Scientists aren't infallible: airborne transmission of Covid
May 7, 2021 10:20 PM   Subscribe

Airborne transmission is driving Covid, not droplet transmission, which means that certain precautions (avoiding indoor spaces, wearing a mask, ventilation) matter much more than others (staying six feet apart, cleaning surfaces). The WHO and CDC just updated their websites this week to reflect the importance of airborne transmission. Zeynep Tufekci: Why did it take so long for scientists to accept that Covid is airborne? Twitter thread. One part of the answer: in 1910, Dr. Charles Chapin attributed the efficacy of social distancing to droplet transmission. This became the conventional wisdom. And there's often "a higher standard of proof for theories that challenge conventional wisdom than for those that support it." posted by russilwvong (148 comments total) 52 users marked this as a favorite
 
This seems very feverishly reported for something that has been broadly accepted conventional wisdom for at least a year.
posted by mr_roboto at 10:43 PM on May 7 [52 favorites]


Exactly. Airborne transmission seemed so obvious to me from the start. No great insight required.
posted by bz at 10:49 PM on May 7 [13 favorites]


Honestly I think the big reason that this wasn't publicly discussed with these words sooner is that airborne precautions require Airborne Infection Isolation Rooms with negative pressure and those are far and few in between, and nobody wanted to point out that with hospitals being basically clouds of covid.
posted by AlexiaSky at 11:14 PM on May 7 [60 favorites]


The virologists I know all assumed it was spread like a gas indoors from the start. A real containment lab for an airborne virus with infected animals is like the bunny suit scenes in Contagion. Lab workers do not stand seven feet away from infected animals indoors and think they are safe. But you can't have an economy if you admit the virus is spread by something that acts like cigarette smoke. If you admit that, then you are forced to provide everyone with N95s to protect them rather than Etsy masks. Who knows what the actual scientists at the CDC thought, the people filtering their announcements were political hacks with no scientific ethics or credentials.
posted by benzenedream at 11:19 PM on May 7 [60 favorites]


bz: Airborne transmission seemed so obvious to me from the start. No great insight required.

To me the puzzling thing is, why did it take scientists so long to catch up? David Fisman says that his "road to Damascus" moments happened in the summer of 2020.
posted by russilwvong at 11:20 PM on May 7 [3 favorites]


If only there were an article entitled "Why did it take so long for scientists to accept that Covid is airborne?" linked in the FPP!
posted by Justinian at 11:21 PM on May 7 [77 favorites]


A real containment lab for an airborne virus with infected animals is like the bunny suit scenes in Contagion.

I work in a CL2 covid lab. This is not true at all. If anyone is getting into anything remotely similar to that, then something has already gone drastically, drastically wrong.
posted by Dysk at 11:27 PM on May 7 [36 favorites]


I am no great expert in the area of disease transmission. But I did take a gander at the literature and recommendations to the public back in 2015 in response to this AskMefi question: How many Americans are getting sick from using public touch screens? If I recall I've looked into it a few times over the years, generally provoked by AskMe questions.

But every time I did look, my overall impression was exactly what I said in my answer to that question:
Every time I look into this, I'm a bit surprised by how little seems to be known about actual transmission of actual germs in real life. You get a lot about transmission via X is possible or Y type of germ can live up to Z hours on Q surface, and so on. But little about, which chain of transmission is, in real life, more or less likely to actually cause infection.
Is, for example, the common cold more likely transmitted when you shake hands with someone, then touch your nose, mouth, or eyes? Or if you touch a doorknob or similar that a sick person touched? Or if you're in a room where a sick person sneezes? Or (a possibility that didn't really come to the fore before Covid) by being in a room where a sick person simply talks, sings, or spends a lot of time breathing heavily?

No one really seemed to have the answers to those questions. They could list off various possible ways the viruses could be transmitted, but seemed to very completely lack the most vital piece of info: How much does each method of transmission contribute to overall disease transmission in the real world, and which are the most important and prominent methods of transmission?

My point is, if we can get some real answers to these questions--and then act on them--this will be one of the most important contributions to public health to come out of this pandemic.

Also: It is very clear to me now that the route of transmission for most respiratory viruses--in particular, cold and influenza viruses--must in general be very, very similar to the way Covid-19 is spread.

That is to say: Very, very seldom do you catch a cold by touching a doorknob an infected person previously touched.

But very, very often do you catch a cold by, for example, spending a few hours in the same poorly ventilated office with an infected person--maybe even 20 or 30 feet away--while that person is loudly regaling a buddy about some favorite fishing stories or whatever.

In short, you're in the same dead pool of air with another infected person, they spray infected droplets all around by talking, singing, heavy breathing, etc, you breath enough of them in and you get sick.
posted by flug at 11:36 PM on May 7 [50 favorites]


(Minor correction to my pervious comment: CL2/CL3 not straight CL2. It's complicated. The central point still stands.)
posted by Dysk at 11:40 PM on May 7 [2 favorites]


To me the puzzling thing is, why did it take scientists so long to catch up?

Hate to recommend actually reading the linked article, but yeah. That is quite precisely what it is about.

In addition, some relevant facts:

- It is really really hard to detect viruses as they circulate in the air, whether in the form of large, medium, small, very small, or any other size respiratory droplet. It is hard to do now, and until quite recently it was just exactly impossible. So everything you postulate about the spread of virus-containing droplets through the air is very close to 100% theoretical, with no real way to test your theory.

- Most of the conclusions about method of transmission are not by somehow tracking the virus itself and its spread in the environment, but by tracking cases. One sick person infects another--now you analyze what kind of contact they had, what they did that led to transmission. You work backwards from this to develop a theory about how it happened. But everything between "Person A was sick and infected Person B; the two had these types of contact" is pure theory, and theory is easy to get wrong.

In particular, you can have two quite different theories that can give quite similar end results. How do you discriminate between two different theories that both give the same end result? (Actually, you can't. You have to find and then accurately measure some way the two theories actually give different results and that is not always so easy.)

- The ability to really precisely model things like aerosol movement in the atmosphere is quite new as well. Sometimes it can take a while and a good reason (ie, a global pandemic) to bring disparate specialized subject-matter experts together.
posted by flug at 11:52 PM on May 7 [39 favorites]


why did it take scientists so long to catch up?

If only there were an article entitled "Why did it take so long for scientists to accept that Covid is airborne?" linked in the FPP!

Since it's an instance of (not) putting a fine enough point on things, just wanted to note that the article, contrary to how it's referenced in the body and title of the FPP, is "Why Did It Take So Long to Accept the Facts About Covid?", not with "scientists" as its central object, so centering this on "scientists" as the main culprits here is a subtle shift.

Yes, consensus-forming in science takes time, yes, there have always been schools of scientific thought. But to frame this, as is being done in this thread in ways that the article doesn't, as a kind of emperor-has-no-clothes reveal is a bit off the actual mark, methinks. The article is (erm) more articulate about the factors of bias that are at play in this, historically. Seems to me it would be unwise to take them, however subtly, out of the crux of the equation that's being examined.
posted by progosk at 11:56 PM on May 7 [17 favorites]


My point is, if we can get some real answers to these questions...

It's frustrating that the COVID era hasn't resulted in massive data capture that could get a lot of answers. We have an entire world of petri dishes right now. Sure, it's not controlled experiments, but the sheer volume would yield insights if we were watching the right things and doing a lot more testing and contact tracing. How important is it to wipe down shopping carts? Does the six-foot rule help? How does restaurant ventilation affect transmission? We have thousands of supermarkets and restaurants and airport lines that are all implementing permutations of the policies, and if we had our eyes open, we could do some comparisons to find out what really works and what is superstition.

I love the 5000-person masked indoor concert experiment recently done in Barcelona. We need more of that. Get some volunteers, put them in a situation that uses a certain COVID safety protocol, measure the result.
posted by qxntpqbbbqxl at 12:06 AM on May 8 [2 favorites]


That goddam Bavarian saltshaker [Reuters 09 Apr 2020] has a lot to answer for misleading the hounds of epidemiology.
posted by BobTheScientist at 12:07 AM on May 8 [5 favorites]


Also I will mention: I've had the misfortune of spending several weeks in hospital with various sick relatives in the past couple of months.

Some of them have been in hospital wards that had previously been Covid wards.

Among the interesting facts we learned there, is that pretty much all the staff (nurses, aides, etc etc) working on those wards had eventually contracted Covid.

I don't know what kind of protective gear they had at that time, but clearly it and whatever protocols they were following were not enough. This is in a major university research hospital, a pretty large regional hospital system, in the U.S.

Also, the staff on that ward was clearly all burned out. Just obviously. I'm sure plenty of PTSD, and so on. Not to mention any possible long-term physical effects from Covid itself. I don't know what they would really need to recover--six months paid vacation to unwind, 10 years of weekly counseling and support services to deal with the mental health aftermath? Something like that, anyway. Whatever it is, they are clearly not getting it.
posted by flug at 12:09 AM on May 8 [46 favorites]


John Snow, often credited as the first scientific epidemiologist, showed that a contaminated well was responsible for a 1854 London cholera epidemic by removing the suspected pump’s handle and documenting how the cases plummeted afterward. Many other scientists and officials wouldn’t believe him for 12 years, when the link to a water source showed up again and became harder to deny.

Clearly he refused to bend the knee to scientific establishment
posted by polymodus at 12:22 AM on May 8 [23 favorites]


Just reading the rest of the Op-Ed and it has a number of brilliant hindsight headbangers: the quarantined cruise ship in Tokyo could only have infected the entire ship if it was caused by airborne aerosol transmission; the WHO was in the dark empirically, because their hospital-centric information and hospitals already have good ventilation, so the only detectable change was from hand hygiene, thus lead the WHO to ignore/downplay aerosols. That's fascinating.
posted by polymodus at 12:33 AM on May 8 [22 favorites]


This seems very feverishly reported for something that has been broadly accepted conventional wisdom for at least a year.

Tufekci is not high on the list of people I’d call “feverish.” But really what this is all about is why it took public health institutions so long to update recommendations to match the simplest explanation for phenomena that, yes, were apparent to a lot of people based on the research coming out months ago.
posted by atoxyl at 12:53 AM on May 8 [18 favorites]


You can really only get good data about transmission in places that don't have a lot of community spread, since once an infected person has been in contact with multiple other infected people, it's going to be pretty hard to determine who was infecting who especially taking unknown asymptomatic spreaders into account.

Unfortunately the feeling I got was that when cases were low, officials were more interested in hoping it would all go away instead of doing any kind of scientific studies.
posted by meowzilla at 12:54 AM on May 8 [8 favorites]


I miss the days when I trusted the CDC.

In my head, this had been settled at least 8 months ago, and closer to a year+. At least, well enough to know that significant aspects of the US public response are still hygiene theater, and that the guidelines about sharing air were insufficient.

Just look at some of the earlier recorded spreading events reported in the news (dates here are from when the academic articles actually cleared peer review ... so the data was available and in the news long before that):
* The cruiseship. We're all familiar with that one.
* The restaurant. April 20, 2020 article
* The bus, again showing infections farther apart than 6 feet. Sept 1, 2020 article describing publication in JAMA. (The actual event was in January; I recall reading about it in the news before the Sept publication, but my google-fu is weak tonight.)
* The South Korean call center (CDC report from August 2020), yet again strongly suggesting airborne transmission
posted by Metasyntactic at 1:05 AM on May 8 [19 favorites]


This part sounds completely insane:

When reviewing airborne transmission, the group focused mostly on studies of air samples, especially if live virus was captured from the air, which, as mentioned above, is extremely hard. By that criterion, airborne transmission of the measles virus, which is undisputed, would not be accepted because no one has cultivated that pathogen from room air.

It can't be airborne because the test doesn't show it to be airborne. However, the test does not show any virus as airborne. Why are we running this test again?

This is like the thermometers that show everyone's temperature to be normal no matter what.
posted by meowzilla at 1:32 AM on May 8 [8 favorites]


- It is really really hard to detect viruses as they circulate in the air,
This is true. But I have seen some people argue that CO2 levels - measurable with a cheap meter - can be a good proxy for particles circulating in the air. The idea is that, if the levels are under about 650ppm then the transmission risk should be acceptable.
posted by rongorongo at 1:55 AM on May 8 [5 favorites]


And here I thought that the government suppressing testing and contact tracing mattered. The USA doesn't seem to have much public health infrastructure to begin with, so, in our country, it was easy to suppress investigations.
posted by eustatic at 2:17 AM on May 8 [4 favorites]


(Minor correction to my pervious comment: CL2/CL3 not straight CL2. It's complicated. The central point still stands.)

Hi Dysk:

I'm more familiar with ABSL levels, and was referring to ABSL-4 with the bunny suit comment:
Animal Biosafety Level 4
Animal Biosafety Level 4 is required for work with animals infected with dangerous and exotic agents that pose a high individual risk of life-threatening disease, aerosol transmission, or related agent with unknown risk of transmission. Agents with a close or identical antigenic relationship to agents requiring ABSL-4 containment must be handled at this level until sufficient data are obtained either to confirm continued work at this level, or to re-designate the level. Animal care staff must have specific and thorough training in handling extremely hazardous, infectious agents and infected animals. Animal care staff must understand the primary and secondary containment functions of standard and special practices, containment equipment, and laboratory design characteristics. All animal care staff and supervisors must be competent in handling animals, agents and procedures requiring ABSL-4 containment. Access to the animal facility within the ABSL-4 laboratory is controlled by the animal facility director and/or laboratory supervisor in accordance with institutional policies.

There are two models for ABSL-4 laboratories:

- A Cabinet Laboratory where all handling of agents, infected animals and housing of infected animals must be performed in Class III BSCs.
- A Suit Laboratory where personnel must wear a positive pressure protective suit (See Appendix A); infected animals must be housed in ventilated enclosures with inward directional airflow and HEPA filtered exhaust; infected animals should be handled within a primary barrier system, such as a Class II BSC or other equivalent containment system.
I know SARS-CoV-2 was at one time BSL-3 for live virus, and groups were agitating to have it downgraded as it was already prevalent and thus no longer capable of establishing a novel outbreak (perhaps that happened and that's why you're at CL2/CL3?). My point, perhaps poorly made, was that (unmasked) humans indoors during an aerosol-spread pandemic are more dangerous than a well controlled ABSL-4 lab (with positive pressure protective suit).

If you are doing animal work, I'd be curious to hear what current precautions are, if you're free to discuss it.
posted by benzenedream at 3:05 AM on May 8 [3 favorites]


This is a slight tangent, but does anyone have reputable resources that encourage people/businesses against too much surface disinfecting hygiene theatre? I've found lots of papers and articles that talk about aerosol transmission being the main issue, but nothing super reputable that clearly states that it's much less important in terms of disease control to be wiping down surfaces all the time.

I ask because my workplace is currently setting limits on how many people can work from the office based on how often the facilities team can wipe down desks and touch points in common areas, and when I raised this as probably more hygiene theatre than actually useful disease control, I found out that the most senior person in charge of risk & business continuity within my organisation is still leaving his groceries untouched for three days before unpacking them - i.e. a tough crowd to convince that fomites are not the biggest problem here.

I suspect given the nature of a pandemic that people will be reassured by some hygiene theatre even if it's more about making them feel safe rather than actually making them statistically safer, but I also suspect that there's a sweet spot that involves less wiping than our cleaning team is currently doing, or which doesn't rely on our capacity to make wiping happen as a key limitation.

(In case anyone suggests it's unethical to be asking people to work in an office at all - the office access we're offering right now is more to accommodate the people who are seriously struggling at home and want to come back; anyone who wants to continue working remotely is welcome to for the foreseeable future.)
posted by terretu at 4:05 AM on May 8 [15 favorites]


I heard this was airborne, from the news, multiple sources, in August 2020. This isn't the first time it's been "admitted" at all.
posted by tiny frying pan at 5:53 AM on May 8 [1 favorite]


I think the current change is important because, even though some people understood that it was airborne last year, the CDC acknowledging that it's airborne is one step along the road to OSHA promulgating sensible rules about how to prevent exposure at work, which our employers can then willfully ignore for increased profits and/or execs feeling good about themselves for getting people back at desks! Also, having the CDC say it means people are less likely to say I'm paranoid when I make choices to minimize potential exposure based on that threat model.
posted by Alterscape at 5:59 AM on May 8 [12 favorites]


Also, having the CDC say it means people are less likely to say I'm paranoid when I make choices to minimize potential exposure based on that threat model.

Absolutely. When I said "aerosols/airborne" a while back, the boss gave me a funny look. It's different when the trusted TV anchor boss follows reports that the CDC has said "aerosols/airborne."
posted by MonkeyToes at 6:21 AM on May 8 [7 favorites]


The paper that confused me the most was "Large SARS-CoV-2 Outbreak Caused by Asymptomatic Traveler, China".
Therefore, we believe A0 was an asymptomatic carrier (7,8) and that B1.1 was infected by contact with surfaces in the elevator in the building where they both lived (9).
I remember being immensely frustrated that they'd leap to that conclusion without at least explaining why they discounted airborne spread, particularly given that elevators are small boxes with poor ventilation where you breath what was left behind by previous passengers.
posted by Candleman at 6:48 AM on May 8 [9 favorites]


I think from public health agencies and governments, there was a lot of ignoring evidence-based health comms and mass communications. Part of this was expressed in an unwillingness to be frank with what wasn't yet known, and an unwillingness to change course out of a perceived risk of losing trust or confusing people. Part of it was based on it being very, very hard to turn the large boat of the guidance industry that had set sail - 'can't unring the bell.'
posted by entropone at 6:56 AM on May 8 [4 favorites]


terretu: I've found lots of papers and articles that talk about aerosol transmission being the main issue, but nothing super reputable that clearly states that it's much less important in terms of disease control to be wiping down surfaces all the time.

A month ago, CDC released this update:

https://www.cdc.gov/coronavirus/2019-ncov/more/science-and-research/surface-transmission.html

which says,

"In public spaces and community settings, available epidemiological data and QMRA studies indicate that the risk of SARS-CoV-2 transmission from fomites is low—compared with risks from direct contact, droplet transmission or airborne transmission"

and

"Quantitative microbial risk assessment (QMRA) studies have been conducted to understand and characterize the relative risk of SARS-CoV-2 fomite transmission and evaluate the need for and effectiveness of prevention measures to reduce risk. Findings of these studies suggest that the risk of SARS-CoV-2 infection via the fomite transmission route is low, and generally less than 1 in 10,000, which means that each contact with a contaminated surface has less than a 1 in 10,000 chance of causing an infection"
posted by Gyan at 7:21 AM on May 8 [10 favorites]


I found The Constant podcast episode on this topic to be excellent. When seen in the context of many centuries of miasma disease theory, you can see why the public health establishment had a particular resistance to being willing to believe that airborne transmission was more important than other factors. As often happens, the pendulum had swung too far.
posted by meinvt at 7:25 AM on May 8 [2 favorites]


From Tufekci's NYT piece:
f the importance of aerosol transmission had been accepted early, we would have been told from the beginning that it was much safer outdoors, where these small particles disperse more easily, as long as you avoid close, prolonged contact with others. We would have tried to make sure indoor spaces were well ventilated, with air filtered as necessary. Instead of blanket rules on gatherings, we would have targeted conditions that can produce superspreading events: people in poorly ventilated indoor spaces, especially if engaged over time in activities that increase aerosol production, like shouting and singing. We would have started using masks more quickly, and we would have paid more attention to their fit, too. And we would have been less obsessed with cleaning surfaces.
The strongest points here are about singing/shouting indoors and allowing socially distant outdoor gatherings. Otherwise, I think there's a lot of wishful thinking in these counterfactuals that assumes people (particularly Americans) would respond rationally.

One big problem is the "hygiene theater" aspect of cleaning surfaces, wherein stopping non-existent transmission on surfaces was a lot easier and more palatable to business owners and political leaders than stopping real airborne transmission by reducing capacity or closing. Another is that air filtration systems that could meaningfully reduce airborne transmission, to the extent that they would have been affordable at all prior to COVID, would have skyrocketed in price, and been plagued by delays that would have kept businesses closed for months, as opposed to operating at 25% or 50% capacity and having underpaid employees spray some surfaces.

I'm also not buying that there's an alternate scenario under which we focused more on proper mask usage and it led to real changes. Anti-mask sentiment became political from the start, despite a lot of resources dedicated to educating people about their use, and this sentiment was not coming from a point of view that would have been swayed by learning that the disease was airborne.

It does seem unfortunate that it's taken so long to correct the guidance here, but I don't know that doing so would have had much of an effect, at least not in the US.
posted by tonycpsu at 8:00 AM on May 8 [21 favorites]


I don't know what kind of protective gear they had at that time, but clearly it and whatever protocols they were following were not enough. This is in a major university research hospital, a pretty large regional hospital system, in the U.S.


My state's governor mounted a covert operation to replace the N95 masks that the president stole from us. It's nice to have prestige, and staff with long publication records and the like, but if you wanted your hospital staff to be protected from Covid under these circumstances, you literally needed a company of National Guardsmen at your command.

While this was going on, makerspaces around my city were scrambling to 3d print face-fitting gaskets that could be fitted with patches of vacuum cleaner filters in case the governor's operation failed to secure those N95s. And this was at the request of the director of Massachusetts General Hospital, one of the most famous hospitals around the world. Fun times.
posted by ocschwar at 8:16 AM on May 8 [30 favorites]


Just my own lay-person's guess, it seemed to me that the tiniest droplets, especially in low humidity or turbulent wind, could fully evaporate before hitting the ground. So that leaves the virus, that is lighter than smoke, floating on its own, no?
posted by StickyCarpet at 8:35 AM on May 8


They’ve been trying to push the good ventilation angle since last summer, here in Germany.(For example, this video from August put out by the Federal Government. My company also put in CO2 sensors in parts of the ventilation system in the office building to ensure it was sufficient. ) But I’m not sure how much it has actually been internalized.
posted by scorbet at 8:37 AM on May 8 [5 favorites]


If the importance of aerosol transmission had been accepted early, we would have been told from the beginning that it was much safer outdoors, where these small particles disperse more easily, as long as you avoid close, prolonged contact with others.

I feel like got shunted onto some kind of alternate time track here because wasn't that.... what we were told? Why there were drastically different recommendations for indoor and outdoor gatherings? Why everyone I know was been socializing in backyards and in parks and on porches instead of inside people's houses for the better part of a year?
posted by escabeche at 8:38 AM on May 8 [30 favorites]


Nice post.

Last week, I walked past blocks of densely packed bars and restaurants and a gym filled with students, then submitted a modified COVID lab reopening plan to a committee of professional scientists that includes wiping down the door knobs and all tool handles after every shift. I was told it would be a mistake to not include that bit. (We have better airflow than pretty much any indoor space that isn't a wind tunnel, rigorous hand washing, nearly complete vaccination, stable and small shift pairing, quarantine after any travel or exposure, KN95 masks at all times. And we normally wear disposable, single-use gloves much of the time anyway. We're doing everything right, as far as we know. And I will continue to dutifully spray IPA on the door knob every time. But, I gaurauntee nobody else will. And they're not wrong.)

But, then, our city opened the restaurants long before the parks. And they consider a fully enclosed tent with a re-circulating heater "outdoor seating." I'm no epidemiologist, but everyone in a leadership position seem to be treating this the way US airport security treats threats. Dumb rules don't just waste time and money, they also teach people to ignore rules.
posted by eotvos at 9:05 AM on May 8 [34 favorites]


I mean, on one hand we're all saying that everybody's known about airborne transmission all along, but on the other we as a whole (at least in the US) sure haven't been acting like that's the case. I had a whole screed written here about what I've seen in the school buildings I've been in over the past month (and my state has been relatively "late" to force staff and students back into buildings compared to many others), but I'm sure everyone has their own examples.

It would be wonderful to think that public policy and personal choices will now be altered based on the support these latest findings lend to what we all say we knew all along, but I'm not holding my breath (except when I'm in the school buildings I serve).
posted by DingoMutt at 9:05 AM on May 8 [3 favorites]


I mean, on one hand we're all saying that everybody's known about airborne transmission all along, but on the other we as a whole (at least in the US) sure haven't been acting like that's the case.

Science and policy are very different things, and rarely does the latter take much amount of the former.
posted by Dysk at 9:12 AM on May 8 [7 favorites]


If aerosol transmission was so obvious to everyone, businesses would have spent more on air purifiers and less on plexiglass barriers.
posted by airmail at 9:18 AM on May 8 [2 favorites]


If aerosol transmission was so obvious to everyone, businesses would have spent more on air purifiers and less on plexiglass barriers.

addressed nicely here
posted by saturday_morning at 9:52 AM on May 8 [3 favorites]


There does seem to be a difference in the airborne transmission of COVID and that of measles. With measles someone with the disease can just walk through a space without lingering but you could catch it something like 2 hours later by walking through yourself. That doesn't seem to be the case with COVID.
posted by hippybear at 10:02 AM on May 8 [3 favorites]


If aerosol transmission was so obvious to everyone, businesses would have spent more on air purifiers and less on plexiglass barriers.

Pretty sure what was obvious there was that plexi barriers are way cheaper than overhauling your entire hvac system.
posted by GCU Sweet and Full of Grace at 10:14 AM on May 8 [24 favorites]


Just my own lay-person's guess, it seemed to me that the tiniest droplets, especially in low humidity or turbulent wind, could fully evaporate before hitting the ground. So that leaves the virus, that is lighter than smoke, floating on its own, no?

As a chemical engineer in an adjacent field, I think your intuition is correct. The time it takes for the droplets to dry is going to depend on humidity, temperature, and drop composition (mucus/saliva content), but the smallest should dry easily in non-humid conditions. I think there's a lot more debate about how that process changes viability the dried out virus particles. But all this research is still ongoing because aerosols are incredibly complex.
posted by crossswords at 10:26 AM on May 8


Zeynep Tufekci's article seems rather ax-grindy. Even the Lancet paper still calls aerosol transmission a hypothesis, providing several lines supporting the hypothesis but no proof, because proof is difficult.

And she vastly exaggerates the significance of the CDC's new announcement. For example:

"If the importance of aerosol transmission had been accepted early, we would have been told from the beginning that it was much safer outdoors, where these small particles disperse more easily, as long as you avoid close, prolonged contact with others."

This is nothing new. We have been treating outdoor activities as safer than indoor from the very beginning. Remember all the discussion back in April and May about outdoor protests vs indoor political rallies?

"If the importance of aerosol transmission had been accepted early, we would have been told from the beginning that it was much safer outdoors, where these small particles disperse more easily, as long as you avoid close, prolonged contact with others. We would have tried to make sure indoor spaces were well ventilated, with air filtered as necessary. "

This is nonsense. Talk all summer was about exactly this. Heck, even Trump's first political rally in Tulsa they made a big deal about the air filtration they were using. All the discussion about opening schools for the last year has been about opening windows and providing air filtration.

It seems she is taking the CDC announcement, which is not a really big deal, and trying to spin it as some conspiracy of information suppression.

But that just the way science works. It is very cautious on making pronouncements based on hypothesis. But she also makes the accusation that everyone was acting as if the hypothesis was false. That is not true. Most of the guidance was as if aerosol transmission was a possibility but without conclusive evidence. Wearing masks, providing indoor ventilation, providing indoor filtration, moving activities outdoors whenever possible.

And we still don't know the relative risk of aerosols vs particles. Tell the truth. Even with this new evidence, are you more concerned about the person three feet from you spraying in your face or the person 20 feet away across the room making aerosols?

Keep in mind that this is not a news article. It's an Op-ed. Her intent is to provoke. So she takes a CDC announcement -- that nobody particular finds groundbreaking since they suspected and acted as if it were the case all along -- and tries to make it into something it is not, a failure of science.
posted by JackFlash at 10:28 AM on May 8 [15 favorites]


I don't know what they would really need to recover--six months paid vacation to unwind,

Yes, please.


10 years of weekly counseling and support services to deal with the mental health aftermath?

I'd settle for six months.


Whatever it is, they are clearly not getting it.

100% correct.
posted by WhenInGnome at 10:35 AM on May 8 [14 favorites]


I found The Constant podcast episode on this topic to be excellent. When seen in the context of many centuries of miasma disease theory, you can see why the public health establishment had a particular resistance to being willing to believe that airborne transmission was more important than other factors. As often happens, the pendulum had swung too far.

In one of the earlier threads or perhaps even an AskMe, there was a recommendation for Smell Detectives: An Olfactory History of Nineteenth-Century Urban America, which was a non-fiction collection of a few historical anecdotes that marked the shift from miasma theory to germ theory in public health, and that's been at the back of my mind since. The book also argued the shift to germ theory placed the authority solely with the scientific community (since they would have the means to detect germs) and reduced the influence citizen action could have in urban planning since bad smells, which can be reported by civilians, became merely a nuisance and no longer a sign of encroaching disease.
posted by cendawanita at 10:40 AM on May 8 [2 favorites]


Yeah, the couple of gaming sessions we managed this were held outside. We also did masks and social distancing, but we only gamed when the weather was good enough to sit outside, because that was going to be the most important factor. I even remember debating if the partial sunscreen we had down on one side enclosed the deck too much. Heck, back in June I cancelled my dental checkup because I didn't see how I could count on it being safe indoors unmasked. Businesses around here were setting up little outdoor work stations in parking lots, beauty parlors and things like that. It's been an emerging consensus, sure, but not a recent one.
posted by tavella at 10:41 AM on May 8


JackFlash, I think you are conflating the early insights from smarties here on MetaFilter and Twitter (often relying on Zeynep's analyses at the time!) with the vast majority of governmental, business, and media guidance, which many more low-info Americans relied on during the pandemic.
posted by PhineasGage at 10:44 AM on May 8 [14 favorites]


Doesn't anyone remember the "Angel of Death" guy and all the media derision for people on public beaches in Florida?!
posted by PhineasGage at 10:45 AM on May 8 [4 favorites]


All I heard about gatherings for over a year is they are safer outside.
posted by tiny frying pan at 10:55 AM on May 8 [3 favorites]


I think you are conflating the early insights from smarties here on MetaFilter and Twitter (often relying on Zeynep's analyses at the time!) with the vast majority of governmental, business, and media guidance, which many more low-info Americans relied on during the pandemic.

I don't know what governmental, business and media you are talking about but this information was all over the news and discussed for at least a year -- masks are important, outdoors is safer than indoors, indoors requires good ventilation and if possible, filtration.

Did you fail to see all of the restaurants moving their tables to the sidewalks? The guidance for indoor restaurants to only have 25% capacity to reduce the amount of aerosols? That wasn't about maintaining 6 foot separation. It was to reduce the amount of people breathing in enclosed spaces. The political arguments about how expensive it would be to retrofit schools for filtration?

This isn't suddenly new stuff.
posted by JackFlash at 11:07 AM on May 8 [7 favorites]


The guidance for indoor restaurants to only have 25% capacity to reduce the amount of aerosols? That wasn't about maintaining 6 foot separation.

It was also about maintaining distance between people, because whether the disease is getting carried by droplets, aerosols, or both, farther away from other people is better; this is another point Tufekci has been good on.
posted by escabeche at 11:10 AM on May 8 [3 favorites]


Regardless of what "the scientific community" believed, the policy implications of the CDC's refusal to acknowledge aerosol transmission were huge. In fact, they still are, since as far as I know they still haven't updated their "close contact" criteria, which are largely based on the 6-foot ballistic droplet model. Just in my personal life, the CDC's decision affected debates in both my workplace and our local schools. Administrators would announce reopening plans based on 6-foot distancing with (therefore) no close contacts ever as long as everyone was 6 feet apart; factions of parents would object based on aerosols, and the superintendent would refer to the state ed department, who would refer to the governor's guidelines, who would refer to the CDC and literally describe you as anti-science if you disagreed with the CDC, no matter how many studies and scientific authorities you cited. And that didn't change in February, March, or April, btw, so it wasn't just a Trump thing. As far as I know, it still hasn't really changed, except that now the governor says that 3 feet is safe for school (based on the CDC who cites three tiny observational studies and the WHO who cites a single meta-study which showed that 1 meter was the smallest distance at which increased distance reduced cases, which if you try to explain to your local superintendent doesn't imply that 3 feet is safe...) So whatever their top-line change on aerosols may be, it still hasn't actually changed some of the key policy recommendations, and I don't expect it to until schools are over and the effect on businesses becomes negligible.

In any case, while I think fundamentally the logic is that they can't accept aerosols are important as long as that means trillion-dollar shutdowns, I would like an even more micro-scale explanation of what happened than Tufekci provides. I'd like to hear the anonymous, off-the-record oral history of policy meetings at the CDC, WHO, EU CDC equivalents, etc; presumably there were minorities in all of them who pushed for this and were rebuffed in various ways, but exactly how would be interesting to hear.
posted by chortly at 11:12 AM on May 8 [32 favorites]


California playgrounds were closed until December, which was nuts, and largely based off of slow changing guidance from the CDC. Other states had playgrounds closed all summer, even the red state I was in. I definitely felt like aerosol transmission was a known thing since late spring, but that wasn’t reflected in policy for lots of stuff.
posted by skewed at 11:24 AM on May 8 [14 favorites]


I feel a need to pitch in my $0.02 here, and in part by regurgitating some of the above comments, because something seems a little less understood about the messaging aspect of this, and overall logic of leaving the aerosol aspect out of the picture.

If you're using a 'powerful' cleaner in the house (like The Works for the bath tub area), or if you're doing practically any type of painting (walls, figures, etc.) in-doors, it is strongly advised to do those things in a well-ventilated area, as the aerosols (of various compounds in cleaners and paints) can build up in an enclosed space. Thus, if you use those products in an enclosed space with poor air movement and/or lack of open windows, you would breathe the compounds in, and face one or many particular symptoms of doing so (feeling high, faint, get nauseous, vomit, etc.). Crack open the windows, turn on some fans, perhaps put on a mask of some variety (to safety code for more powerful products), you'll be alright with the aerosols in the room as they'll be diluted and heading out, and you may even have a mask as a last defense against the dangerous compounds.

So we have COVID, and it's spreading in areas like beautifully listed in this comment above, and we saw surges as schools re-opened, peaks around the holidays when people gather indoors, etc etc etc. People were aerosol cans for COVID, activated by talking and breathing, in mostly poorly ventilated areas. Coexisting with the aerosols would be ok if the gatherings were in better ventilated areas or outdoors (so long as people didn't crowd up unmasked to produce COVID clouds).

Thus, the real driver of COVID has been and will continue to be poorly ventilated indoor areas and/or in clouds of crowding unmasked people outdoors. Airborne is the state the virus is in when it zeroes in on hosts, either as an aerosol or respiratory droplet. Fomites can last a while in controlled environments, but as noted above, they don't stand as good of a chance in the wild.

And this gets to the crux of the matter: when I think (and I'm confident a good number of other people do too) of a dangerous, seemingly uncontrolled and growing biological thing being airborne and an aerosol, my knee jerk, unprocessed reaction, as it's not a household chemical I can control, is shut the windows, do not dare go outside (or get super masked/shielded up if you do), and essentially pray to gods that it doesn't creep in and take my loved ones or my own life. If COVID we're that dangerous, we'd see a real order of magnitude more people sick and dead, and the numbers globally now are bad enough. The US would've been smacked harder with COVID in January 2020. The essential works would be unbelievably more difficult to pull off (warehouse stuff, grocery stores, meat processing [yes, that was poorly managed for sure], medical, etc.), as people would be dropping like flies.

To not broadcast the aerosol aspect of the virus was frankly one of the few smart communications moves made early in the pandemic. It takes a while to explain exactly how that plays out, and ultimately is not the best first dose of information to get about the virus in terms of keeping public panic to a minimum. The early lockdowns worked really well focusing on the driver of poorly ventilated areas. Period.
posted by JoeXIII007 at 11:25 AM on May 8 [1 favorite]


Was it not as recently as a couple of months ago that an elevator button or a trash can lid was (officially?) considered to be a source of a spread in New Zealand? I think one of those two was later reconsidered but not sure.
posted by asra at 11:57 AM on May 8


Yeah, a trash can lid in a quarantine hotel in September 2020. Later analysis showed that there were 20 hours between patient C touching the trash-can lid and patient D, but their rooms were next to each other, and during testing, there was a 50-second window between closing the door to one room and opening the door to the other.
posted by ectabo at 12:40 PM on May 8 [17 favorites]


I think people are confusing efforts by scientists and journalists like Tufekci to acknowledge airborne spread with actual public health bodies acknowledging it. WHO only acknowledged the POSSIBILITY of aerosol spread in July 2020, and now that it is likely in May 2021. There have been a lot of policy decisions based on this.
posted by snofoam at 12:49 PM on May 8 [17 favorites]


Thank you snofoam for returning to the point of the original article. I spent much of the past year doing COVID Contact Tracing and we new a duck of a lot more about what was effective prevention than what CDC, WHO, and other public health bureaucracies were saying to the public.

he point is the public authorities were slow to figure out and then disseminate correct guidance, for all the reasons cited in that op-ed. And a lot of major organizations - governmental and corporate - relied on that late/wrong guidance, whether out of simple trust, lack of their own in-house expertise, or fear of legal liability.
posted by PhineasGage at 1:23 PM on May 8 [5 favorites]


This kind of thing makes it harder to blame people for being wary of vaccination campaigns.

We really must be better about communicating complexity and uncertainty, and about giving professionals the safety to make good decisions and to communicate completely, if we are EVER going to build trust back up.
posted by amtho at 1:31 PM on May 8 [1 favorite]


I think that main article misses or deliberately de-emphasizes a lot of the reasons that droplets were thought to be at fault. For example, that Korean restaurant that had lots of transmission downwind of an air conditioner (which would blow the droplets further then six feet) but none in the rest of the restaurant, and the fact that COVID is so bad at spreading itself compared to things like measles.
posted by Canageek at 1:33 PM on May 8 [6 favorites]


There have been a lot of policy decisions based on this.

Name one that is new. Tufekci claims that outdoors is safer than indoors and that indoors spaces should be ventilated is new. They aren't new at all. I'm failing to see what is ground breaking in this op-ed and how it changes public guidance. It seems she is just making shit up to get clicks.

People seem to be hanging on the word "aerosols" as if that is some new revelation. Aerosols isn't even a well defined term. It is just a ill-defined difference between large droplets and smaller droplets that has different meanings for different scientists. Here is an article that discusses this from way back in April 2020, more than a year ago. Is it 2 µm, 5 µm, 10 µm, 20 µm, or even 100 µm.

"Small droplets will remain in the air for very long periods of time (become airborne), but the exact cutoff is unknown, and can change significantly based on factors like temperature and humidity." So what "aerosols" means is not clear.

Both the CDC and WHO are saying that close contact, within 1 meter, from droplets is still the primary means of transmission. Longer distance transmission by "aerosols" is possible but unquantified. This doesn't change the guidance at all -- mask, social distancing, ventilation, outdoors is better than indoors.
posted by JackFlash at 1:46 PM on May 8 [8 favorites]


This doesn't change the guidance at all -- mask, social distancing, ventilation, outdoors is better than indoors

In support of the other comments, i can tell you this much for my country: the slow walk WHO has been doing has meant the last two hasn't been emphasized by my country at all. If there are feints in that direction it's due to public pressure, and one that every so often is visibly disagreed with by the health ministry leading to no change at federal-level regs. fomite transmission is still taken a given. Even in the early days, ministers who masked up were then shamed into not masking in public appearances, because the health director-general won't.
posted by cendawanita at 2:15 PM on May 8 [9 favorites]


Around here, parks and playgrounds were closed to the public as late as October 2020, months after indoor businesses like hair salons had reopened. The public guidance around “outdoors is better than indoors” has absolutely lagged the science, in some areas more than others.
posted by mbrubeck at 2:33 PM on May 8 [8 favorites]


Policy changes: it is now OK to walk around outside without a mask in California, while for the past year it was not. There is diminished call for "disinfecting surfaces" like personal groceries OR public facilities, when before it was recommended.

Fact: CDC and WHO have changed their guidelines. Fact: those public changes far lagged the known information. Tufecki has been one of the sanest, most insightful voices throughout this past year. Anyone accusing her of click-bait isn't reading her well. Why is this such an argument?
posted by PhineasGage at 2:33 PM on May 8 [11 favorites]


The CDC's failure to acknowledge airborne transmission has undoubtedly led to the spread of Covid in the workplace. My large employer decided early on that CDC guidance and CDC guidance alone would dictate our response to Covid. I was involved in much of the early decisionmaking about safety protocols and if you couldn't cite to a CDC recommendation, it didn't happen. As a result we continued to hold meetings of unmasked people in closed rooms in unventilated buildings, as long the participants sat six feet apart.
posted by HotToddy at 3:03 PM on May 8 [17 favorites]


As a result we continued to hold meetings of unmasked people in closed rooms in unventilated buildings, as long the participants sat six feet apart.

It's unclear what time period you are talking about. The CDC was recommending general mask wearing at least from the beginning of April 2020, over a year ago.

Before that most scientists were working under the assumption that Covid-19 was like the previous SARS epidemic and was spread by symptomatic individuals who could be isolated. It was only with more data that they realized that Covid-19 was different and could be spread by asymptomatic individuals unknowingly. With that new knowledge came recommendations that everyone wear masks.
posted by JackFlash at 3:22 PM on May 8 [1 favorite]


They aren't new at all. I'm failing to see what is ground breaking in this op-ed and how it changes public guidance.

It’s pretty well documented that institutions have had to be dragged to acknowledge aerosol transmission and dragged again to take any kind of leadership in offering guidance on it. This recent update is less a sea change in and of itself and more symbolic of how sluggish the change has been all along.

And there’s absolutely a difference between the mental model of transmission provided by an emphasis on aerosols versus particles. It’s not “am I six feet away from other people?” It’s not “is there a plexiglass barrier between us?” And it’s not “has this table been disinfected?” It’s “how much of other people’s air am I breathing, for how long, and if I can’t avoid that can I filter it?” That should be at the top of everyone’s COVID safety checklist, and I suspect there are a lot of people for whom it still is not, because they are still installing plexiglass barriers instead of air filters.
posted by atoxyl at 4:56 PM on May 8 [16 favorites]


This recent update is less a sea change in and of itself and more symbolic of how sluggish the change has been all along ... And there’s absolutely a difference between the mental model of transmission provided by an emphasis on aerosols versus particles.

But there is no sea change. There is no emphasis on "aerosols vs particles." From the link in the op-ed the CDC says how it spreads:

1. Breathing in air with small droplets or particles that contain the virus when people are less than 6 feet apart -- Common

2. Breathing in air with small droplets or particles that contain the virus when people are far apart or have been in the same enclosed space for more than a few minutes -- Uncommon

3. Touching eyes, nose, or mouth with hands that have the virus on them -- Uncommon

In all cases they say to avoid poorly ventilated indoor spaces. Which is pretty much the same as always -- close up interactions are the major means of transmission.
posted by JackFlash at 5:49 PM on May 8 [1 favorite]


Welp, time to go back in time and kill Charles Chapin.

(is beaten repeatedly with a bamboo cane)

I have made a terrible mistake.
posted by BiggerJ at 6:01 PM on May 8 [3 favorites]


In all cases they say to avoid poorly ventilated indoor spaces. Which is pretty much the same as always…
Again, as late as October 2020, the same page made no mention of ventilation or enclosed spaces.
posted by mbrubeck at 7:09 PM on May 8 [7 favorites]


But there is no sea change.

Which is what I said. I’m really not sure what you’re arguing here. I don’t know the full timeline of updates to this website but mbrubeck has produced an example of a version that doesn’t acknowledge aerosols at all. I think Tufekci might agree with me that labeling items 2 and 3 on that list both simply as “uncommon” still understates the practical importance of the former relative to the latter, but at least they are items 2 and 3, respectively.
posted by atoxyl at 7:48 PM on May 8


It does appear that there are versions from earlier this year that acknowledge (albeit downplay somewhat) airborne spread, if that’s what you’re arguing (i.e. that the meaningful updates happened less recently than implied).
posted by atoxyl at 7:53 PM on May 8


The Governor of California shut down campgrounds, including back country ones, until January 28, 2021, despite the information that outdoors was safe so long as you didn't crowd together. I think it's fair to suggest messages have been mixed.
posted by small_ruminant at 8:46 PM on May 8 [10 favorites]


outdoors was safe so long as you didn't crowd together.

I always figured the "crowd together" thing was exactly why so many public spaces were getting shut down. Seriously, I think one of the hardest things about going out in pandemic is literally physically keeping distant from other people, especially when moving around in spaces with lots of other people in them. People move and wiggle and WANT to get close to each other. Not that I've been to the beach or whatever during any of this, maybe it's not as bad there, but I'm just seeing packs of people out everywhere a lot of the time these days and I guess they just don't care any more?

I'm not saying it's right, mind you, I just think that was probably some of the logic with that.

Also, "literally this stuff is in the air you breathe all over the place" scares the shit out of me and I don't know how the hell you combat that indoors without a whole lot of technological building changes that I'm assuming many organizations either don't wanna do and/or can't afford to do, so they'd rather do a lot of cleaning of surfaces and plexiglass installation.
posted by jenfullmoon at 9:34 PM on May 8 [6 favorites]


OP here. It's an epistemological problem. We live with a lot of noise and misinformation. Usually when two people disagree, trusting the person who's the expert makes sense. But in this case the conventional scientific wisdom turned out to be wrong, it took a while to correct the error (which is totally understandable), and listening to generalists like Tufekci would have been better.

I guess the Canadian metaphor is that you want to "skate where the puck is going" - when health officials are deciding on public health restrictions, you need to keep in mind that the scientific consensus can move during a novel emergency situation, and you want to keep an eye out for evidence that may lead to rethinking. Like the spread of Covid on the Diamond Princess, which according to Tufekci was a factor in the thinking of public health authorities in Japan.

Otherwise you can end up with workplace guidelines, e.g. wiping surfaces while disregarding ventilation, that are something like the Maginot Line. A lot of effort, but not very effective.

I'm also reminded of the observation that sometimes things work in practice even when we don't have a good understanding of how they work in theory. South Korea had gone through MERS recently, in 2015, so Korean officials had a good idea of what worked in practice. In a country like the US, which hadn't had a similar experience in recent memory, health officials would have been relying more on theory.
posted by russilwvong at 9:39 PM on May 8 [8 favorites]


Otherwise you can end up with workplace guidelines, e.g. wiping surfaces while disregarding ventilation, that are something like the Maginot Line.

I think all the useless bollocks you have to go through at the airport is a better analogy, because what this is is contagion control theatre. It's hard and expensive to do the right thing, so let's just do stuff that's very visible and disruptive, but easy and cheap.
posted by Dysk at 11:08 PM on May 8 [10 favorites]


Also, "literally this stuff is in the air you breathe all over the place" scares the shit out of me and I don't know how the hell you combat that indoors without a whole lot of technological building changes

Indoors isn't going to be suuuper safe in an airborne pandemic no matter what but using n95 masks instead of whatever trash piece of cloth someone found under the couch would make a big difference. And they've been easily available for order online post the first few months of the pandemic.

Yeah you still can't really order the gold standard 3M 1860 n95 health care particulate respirators unless you're a hospital or something but the foldable ones being produced in the hundreds of millions are still way better than an old bandana or whatever.

(Another implication of covid being aerosol is that the experts should have been pushing universal n95 masking from the very beginning. Which some folks have been saying since, again, the very beginning.)
posted by Justinian at 11:22 PM on May 8 [5 favorites]


dysk: It's hard and expensive to do the right thing, so let's just do stuff that's very visible and disruptive, but easy and cheap.

??? During Covid, countries have done a lot of super-expensive stuff - basically shutting down entire sectors of the economy (travel, tourism, restaurants), spending hundreds of billions on unemployment spending and wage subsidies, spending billions on vaccine development and production.

I disagree with the "theatre" framing because it implies that health officials knew what they were mandating was useless. What seems to have happened is that health officials who were following WHO and CDC guidelines believed they were doing the right thing - but it turns out that a lot of what they were doing was not useful, because WHO and CDC were wrong in their theory about how Covid spreads.
posted by russilwvong at 11:26 PM on May 8 [2 favorites]


The opening up that's happening around me is full of activities that are very visible, but almost completely useless. The UK government cannot still be claiming to be following the science, nor can the retail establishments following them, while they're all about wiping down surfaces and plexiglass screens, etc, etc, and doing nothing to address ventilation and airflow. That would be too expensive. Let's do some irrelevant, visible shit to reassure people instead.

Theatre.
posted by Dysk at 11:47 PM on May 8 [10 favorites]


(And I don't dispute that lots of expensive stuff was done. It's just that it really feels like the appetite for that is slipping, and so we have the grand but empty gestures replacing it: screens at the bar, rather than the bar staff being paid to keep the place shut, shops and hairdressers having to clean every surface with alcohol every hour, rather than being paid to stay shut, and so on. They could have opened them up and mandated a minimum number of air changes, filtered ventilation, etc, but they didn't. They went with the stuff that's very easy to see, and comparatively cheap to implement.)
posted by Dysk at 12:05 AM on May 9 [3 favorites]


Tufekci claims that outdoors is safer than indoors and that indoors spaces should be ventilated is new.

Uh, no?.. The article is all about how even though the theory of aerosols has been around for quite some time, only now are public agencies changing their guidance in meaningful ways. Tufecki has been talking about aerosols since at least the beginning of last summer. She knows these claims aren't new because she's been making them for months.
posted by oneirodynia at 12:10 AM on May 9 [12 favorites]


I work at a college that reopened for in-person classes in August 2020 and has been maintaining the fiction since June that as long as we disinfected every surface, wore masks, and stayed 6 feet away from each other, everything was going to be fine. And it's honestly really hard to tell how much of that was the scientific information people were picking up from the media, and how much of that was a capitulation to financial necessity:

The college is going to lose too much revenue to survive if we don't reopen for in-person classes; therefore, we're going to reopen for in-person classes; therefore, we're going to do our level best to collectively pretend that we can reopen for in-person classes in a way that's safe for students and faculty.

I also live in a state where everything has been open since summer 2020 because the governor said so, and at some level I think a lot of people believe that if the government says that we can reopen safely then it can't be that bad.

Things really are different in the rural midwest, not just in terms of policy and not just because of anti-mask conspiracy theorists. It's in the way people build their own ideas about scientific information based on what the other people in their life are saying and doing, it's in the way that the radio keeps advertising socially distanced gun shows and bridal shows and home decor shows. People really believe, because they want to believe it, that they can spend a ton of time in poorly ventilated indoor spaces as long as they stay six feet apart. And when I got sick in November (and I tested negative, but I had a pretty hard time with things like breathing and moving), nobody recommended that my coworkers be tested or quarantined, because even though we'd spent hours in the same enclosed spaces, we hadn't spent fifteen minutes within six feet of each other.
posted by Jeanne at 4:26 AM on May 9 [21 favorites]


The article is all about how even though the theory of aerosols has been around for quite some time, only now are public agencies changing their guidance in meaningful ways.

But that isn't true. Nothing has changed in any meaningful way. Even today the CDC says that long distance aerosols are not the primary means of transmission, so it changes nothing. The suggestions are the same we have been following for a year -- use masks, social distance, avoid crowded places, especially indoors.

She has an ax to grind with the CDC. It's her thing. Some people want to have someone to blame for this bad year so there's a market for her stuff.
posted by JackFlash at 6:17 AM on May 9 [1 favorite]


Politics, including signaling, keeping the economy working and plain old bureaucracy, might explain a lot more of this than an actual lag in scientific understanding. I am not a research scientist but know many and when my state in the US closed public parks in April 2020 it was well understood that this was at best a misguided attempt to convince people to take COVID seriously and at worst a theatrical display that would make things worse by forcing people indoors. Everyone knew the bad spreading events were all connected to poor indoor ventilation. Both the WHO and the CDC are ultimately political institutions, not clearinghouses for scientific knowledge.
posted by ecreeves at 6:52 AM on May 9 [3 favorites]


Did the CDC say to close public parks? I thought states closed public parks, for their own reasons.
posted by tiny frying pan at 6:56 AM on May 9


tiny frying pan, you are correct. My point was that actual individual scientists looking at the case studies had a good idea what was driving this for the most part back in April 2020. What the states did and what the CDC and WHO recommended were driven by many more factors than just scientific understanding.
posted by ecreeves at 7:18 AM on May 9 [5 favorites]


I'd like to hear the anonymous, off-the-record oral history of policy meetings at the CDC, WHO, EU CDC equivalents, etc; presumably there were minorities in all of them who pushed for this and were rebuffed in various ways, but exactly how would be interesting to hear.

What I remember reading was that people tried to being this up at the WHO early on, but were essentially shouted down by a few people who were adamant about stressing handwashing above and beyond any other factor, and who viewed any evidence that was not something like a randomized controlled trial to be inadmissible. It’s a similar situation to when they said there was no evidence that people couldn’t be reinfected: technically true but incredibly misleading (vs. something like “we don’t have any data on how strong immunity is post-infection or how long it lasts”). This was obviously way too conservative an evidentiary standard for a rapidly evolving situation like a novel pandemic. Plus as the article said there was a sort of paternalistic dimension about not trusting people to make the right decisions if given all the information.
posted by en forme de poire at 8:31 AM on May 9 [6 favorites]


I think one factor is that when there's an all-out assault on science itself, it becomes a lot harder to point out science that's actually below the best quality.
posted by TheophileEscargot at 9:16 AM on May 9 [5 favorites]


BTW in terms of practical advice, here is an excellent FAQ written by some aerosol scientists and engineers. A HEPA filter taped to a box fan will be more useful than endlessly wiping down surfaces. It also covers some cheap ways of estimating aerosol concentration using CO2 meters.
posted by airmail at 9:47 AM on May 9 [6 favorites]


Just as a data point, here's the document produced by my kids' school district in February about what they had been doing all winter to get schools ready to open again in person. It is almost entirely about upgrading the air filtration system (including HEPA in the nurse's office, something they were not able to do for the entire building) and increasing outdoor airflow. Everything not having to do with ventilation (surface cleaning, desk distancing, masks) are in a short section at the end called "Other COVID 19 Mitigation Practices in Place." It really seems to me like "ventilation is the key thing for situations where it's important to bring a lot of people together indoors" has been a basic part of the POV of government decisionmakers for a long time now.
posted by escabeche at 1:17 PM on May 9 [2 favorites]


I pretty much wrote off social distancing as wishful thinking when I saw people arguing about if you needed to be 6'1" or a full 7' apart to be outside the covid range and 100% safe.

I dunno what aerosol fluid dynamics simulation package they use at the CDC, but I've seen youtube videos of dudes vaping. Lol 6 ft.
posted by ryanrs at 2:05 PM on May 9 [1 favorite]


escabeche, my mother's school really paid attention to ventilation and air flow too, but they got a grant over the summer to upgrade their ventilation system, and it was definitely more than most other schools in their state were doing, unfortunately.
posted by eviemath at 4:21 PM on May 9


There was that aerosol visualization in the Vietnamese public service music video back in March 2020. I've avoided indoor spaces since.
posted by romanb at 10:43 PM on May 9 [1 favorite]


It really seems to me like "ventilation is the key thing for situations where it's important to bring a lot of people together indoors" has been a basic part of the POV of government decisionmakers for a long time now.

Maybe that's true in the "People's Republic of Madison" but do you think is true in, say, Rib Lake or Appleton? I've spent good portions of the school year in several different schools here in Iowa, and I can't say I've been especially impressed. Six feet is wishful thinking in the schools I worked in. Maybe 50% of students and staff properly wear their masks. I was literally given advice to pull my mask off my face so students could hear me better. The college I'm attending is about the same.

Me? I've been wearing a 4-layer mask (two woven cotton, two non-woven disposable shop towels) religiously and hoped like hell I wouldn't get sick before I got my vaccine shots last month.
posted by Big Al 8000 at 11:01 PM on May 9


"ventilation is the key thing for situations where it's important to bring a lot of people together indoors"

I still feel the direct evidence of arisolized transmission via mechanical ventilation impacting the spread is pretty weak. I'm pretty sure that too many people just saw that cheesy movie Contagion where Dustin Hoffman says "It's in the vents" and are moving on from that.

First, 'adequate mechanical ventilation' is undefined, but my area's schools have been opened a long time, they have weak old 1970s ventilation systems, and they have had very few cases of COVID. Bars have been opened a long time, and now there are several stores that are maskless. Every place is air conditioned, but I'm sure they don't all have new HEPA filters and most certainly haven't upgraded their systems.

Not only that, hispanic and black populations have suffered way more from COVID, and they, on average, have less central air conditioning than upper middle class Caucasians do.
Not only that, if ventilation was an issue, then winter should see dramatic increases in cases where radiated heat becomes more common and air-pushed heat less common. Winter on average should see dramatically higher number of cases, as people spend more time indoors, just like the flu.

But those don't seem to be significant factors, and that needs an explanation. Small towns haven't generally been ravaged- again less A/C usage.

It seems currently that *any* centralized A/C system moves air enough to combat COVID.

Basically, I'm surmising that we have the evidence to judge A/C as a factor and it's really not one. Completely ventilated spaces - gyms, concerts, etc? Who knows?

Going one step farther, my kids' school has had so few cases, they have already said next fall is mask optional return to normal school protocol. Now you could cynically say they are ignoring the dangers, but the district is 60,000 students and has multiple doctors on staff, so I disagree they made this decision lightly or without evidence. Their school was built in the 1970s, is prison-ish with few windows (zero in many classrooms) so one could say this will be a really good test case as to real causes of COVID transmission.

It would be really nice if COVID would only punish the risk-takers and give us clear evidence of what to do, but life just doesn't work that way.
posted by The_Vegetables at 8:40 AM on May 10


People without AC open their windows, which provides way more ventilation than your average small air conditioner. The recommendations even my campus is following involve changing the AC settings to continuously bring in fresh air rather than recirculate. I suspect it's the fresh air versus recirculation that makes the difference, rather than the air conditioner.
posted by hydropsyche at 9:13 AM on May 10 [4 favorites]


that cheesy movie Contagion where Dustin Hoffman says "It's in the vents"
Side note: The cheesy movie with Dustin Hoffman was Outbreak (1995). Contagion (2011) was the non-cheesy movie with Matt Damon which was actually based on very accurate science! I highly recommend the latter, not the former.
posted by mbrubeck at 9:24 AM on May 10 [1 favorite]


A very long Twitter thread by Jose-Luis Jiminez:
TIME FOR SOME AIRBORNE + DROPLET HISTORY

Now that @WHO and @CDCgov have finally accepted *after a year of denial and delays* that airborne transmission is a major mode for COVID-19, it is time to review the history to try to understand why this response was so poor.

@zeynep published an outstanding article yesterday in the @nytimes where she explains the context, the implications, and some of the history.

I wanted to give some more historical detail, without the word limits that she faced in @nytimes.
posted by russilwvong at 10:04 AM on May 10 [6 favorites]


Now that @WHO and @CDCgov have finally accepted *after a year of denial and delays* that airborne transmission is a major mode for COVID-19,

This is absolutely false and a good reason not go get your health information from twitter. The CDC has not said that airborne transmission is major. They have said just the opposite, that it is uncommon.

The CDC has said:
1. Breathing in air with small droplets or particles that contain the virus when people are less than 6 feet apart -- Common

2. Breathing in air with small droplets or particles that contain the virus when people are far apart or have been in the same enclosed space for more than a few minutes -- Uncommon

3. Touching eyes, nose, or mouth with hands that have the virus on them -- Uncommon

It's amusing (not really) that people ridicule wiping down surfaces for fomites as "security theater" and simultaneously trumpet long distance aerosol transmission as a momentous revelation. Both of these the CDC rate as "uncommon."

The CDC guidelines are the same as always. Most transmission is by close contact within 6 feet. Both fomites (surface contamination) and aerosols (long distance transmission) are considered uncommon. Not impossible, just uncommon and probably not worth spending lots of effort on. Masking and social distancing are still the key strategies.
posted by JackFlash at 10:22 AM on May 10


JackFlash: The CDC has not said that airborne transmission is major. They have said just the opposite, that it is uncommon.

What your quote says is that airborne transmission over longer distances is uncommon.

Scientific Brief: SARS-CoV-2 Transmission
Infectious exposures to respiratory fluids carrying SARS-CoV-2 occur in three principal ways (not mutually exclusive):

(1) Inhalation of air carrying very small fine droplets and aerosol particles that contain infectious virus. Risk of transmission is greatest within three to six feet of an infectious source where the concentration of these very fine droplets and particles is greatest. ...

Transmission of SARS-CoV-2 from inhalation of virus in the air farther than six feet from an infectious source can occur

With increasing distance from the source, the role of inhalation likewise increases. Although infections through inhalation at distances greater than six feet from an infectious source are less likely than at closer distances, the phenomenon has been repeatedly documented under certain preventable circumstances. These transmission events have involved the presence of an infectious person exhaling virus indoors for an extended time (more than 15 minutes and in some cases hours) leading to virus concentrations in the air space sufficient to transmit infections to people more than 6 feet away, and in some cases to people who have passed through that space soon after the infectious person left. Per published reports, factors that increase the risk of SARS-CoV-2 infection under these circumstances include:
  • Enclosed spaces with inadequate ventilation or air handling within which the concentration of exhaled respiratory fluids, especially very fine droplets and aerosol particles, can build-up in the air space.
  • Increased exhalation of respiratory fluids if the infectious person is engaged in physical exertion or raises their voice (e.g., exercising, shouting, singing).
  • Prolonged exposure to these conditions, typically more than 15 minutes.
posted by russilwvong at 10:36 AM on May 10


Transmission of SARS-CoV-2 from inhalation of virus in the air farther than six feet from an infectious source can occur

Yes, but the CDC says that is "uncommon." So this momentous revelation that people are spouting changes nothing. Close distance is still the major cause of transmission. The CDC rates both long distance transmission and surface contamination as "uncommon. So if wiping surfaces is considered "security theater" then so should HEPA filters. Both may help but neither may be majorly significant. Some people are making this aerosol thing a big deal when it really is not according to the CDC.
posted by JackFlash at 11:11 AM on May 10


JackFlash: Close distance is still the major cause of transmission.

You seem to be equating "aerosol transmission" with "long distance," and "droplet transmission" with "close contact." You can get aerosol transmission at close distances even when the infectious person has no symptoms at all - they're not producing droplets by coughing or sneezing, just aerosols by breathing or talking. Diagram.
posted by russilwvong at 11:21 AM on May 10 [10 favorites]


JackFlash you seem impervious to facts in this conversation. Many comments upthread have included specific citations of the science and of the major health agencies' changing guidlines, all directly related to the original article's points about how and why these bureaucracies didn't serve the public well.

Your use of "common" and "we all knew" doesn't refute the specifics of the original article nor the comments above. What main point are you trying to make, in your repeated comments here? That CDC and WHO did a good job and communicated well to the public?
posted by PhineasGage at 11:27 AM on May 10 [7 favorites]


You can get aerosol transmission at close distances

Oh, for sure. But that isn't what the "aerosol" advocates are saying. They are claiming that if aerosol transmission is possible, then HEPA filters and ventilation changes everything. They are saying aerosols mean that long distance transmission is a major cause of infection. That's why they are making such a big deal about aerosols. But the evidence does not support that.

Otherwise "aerosols" really isn't anything new. Scientists don't even agree on the definition of aerosols vs droplets -- is it 2 µm, 5 µm, 10 µm, 20 µm, or even 100 µm. What the CDC is saying is that whatever you call it, aerosols or droplets, that close contact is the major factor. Long distance transmission, by aerosols or whatever, is uncommon.
posted by JackFlash at 11:32 AM on May 10 [4 favorites]


What main point are you trying to make?

Just trying to set things straight. When I see garbage like this:

Now that @WHO and @CDCgov have finally accepted *after a year of denial and delays* that airborne transmission is a major mode for COVID-19

Not only is it totally wrong, it is needless fearmongering and dangerous if it leads to incorrect public responses.
posted by JackFlash at 1:11 PM on May 10


JackFlash: I have no idea what point you're trying to make. No, it's not "anything new" because we've known this since at least the Mount Vernon, Washington choir superspreading event over a year ago, not to mention the Vietnam Airlines cluster, the Guangzhou restaurant cluster with the air conditioner, hotel transmission in New Zealand quarantine, and the recent cluster on a New Delhi-Hong Kong flight, just to name a few such reports off the top of my head. If you're the sort of person who spends time reading Emerging Infectious Diseases on a regular basis, it's not new, but since that's not most of the population, and most people were never even really given or absorbed basic guidance like "outdoors is safer than indoors," this is new. A lot of people have operated under the mistaken belief, a belief grounded in the messages they received over the past year, that they can crowd into poorly-ventilated indoor spaces 6' apart all day long and magically be safe, something with significant impact on workplaces and schools, and we've had evidence all along that's simply not true. We've had many, not all but many, workplaces and schools obsessively focus on cleaning and sanitizing surfaces while doing nothing to address ventilation.

Governments in the US, at all levels, by and large have done a poor job of effectively communicating accurate and practical information about how the virus spreads and how people should behave as a result. The failure to acknowledge airborne transmission and create policy around it has been a major part of that problem.
posted by zachlipton at 1:12 PM on May 10 [6 favorites]


Not only is it totally wrong, it is needlessly fearmongering and dangerous if it leads to incorrect public responses.

Could you perhaps give an example of what you believe a dangerous "incorrect public response" would be to this information?
posted by zachlipton at 1:12 PM on May 10


Side note: The cheesy movie with Dustin Hoffman was Outbreak (1995).

Starting Ross' pet monkey Marcel.
posted by mikelieman at 1:24 PM on May 10


Could you perhaps give an example of what you believe a dangerous "incorrect public response" would be to this information?

If people started demanding millions of dollars to retrofit schools with HEPA filters and keep their kids out because of the "aerosols". If people stopped going to grocery stores because the air is filled with "aerosols". The CDC considers these types of transmission to be uncommon. You've already had people above complaining about the "security theater" of wiping surfaces. You don't want to add another about aerosols. You don't want distractions from what the CDC thinks is most important -- masking and social distancing.
posted by JackFlash at 2:59 PM on May 10 [2 favorites]


Mod note: Hey JackFlash, maybe give this thread a little breathing room, please. Thank you.
posted by jessamyn (staff) at 3:50 PM on May 10 [2 favorites]


There's documented transmission in a South Korean restaurant at 21' with five minutes of overlap and you're worried people might have overreacted if they were told about airborne transmission? A reasonable reaction to that information, coupled with other information, might well have been to not have indoor dining—and pay workers and restaurant owners to stay closed—in areas where the virus isn't well-controlled. A reasonable reaction to that information would be to not think of opening indoor bars in areas with active community spread. That is certainly not what many parts of the country did. Don't you feel that kind of information is something that restaurant workers, bartenders, meat packing plant and other agricultural processing workers, and everyone else required to work in indoor spaces with others, especially spaces filled with unmasked people, deserved to know? A reasonable reaction to that information might be to not have indoor religious services where people sing, especially without masks, because they think they're safe sitting 6' apart. A reasonable reaction to that information might have involved workers demanding N-95 masks instead of just being told to keep 6' apart.

The issue with the "security theater" of wiping surfaces wasn't that people wasted their time and bought too many Clorox products. The issue is that people falsely believed they were in a safe environment because of the surface cleaning when they were actually in high risk environments. Why possibly would it be a dangerous and incorrect response to demand better ventilation and air filtration in schools where kids and teachers sat in stuffy classrooms all day during a respiratory pandemic?

581,000 people and counting in the US alone have died, and you're worried people might have overreacted if they were given more information about the transmissibility of the virus? We wildly underreacted.

There's been a persistent pattern throughout the pandemic of health authorities trying to do exactly what you're talking about, trying to gauge the second and third order effects of communicating scientific information out of fear for how people will behave if they have it instead of simply clearly and accurately stating what we know, how sure we are, and what we're uncertain about. Fear of how people would react to information is the thought process that gave us official advice not to wear masks. Public health information needs to be accurate and reflect what we know about transmission, not the virus as we wish it was, even if that makes people alarmed or exposes wishful thinking approaches to infection control as useless.
posted by zachlipton at 3:52 PM on May 10 [17 favorites]


> zachlipton: "trying to gauge the second and third order effects of communicating scientific information out of fear for how people will behave if they have it instead of simply clearly and accurately stating what we know, how sure we are, and what we're uncertain about. Fear of how people would react to information is the thought process that gave us official advice not to wear masks."

This was one of the weirder aspects of this whole thing to me. I was previously following along the evolution of this in Dr. Michael Osterholm, the head of CIDRAP (Center for Infectious Disease Research and Policy) at U. Minn. Earlier on in the pandemic, he had voiced some skepticism on the efficacy of masks and face coverings but, even more, he was (probably rightly) ticked off at a lot of the rather sketchy studies that were circulating to justify the use of masks. The thing is, at the same time, he was speculating that maybe we shouldn't be encouraging mask use because that might make people behave less scrupulously in other ways. But when I heard that, I wondered why he could take that kind of second-order effect for granted (presumably with even less scientific evidence) while the first-order effects of simply wearing the masks could not.

Anyways, Osterholm ended up for a little while getting cited a lot by hardcore anti-maskers and he did eventually turn around his stance. You can get some of the flavor of this whole thing here in this transcript (pdf) from one of his podcast episodes from June 2020 where he goes into why he was so skeptical earlier and how he's less skeptical (though not actually convinced, it seems) by then.
posted by mhum at 4:57 PM on May 10 [6 favorites]


he was speculating that maybe we shouldn't be encouraging mask use because that might make people behave less scrupulously in other ways

I think there's been an undercurrent of fear of risk compensation throughout the pandemic, that if we tell people to wear masks or socialize outdoors or take low-cost rapid screening tests and we're not absolutely positively sure about the science, it will backfire and people will engage in riskier behavior as a result. We saw that in some places last winter, with authorities actively trying to discourage people from getting tested before family gatherings over the holidays for fear people would interpret negative test results as a green light to have unsafe events, nevermind that people were having the gatherings anyway.

And I get the fear—it's more difficult to explain "please don't gather at all, but if you do gather anyway, do it outdoors"—but there's been some really solid opposition to that approach from physicians who have been proponents of harm reduction in general, especially from the HIV and addiction medicine community, arguing that it's paternalistic to withhold information that can help people make safer choices for fear it might be misused. And that approach leads to some interesting messaging, like the "Three C's" flyer in Japan, that presented information that wasn't widely distributed and acted upon in many parts of the US.

We did a bunch of wildly big and expensive things to help prevent COVID transmission more-or-less on the precautionary principle (see Fauci's "if it looks like you're overreacting, you're probably doing the right thing"), like shutting down entire segments of the economy, yet when it came to smaller actions that appeared likely to help but about which we didn't yet have really thorough evidence—like masking, screening testing, harm reduction approaches to risk messaging, and ventilation—all of a sudden the evidentiary standard became much higher and everyone got all concerned with "well if we tell people this information, then they'll make other riskier choices" thinking instead of just clearly communicating what we knew and what we didn't.
posted by zachlipton at 5:39 PM on May 10 [13 favorites]


> zachlipton:"We did a bunch of wildly big and expensive things to help prevent COVID transmission more-or-less on the precautionary principle [...] like shutting down entire segments of the economy, yet when it came to smaller actions [...] all of a sudden the evidentiary standard became much higher and everyone got all concerned [...]

I could have sworn that I read a comment here on the blue that this was part of the reasoning that Sweden adopted in not shutting down their economy -- namely, that there was insufficient scientific basis for it. Which, of course, invites allusions to this classic paper evaluating the RCT data regarding the effectiveness of parachutes in preventing major trauma related to gravitational challenge.
posted by mhum at 6:07 PM on May 10 [4 favorites]


The hotel quarantine cases in Australia (where people caught COVID from other infected travellers despite quarantining in their own rooms) are good evidence that sometimes aerosol spread happens. (There were also cases where nurses at the nursing station away from positive patients got infected.)

There was a comment on metafilter that stuck with me- they did all the precautions, saw no-one and still the daughter caught COVID. The comment that if you can hear noises from another room in a hotel, there's an air gap, obviously cooking smells etc sometimes spread between apartments. Is apartment living a risk factor for COVID? That is absolutely horrifying if true.

On restrictions and whether or not they were warranted: A few people have mentioned the public parks, back country camping etc being closed down. Remember at the start of the pandemic, they were trying to reduce COVID risk but also regular risk risk. Don't do silly stuff that might get you injured and then require a hospital bed, beds being a finite resource. As well as trying to stop the spread, authorities (at least here in Australia) were trying to protect hospital capacity in case we needed it.

So yeah when we had the fishing ban in my state, people were like "how am I going to catch covid all by myself wetting a line?" But it wasn't just about covid risk.
posted by freethefeet at 6:18 PM on May 10 [2 favorites]


Here's the result of that "Nordic experiment," with Sweden not shutting down, while Finland and Norway did: not good.
posted by PhineasGage at 6:26 PM on May 10 [4 favorites]


The hotel quarantine cases in Australia (where people caught COVID from other infected travellers despite quarantining in their own rooms) are good evidence that sometimes aerosol spread happens.

One instance of hotel spread was blamed on a quarantined guest using a nebuliser. There was a whole lot of back-and-forth about whether he had told staff about it or what, but the story clearly was: this man used a nebuliser, and that caused the breakdown of quarantine via the spread of infectious droplets, and consequently a third lockdown here in Victoria.

Except, it now allegedly turns out that there were a lot of breaches by staff, including by the general manager of the government agency COVID-19 Quarantine Victoria (CVA), and the current belief is that the initial spread occurred when another quarantined guest was being swabbed, in the open doorway of her room, and that currents from the air conditioning blew virus particles down the hall, outside the room where the man with the nebuliser and two other persons were staying. I think the current assessment is that the man with the nebuliser was the second person to contract the disease, and he passed it on to the other persons in the room as well as a person next door and someone working below.

Be that as it may, if guidelines had warned people about the potential spread of the disease by aerosols I don't think we'd have been so complacent about sticking a bunch of potentially infected people in hotels, or letting them stand in doorways with an air conditioner at their backs. We'd also have done things like provide better (or, honestly, any) natural ventilation, and not switched the A/C off at nights to save money. And we probably wouldn't have been so hard on the guy with the nebuliser, while ignoring other transmission routes.
posted by Joe in Australia at 8:27 PM on May 10 [6 favorites]


Stat, CDC’s slow, cautious messaging on Covid-19 seems out of step with the moment, public health experts say
“In every public health crisis the complaint is made that the CDC is too slow to make recommendations,” said Besser, who served as the acting CDC director in 2009. “It’s an issue that the CDC has always grappled with and will continue to grapple with.”
posted by zachlipton at 9:10 AM on May 11 [1 favorite]


More on how and why CDC's estimate that less than 10% of transmissions happened outdoors is still much too high.
posted by PhineasGage at 9:43 AM on May 11 [3 favorites]


I always struggle with how much to bring this up during staff meetings. You don't want to make people feel less safe but on the re-opening call (I work in a public high school), there's people asking about what the procedure will be for bringing bags into the building because at their church(!!!) they have a rule that only car keys can be brought into the church where they'll all stand next to each other singing without masks on for two hours.

People's mental wellbeing is also important, I get that, but it's like the church needs these crazy rules about leaving bags outside because there's nothing they can do to change the underlying risk of bringing people together in a small, enclosed space for hours.

At school, not only do we all have our own PPE in each classroom, but the cleaning staff come in to wipe down the desks that each student was sitting at, between each period, like in a restaurant. I think this choice was made based on asking staff what would make them feel safest to return to work. And it works for that purpose, everything thing feels purposeful and under control. Meanwhile, as another part of the re-opening plan we've gone from a half-day schedule, which would have allowed students to each lunch at home, to a full-day schedule where they're all eating together in the cafeteria.

We can talk about how much "we knew" about the fact that the virus spreads through the air in badly-ventilated indoor spaces, but it is really important to have this messaging coming from the top. Telling people their obsession with hand sanitizer is safety theater just makes me feel like a jerk, taking away people's one figleaf of control in a situation they can't control. I'd love for this messaging to come from somewhere else and be common, accepted wisdom so we can actually keep people safe and I don't have to be the bad guy.

On the plus side, the school reopening plan in New Jersey included money for schools to improve their ventilation systems. So that part was known and implemented, and all the rest seems to be helping with everyone's peace of mind. But please, let the people who are paid to be experts be the bearers of bad news. It's not fair to put that cost on individuals.
posted by subdee at 10:14 AM on May 11 [12 favorites]


Somewhat related, line cooks have one of the highest COVID mortality rates of any profession. Restaurant kitchens are notoriously hot, badly ventilated and crowded. And going to a takeout model doesn't do anything to help the cooks.

https://www.jacobinmag.com/2021/05/service-industry-workers-minimum-wage-welfare-benefits-coronavirus

Business owners around the country are offering up a lament: “no one wants to work.” A McDonalds franchise said they had to close because no one wants to work; North Carolina congressman David Rouzer claimed that a too-generous welfare state has turned us all lazy as he circulated photos of a shuttered fast-food restaurant supposedly closed “due to NO STAFF.”

Most of these complaints seem to be coming from franchised restaurants. Why? Well, it’s not complicated. Service workers didn’t decide one day to stop working — rather huge numbers of them cannot work anymore. Because they’ve died of coronavirus.

posted by subdee at 10:24 AM on May 11 [10 favorites]


A McDonalds franchise said they had to close because no one wants to work;

Have you seen the masks that McDonalds made for workers? They’re a fucking joke. Sheets of foam that don’t fit loosely on the face.
posted by Big Al 8000 at 10:53 AM on May 11 [1 favorite]


And going to a takeout model doesn't do anything to help the cooks

Well, to be fair it's not enough but it's not nothing. If you don't have hundreds of random customers coming in and breathing up the joint/servers running between possibly infected diners and the kitchen, the potential exposures ARE less. But they're not zero and unfortunately it only takes one infected person in those close kitchen quarters to bring about a real disaster.
posted by We put our faith in Blast Hardcheese at 12:05 PM on May 11 [3 favorites]


Meanwhile, as I was looking up with Osterholm has been up to since I stopped following along his mask evolution, I notice that he was one of the co-signers on an open letter to the CDC, White House, and Dr. Fauci (pdf) from February 2021 urging them to be more forceful in their recommendations regarding inhaltion exposure for Covid:
In October, the CDC recognized inhalation as a route of exposure that should be controlled to protect against COVID-19 [9], but most CDC guidance and recommendations have not yet been updated or strengthened to address and limit inhalation exposure to small aerosol particles. CDC continues to use the outdated and confusing term “respiratory droplets” to describe both larger propelled droplet sprays and smaller inhalable aerosol particles. It also confuses matters with “airborne transmission” to indicate inhalation exposure exclusively at long distances and does not consider inhalation exposure via the same aerosols at short distances.

This artificial distinction needs to be replaced with up-to-date terminology [10], as advocated by the National Academies workshop on Airborne Transmission [11], focused on routes of exposure via a) touch, b) large droplets sprayed onto the body, and c) inhalation of small aerosol particles [12].

CDC guidance and recommendations do not include the control measures necessary for protecting the public and workers from inhalation exposure to SARS-CoV-2. Most recommendations from other agencies are also out of date.
Here's an article that provides a summary.

As well, the latest episode of Osterholm's podcast has a discussion of the recent updated WHO guidance (discussion starts around the 17-minute mark, transcript here):
Well, this is amazing, this language change. This was many years in coming and after much research. So the fact that now WHO surely recognizes and endorses the point of aerosols, this has a lot to do about what do we do to reduce transmission? What kind of masking or respiratory protection do we need? What kind of building ventilation do we need? What does indoor versus outdoor air mean? So this is a great step forward. Now we need to see what CDC is going to do.
posted by mhum at 2:54 PM on May 11 [3 favorites]


On the plus side, the school reopening plan in New Jersey included money for schools to improve their ventilation systems

Unfortunately, I have bad news about how a number of schools in New Jersey spent that money.

This is another reason why timely clear guidance from the top would have helped; somebody might have tried to stop schools from buying ozone emitters instead of safe and effective strategies that don't result in big paydays for manufacturers, like "more outside air pumped into classes, MERV 13 filters in heating systems and portable HEPA filters"
posted by zachlipton at 3:25 PM on May 11 [6 favorites]


-_-
posted by subdee at 3:49 PM on May 11


"more outside air pumped into classes, MERV 13 filters in heating systems and portable HEPA filters"

Honestly, what many buildings (not all, obviously!) need is just openable windows.
posted by Joe in Australia at 4:17 PM on May 11 [3 favorites]




This all seems very sweaty and about 10 months ago. There are two weird nonintersecting conversations in this thread. Some people are saying: "we wear masks and have avoided indoor spaces for the past year." Other people are saying: "we just discovered that you should wear masks and avoid indoor spaces!"

There's a total disconnect and I guess it has to do with CDC politics? Really in-the-weeds stuff.

It's a very good vaccine so what's up dudes.
posted by mr_roboto at 11:02 PM on May 11 [3 favorites]


There's a total disconnect

Because the CDC and the politicians kept walking back the science to say things that were friendlier to businesses and schools re-opening last May (and again this May). They didn't want to say anything too scary like "this virus spreads indoors at any distance unless you are wearing hospital-grade masks, have good ventilation and have the windows open" because that solution was a lot more difficult and less visible than wiping down the tables between customers and keeping apart.
posted by subdee at 7:46 AM on May 12 [2 favorites]


There are two weird nonintersecting conversations in this thread. Some people are saying: "we wear masks and have avoided indoor spaces for the past year." Other people are saying: "we just discovered that you should wear masks and avoid indoor spaces!"


Yes, because they just did.

Metafilter tends toward the type of user who obsessively researches, goes straight to primary sources, has facility with and access to various professional publications, and as such has a deep and intimate knowledge of the expert opinions on COVID from basically March 2020 onward.

The ordinary person, particularly in the United States, does none of these things and in fact has an extremely loose and incorrect perception of what all is actually going on and they stopped paying attention a while ago when hand san and plexiglass were The Thing; they are still leaving their groceries on the porch for a day and microwaving their mail because that's what they heard last, and nobody frankly has gone to great effort to tell them otherwise because that would be Bad For Business.
posted by We put our faith in Blast Hardcheese at 8:26 AM on May 12 [5 favorites]


And some of us disagree that is the case, I think. I have heard nothing from major media outlets for a year but that gathering outside and wearing masks is ideal and that indoors is risky. I don't think it was THAT possible to miss that messaging. People's experiences are all over the map on this I'm sure, but that's all some are saying in this thread - that this messaging for them and their area was extremely hard to miss.
posted by tiny frying pan at 8:58 AM on May 12 [1 favorite]


that this messaging for them and their area was extremely hard to miss


In my major metropolitan, largely blue, largely pro-vaxx and pro-science area, yes. News outlets have been banging the outdoors-is-best drum all along. However, when someone is walking around town and sees that all of the indoorses are open, all of the schools are open, all of the bars are full, etc., they are just as likely to think "well I guess the news is just overreacting then" as they are "oh no, what a terrible idea, given the science."

Cities in the US have been very much "do as we say, not as we do" and when one is accustomed to writing off the news as sensationalist (which in general, Mefites are happy to do), it's the faulty evidence of one's lying eyes that wins out.
posted by We put our faith in Blast Hardcheese at 9:29 AM on May 12 [2 favorites]


that this messaging for them and their area was extremely hard to miss

In my Fox-watching, mask-hating, OpentheState rally-friendly area, most folks still use words like "hoax," "lie," "power grab by the governor," and "media is blowing this virus way out of proportion" to terminate any conversational thread about how dangerous and easily-spread COVID-19 is. Mask-wearers are vastly outnumbered by half- and no-maskers, and anti-mask folks point to the gyms and restaurants and schools being open as proof that there's no threat to public health, and as heroic action against an oppressive government. They do not want to hear messaging about mitigation, or care about changing guidance, when their high school friends on Facebook--now local elected representatives--are also telling them that all of this, illness and safety measures alike, is bullshit that gets in the way of earning a paycheck. They. Don't. Care. Changing guidance is only proof that the scientists never knew what they were talking about. Not that my double-masked-in-public ass is bitter or anything.
posted by MonkeyToes at 10:26 AM on May 12 [7 favorites]


Absolutely, MonkeyToes, those people would ignore the CDC anyway.
posted by tiny frying pan at 11:12 AM on May 12


Man you just gotta keep banging the drum even when people aren't listening. One day you'll get through to at least some of them.

(Says the high school teacher.)
posted by subdee at 2:28 PM on May 12 [5 favorites]


I don't think it's just about right wing media, although that's certainly part of the problem. I think one blind spot a lot of mefites have is just how many people are not regular news-readers, or Extremely Online, or otherwise actively seeking new information about things like this - whether that's due to access, apathy, busyness, whatever - from any outlet. A lot of people mostly get their information by word-of-mouth and relatively-boring things like "improved understanding of transmission mechanisms!" just don't travel the same way that scarier or sexier information does.

We need a massive campaign of PSAs and ads on the side of buses and community educators and school newsletters etc etc to ensure that more people are aware of updated information about COVID, not just news stories. I've seen some of that, but (imo) far from enough.
posted by mosst at 10:59 AM on May 13 [2 favorites]


NYT: "In a sharp turnabout from previous recommendations, federal health officials on Thursday advised that Americans who are fully vaccinated against the coronavirus may stop wearing masks or maintaining social distance in most indoor and outdoor settings, regardless of size."
posted by MonkeyToes at 11:51 AM on May 13 [1 favorite]


There is no mechanism for enforcing that rule, so how the hell is anyone supposed to verify that every maskless person at indoor venues is 2+ weeks post-final shot? Anti-maskers and anti-vaxxers already showed a predilection for violence at the beginning of the lockdowns, after 14 months they're going to be straight-up murderous. This feels like it guarantees an upswing in right-wing assaults in public places as well as uncontrolled outbreaks if the strain mutates.
posted by Glegrinof the Pig-Man at 12:31 PM on May 13 [4 favorites]


There is no mechanism for enforcing that rule...

Somewhat annoyingly, it's not a rule; the CDC guidance calls for local jurisdictions to make rules. However, I think it's an important recognition of the reality that the vaccines work very, very well and that vaccinated individuals aren't at any significant risk for COVID or for transmitting COVID.
posted by mr_roboto at 1:29 PM on May 13


CDC: "Fully vaccinated people can resume activities without wearing a mask or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance."

I am hoping that indoor spaces shared by vaccinated and unvaccinated adults and non-vaccine-eligible children will err on the side of continued mask-wearing...but I am not at all certain of how that decision will go.
posted by MonkeyToes at 1:52 PM on May 13


I'm in the office today with more people than have been here since March 13, 2020. Almost right after the CDC announcement, our chief sent out an email saying masks will still be required until we get direction from the county and our headquarters.

I know there are coworkers who are not vaccinated, but I don't know who they are. And it's hard to convince myself being indoors maskless is safe...
posted by suelac at 2:34 PM on May 13 [1 favorite]


I hate people, so regardless of what the advice, rules, regulations, laws, policies, etc. are, I'm not giving up masks and my 6' of personal space.
posted by mikelieman at 3:05 PM on May 13 [5 favorites]





CDC: "Fully vaccinated people can resume activities without wearing a mask or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance."


I hate this so much, they're just punting like cowards. It's exactly what I was complaining about, now every person standing up for a local regulation to wear a mask will take all the heat.

*Reports to new thread*
posted by subdee at 7:53 PM on May 13 [1 favorite]


In Wired, M. Molteni reconstructs (archived) another part of the aerosols vs droplets wrestling between scientists and public health bodies, tracing more of its history. (Again, annoying that in the subhead they use “error”, and in the title “screwup”, when the story details that it’s more an issue of biases tainting policy decisions, not the actual science those are based on...)
posted by progosk at 10:53 PM on May 13 [6 favorites]


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