Air Date: 9-18-2020|Episode 599
This week we welcome back Brad Prezant to Iaqradio+. Its been 8 years since we had Brad on the show he is now working in Australia. We look forward to getting his perspective on COVID 19 and the new COVID 19 Infection Risk Manager.
Brad Prezant is an evidence-based public health scientist with a background in epidemiology, occupational health & hygiene, and ergonomics. Until the company was sold in 2007, he operated Prezant Associates, Inc. in Seattle, providing consulting, training, and laboratory services for 20+ years. After migrating to New Zealand in 2008, Mr. Prezant spent 3 years at Massey University researching a variety of occupational health issues including solvent exposure to auto body painters, fumigant and VOC exposures from shipping containers, and dust exposures to woodworkers. He previously was Chief Editor of AIHA’s first edition of Recognition, Evaluation, and Control of Indoor Mold, an author of several other standard of care documents, and is the current Vice President for Practice of ISIAQ (International Society of Indoor Air Quality & Climate). Since 2015, he is Chief Scientific Officer at VA Sciences, an occupational health consultancy, IICRC training facility (TESA Directive), and microbiological laboratory (Symbiotic Labs) in Melbourne, Australia. He is involved in a wide variety of indoor air quality and occupational health issues, from indoor moisture and mould to ventilation, traditional IH exposure assessment, and infection transmission indoors.
This week the Z-man is on vacation and the Restoration Global Watchdog worked the show with Radio Joe. Here is a Watchdog recap of today’s show…
Brad Prezant, MSPH, CIH, CPE
What is the COVID 19 Infection Risk Manager?
This week we welcome back Brad Prezant to IAQradio+. It’s been 8 years since we had Brad on the show he is now working in Australia.
Brad Prezant is an evidence-based public health scientist with a background in epidemiology, occupational health & hygiene, and ergonomics.
Until the company was sold in 2007, he operated Prezant Associates, Inc. in Seattle, providing consulting, training, and laboratory services for 20+ years.
After migrating to New Zealand in 2008, Mr. Prezant spent 3 years at Massey University researching a variety of occupational health issues including solvent exposure to auto body painters, fumigant and VOC exposures from shipping containers, and dust exposures to woodworkers.
He previously was Chief Editor of AIHA’s first edition of Recognition, Evaluation, and Control of Indoor Mold, an author of several other standard of care documents, and is the current Vice President for Practice of ISIAQ (International Society of Indoor Air Quality & Climate).
Since 2015, he is Chief Scientific Officer at VA Sciences, an occupational health consultancy, IICRC training facility (TESA Directive), and microbiological laboratory (Symbiotic Labs) in Melbourne, Australia.
He is involved in a wide variety of indoor air quality and occupational health issues, from indoor moisture and mould to ventilation, traditional IH exposure assessment, and infection transmission indoors.
Q: What has Brad been up to since the last time he wason in Jan. 2012
After completing his epidemiology research in New Zealand, he immigrated to Australia and for the past five years has been living and working in Melbourne in the state of Victoria as a consultant.
Q: How is Australia handling COVID?
- Some states are COVID free; Melbourne has been in a strict lockdown.
- Various states around the country have closed their borders to other states to control transmission (in some cases, 0 case states are closed to 0 case states).
- There are various government support programs including JobKeeper and JobSeeker, as well as salary support to small companies and select industries to prevent unemployment.
- The government supports minimum pay for persons forced to isolate due to possible COVID -19 infection.
- There are “back packer” types around the country “looking for work” and as non-citizens get no government support.
Q: Are schools open, bars, restaurants and what about travel restrictions?
- The hospitality industry has been hurt bad.
- No theaters, no arts (except online), etc.
- Victoria is the worst impacted state, particularly Melbourne.
- The states call the shots on border restrictions, accepting overseas returning citizens, etc.
- Certain state borders get closed and opened based on transmission risk and fluctuations of confirmed cases.
- Travel to New Zealand has been erroneously reported through the rumor mill though has been proposed as a self-contained bubble – only permitted travel is permitted currently for critical business reasons andselect compassionate reasons, and only with hotel quarantine.
- There is no tourism except within state when allowed at present.
- Business travel requires rigorous screening/vetting and requires quarantining
Q: How have people responded to masks, distancing etc.?
- There is a Federal Health Minister but the state governors oversee governance policy to control transmission
- Mask wearing has not been “political” like in the USA
- Australia has a parliamentary governance model like the UK
- There is about a 95%+ compliance rate with mask wearing, at least in Melbourne.
- Even is rural areas with zero cases you’ll see people wearing masks
- The Aussies don’t understand all the drama in the USA over this issue!
Risk = Hazard + Outrage
This is fromPeter Sandman’s landmark book on risk communication published by AIHA several decades ago, but still very much relevant. The risk scientists focus on the first term, hazard, and ignore outrage. The public focuses on outrage, and ignores hazard.
They are speaking different languages and one group therefore doesn’t understand the other. We see this playing out with what may indeed turn out to be a very safe effective vaccine, but will raise considerable outrage and therefore will likely not be accepted by a significant percentage of the public, due to previous issues (now disproven, at least from the perspective of the risk scientists) such as risk of autism.
Sandman asks 12 questions relating to perception of risk in his book, including voluntary versus coerced, exotic versus familiar, and several other COVID-relevant issues that should be considered when managing risk communication on this issue and minimizing outrage.
Q: Brad you have been influenced by the Sandman book, can you tell us more about this and one of the components, voluntary versus coerced action?
- The same dynamics that exist reading the perception of risk as detailed by Sandman will play out as we begin to return to re-occupying buildings.
- People will only reoccupy buildings when they are comfortable doing so, not when told to do so by various authorities such as the government, their employer, etc. (versus coerced).
- Given the above, the return to normal needs to be managed with an awareness of the issues Sandman discusses in his risk communication essay. These issues go well beyond the one cited, voluntary versus coerced.
- Risk communication is as important as risk management and risk assessment if the process of re-occupancy is to be successful.
Q: What led to the development of the COVID 19 Infection Risk Manager?
In answering this question Joe allowed Brad to share the Zoom screen and a live demo and explanation of the Risk Management model referred to as a “calculator” ensued for several minutes. This included some Q&A from the chat log with live callers facilitated by Radio Joe.
Q: How do you envision using the calculator with the public as a risk communication tool?
Reply:There are many calculators out there that are designed by scientists for use by scientists, that basically do what our calculator does, that is, use the building characteristics, the occupant activity characteristics, and what is known about SARS-CoV-2 to calculate a risk of infection, based on established models such as the Wells-Riley. This calculator is designed to be used by both scientists and building occupants so it can facilitate occupants conducting their own assessment of the risks involved in a particular room, if they can define the number of persons present and the length of the meeting in hours/minutes. The calculator uses predefined values for the volume of the room and air exchange, values previously entered into the modelby the building definer, and stored by the model for further analysis.
Note: This led to a series of questions during the demo by Radio Joe addressed by Brad as he took the live audience through the COVID calculator demo.
Some of the issues addressed were:
- Any thoughts about adding cubic feet?
- What is meant by Time to re-occupancy?
- What type of cleaning and disinfecting protocol is recommended?
- Is social distancing accounted for in the calculations? Is so, how?
- Why doesn’t the probabilityof infection go up when number of people goes up?
- Do you plan to add anything that accounts for different breathing rates: office vs. gym or speaking vs. listening
- How did you come up with the mask efficiency variables? 30% seems a little high from what I have seen is that for a double layer cloth?
- Does the probability of infection vary based on symptomatic and asymptomatic?
- Any other variables you would like to address?
Key talking points:
- The tool is a good communication tool that can be used with the public to identify the risk of infection in a green/yellow/red risk band approach, which is a function of the “quanta” in the air, a measure of the “infective dose”.
- The COVID calculator is in essence a model for calculating the concentration of quanta in the air and then applying that value to the Wells-Riley infective model to predict infection risk.
- A lot of time was spent demoing and talking about the various assumptions made to use the calculator based on type of building and the activities and inhalation/exhalation of its occupants. All the assumptions can be modified by the user in an “expert” mode, for which access can be granted or withheld from users by the building definer.
- The tool is in metrics (it can be easily converted) so in a tongue and cheek moment Brad said, “I suppose it might need to be converted for use in the USA”!
- In an ideal world the public will defer to public health authorities to establish risk limit guidance, and defining the bounds of the green, yellow, and red color thresholds of infective risk. The model permits these to be adjusted based either on this guidance or company policy.
Links for the calculator that describe its use:
Q: Are you aware of competing apps on the market? If so, how is yours different?
Brad Reply: There are several models out there based on academic research like the Excel-based one byJose Jimenez&Shelly Miller and from the University of Colorado/Boulder.
There is one by NIST (US federal government agency, National Institute of Science & Technology), and several others by university-based researchers around the world. There will be an October seminar organized by Professor Morawska of QUT and sponsored by ISIAQ presenting 12 of these.
Joe Comment: We will include several resource links in the blog!
Q: Is the anything you would like to add?
Reply:In my role as Vice President for Practice of ISIAQ (International Society of Indoor Air Quality & Climate), I’d like to put in a plug for the association’s upcoming events.
This November, Indoor Air 2020 originally scheduled for Seoul South Korea as an in-person conference will be a Virtual Conference:http://indoorair2020.org/
The Healthy Buildings Europe is in Norway in June of 2021: http://hb2021-europe.org/
In late Summer/Fall of 2021 the ISIAQ Healthy Buildings Conference North America is in Hawaii: https://www.isiaq.org/
Note: The Hawaii Conference is being held in conjunction with the Annual Conference of CIRI (Cleaning Industry Research Institute): https://www.ciriscience.org/
Restoration Global Watchdog…Over & Out!
Supplemental Resource for IAQradio+ loyal followers from Radio Joe
and the tool:
Lidia Morawska’s lab with much background on the issue of aerosol transmission:
and their calculator: