Thread by @ARISense_AQ

#AAAR2022 PANEL #2

Gaps in the Aerosol Science Identified During the COVID-19 Pandemic

Q: What is the one thing we still need to know about infectious transmission?

Ans: We talked about this a little bit already.. it would be really really nice to collect a virus and say yes/no on infectious without a lab.

Most of my stuff is PCR analysis. How do you know if it's infectious?

Avoid the culture.

Ans. What size of particles mediate transmission - cause that would tell us about how to approach mitigation. Clues out there.. all sizes seem to be in play - but if we knew the size range for the majority of transmission that would HELP A LOT.

Ans. Sharing some papers from the 30s and 40s - 1961 paper Richard Riley - summarized everything was known and we hardly know any more than that now. And in fact we've forgotten most of it!

Riley was an MD. He really was one of the people that showed that TB was airborne. Problem was that they didn't convince those in the infection control community that all these other viruses were airborne as well!

How do we convince the infection control community to take this shit seriously?

Size dependence of viral load. Key parameter. Time and time again - dose. What dose is required to get you sick?

Q: Changes in aerosol infectivity. What are the key things we know and don't know about that?

Ans: I was involved in a paper looking at virus survival as function of humidity to temp - but I hesitate to apply to the real world - cause it was in culture media. Almost all the papers on virus survival involved the virus in culture media. A certain pattern emerges.

Real-world lung cells growth - completely changes everything. I thought that I knew what was going on, and now I don't..

Ans: I am new to this area. There are some things that we do know. We do know that the phase of the particle plays a role the pH of the particle is important. I think there are some coarse factors that we can use as coarse drivers for better understanding infection.

Need to work harder to translate these things - in those lab studies - we need to bridge the model lab systems to real-world systems. Making measurements on sampled aerosol exhaust from humans. Traditionally - airborne survival has been hyper focused on bio-warfare.

Ans: Coming at it from a medical point of view - this anisotropic infection - Basically get a head-cold requries doses 10^5-10^7 ...

but tiny dose via aerosols can lead to much more severe outcomes..

Need to understand what's going on here as far as airborne transmission.

Q: HVAC prevention of indoor transmission. Unprecedented climate change events.. Sustainable clean indoor air agenda?

Ans. I do think we need to work with architects more. We collaborate with other engineers. Scientists. Very little with architects. They are advancing

building design that makes better use of natural ventilation - and we would gain a lot if you build collaboration with architects.

Ans. Be aware of the problem. The fact that you have a better filter doesn't mean you have to increase the energy consumption. (That's right. CR box is NOT HIGH ENERGY CONSUMPTION PEOPLE)

Ans. G-UV interest is with the idea - you could achieve very high rates of clean air delivery of infectious agents relative to the energy input. But you could do as well with optimizing the filtration methods (cause THESE ALSO REMOVE ALL THE ALLERGENS AND POLLUTION)

Ans. Don't necessarily need to bring in outside air to make indoor air clean. FILTRATION.

Ans. HVAC consumption / Filtration energy consumption. My assumption has been that you can get to 100s of eq. air changes per hour - upfront investments is high. In UK schools they can get more efficiency cleaning for less power with in-room filtration..

Ans. I am a lab scientist. Value lab work. As soon as you start dealing with infectious disease on a population scale - to convince policy makers you need randomized control trials. Really need those large studies to really work out which mitigations have the value. Reid RTC.

Ans. If pH is important... exhaled aerosol is quite basic. Condense-able acids. Remove buffering acidic vapors you could keep the infectious load down in the room.. (interesting)

Q: To what extent to you think research in the aerosol field made a difference over the past few years?

Ans: Obviously, there's been a lot of papers. I would argue that the reviews and commentaries that said it was airborne helped a lot. More of an impact.

Ans: Work that showed that masks worked and did not cause harm. It helped shift the narrative that any mask was better than no mask and some masks were way better than other masks.

Ans: Other papers on masks - Timely stuff - helping to identify that masks reduced shedding - and communicating results to political forces - downloaded 2M times in first few months. Timing is everything. Impact was large.

Ans. Recurring theme. How well do we ACTUAL know the literature. How well do we get the messages across, to convey the most important aspects of all this knowledge.

Ans. VENTILATION is a word that's harder to understand as HANDS, FACE, SPACE.

Q: Recently pandemic was declared over. Also, funding. How do we make sure there's continued funding and engage on this? Gap? THere's a MONEY gap...

Ans; Tough one. It's an important question. I have no answer. How you get people to focus on something when then think that the problem is going away?

Ans. Emergency stage of the pandemic is over - but we're going to be cycling through this for quite some time now.

Ans: So far this semester - we've had more cases of COVID than we had in the entire Fall of 2021 or Spring of 2022. But the campus thinks that it's over. Admin has turned down my offer of CR boxes for all the shared air spaces. I don't think there's a solution to this prob.

Ans. We respond to emergencies and we want to actively forget what it was like. When you look at what happen at what happened in 1918 and the literature in the following years - there was VERY LITTLE stuff talking about the experience. And that's not an accident.

Attitude is: We don't want to talk about the bad old days. We want to forget. We want to just move on with our lives.

Ans. View from the UK. I can remember the 80's. Aero-biology. Lot of work around bio-warfare. Expertise has been lost in that field. Knowledge and skills to advise government was lacking.. Much better agile network in the UK - people working in different areas working on it.

There's a real willingness across field to collaborate to work on these problems that fall at the boundaries between research councils. Identifying sources of funding has always been a challenge - not clear where the funding will come from. But there is a willingness to to work

together on it.

Q: UV technologies - how much do we actually understand about this stuff - relative to real-world aerosol composition?

Ans. Best data we have is from the TB studies in Baltimore in the 1950s. Peru. South Africa. Results showed 80% reduction of TB transmission in those studies.

We know a whole lot less about far-UV. Question about the dose / short range aerosol transmission.

What is the optimal way to design and spec and verify these systems? 5-10x more CADR effective with a ceiling fan integrated system embedded with UV..

We need some real world studies to get at this - and we need more efficacy studies to determine how much can we reduce transmission in the real-world environment. Think carefully about what it is that you CAN accomplish.

Even if you put UV in all the public spaces in a town.. what can you accomplish? Lot to think about in that context..

Q: COVID was bad. Ebola seems like it could be worse (acutely lethal). How would you want the response to be different?

Ans: I want to have a lot of different disciplines at the table, not just infection control people.

Ans: If we faced a pathogen with a 10% mortality

rate, more people would mask up.

Q: When do you think its sufficient to stop masking in public spaces?

Ans. Here's the thing about masking.... tradeoffs - cost vs benefit is not a science question.

Ans. In the public science communication panel, I pointed out that we are well qualified to provide mask advice - but there are policy experts that weigh things differently - I don't think it's our responsibility to weighing in on policy... I think we would have better trust

if we stick with the science..

What I say - That's a policy question. If we choose to have universal masking this is what the science says we would achieve.

Ans. Honest broker (scientist) rather than campaigner (policy changers).

At some level you sacrifice your right to express some independence to give scientific advice...

How we think about risk. We all respond in different ways..

Ans. Coming from a school of public health. Discussion - that by public health trying to become more scientific - gave up it's power - by being advocates PH got things done... clean water, etc. - but you need people with technical expertise to push for things to happen

Environmental justice issues - if you don't come at it as an advocate with passion - to solve this problem. Try and identify the different roles for different people. I do some amount of advocacy. I mostly try to measure stuff and tell people what I find..

Ans. Add one thing. Diff roles for diff people. I have tried to be very careful. I am a woman. I am not white. I feel that I am subject to a different level of scrutiny. People will attack me that much more - just looking for a reason or a chance.

Table top exercises - how we respond to an emerging threat.

A new respiratory virus emerges in a school in the US - what are the things that are indicators to you that a mitigation needs to be put into place?

Ans. When I saw that the first paper coming out of Wuhan had a 10y airway collapse - that's going to generate aerosols as a vector.

Ans. I'd look at hospitalization and mortality numbers - you need to avoid the cost and numbness of going on high alert.

Ans. Contact tracing.

Ans. Pre-cautionary principle balanced.

Ans. Seems to me tho - that we have all of our schools with good air hygiene. Vent/Filtration - so that our public spaces are resistant to the transmission of respir. viruses. Make these spaces the safest poss

We need to create environments that don't make this transmissible. Think about conferences that turn into superspreader events. I think it was the bars that people went to / dancing / screaming ...

Q: Inclusion of people from agricultural field. Start to attack the problem closer to the origin.

Ans. Nurse on the special isolation ward. Ebola case in the US. She really valued our research. Had a ton of good ideas to share. Talking with people who are faced w. this

and who rely on aerosol science. Hearing from someone who works at facilities dept at schools. Understand their constraints.

Ans. How we train aerosol scientists... think it's really important to think carefully about how we train the next generation. Inter-disciplinary

We need to building all this into how we train.

Program called One Health. Looking at animal to human - monitoring health status and virus across both.

Q: End on positive note: Suggestions to early career ppl - how to get into this field/guidance.

Ans. Find a good collaborator. Be willing to face rejection along the way.

Ans. Do it. Lab. Org. NIOSH. NIST, NIH - need your help

Ans. Prepare to work at the boundaries.

Those boundaries are where the advances happen - talk to people not like you and work with them.

Ans. Collaboration with real aerosol scientists and get a thick skin.

Keep rolling with it. You'll get there.

PANEL #2 - END.

(me - peace out y'all)