = Infectious aerosol-free ventilation rate per person, L/s per person
(HVAC outdoor air + virus filtered recirculation air + envelope infiltration
air)
Ve = efficiency of supplying ventilation air to each person's breathing
zone
Ve = 1 in uniformly mixed system
Ve = 0.65 Fully loaded subway car and a narrow-body aircraft
Ve = 0.90 Stadium
Ve = 1.00 Remaining settings
Ve tends to be lower the higher the occupancy density
D = IC integration => D = IC * time exposed
D = IC = p * [NI/VVe] * {t + [OD/VVe] * [exp(-VVet/OD)-1] }
D = Virus inhaled or virus dose
I = Inhalation rate L/s
p = Fraction of infected persons = 1, the person next to you is infected
Infected when D > 1000
1 cu-m = 1000 liters
1 cu-m = 35.3 cu-feet
Ver = Virus Exposure Risk factor
Ver = D/Baseline when worse = -Baseline/D when better
e.g. Ver = 3 suggests the exposure risk is 3 time worse than the baseline,
Ver = -2 suggests the exposure risk is 2 times less
Scenarios |
N |
t hr |
t sec |
v vol |
v vol |
v vol |
V=V*Ve |
liters / hr |
cu-m / hr |
V/v |
Effective |
C1 |
I |
D1 |
p |
D |
1 mask |
2 masks |
Ver Baseline / D |
Office |
20 |
1 |
3600 |
999 |
28.3 |
28300 |
23.1 |
83160 |
83.16 |
0.8 |
2.9 |
0.82 |
0.15 |
443 |
1 |
467 |
117 |
29 |
-1.30 |
Office |
20 |
8 |
28800 |
999 |
28.3 |
28300 |
23.1 |
83160 |
83.16 |
0.8 |
2.9 |
0.87 |
0.15 |
3740 |
1 |
3740 |
935 |
234 |
6.17 |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Subway Car |
20 |
0.50 |
1800 |
25 |
0.70 |
700 |
8.90 |
32040 |
32.04 |
12.7 |
45.8 |
2.25 |
0.15 |
607 |
1 |
606 |
152 |
38 |
1.00 |
Narrow Body Aircraft |
20 |
6.00 |
21600 |
35 |
1.00 |
1000 |
6.10 |
21960 |
21.96 |
6.1 |
22.0 |
3.28 |
0.15 |
10623 |
1 |
10622 |
2656 |
664 |
17.52 |
Wide Body Aircraft |
20 |
14.00 |
50400 |
56 |
1.60 |
1600 |
11.80 |
42480 |
42.48 |
7.4 |
26.6 |
1.69 |
0.15 |
12814 |
1 |
12813 |
3203 |
801 |
21.13 |
Classroom Grades 9+ |
20 |
6.00 |
21600 |
286 |
8.10 |
8100 |
10.90 |
39240 |
39.24 |
1.3 |
4.8 |
1.83 |
0.15 |
5945 |
1 |
5945 |
1486 |
372 |
9.80 |
Auditorium Theater |
20 |
4.00 |
14400 |
360 |
10.20 |
10200 |
10.60 |
38160 |
38.16 |
1.0 |
3.7 |
1.89 |
0.15 |
4075 |
1 |
4075 |
1019 |
255 |
6.72 |
Classroom Grades 3-8 |
20 |
6.00 |
21600 |
399 |
11.30 |
11300 |
12.10 |
43560 |
43.56 |
1.1 |
3.9 |
1.65 |
0.15 |
5355 |
1 |
5355 |
1339 |
335 |
8.83 |
Stadium |
20 |
4.00 |
14400 |
939 |
26.60 |
26600 |
11.30 |
40680 |
40.68 |
0.4 |
1.5 |
1.77 |
0.15 |
3815 |
1 |
3823 |
956 |
239 |
6.30 |
Office |
20 |
8.00 |
28800 |
999 |
28.30 |
28300 |
23.10 |
83160 |
83.16 |
0.8 |
2.9 |
0.87 |
0.15 |
3740 |
1 |
3740 |
935 |
234 |
6.17 |
Notes:
1. V=V*Ve Infection Free Ventilation air all sources L/Sec includes the effects
of filtered recirculated air and outside air mixing [1].
2. Minimum outside air supply rates for building environments ASHRAE Standard
62.17 [1].
3. Transportation environment outside air supply rates ASHRAE Standard 161
(aircraft) [1].
4. Filtration ASHRAE Standard 161
5. UV-C is not considered in this model.
6. At rest Inhalation is 0.15 Liters it can go as high as 4 (female) to 6
(male) Liters
Current US Infrastructure Key Findings
This analysis models the space around a person. For example the Auditorium Theater scenario space is 360 cu-ft. With a 10 ft ceiling the floor space is 6 ft X 6 ft. The ventilation rate translates into an AUC of 3.7. So a building packed with people that are spaced 6 feet apart with a 10 ft ceiling and an AUC of 3.7 will result in 4075 virus particles being inhaled in 4 hours. Since the infection threshold is 1000 virus particles, there will be infection. If 1 mask is introduced the virus inhaled count will be 1019 and with 2 masks it will be 255.
This analysis shows that in each of these scenarios everyone gets infected without a mask except for the Subway. We see airplanes are the worst case scenarios, which is what this text speculated when it was started in April 2020. As the at rest inhalation rate increases because of activity (e.g. laughter, talking, singing, exercise), the infection rate increases. We see that if we increase the personal space, the level of infection drops. We also see that as we increase the AUC, the level of infection drops.
Other analysis in this text suggests that the scenarios are worse than suggested in this analysis. Extreme care must be taken when examining these numbers. The Wells-Riley Probability of infection is a better predictor of the results because this model assumes uniform distribution and that is not the case in a real world setting. This analysis suggests that all will be well for some scenarios if masks are worn but the Wells-Rile Probability of infection suggests that even with masks there is a relatively high probability of infection (Office Scenario) [3].
A key question remains and that is what happens with repeated exposure. Is the virus cumulative or does something act to eliminate the non-infectious virus load, such as the Innate Immune System. Something is clearing the low dose virus exposure or else the virus spread would have been significantly worse than we have experienced to date (October 2020). However, we do see the extreme danger in small spaces packed with people like classrooms, bars, and restaurants. The occupancy rates must be controlled and the AUC must be drastically increased in these settings.
Infrastructure Modifications
Obviously others are working to determine how to mitgate the risk of infection within indoor spaces. The body of knowledge goes back into the last century. In 1943 there was a 6 year study in Philadelphia on the effects of the use of UV-C ceiling level lights. The study begins with: the prevalence of respiratory infection during the season of indoor congregation suggests a natural relationship between ventilation and communicable disease and concludes that the level of infection was much lower in the irradiated classroom compared to the unirradiated classroom despite the fact that there were more susceptibles in the irradiated classroom than the unirradiated classroom. According to CDC guidelines there is upwards of 90 percent effectiveness applying UV-C lights and they effectively boost the air changes per hour where there can be 17 additional air changes per hour. However, they need to be properly managed to ensure hot air is not trapped at the ceiling level, the air must circulate. [4]
Do we have the technology to modify our infrastructure? The short answer is yes. This is not a technology problem. Given that the US has spent trillions of dollars thus far on this disaster, this is not an economic problem. This is a social problem. It is all just a matter of national will and leadership. Proposed legislation text was prepared in July 2020 but there has been no action as of October 2020 [5].
Author Comment: The US issued trillions of dollars to maintain a status quo, basically doing nothing except for parking people and resources. A fraction of that money could have been used to update all the buildings leading up to the Winter of 2020. Instead the virus will spread at a higher rate and the US Infrastructure will continue to be a source of all types of infection spread. In this case the infection death rate is very high and there is large loss of long term health yet to be quantified.
References:
[1] Germs and Flying: Developing Ventilation System Criteria, SAE International, October 18, 2011. webpage http://indoorair.ca/veft/pdf/SAE_paper_Germs_and_Flying_2011-01-2690.pdf, October 2020. Germs and Flying: Developing Ventilation System Criteria
[2] COVID-19 and Beyond A Brief Introduction To Passenger Aircraft Cabin Air Quality, ASHRAE Journal, October 2020. webpage https://www.ashrae.org/file%20library/technical%20resources/covid-19/12-19_walkinshaw.pdf, October 2020. COVID-19 and Beyond A Brief Introduction To Passenger Aircraft Cabin Air Quality
[3] See section Wells Riley Probability of Infection.
[4] How Can Airborne Transmission of COVID-19 Indoors be Minimized?, May 01, 2020. https://www.youtube.com/watch?v=jK6Cef5A8FQ. local transcript
[5] See section Proposed Legislation.
Classroom & Other Designs
When this analysis was started there was no idea that it would lead to a potential design for a classroom. The goal of the analysis was to gain further insight into the behavior of the virus from an engineering perspective. As the analysis unfolded the possibility of developing indoor venue designs surfaced.
The key to virus safe classroom design is proper ventilation. Ventilation moves outdoor air into a building or a room and distributes the air to provide healthy air for breathing. Ventilation is accomplished by both diluting internal pollutants and removing the pollutants. In this case there is a need to dilute as quickly as possible, capture, and remove any floating virus in the air. The recycled air must be subjected to UV-C and virus level filters. There are three methods used to ventilate a building: natural, mechanical and hybrid (mixed-mode) ventilation. Ventilation has three elements:
One of the key reports to review to gain a better understanding of ventilation and common sense building management is from the WHO [1]. Look at the pictures of the designs of the buildings. Look at the natural ventilation ACH numbers throughout the report. Natural Ventilation for Infection Control in Health-Care Settings, WHO, 2009 . local
In addition to ventilation the use of ceiling level UV-C lights is a key element to the system that will reduce the risk of infection. The UV-C lights boost the air changes per hour where there can be 17 additional air changes per hour. However, they need to be properly managed to ensure hot air is not trapped at the ceiling level, the air must circulate.
All this analysis can now be used to develop a potential design for an generic enclosed space. The selected generic space is a classroom. These are the system requirements:
Those are the key requirements to be used to upgrade the classroom.
Each school district in the US should build a prototype classroom adapted to their unique needs using this generic classroom design. It should then be subjected to validation using a test and evaluation effort that will tweak the design (described below). This should then be used to update all the classrooms and common areas in the school district.
Indoor Classroom Converted to Outdoor Environment |
Open windows in a Public School cafeteria |
In the early 1900s while dealing with tuberculosis it was detected that children do better in the open air. The first fresh-air school in the US for tubercular children opened in Providence in 1908 and by 1910 there were 65 fresh-air schools in the country [2]. Some are currently suggesting that classrooms be moved outside to prevent the spread of the virus to school children and teachers [3]. They also suggest that plastic shields going up around desks is not the answer and they cynically state that - That's our creative solution? [3].
What is missing in the dialog is sound engineering. It is over 100 years since 1908 when there were few engineering alternatives. The proposed classroom design suggested by this analysis can be accomplished in any school in the US with minimal costs. The capability and industrial infrastructure exists and can be quickly rolled out across the country.
|
Classroom Design Swarthmore Public School |
Classroom Design Validation
The prototype classroom and each resulting modified classroom can be validated using a common sense test and evaluation program.
The testing and evaluation is performed by placing smoke emitters at the different student desks. The smoke is monitored with and without the ventilation turned on. Test subjects are placed at each desk to monitor the airflow and look for dead air zones. The test subjects can be parents or students from the community. The smoke emitter is placed at each of the student desks as part of separate test events. This entire project can be made part of the science classes offered when the school session is started.
Can higher tech testing be done - Yes. This is the lowest common denominator validation approach and it will also instill confidence in the community because everyone will see and understand the results.
At this point few will trust a report based on high tech testing. Does that mean the high tech testing should not be performed - No. Do the high tech testing approach and then do the simple common sense smoke test before a classroom is certified as being as safe as modern engineering can make the classroom safe.
Classroom Ventilation On |
Classroom Ventilation Off |
As of July 2020, 31% of the children in Florida are positive for the virus and the Florida statewide average is 11% [4]. Each school district has the following options:
It is gravely important that if option #3 is followed you behave as an educated stakeholder and ask the questions raised in this analysis. They must educate you and what they provide must make sense. You now know the air needs to be mixed to dilute the virus. You also know that the air needs to be exchanged at a rate (AUC) to remove the virus. If the recommendations are less, then you must be convinced using logic, common sense, and transparent engineering analysis that is understood by everyone including the parents and older children. The children are the most important stakeholder in this system.
Do not open the schools until the virus is under control and the students can be properly screened before entering the building. Realize that school children will not social distance, constantly wear masks, wash their hands, and may even come to school sick. Respect that reality, any management driven desires or talking points are irrelevant, the virus is in control.
To view the analysis that supports this design go back and read the section: Virus Diffusion Classroom Design
Key Stakeholder Statements
The Essex County Education Association provided a statement on the in-person reopening of schools [6]. The position titles were kept but many of the names have been removed from the statement.
Essex County Education Association Statement on the In-Person Reopening of SchoolsJuly 24, 2020
To:
Interim Executive County Superintendent; Assemblywoman, Vice-Chair of the Assembly Education Committee; Assemblyman, Member of the Assembly Education Committee; Essex County Executive; Sen. Richard Codey; Sen. Teresa Ruiz, Chair of the Senate Education Committee; Sen. Ron Rice; Sen. Nia Gill; Sen. Kristin Corrado; Sen. Joe Pennacchio; Assemblywoman various; Assemblyman various; and the Essex County Freeholder Board.
Out of the more than three thousand counties in the United States, Essex County New Jersey ranks in the top ten nationally for the number of Covid-19 deaths. We mourn for the more than two thousand residents who lost their lives and recognize that each one represents a family that will never be the same. As president of the Essex County Education Association, I represent more than twelve thousand educators across the county and for us the danger that Covid-19 presents is all too real.
For the last several weeks our members have been faithfully participating in reopening committees in our districts. We would like nothing more than to return to our classrooms and offices to educate our students in a safe environment. However, it is clear that the science supports that reopening school buildings this fall is unsafe.
Therefore, the Essex County Education Association cannot, in good faith, support the reopening of public schools for in-person instruction in September. Simply put, despite the best of intentions and planning, the risk to the health and safety of our students and staff is too high.
We know that indoor activities in small spaces for long periods of time presents the highest risk for the spread of Covid-19. Currently, the NJ Department of Health acknowledges that short term, indoor dining is not safe. The World Health Organization now agrees that Covid-19 may spread through the air in indoor enclosed spaces [A].
Just this week it was reported that scientists also believe that Covid-19 may be spread by HVAC units [B]. Enclosed spaces and long periods of time describe the exact conditions in our classrooms. In addition, chronic problems with HVAC systems in our buildings are prevalent across the county even in well-resourced districts. To address just that one issue it would likely take tens of millions of dollars and probably more than a year. This reflects the magnitude of the problems we face.
There are countless other health and safety issues that are equally daunting, including busing and Covid testing and tracing and they come during a time when we are facing budget shortfalls and no guarantee of assistance from the Federal Government.
The other huge issue that makes resuming in-person instruction unsafe is compliance. Small children are not developmentally able to understand or undertake social distancing. It will be an impossible task to keep them apart. As educators, we are problem solvers and inherently optimistic. Just try to teach a lesson on Halloween and you will see optimism personified. But this is not a challenge to be overcome, it is an impossibility.
If we open buildings for in-person instruction, make no mistake, students will not maintain social distance and the results may be deadly. For some of our students, compliance with rules is often difficult. Therefore, regardless of age level, the maintenance of safety protocols is utterly unrealistic.
The guidelines from both the NJDOE and the AAP are simply that, guidelines. They are unproven and untested. They cannot assure parents that their children are safe from contracting the virus or bringing it home. The guidelines cannot guarantee that teachers will not get sick and die.
In a large-scale, systematic study of 65,000 people in South Korea, results found students between ages 10 and 19 spread the virus at the same rate as adults [C]. What are the implications for our middle and high school students, their families, and educators?
We have already seen camps and summer schools with small groups, who followed social distancing guidelines and mask requirements, report cases of Covid 19 and close, some within a few days of opening.
- Newark summer school site was temporarily closed due to coronavirus case [D]
- Covid Case Suspends In-person Summer School At Norwalk High [E]
- Reopening New Jersey: Manasquan Pauses Summer Camp Program After Workers Test Positive For Covid-19 [F]
We understand that parents want to resume a sense of normalcy for their children. We want that too. But we all need to understand the new realities of classrooms in the age of Covid. As a teacher for the last twenty-four years I can attest that educators have spent the last decade engaged in an effort to emphasize the social and emotional development of our students.
Simply put, we understand now more than ever that for students to learn they must feel safe, welcome, and part of the community. How exactly will they do that with desks spaced 6 ft apart? How will they feel as they are constantly reminded to stay apart from their friends, and to not touch their masks, and to not share supplies and keep to their plexiglass “personal space” in the classroom? How will that work exactly, with kindergarteners? Many schools will require a “door to door” mask policy. The teacher will be wearing a mask and face shield. One to one help will be restricted under the guidelines. Group work and labs with shared supplies will not occur. The simple gesture of a reassuring smile or fist bump will vanish.
The school day may be abbreviated with students either eating lunch at home, getting a boxed lunch to take home, or eating in their classroom. Going to the bathroom will now require the careful orchestration and logistics of an air traffic controller at Newark Airport.
Precious instructional time will be lost to monitor sanitizing and compliance to social distancing and mask wearing. Socially and emotionally every single person - both students and adults - present in these buildings under these conditions will be totally stressed out all the time. Yet, even with all these draconian measures, there is still no guarantee that students will be safe from Covid-19.
Impact on Families
The Essex County Education Association recognizes the severe burden that closed school buildings presents for working families and we did not arrive at this decision to support a remote start lightly. Many teachers are working parents too. However, an intermittent start and stop due to an outbreak of new cases is far more disruptive and unstable than planning now for remote learning for all families.
While some European schools have opened with limited transmission, schools in China, Israel and South Korea have been forced to close.
Next Steps
We are asking that you recognize the obvious, that it is totally unrealistic to expect that we can safely open our schools for in-person instruction in September.
By declaring a remote start for school in September now, this will provide parents time to arrange for childcare and educators to better prepare for remote instruction. Time though, is of the essence. Districts are wasting precious weeks creating plans with convoluted schedules and Plexiglas dividers that are plainly unworkable.
Staffing these plans will prove to be impossible. We had a severe substitute shortage before the pandemic. Many educators are preparing to leave the profession rather than risk their lives in buildings that they know cannot be made safe over the next six weeks.
Ultimately, once cases of Covid start showing up - and they will - these plans fall apart like a house of cards.
Where do districts, families and students end up in that case? Right back in remote learning anyway, but without the benefit of planning and preparation because we were too busy figuring out who is going to be taking temperatures and sanitizing every surface each day.
- Educators can use the remaining weeks before school to engage in professional development in effective remote instruction
- Administrators can work to provide technology support for those families in need.
- Districts can focus on public/private partnerships and other funding sources to help their students as outlined by Governor Murphy’s initiative, “Closing the Digital Divide.”
- Districts that had successes with remote learning could share best practices with districts that struggled.
As always, our members stand ready to work with the communities we serve to help reduce the burden of remote instruction. We are interested in creative ideas that can help working families and support students, but do not put lives at risk.
We are simply asking that as leaders you take the next step and support a remote start to the year so that during this unprecedented crisis we can continue to deliver the best quality education that made NJ schools the best in the nation.
Sincerely,
President Essex County Education Association and Livingston Education Association, Co-President: Essex Fells Education Association, President: Irvington Education Association, President: Cedar Grove Education Association, Co-President: West Essex Regional Education Association, President: Orange Education Association, Co-President: Essex Fells Education Association, President: Education Association of Nutley, Co-President: West Essex Regional Education Association, Co-President: Essex Fells Education Association, President: Bloomfield Education Association, President: Millburn Education Association, President: South Orange-Maplewood Education Association, President: West Orange Education Association, President: East Orange Resource Professionals Association, President: Caldwell-West Caldwell Education Association, President: Belleville Education Association, President: East Orange Education Association, President: Roseland Education Association, President: Essex County Vocational & Technical Education Association, Co-President: Glen Ridge Education Association, Co-President: Glen Ridge Education Association, President: East Orange Service & Maintenance Association, President: Verona Education Association, President: East Orange Charter School Education Association
American Federation of Teachers
The nation’s second largest teachers union with 1.7 million members, American Federation of Teachers (AFT), issued a resolution saying it will support any local chapter that decides to strike over reopening plans because of unsafe working conditions in schools due to the coronavirus pandemic. According to the union the safeguards must include [7]:
HVAC Industry
The HVAC and ventilation issue has started to surface in popular media as of July 28, 2020. There is acknowledgement that upgrading building HVAC systems will help to mitigate the risk of infection and companies are being asked to provide potential solutions. Property managers are upgrading heating, ventilation and air conditioning systems before reopening buildings. Building specialists are examining filters that block microbes, systems that use ultraviolet light or electrically charged particles in the ductwork to kill the virus, air monitoring sensors, and portable filter machines to help make up for deficiencies in central ventilation systems. There are many tradeoffs [8]:
Many approaches to reduce pathogens have been available for decades, such as UV light and bipolar ionization, which releases electrically charged atoms that attach to and neutralize viruses and bacteria. These technologies are geared more to hospitals than commercial buildings, which put more of an emphasis on saving energy than killing germs. Demand is now coming from schools and small offices [8]
References:
[1] WHO Publication/Guidelines Natural Ventilation for Infection Control in Health-Care Settings, World Health Organization (WHO), 2009. webpage https://www.ncbi.nlm.nih.gov/books/NBK143284/pdf/Bookshelf_NBK143284.pdf, May 2020. Natural Ventilation for Infection Control in Health-Care Settings, WHO, 2009 . local
[2] Fighting TB with Fresh-Air Schools, RIMS Doctors Launch a Movement, Rhode Island Medical Journal, Mary Korr, September 2016. webpage http://www.rimed.org/rimedicaljournal/2016/09/2016-09-75-heritage.pdf, July 2020. Fighting TB with Fresh-Air Schools, RIMS Doctors Launch a Movement
[3] Schools Beat Earlier Plagues With Outdoor Classes. New York Times, Ginia Bellafante, July 17, 2020. webpage https://www.nytimes.com/2020/07/17/nyregion/coronavirus-nyc-schools-reopening-outdoors.html, July 2020. Schools Beat Earlier Plagues With Outdoor Classes
[4] Nearly one-third of children tested for COVID in Florida are positive. Palm Beach County’s health director warns of risk of long-term damage, By Skyler Swisher, South Florida Sun Sentinel July 14, 2020. webpage https://www.sun-sentinel.com/coronavirus/fl-ne-pbc-health-director-covid-children-20200714-xcdall2tsrd4riim2nwokvmsxm-story.html, July 2020. Nearly one-third of children tested for COVID in Florida are positive
[5] Almost one-third of Florida children tested are positive for the coronavirus, The state’s outbreak continues to surge as new data reveal children may be more impacted than previously thought., By Alexandra Kelley The Hill, July 15, 2020. webpage https://thehill.com/changing-america/well-being/prevention-cures/507442-almost-one-third-of-florida-children-tested-are, July 2020. Almost one-third of Florida children tested are positive for the coronavirus
[6] Essex County Education Association Statement on the In-Person Reopening of Schools, West Essex NOW, Carolyne Volpe Curley, July 24, 2020. webpage https://www.westessexnow.com/new-jersey-education/essex-county-education-association-statement-on-the-in-person-reopening-of-schools, July 2020. Essex County Education Association Statement on the In-Person Reopening of Schools
[7] Teachers union authorizes strikes if schools reopen without certain safety measures, The Hill, Zack Budryk, July 28, 2020. webpage https://thehill.com/policy/healthcare/509373-teachers-union-authorizes-strikes-if-schools-reopen-without-certain-safety, July 2020. Teachers union authorizes strikes if schools reopen without certain safety measures
[8] Can Covid Spread With Air Conditioning? HVAC Makers Plan Upgrades, Bloomberg msn.com, July 27, 2020. webpage https://www.msn.com/en-us/money/other/can-covid-spread-with-air-conditioning-hvac-makers-plan-upgrades/ar-BB17eMF8?ocid=se, July 2020. Can Covid Spread With Air Conditioning? HVAC Makers Plan Upgrades
[A] WHO acknowledges 'evidence emerging' of airborne spread of COVID-19, Reuters, July 7, 2020. webpage https://www.reuters.com/article/us-health-coronavirus-who-airborne/who-acknowledges-evidence-emerging-of-airborne-spread-of-covid-19-idUSKBN2482AU, July 2020. WHO acknowledges 'evidence emerging' of airborne spread of COVID-19
[B] Most air conditioning systems don't protect against the coronavirus. In some cases, they can actually facilitate spread, USA Today, Adrianna Rodriguez, July 15, 2020. webpage https://www.usatoday.com/story/news/health/2020/07/15/covid-air-conditioning-could-facilitate-coronavirus-airborne-spread/5429919002 July 2020. Most air conditioning systems don't protect against the coronavirus. In some cases, they can actually facilitate spread
[C] Older Children Spread the Coronavirus Just as Much as Adults, Large Study Finds, New York Times, Apoorva Mandavilli, July 18, 2020. webpage https://www.nytimes.com/2020/07/18/health/coronavirus-children-schools.html, July 2020. Older Children Spread the Coronavirus Just as Much as Adults, Large Study Finds
[D] Newark summer school site was temporarily closed due to coronavirus case, Chalkbeat, Patrick Wall ,July 21, 2020. webpage https://newark.chalkbeat.org/2020/7/21/21332949/newark-summer-school-site-closed-coronavirus-case, July 2020. Newark summer school site was temporarily closed due to coronavirus case
[E] COVID case suspends in-person summer school at Norwalk High, The Hour, Erin Kayata, July 8, 2020. webpage https://www.thehour.com/news/article/Norwalk-High-closed-after-person-in-building-15393796.php, July 2020. COVID case suspends in-person summer school at Norwalk High
[F] Reopening New Jersey: Manasquan pauses summer camp program after workers test positive for COVID-19, Eyewitness News WABC TV 7 NY, July 13, 2020. webpage https://abc7ny.com/manasquan-covid-coronavirus-summer-camp-nj-pause/6315058, July 2020. Reopening New Jersey: Manasquan pauses summer camp program after workers test positive for COVID-19
Virus Diffusion Other Indoor Designs
All the information needed to understand virus diffusion and develop working designs is in section Virus Diffusion Classroom Design. The generic classroom design can be adapted for restaurants, bars, small office spaces, movie theaters, small retail shops. Large office buildings should engage large HVAC companies to develop the designs based on findings of the analysis that resulted in the generic classroom design. The issue is who will test and certify these spaces.
This begs the question - what is going on with the HVAC industry because there is no serious dialog in the public media on this subject as of July 2020.
Personally Dealing With Enclosed Spaces
The data from the previous analysis has been reduced to provide personal guidance on dealing with enclosed spaces. The enclosed spaces are both indoor and outdoor settings.
The analysis findings are significant. Wearing a mask in a small enclosed space with social distancing but no ventilation or poor ventilation may still quickly lead to virus infection. Big spaces like big box stores are less risk because of the massive space for the virus to diffuse allowing enough time for it to be exhausted. Personal experience suggests that many big box stores turned on their ventilation systems to the maximum levels. Outdoor venues can have the same characteristics as small spaces with no ventilation and they are at the same high risk of virus infection. However outdoor settings with a gentle breeze, minimal crowds and social distancing are low risk.
The following guidance is offered on how to proceed and the data follows the guidance.
When you enter a small space
check for ventilation, if there is no ventilation that you can feel and hear
get out as soon as possible, follow up and tell the management why you left
When in an outdoor space
in a large crowd, if there is no open wind that you can feel get out as soon
as possible, avoid the middle of the crowd, follow up and tell the management
why you left
Enjoy the outside when there
are gentle winds in places with few crowds where people are spaced 6 to 12
feet apart, a distance of 1 foot will lead to infection
Enjoy walking, running, bike
riding outside in places with few crowds where people are spaced 6 feet apart
Wear a mask, masks are critical
but do not fully rely on the masks to protect you, you must use your common
sense about ventilation, it is instinctive
The analysis that led to these findings are from:
All the analysis is consistent, appears to match the empirical data, and appears to match what people are experiencing. Before the analysis summary is offered the following relationships are provided to further help people understand how the virus can be transmitted.
Words are cheap. It is always about the performance characteristics. All performance characteristics are stated in terms of numbers. Any system that does not have a full understanding of the performance characteristics is a very bad and potentially dangerous system. For example, someone can say that a car stops, but there is a big difference between stopping within 250 feet and stopping within 1000 feet from a speed of 60 miles per hour. This is what may happen when there is a primary brake hydraulic failure. Only the rear brakes work. In the first scenario people are shaken up but okay. In the second scenario people are going to the hospital and someone may die or lose their health.
All systems must have their performance clearly stated using numbers, even televisions and stereos. Otherwise there is no way to compare different solutions and take appropriate actions. In all systems the performance must be clearly understood. The understanding eventually leads to some key relationships. These are some key relationships to understand the COVID-19 disaster and its system space.
This is why mask wearing is so critical especially in the unsafe indoor spaces. This analysis shows that the indoor spaces can be made safe but it will cost lots of money and no one wants to pay for it at this time. The government knew all this day one, never forget that as long as you live, make sure your children and their children never forget this.
This is the analysis summary details. Remember this is just the summary. The detailed analysis is provided in other sections of this report.
Virus Diffusion by Distance and Windspeed
From the empirical data from around the world as of July 2020 we know that it is safer to be outside than indoors. From the analysis we have numbers to show that this is a valid observation. The analysis also shows that there are unsafe outdoor scenarios and they include being up against a wall even if there is a 1 mile per hour wind and being outside when there is no wind such as inside a tent or a swimming pool setting surrounded by people. The wind must blow or you must leave the setting. Also the wind must blow freely and not stop where you are standing or sitting. (Diffusion of particles as a function of distance and windspeed) [spreadsheet Diffusion]
Source Virus/min |
Wind Miles/Hr |
Distance Feet |
Time to Reach |
Risk |
Location |
Scenarios |
1200 |
1 |
6 |
3168 |
Low |
Outside, Beach, Park |
Free space air movement |
1200 |
1 |
16 |
22528 |
Low |
Outside, Beach, Park |
Free space air movement |
1200 |
1 |
6 |
106 |
High |
Outside wall |
Up against wall |
1200 |
0.01136 |
6 |
36 |
Unacceptable |
Outside No Wind, Tent |
Free space no air movement |
1200 |
0.01136 |
16 |
256 |
High |
Outside No Wind, Tent |
Free space no air movement |
From the empirical data from around the world as of July 2020 we know that it is unsafe being indoors under many conditions. From the analysis we have numbers to show that this is a valid observation. The analysis shows that it is critical that the spaces are ventilated to dilute the virus and then the air is exhausted so that the virus is removed from the space, both as soon as possible. Small spaces are more unsafe than large spaces.
Virus Density by Volume and Air Mixing
The following table shows that the time before the virus load is reached in a ventilated space to dilute the virus is high except for the sneeze event.
In this analysis there is a mechanism that is able to distribute the virus evenly throughout the room before anyone next to the infected person can get a whiff of the virus load. For example, fans are used to distribute the virus fully every minute. The next step is to determine how long it will take for the entire room to reach the virus load. So an infected person breathing 20 viruses per breath, taking 1 breath per second will produce 1200 virus particles around their head (about 1 cu-ft) in one minute. If the room is 10,800 cu-ft, it will take 9,000 minutes for the entire room space to be filled with 1000 virus particles for each cu-ft in the room. If the room is able to constantly distribute the virus and then change the room air with clean air then infection will be prevented. In the case of breathing and a cough the analysis suggests that even a very small AUC will have very low risk of infection. In the case of a sneeze the air must be fully exchanged with an AUC of 14.81. The challenge with this model is to ensure that the air in the room is constantly moving and random so that the virus is evenly diluted before being expelled from the room. Although this analysis is deterministic and based on simple math the real world scenario and results will be less optimistic. An alternative analysis based on the Well-Riley equation is more representative of what is observed in real world settings.
This metal model of an infection cloud building up around an infected person is important and should be considered in all analysis checks. In 1 minute the cloud is relatively small. A male exhales 6 liters per breath or about .21 cu-ft per breath. In 5 seconds that is about 1 cu-ft. In 50 seconds that is about 10 cu-ft. Some of the virus particles will fall to the ground and some will stay in the air. As time moves on the virus cloud grows first placing individuals near the infected person at risk and then eventually those farther away from the infected person are at risk as time moves on. This is common sense and intuitive. [spreadsheet Diffusion]
Source |
L |
W |
H |
Cubic-Ft |
Virus/Cubic-ft |
Virus Fully Diluted |
Time to Reach |
Risk |
Location |
Scenarios |
1,200 |
30 |
30 |
12 |
10,800 |
0.11 |
Yes |
9,000 |
Virtually none * |
Classroom, restaurant, office, small shop |
Breathing |
720 |
30 |
30 |
12 |
10,800 |
0.07 |
Yes |
15,000 |
Virtually none * |
Classroom, restaurant, office, small shop |
Cough 6/hr 80% Droplet Infection |
2,666,667 * |
30 |
30 |
12 |
10,800 |
246.91 |
Yes |
4 |
Low only with |
Classroom, restaurant, office, small shop |
Sneeze 1/hr 80% Droplet Infection |
. |
|
|
|
|
|
|
|
|
|
|
1,200 |
100 |
100 |
40 |
400,000 |
0.00 |
Yes |
333,333 |
Virtually none |
Grocery store, big box store, garage, warehouse |
Breathing |
720 |
100 |
100 |
40 |
400,000 |
0.00 |
Yes |
555,556 |
Virtually none |
Grocery store, big box store, garage, warehouse |
Cough 6/hr 80% Droplet Infection |
2,666,667 |
100 |
100 |
40 |
400,000 |
6.67 |
Yes |
150 |
Virtually none |
Grocery store, big box store, garage, warehouse |
Sneeze 1/hr 80% Droplet Infection |
* Note that the Wells-Riley equation suggests that the risks are very high. This analysis is provided further in the document.
The following table shows that the time before the virus load is reached in an unventilated space is very low. It is less than a minute in some cases. This does assume the infected person is near you not practicing social distancing. (Density as a function of volume and air mixing) [spreadsheet Diffusion]
Source |
L |
W |
H |
Cubic-Ft |
Virus/Cubic-ft |
Virus Fully Diluted |
Time to Reach |
Risk |
Location |
Scenarios |
1,200 |
30 |
30 |
12 |
10,800 |
1,200 |
No |
0.83 |
Unacceptable |
Classroom, restaurant, office, small shop |
Breathing |
720 |
30 |
30 |
12 |
10,800 |
720 |
No |
1.39 |
Unacceptable |
Classroom, restaurant, office, small shop |
Cough 6/hr 80% Droplet Infection |
2,666,667 |
30 |
30 |
12 |
10,800 |
2,666,667 |
No |
0.00 |
Unacceptable |
Classroom, restaurant, office, small shop |
Sneeze 1/hr 80% Droplet Infection |
. |
|
|
|
|
|
|
|
|
|
|
1,200 |
100 |
100 |
40 |
400,000 |
1,200 |
No |
0.83 |
Unacceptable |
Grocery store, big box store, garage, warehouse |
Breathing |
720 |
100 |
100 |
40 |
400,000 |
720 |
No |
1.39 |
Unacceptable |
Grocery store, big box store, garage, warehouse |
Cough 6/hr 80% Droplet Infection |
2,666,667 |
100 |
100 |
40 |
400,000 |
2,666,667 |
No |
0.00 |
Unacceptable |
Grocery store, big box store, garage, warehouse |
Sneeze 1/hr 80% Droplet Infection |
Virus Density by Distance and Mask Filtering Levels
From the empirical data from around the world as of July 2020 we know that wearing a mask will reduce the risk of infection. From the analysis we have numbers to show that this is a valid observation. The problem is that when we enter a small enclosed space that is not ventilated and exhausted the risk of reaching the virus load with a mask is still unacceptable in many settings even when everyone is wearing a consumer grade mask. [spreadsheet Diffusion]
Source |
Indoor |
Time to Reach |
Work / School Risk |
Shopping Risk |
Scenarios |
1200 |
6 |
120 |
Unacceptable |
Unacceptable |
Indoor, 1 Mask filter effectiveness 75% consumer grade |
1200 |
6 |
480 |
Unacceptable |
Med |
Indoor, 2 Masks filter effectiveness 75% consumer grade |
1200 |
6 |
300 |
Unacceptable |
High |
Indoor, 1 Mask filter effectiveness 90% consumer grade |
1200 |
6 |
3000 |
Low |
Low |
Indoor, 2 Masks filter effectiveness 90% consumer grade |
1200 |
6 |
3000 |
Low |
Low |
Indoor, 1 Mask filter effectiveness 99% |
1200 |
6 |
30000 |
Virtually None |
Virtually None |
Indoor, 2 Masks filter effectiveness 99% |
This analysis assumes there is no mask failure. Mask failure includes the leaks around the face where the mask does not make full contact and also when the mask is removed periodically as needed to deal with different life scenarios and unexpected events. There is a big difference between a medical practitioner that may have breaks where the mask is removed and a person or child wearing a mask for 8 straight hours.
Unfortunately, until the virus is gone we will need to change our physical building ventilation systems and we will need to change how we behave in situations where the ventilation is poor or nonexistent.
Wells Riley Probability of Infection
The following analysis is very sobering and difficult to present. Hopefully this analysis will never come to pass. It is offered to show the risks associated with different size indoor spaces, the time spent in the spaces, and the role of masks. It is based on the Wells-Riley equation that was previously discussed in the other analysis areas. (Wells-Riley Probability of Infection) [spreadsheet Probability]
In the school scenario when the children are infected they bring it home. Basically when they go to school everyone goes to school. The same applies for any of the other scenarios.
The outside beach park scenarios show relatively low probability of infection. This assumes only 1 infection source. As the number of infected people increase over time the number in these settings will increase [1]. One approach is to assume social distance practices and then assume a certain percentage of the population is infected. The square footage of the social distance divided into the scenario square footage will provide the number of people in the environment. The percentage of infected population will then provide the number of Infectors. The impact is approximately linear. See section Wells-Riley Equation.
This analysis is also much less optimistic about a small enclosed room such as a classroom with natural ventilation. This is why testing must be performed in the National Labs using the best science and engineering a nation state like the US can provide. See section Proposed Legislation.
time |
Masks |
P |
Chance of |
Space |
AUC |
Population |
Infected |
Deaths |
Ventilation |
Scenario |
1 |
Yes |
0.0449626 |
4% |
10,800 |
4.00 |
328,000,000 |
14,747,747 |
516,171 |
Expected |
Small indoor space |
1 |
No |
0.7194023 |
72% |
10,800 |
4.00 |
328,000,000 |
235,963,957 |
8,258,738 |
Expected |
Small indoor space |
8 |
Yes |
0.0624976 |
6% |
10,800 |
4.00 |
328,000,000 |
20,499,212 |
717,472 |
Expected |
Small indoor space |
1 |
Yes |
0.0021082 |
~ 0% |
400,000 |
4.00 |
328,000,000 |
691,475 |
24,202 |
Expected |
Large indoor space |
8 |
Yes |
0.0150030 |
2% |
400,000 |
4.00 |
328,000,000 |
4,920,984 |
172,234 |
Expected |
Large indoor space |
1 |
Yes but |
0.9938008 |
99% |
10,800 |
1.00 |
328,000,000 |
325,966,659 |
11,408,833 |
Poor |
Small indoor space |
1 |
Yes but |
0.7194023 |
72% |
10,800 |
4.00 |
328,000,000 |
235,963,957 |
8,258,738 |
Expected |
Small indoor space |
1 |
Yes but |
0.1193397 |
12% |
10,800 |
40.00 |
328,000,000 |
39,143,428 |
1,370,020 |
Massive Natural |
Small indoor space |
1 |
No |
0.0056322 |
1% |
10,800 |
3600 |
328,000,000 |
1,915,155 |
67,030 |
wind 1 mile / hr |
Outside small enclosed back yard |
1 |
No |
0.0011290 |
0.11% |
10,800 |
18000 |
328,000,000 |
370,309 |
12,961 |
wind 5 mile / hr |
Outside small enclosed back yard |
1 |
No |
0.0001525 |
0.02% |
400,000 |
3600 |
328,000,000 |
50,016 |
1,751 |
wind 1 mile / hr |
Outside beach park |
1 |
No |
0.0000305 |
0.00% |
400,000 |
18000 |
328,000,000 |
10,004 |
350 |
wind 5 mile / hr |
Outside beach park |
1 |
No |
0.0000152 |
0.00% |
4,000,000 |
3600 |
328,000,000 |
5,002 |
175 |
wind 1 mile / hr |
Outside large beach park |
1 |
No |
0.0000030 |
0.00% |
4,000,000 |
18000 |
328,000,000 |
1,000 |
35 |
wind 5 mile / hr |
Outside large beach park |
Public Transportation
As the research has started to suggest that the virus may have an airborne element and this research has shown the effects of virus infection based on different ventilation scenarios the popular media has started to report on the ventilation story. The Southeastern Pennsylvania Transportation Authority (SEPTA) has released information on ventilation rates of their public transportation systems. It has also been stated that most of these ground based transportation systems have similar ventilation characteristics and that they do not appear to be a source of virus infection as of August 2020. [2]
There are no standards from the Federal Transit Administration that regulate ventilation. New air refreshes cars on both the Broad Street Line and Market-Frankford Line every 2 to 3 minutes and there are similar rates across the system: on Buses, Regional Rail and Trolley Cars. SEPTA’s rate is probably common across many ground transportation system because many transit authorities use similar vehicles. [2]
Vents at the top of all SEPTA’s subway cars are constantly pushing air in and out with the natural movement of the vehicle. The train’s airflow is always in flux, leading to a full exchange of air every 2 to 3 minutes. On buses, there’s a hatch at the top of the vehicle that can be opened in good weather to increase airflow. More air circulates when the doors open and close. The following are the ventilation rates for the SEPTA systems [2]:
New York’s subway cars ventilate roughly 18 times per hour (equivalent to once every 3.3 minutes). [3]. This is similar to SEPTA’s ventilation rate.
A contact tracing effort in Paris found that none of the city’s 150 coronavirus clusters from early May to early June spread on public transit. As of July 15, four transport clusters had been identified in Paris, accounting for roughly 1% of 386 total clusters. Japan, a country known for crowded commuter trains failed to connect a single cluster to the country’s commuter trains. [5] In Japan, subway windows are left open to enhance airflow.
Fully ventilating all the air in an indoor space every 2 to 3 minutes far exceeds the recommendations for physical spaces like restaurants. Under most current codes, a restaurant replaces all of its air with outside air about once every hour. [6]
Unlike in a restaurant where people spend a long time eating and enjoying the time out in a social setting, people usually spend little time on commuter public transit. The trip may last from 5 to 15 minutes within a city. Commuting from outside the city may be a 45 minute trip. A restaurant session typically lasts from 1 to 3 hours.
These scenarios and ventilation rates have been plugged into the Well-Riley equation and the results are as follows. [spreadsheet Public Transit]
| Scenario | Masks | Chance of Infection | AUC | Ventilation |
| Trolley, Bus, Train | Yes |
< 1% to 1% |
20-30 | Transit |
| Trolley, Bus, Train | No |
10% to 20% |
20-30 | Transit |
| Trolley, Bus, Train | Yes |
6% |
1 * |
Poor like in a restaurant |
| Trolley, Bus, Train | No |
97% to 99% |
1 * |
Poor like in a restaurant |
| Japan Commuter Train open windows | Yes |
0% |
3600 | outside 1 mile / hr wind |
| Japan Commuter Train open windows | No |
0.07% ** |
3600 | outside 1 mile / hr wind |
* These extremely low AUC rates are not in ground transportation systems.
This is shown here to demonstrate the importance of proper ventilation.
** This assumes there are no dead air conditions such as up against a wall
or someone is not downwind from a close infection source - wear a mask until
the virus is gone. See section
Virus Diffusion Classroom Design
& Other Takeaways nuclear engineering model.
The analysis appears to match the findings from France. The analysis also shows the importance of ventilation and wearing a mask. When there is poor ventilation it is clear that a mask will significantly reduce the risk of infection. This analysis and empirical data of the transportation systems also shows that ventilation systems must be upgraded in small spaces to reduce the risk of infection.
References:
[1] 24 LBI lifeguards positive for coronavirus after attending social gatherings together, NJ.com, July 25, 2020. webpage https://www.nj.com/coronavirus/2020/07/20-lbi-lifeguards-test-positive-for-coronavirus-after-attending-parties-together.html, July 2020. LBI lifeguards positive for coronavirus after attending social gatherings together
[2] SEPTA trains and buses have great airflow - which means less coronavirus risk for riders, WHYY PBS Philadelphia whyy.org, August 7, 2020, webpage https://whyy.org/articles/septa-trains-and-buses-have-great-airflow-which-means-less-coronavirus-risk-for-riders, August 2020. SEPTA trains and buses have great airflow - which means less coronavirus risk for riders
[3] Is the Subway Risky? It May Be Safer Than You Think, New York Times, August 2, 2020. Webpage https://www.nytimes.com/2020/08/02/nyregion/nyc-subway-coronavirus-safety.html, August 2020. Is the Subway Risky? It May Be Safer Than You Think
[4] Japan has long accepted COVID's airborne spread, and scientists say ventilation is key, CBS News, July 13, 2020. webpage https://www.cbsnews.com/news/coronavirus-japan-has-long-accepted-covids-airborne-spread-and-scientists-say-ventilation-is-key, August 2020. Japan has long accepted COVID's airborne spread, and scientists say ventilation is key
[5] There Is Little Evidence That Mass Transit Poses a Risk of Coronavirus Outbreaks, Scientific American, July 28, 2020. webpage https://www.scientificamerican.com/article/there-is-little-evidence-that-mass-transit-poses-a-risk-of-coronavirus-outbreaks August 2020. There Is Little Evidence That Mass Transit Poses a Risk of Coronavirus Outbreaks
[6] As restaurants reopen, here’s what you should know about air conditioning, air flow and the coronavirus, Washington Post, May 28, 2020, webpage https://www.washingtonpost.com/news/voraciously/wp/2020/05/28/as-restaurants-reopen-heres-what-you-should-know-about-air-conditioning-air-flow-and-the-coronavirus, August 2020. As restaurants reopen, here’s what you should know about air conditioning, air flow and the coronavirus
Virus Exposure Risk (Ver)
It is very difficult personally dealing with all these numbers. The stakeholders want to know what to do. To help guide this decision a Virus Exposure Risk (Ver) scale is provided that compares the exposure risk against one or more baselines that are considered safe. The comparison results in a scale that is based on how many times more or less risky one living scenario is compared to another living scenario. This is a multiplication factor. For example scenario 1 is 10 times more risk than scenario 2 where scenario 2 is considered the most safe scenario. The Ver can be calculated for each of the analysis approaches that were used to determine the risk of virus infection. The following analysis was used to determine the Virus Exposure Risk (Ver) scales.
If the number is negative it means that the scenario is worse than the baseline scenario. So -60 means it is 60 times worse. This can be used to apply to a time factor. For example if it takes 1 hour to reach the virus load in the baseline, then it will take 1 minute to reach that same virus load in the scenario with a rating of -60 Ver. Conversely if it takes 1 hour to reach the virus load in the baseline, then it will take 60 hours to reach the virus load in the scenario with a rating of 60 Ver.
The following analysis shows the Ver using Virus Density by Distance (Electrical Engineering). The results show that you must keep your distance.
Scenario |
Distance |
Virus |
Comment |
|
1 |
0.5 |
-144 |
Times Worse than 6 feet |
  |
2 |
1 |
-36 |
Times Worse than 6 feet |
|
3 |
6 |
1 |
Baseline Standard Guidance |
|
4 |
16 |
7 |
Times Better than 6 feet |
|
5 |
26 |
19 |
Times Better than 6 feet |
|
6 |
36 |
36 |
Times Better than 6 feet |
|
7 |
46 |
59 |
Times Better than 6 feet |
|
8 |
56 |
87 |
Times Better than 6 feet |
|
9 |
66 |
121 |
Times Better than 6 feet |
|
10 |
76 |
160 |
Times Better than 6 feet |
|
The following analysis shows the Ver using Virus Diffusion by Distance and Windspeed (Nuclear Engineering). The results show that you must keep your distance. It becomes more critical to keep your distance as the wind speed drops. This will happen in the middle of a crowd or up against a wall.
Scenario |
Distance |
Ver |
Ver |
Ver |
Worse (-) or Better than baseline |
1 |
0.5 |
-144 |
-288 |
-576 |
|
2 |
1 |
-36 |
-72 |
-144 |
|
3 |
6 |
1 |
1 mile per hour |
1 mile per hour |
|
4 |
16 |
7 |
4 |
2 |
|
5 |
26 |
19 |
9 |
5 |
|
6 |
36 |
36 |
no need |
no need |
|
7 |
46 |
59 |
no need |
no need |
|
8 |
56 |
87 |
no need |
no need |
|
9 |
66 |
121 |
no need |
no need |
|
10 |
76 |
160 |
no need |
no need |
|
The following analysis shows the Ver using Virus Probability of Infection (Wells-Riley). There are 2 different baselines that are used to make the comparison. Both baselines are a large indoor space but Baseline 1 does not use a mask and Baseline 2 uses a masks where both the infected and uninfected individuals are wearing mask. The results are more difficult to see but they show that small indoor spaces like classrooms and restaurants have a very high Ver. Also it shows that a mask should be worn in large indoors spaces. Finally we see that outdoor spaces have the best Ver and allow for normal life to proceed as long as the outdoor space is not converted to an indoor type of space because of large crowds and blocked areas such as up against a wall.
No |
Scenario |
time |
Masks |
Chance of |
Space |
AUC |
Ver |
Ver |
|
1 |
Small indoor space |
1 |
Yes |
4% |
10,800 |
4.00 |
-1 |
-21 |
|
2 |
Small indoor space |
1 |
No |
72% |
10,800 |
4.00 |
-21 |
-341 |
|
3 |
Small indoor space |
8 |
Yes |
6% |
10,800 |
4.00 |
-2 |
-30 |
|
4 |
Large indoor space |
1 |
Yes |
~ 0% |
400,000 |
4.00 |
16 |
1 |
|
5 |
Large indoor space |
8 |
Yes |
2% |
400,000 |
4.00 |
2 |
-7 |
|
6 |
Large indoor space |
1 |
No |
3% |
400,000 |
4.00 |
1 |
-16 |
|
7 |
Small indoor space |
1 |
Yes but |
99% |
10,800 |
1.00 |
-29 |
-471 |
|
8 |
Small indoor space |
1 |
Yes but |
72% |
10,800 |
4.00 |
-21 |
-341 |
|
9 |
Small indoor space |
1 |
Yes but |
12% |
10,800 |
40.00 |
-4 |
-57 |
|
10 |
Outside small enclosed back yard |
1 |
No |
1% |
10,800 |
3600 |
6 |
-3 |
|
11 |
Outside small enclosed back yard |
1 |
No |
0.11% |
10,800 |
18000 |
30 |
-1 |
|
12 |
Outside beach park |
1 |
No |
0.02% |
400,000 |
3600 |
221 |
14 |
|
13 |
Outside beach park |
1 |
No |
0.00% |
400,000 |
18000 |
1106 |
69 |
|
14 |
Outside large beach park |
1 |
No |
0.00% |
4,000,000 |
3600 |
2212 |
138 |
|
15 |
Outside large beach park |
1 |
No |
0.00% |
4,000,000 |
18000 |
11059 |
691 |
|
The scenario associated with Retail Work shows a -7. That is because it is compared against the ideal case where a stakeholder spends only 1 hour in a large retail store while the worker is in that environment 8 hours during a 1 day snapshot. The issue is to ensure that the large retail space is safe for the retail staff. This can only happen with a larger AUC (more than 4). Using a higher quality mask such as one that moves from the analysis baseline of 75% (4X reduction) to 90% (10X reduction) is also important.
Although the Ver can be a useful guide for stakeholders to compare different living scenarios, ultimately the probability of infection must be known and understood for each living scenario. That means looking at the detailed numbers and getting a feel for the level of safety in each scenario.
Modeling Equations
The following is a disclosure of the modeling equations used and considered in this analysis.
Equation |
Used In This Analysis |
Source |
| C1*V1 = C2*V2
C1 = infection event (breathing, cough, sneeze)
V1 = TL = Total lung capacity (cu ft) = assumption |
Yes |
Sneeze Analysis Model. Based on Boyle's Law: P1V1 = P2V2. |
| AUC = Idh / IL = Isb * Bs *3600 / IL
Isb = Infected Single Breath (virus load) = assumption AUC = Idh/IL = Ed * Ip * Epe * Eph / IL
Ed = Event - Cough (droplets) = assumption |
Yes |
Virus Load Air Exchanges Needed Model. Engineering based. |
| AUC = Eth * N
Epe = Event - Sneeze / Event = assumption This led to an analysis based on probability of exposure. |
Yes |
Event Based Air Exchanges Needed Model. Engineering based. |
| t2 - t1 = - [ln (C2 / C1) / (Q / V)] X 60, with t1 = 0
t1 = initial timepoint in minutes |
Yes |
CDC Airborne Contaminant Removal Model. [1] [2] |
| TBIL = IL/(Bs * (3600/AUC) * VL)
TBIL = IL/Vi1
AUC = AUC/Hour = Assumptions |
Yes |
Full Picture Static Model. Engineering based. |
Infection Prediction = Virus Load * Time
|
Yes |
Virus Transmission Mental Model. |
| Pd=Ps/d^2
Pd = Power density at the target surface
Virus Load Destination = Pd |
Yes |
Virus Density by Distance (Electrical Engineering). |
| Ca= B*Qi / (u*x^2)
Ca = concentration at the point of interest (Bq/m3)
Virus Load Destination = Ca |
Yes |
Virus Diffusion by Distance and Windspeed (Nuclear Engineering). [3] |
| (1) V(dCz/dt) = PQinfCoa(t) + QsCs(t) + G(t) - (Qr + Qix + MacQac)Cz(t)
- Sum [(i=1 to Ns) VdiAsiCz(t)]
(2) Asi(dLsi/dt) = VdiAsiCz(t)
C = particle concentration in air [kg/m3], subscripts: zone, outdoor air,
and supply |
No |
National Institute Of Standards (NIST) - A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA). [4] |
| P = D/S = 1 - exp ( - (Ipqt/Q) )
P = probability of infection for susceptibles Infection Load * Virus / Breath * Breaths / Sec * Sec to Infection = q / sec |
Yes |
Wells-Riley Probability of Infection. World Health Organization Natural Ventilation. [5] |
| P = D/S = 1 - exp ( - (Ipqt/Q) )
P = probability of infection for susceptibles
Q = Space Cubic Feet * AUC Infection Load * Virus / Breath * Breaths / Sec * Sec to Infection = q / sec |
Yes |
Wells-Riley Probability of infection. World Health Organization Natural Ventilation. Expanded to include various scenarios and AUC. [5] |
| . |
|
|
| C1 = [N/(V*Ve) * [1-exp(-V*Ve*t/v)]
C1 or C = Bioeffluent infectious aerosol concentration in the space at time
t, virus/L
D = IC integration => D = IC * time exposed
D = Virus inhaled or virus dose
Infected when D > 1000 |
Yes |
HVAC industry. [6] [7] |
| . | ||
| . | ||
| AUC = Air Updates / Hour - Air Update Change ACH = Air Changes / Hour - Air Change Rates Changes = Updates Note: fresh air exchange is identified separately such as Air Exchange Rates Min/Chg - Minutes / Change l/s = Liters / Second cfm = Cubic Feet / Minute |
Yes |
Used in the various calculations. |
References:
[Library/Building-Ventilation]
[1] Appendix B. Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003). webpage https://www.cdc.gov/infectioncontrol/guidelines/environmental/appendix/air.html, May 2020. Appendix B. Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003)
[2] Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003) Updated July 2019. webpage https://www.cdc.gov/infectioncontrol/pdf/guidelines/environmental-guidelines-P.pdf, May 2020. Air Guidelines for Environmental Infection Control in Health-Care Facilities (2003) . Library
[3] Generic Models For Use In Assessing The Impact Of Discharges Of Radioactive Substances To The Environment, Safety Reports Series No.19, International Atomic Energy Agency (IAEA), Vienna, 2001. Printed by the IAEA in Austria September 2001, STI/PUB/1103. webpage https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1103_scr.pdf, July 2020. Generic Models For Use In Assessing The Impact Of Discharges Of Radioactive Substances To The Environment . local
[4] A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA), NIST Technical Note 2095, U.S. Department of Commerce, June 2020. webpage https://doi.org/10.6028/NIST.TN.2095 A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA) . local
[5] WHO Publication/Guidelines Natural Ventilation for Infection Control in Health-Care Settings, World Health Organization (WHO), 2009. webpage https://www.ncbi.nlm.nih.gov/books/NBK143284/pdf/Bookshelf_NBK143284.pdf, May 2020. Natural Ventilation for Infection Control in Health-Care Settings, WHO, 2009 . local
[6] Germs and Flying: Developing Ventilation System Criteria, SAE International, October 18, 2011. webpage http://indoorair.ca/veft/pdf/SAE_paper_Germs_and_Flying_2011-01-2690.pdf, October 2020. Germs and Flying: Developing Ventilation System Criteria
[7] COVID-19 and Beyond A Brief Introduction To Passenger Aircraft Cabin Air Quality, ASHRAE Journal, October 2020. webpage https://www.ashrae.org/file%20library/technical%20resources/covid-19/12-19_walkinshaw.pdf, October 2020. COVID-19 and BeyondA Brief Introduction To Passenger Aircraft Cabin Air Quality
This analysis identifies the number of potential infected people and deaths as a result of holiday travel in 2020 using airplanes. There are three key numbers that drive the analysis: Number of Travelers, Percent of Population Infected, R0 basic reproduction number, the average number of new infections caused by each case.
The R0 number is based on examining various studies and performing a cross check using a passenger movement study [1] [2].
This figure shows the seating of the passengers for the SARS outbreak that occurred on a flight from Hong Kong to Beijing on March 15, 2003:
[spreadsheet Travel, Airplane R0]
Observation: There is a large cluster of people sitting near the infected person that were not interviewed.
Categories |
Count |
IP - Infected |
1 |
S - Probable SARS Case |
18 |
e - Empty Seat |
17 |
ni - No Illness Person Not Interviewed |
46 |
pi - No Illness Person Interviewed |
47 |
c - Crew |
7 |
Sc - Sick Crew |
2 |
CI - Chinese officials unknown seats |
2 |
Total New SARS Cases = R0 |
22 |
The total new SARS cases experienced on this airplane flight is the R0 for this setting.
This figure shows the seating of the passengers for the COVID-19 outbreak that occurred on a flight from London to Hanoi on March 2, 2020:
[spreadsheet Travel, Airplane R0]
Observation: The infection cluster suggests that the business class cabin area had poor ventilation.
Categories |
Count |
IP - Infected |
1 |
S - Probable SARS Case |
14 |
e - Empty Seat |
80 |
ni - No Illness Person Not Interviewed |
30 |
pi - No Illness Person Interviewed |
158 |
c - Crew |
4 |
Sc - Sick Crew |
1 |
. |
. |
Total New COVID-19 Cases = R0 |
15 |
The total new COVID-19 cases experienced on this airplane flight is the R0 for this setting.
This is the probability of being in contact with the infected person based on passenger movement in an airplane with an infected person sitting in the middle of the cabin area [2]:
[spreadsheet Travel, Airplane R0]
This information was used to determine a possible R0. From the figure we see an R0=11 as represented by the seats marked with 100. The question then becomes what are the additional factors that might contribute to the R0. The approach was to multiply the contact probability by the number of seats at that level and then apply a 10% probability of infection to that factor.
R0a = R0 addition factor = contact probability * number of seats at that level * 10% probability of infection (based on ~ wells-riley with some time mask off)
e.g. 80% * 4 = 3.2 * 10% = 0.32
R0 final = R0 + sum (R0a) results in an R0 of 18.
This is the probability of being infected in airplane with an infected person sitting in the middle of the cabin area [2]:
[spreadsheet Travel, Airplane R0]
This information was used to determine another possible R0. From the figure we see an R0=11 as represented by the seats marked with 100. The question then becomes what are the additional factors that might contribute to the R0. The approach was to multiply the probability by the number of seats at that level. That results in an R0 of 13.4.
R0a = R0 addition factor = infection probability * number of seats at that level
e.g. 3% * 8 = 0.24
R0 final = R0 + sum (R0a) results in an R0 of 13.4.
These R0 numbers are significant because they most likely represent the true R0 number for the virus before social distancing and masking practices were adopted within the society.
The analysis results are:
[spreadsheet Travel, Airplane R0]
Events |
Travelers |
Newly Infected Population |
% Infected Pop |
R0 Travel |
Infections |
Deaths |
Comment |
| Thanksgiving 2020 | 9,400,000 [5] |
4,000,000 [D] |
1.22% |
18 |
2,063,415 |
61,902 |
More than 9.4 million people screened in Thanksgiving travel window, which began on Friday before holiday [5]. |
| Christmas 2020 | 14,379,042 [6] |
5,000,000 [D] |
1.52% |
18 |
3,945,469 |
118,364 |
TSA screened 7,189,521 people to Christmas Eve. People who left for the holiday will come home [6]. |
Multiple areas of this analysis have suggested that the initial transmission of the virus was via airplanes and airports. This was all clearly published March 6, 2020 [3]. The behavior of SARS on an airplane was studied in 2003 and 2018 [1] [2] with simple results that should have translated into policy when COVID-19 broke out in 2020 with an emphasis on maintaining that policy through the holiday travel rush. The policy was simple:
We see that during the 2020 Thanksgiving and Christmas holidays the infection rate spiked with each event. It was clear that numbers did not need to be provided because all the other analysis provided overwhelming evidence that airplane and airport crowd control modifications were needed [A] [B]. They did not happen. The policy makers gravely failed once again [C] [F] [G].
References:
[1] Transmission of the Severe Acute Respiratory Syndrome on Aircraft, New England Journal of Medicine, N Engl J Med 2003; 349:2416-2422, December 18, 2003. webpage https://www.nejm.org/doi/full/10.1056/nejmoa031349, December 2020. PDF . Transmission of the Severe Acute Respiratory Syndrome on Aircraft
[2] Behaviors, movements, and transmission of droplet-mediated respiratory diseases during transcontinental airline flights, Emory University, April 3, 2018. webpage https://open.library.emory.edu/publications/emory%3As93rr, https://open.library.emory.edu/publications/emory:s93rr/pdf, December 2020. PDF . local . local
[3] Here’s how coronavirus spreads on a plane-and the safest place to sit, National Geographic, March 6, 2020. webpage https://www.nationalgeographic.com/science/2020/01/how-coronavirus-spreads-on-a-plane, December 2020. Here’s how coronavirus spreads on a plane-and the safest place to sit
[4] Transmission of SARS-CoV 2 During Long-Haul Flight, Centers for Disease Control and Prevention, Emerging Infectious Diseases, CDC, October 17, 2020, September 08, 2020, November 2020. webpage https://wwwnc.cdc.gov/eid/article/26/11/20-3299_article, https://wwwnc.cdc.gov/eid/article/26/11/pdfs/20-3299.pdf, December 2020. PDF . local
[5] Sunday was the busiest day for US air travel since the pandemic began, CNN, November 30, 2020. webpage https://www.cnn.com/travel/article/thanksgiving-travel-volume-2020-pandemic/index.html, December 2020. Sunday was the busiest day for US air travel since the pandemic began
[6] Nearly a million people flew in America on Christmas Eve, December 25, 2020. webpage https://www.cnn.com/2020/12/25/business/tsa-air-travel/index.html, December 2020. Nearly a million people flew in America on Christmas Eve
[A] See section Current US Infrastructure Virus Concentration.
[B] See section Virus Diffusion.
[C] See section System Collapse.
[D] See section Death Rates.
[E] See section Droplets Versus Aerosols.
[F] See section Return To Life Systems Performance.
[G] See section Second Wave Accountability.
Certification
Certification applies to systems that must be safe and secure under all conditions including in the presence of multiple failures. This is typically accomplished with inherent system safety and security and with significant levels of fault detection, fault tolerance, and fail-safe mechanisms. Trying to certify a system without fault detection, fault tolerance, and failsafe mechanisms is usually a sign of a severely compromised organization. It is rare when a system can be certified with just inherent safety and or security in the architecture and the resulting implementation.
Certification is given by a third-party entity such as a government agency.
Certification includes analysis of the process and the solution. It can involve proof like elements. The developers need to show that there was a consistent process that was followed to design and implement the system. Deviation from the process raises concern because it may represent compromises in system. The solution needs to be documented and show strong traceability, especially to the tests. Without the traceability there is concern because once again it may represent compromises in the system.
During certification all information products (plans, analysis, specifications, design artifacts, tests, manuals, etc.) are examined and a confidence level is achieved so that the system can be certified.
A separate body of people based on the certification evidence certifies the system. This is the certification board. The certification board consists of representatives from: Engineering, Test, Quality, Production, Users, Maintenance, Support, Logistics, Training, Deployment, Users. Since most systems use machines and significant technology the greatest weight is carried by the Engineers and Testers. The other organizations will typically approve the system because their concerns are easiest to address. Engineering on the other hand looks inside the system and has an enormous responsibility to ensure nothing was missed. Next comes test who provide the test results. The issue with test is similar to engineering to ensure in this case that no tests were missed or incorrectly performed.
The certification process starts with the architecture. If the architecture is flawed the system cannot be certified. It continues with the design, implementation, production, distribution, and use. At any point the certification can be rejected. This suggests that certification begins with the start of the project. Information products are developed and offered to the certification board. The information products in sequence are:
As the system unfolds the information products are updated and provided to the certification board. This ensures that the board is not overwhelmed with data and the board can check the system to see if there may be certification problems moving forward. Most automation-based system developers run at risk and continue with system development and do not wait for the board to provide comments. This is contrary to physical systems like an office building where activity stops or slows significantly until there is an official signal from the certification authority to continue.
Most people equate diagnostics with maintenance and trying to isolate a fault so that it can be repaired. However, diagnostics are also used to certify that a system is ready to be used. Well check or certification diagnostics are used to surface faults in an operational system. The idea is that the diagnostics stimulate all the critical points in the system that normal operations may not immediately stimulate.
The diagnostics can be manual or automated. Most people think in terms of automated diagnostics especially in computer-based systems. However, manual diagnostics are just as important. A manual diagnostic might be a visual inspection using an approved or certified checklist. For example, those who fly small personal airplanes check the airplane using an approved checklist prior to starting the engine and proceeding to taxi. The checklist includes visual inspection of the tires, landing gear, rudder, tail, ailerons, wings, flaps, propeller, fuselage, etc. When the automobile was new it was not uncommon for people to check the belts, tires, fluids, brakes, lights, and filters prior to a long trip.
This is a description of a certification strategy for a generic system or product. With each new activity the artifacts from the previous activities are updated. The issue is that all the artifacts must be current and consistent or certification will be rejected because of a loss of confidence in the process and execution.
| Activity | Formal Systems Practice | Artifact | Comment |
| Description of Certification Process | - Planning | Certification Plan | Provided to the certification authority at the start of the project. |
| Identification of Unsafe Events | - Safety analysis | Unsafe Events List | Provided to the certification authority as soon as the project technical work begins and is refined during the project. |
| Identification of Safety Critical requirements | - Safety requirements analysis - Refined safety analysis |
Safety Critical Requirements Specification | Provided to the certification authority as soon as the project technical work begins and is refined during the project. |
| Fault Tolerant Failsafe Architecture | - Safety architecture development - Traceability to safety requirements - Fault Tree Analysis - Performance Analysis - Refined safety critical requirements |
Fail Safe Architecture Analysis Document | Provided to the certification authority as soon as it is available and is refined during the project. |
| Fault Tolerant Failsafe Design | - Safety design - Matches architecture - Traceability to safety requirements - Updated Fault Tree Analysis - Failure Mode Effects Analysis |
Fail Safe Architecture & Design Analysis Document | Provided to the certification authority as soon as it is available and is refined during the project. |
| Design Implementation | - Safety Implementation - Matches design - Traceability to safety requirements - Updated Fault Tree Analysis - Failure Mode Effects Analysis |
Implementation artifacts like software code and pre-production prototypes | Provided to the certification authority as soon as it is available. |
| Preliminary Safety Critical Testing, Verification, & Validation | - Safety critical testing | Preliminary safety critical test plan, procedures, and report | Provided to the certification authority as soon as it is available. |
| Production | - Proof that production matches design implementation | Production plan and final production system or product | Provided to the certification authority as soon as it is available. |
| Final Safety Critical Testing, Verification, & Validation | - Safety critical testing | Final safety critical test plan, procedures, and report | Provided to the certification authority as soon as it is available. |
| Tamper Proof Distribution | - Safety critical testing | Final safety critical test plan, procedures, and report | Provided to the certification authority as soon as it is available. |
| Tamper Proof Operation & Maintenance | - Safety critical testing | Final safety critical test plan, procedures, and report | Provided to the certification authority as soon as it is available. |
| Certificate Issued | N/A | N/A | System or product can now be provided to the users. |
The technical activity begins with the identification of unsafe events and safety critical requirements.
The unsafe events are used to determine if the system will result in an unsafe condition. This is usually performed using a formal fault tree analysis. Words and logic cannot be used because the informal method does not provide the rigor to surface unintended consequences like a formal method such as fault tree analysis. The fault tree analysis begins with the architecture, is refined with the design, and is finally refined with the implementation. During implementation the formal top down fault tree analysis is augmented with a bottoms up formal Failure Mode Effects Analysis. FMEA is also a formal method that is based on extreme rigor.
The following is a list of possible unsafe events for a vaccine:
The possible safety critical requirements start by examining the list of unsafe events. The possible safety critical requirements for a vaccine based on the identified unsafe events are:
The actual safety analysis should be significantly more complete than this simple example. The safety analysis also needs to be augmented with a security analysis to ensure the vaccine is not compromised by bad actors. There are also additional safety analysis areas that include distribution and delivery.
If we examine this simple example we see the importance of the test plan, procedures, and results. The tests include both animal and human tests. There are also extreme details which will affect the expected effectiveness of the vaccine. For example, humans were not consciously infected with the virus. Even though the effectiveness may be less than anticipated the tests should have determined if there are any bad side effects from the vaccine. The issue in this case is the test population subjected to the vaccine. For example pregnant women were not subjected to the vaccine.
In this type of setting with unknowns typically the system or product is rolled out slowly and closely observed for negative unintended consequences. With the vaccine this slow roll out is a natural artifact with the production and logistics limitations. The implications are that the true final certification will happen when the first group of people are vaccinated. This is typically called system validation for other mission critical systems. For example air traffic control systems and their updates are not validated until they appear at the first site and are subjected to live operations.
This entire process of certification is an evolving process of building confidence using our best uncompromised efforts.
Pfizer / BioNTech disclosed their Phase 1/2/3 study. The study evaluates the Safety, Tolerability, Immunogenicity, and Efficacy of the SARS-CoV-2 RNA vaccine against COVID-19 In healthy individuals. This is a critical information product used to certify the vaccine [1] [2]. The study was performed on healthy individuals. It is unclear what the implications are for unhealthy individuals and that is something the Certification Authority must consider when addressing the entire system not just the vaccine. The system includes vaccine manufacturing, distribution, delivery and follow up. The Pfizer / BioNTech vaccine is only one part of the system. See section Vaccine Systems Perspective.
The purpose of the study is to rapidly describe the safety, tolerability, and immunogenicity of 2 BNT162 RNA-based COVID-19 vaccine candidates against COVID-19, and the efficacy of 1 candidate, in healthy individuals. From the study [1]:
The development of an RNA-based vaccine encoding a viral antigen, which is then expressed by the vaccine recipient as a protein capable of eliciting protective immune responses, provides significant advantages over more traditional vaccine approaches. Unlike live attenuated vaccines, RNA vaccines do not carry the risks associated with infection and may be given to people who cannot be administered live virus (eg, pregnant women and immunocompromised persons). RNA-based vaccines are manufactured via a cell-free in vitro transcription process, which allows an easy and rapid production and the prospect of producing high numbers of vaccination doses within a shorter time period than achieved with PF-07302048 (BNT162 RNA-Based COVID-19 Vaccines) Protocol C4591001 traditional vaccine approaches. This capability is pivotal to enable the most effective response in outbreak scenarios.
The following are some of the key elements described in the study [1]:
Local Reaction Grading Scale [1]:
| Symptom | Mild (Grade 1) |
Moderate (Grade 2) |
Severe (Grade 3) |
Potentially Life Threatening (Grade 4) |
| Pain at the injection site | Does not interfere with activity | Interferes with activity | Prevents daily activity | Emergency room visit or hospitalization for severe pain |
| Redness | >2.0 cm to 5.0 cm (5 to 10 measuring device units) |
>5.0 cm to 10.0 cm (11 to 20 measuring device units) |
>10 cm >= 21 measuring device units) |
Necrosis or exfoliative dermatitis |
| Swelling | >2.0 cm to 5.0 cm (5 to 10 measuring device units) |
>5.0 cm to 10.0 cm (11 to 20 measuring device units) |
>10 cm >= 21 measuring device units) |
Necrosis |
Systemic Event Grading Scale [1]:
| Symptom |
Mild |
Moderate |
Severe |
Potentially Life Threatening |
| Vomiting | 1-2 times in 24 hours | >2 times in 24 hours | Requires IV hydration | Emergency room visit or hospitalization for hypotensive shock |
| Diarrhea | 2 to 3 loose stools in 24 hours | 4 to 5 loose stools in 24 hours | 6 or more loose stools in 24 hours | Emergency room visit or hospitalization for severe diarrhea |
| Headache | Does not interfere with activity | Some interference with activity | Prevents daily routine activity | Emergency room visit or hospitalization for severe headache |
| Fatigue/ tiredness | Does not interfere with activity | Some interference with activity | Prevents daily routine activity | Emergency room visit or hospitalization for severe fatigue |
| Chills | Does not interfere with activity | Some interference with activity | Prevents daily routine activity | Emergency room visit or hospitalization for severe chills |
| New or worsened muscle pain | Does not interfere with activity | Some interference with activity | Prevents daily routine activity | Emergency room visit or hospitalization for severe new or worsened muscle pain |
| New or worsened joint pain | Does not interfere with activity | Some interference with activity | Prevents daily routine activity | Emergency room visit or hospitalization for severe new or worsened joint pain |
Scale of Fever [1]:
| Fever | Action |
| >=38.0-38.4 C (100.4-101.1 F) | |
| >38.4-38.9 C (101.2-102.0 F) | |
| >38.9-40.0 C (102.1-104.0 F) | Telephone contact should occur to gather more details and determine whether a site visit is clinically indicated. |
