1/ Nature had a news piece on the COVID-19 aerosol letter.
nature.com/articles/d4158…
I read it trying to understand the resistance to aerosols. Shocking that the aerosol-resisting researchers do not seem to have any good arguments.
Some key points to understand the debate below:
nature.com/articles/d4158…
I read it trying to understand the resistance to aerosols. Shocking that the aerosol-resisting researchers do not seem to have any good arguments.
Some key points to understand the debate below:
2/ Nat: boundary of 5 um btw larger droplets that fall to the ground very quickly (in 1-2 m), and aerosols that stay suspended in air longer E.g. "These bigger droplets, more than 5 um [..] drop out of the air quickly because they are too heavy to ride on light air currents."
3/ This is a very stubborn error. Droplets need to be larger than ~ 50 um (not 5) to fall to the ground in 1-2 m. Smaller ones can stay afloat minutes to hours (see ).
Those can be inhaled, and can infect through the aerosol pathway.
Those can be inhaled, and can infect through the aerosol pathway.
4/ Nature: "Since the 1930s, public-health researchers and officials have generally discounted the importance of aerosols — droplets less than 5 micrometres in diameter — in respiratory diseases such as influenza. Instead, the dominant view is that respiratory viruses are...
5/ transmitted by the larger droplets or through contact with droplets that fall on surfaces or are transferred by people’s hands. When SARS-CoV-2 emerged at the end of 2019, the assumption was that it spread in the same way as other respiratory viruses...
6/ ... and that airborne transmission was not important."
Issue: as WHO admitted recently, the modes of transmission it recommends are based on that assumption, which is based on a historical belief, not on having more evidence than aerosols.
Issue: as WHO admitted recently, the modes of transmission it recommends are based on that assumption, which is based on a historical belief, not on having more evidence than aerosols.
7/ Nat: "although the WHO acknowledges that airborne transmission is plausible, current evidence falls short of proving the case."
Issue: no more evidence for the WHO-favored routes, just an entrenched bias on their favor. See:
Issue: no more evidence for the WHO-favored routes, just an entrenched bias on their favor. See:
8/ Nat: “The highest-risk contacts are those that are individuals you share a home with or that you’ve been in a confined space with for a substantial period of time, which would lead me to believe it’s probably driven mostly by droplet transmission,” she says, although she ...
9/ ... says that aerosol transmission might occur on rare occasions."
Issue: no basis to conclude that droplets dominate based on that evidence. Aerosols most important at close contact (sciencedirect.com/science/articl…).
Reflects anti-aerosol bias and misunderstanding of dispersion.
Issue: no basis to conclude that droplets dominate based on that evidence. Aerosols most important at close contact (sciencedirect.com/science/articl…).
Reflects anti-aerosol bias and misunderstanding of dispersion.
10/ Nature: “All these researchers are struggling to find the viable virus” in clinical settings"
Issue: finding the virus in the air is really difficult technically, while finding it in droplets and surfaces is much technically.
See Don Milton's take:
Issue: finding the virus in the air is really difficult technically, while finding it in droplets and surfaces is much technically.
See Don Milton's take:
11/ Nat: “Why don’t we ask ourselves why are these theories coming mainly from engineers, aerobiologists, and so on, whereas the majority of the clinical, infectious-diseases, epidemiology, public health, and infection-prevention and control people do not think exactly the same?
12/ Issue: 1st WHO assertion is wrong, as Nat. points out 60 signatories are on those fields that supposedly don't agree w/ aerosols. 2nd, I suspect the key is that many in the latter fields don't understand aerosols. Apparent reading their papers and thru interactions w/ them.
13/ Conclusion: as Julian Tang says in Nature: “In fact, the airborne-transmission evidence is so good now, it’s much better than contact or droplet evidence for which they’re saying wash [your] hands to everybody.”
/end
/end
