239 Experts with 1 Big Claim: The Coronavirus Is Airborne

At the beginning there was 4 different routes were considered: fecal-oral route, touch-hand-face, droplets in the air, airborne viruses. Fecal-oral route seems to either nonexistent or incredibly small. Airborne (aerosol) risk has been considered very small.

Two main routes are touch-hand-face and droplets in the air. It seems that droplets are the main route (60-70% of infections) rest come from touching things. Social distancing. 2m indoors and hand washing seems to work.

If there is aerosol transmission it seems to be much smaller percentage than two other transmission mechanisms.

Claiming that aerosol vs droplet transmission is artificial distinction is incorrect. Droplets fall down relatively fast and don't linger in the air 10s of minutes like aerosol. Aerosol transmission is more dependent on moisture in the air, they linger longer in dry air. We should see strong seasonal and climate forcing in transmission rates.

Simulations of indoor airflow that show the difference between aerosol and droplet transmissions:

(caution: just inhaling viruses is not enough to cause infection, you need to inhale a dose that is large enough to cause infection)

https://www.aalto.fi/en/news/modelling-confirms-isolating-th...

VTT simulation with only droplets with and without mask:

https://www.youtube.com/watch?v=1YWuD4jdjLc

https://www.youtube.com/watch?v=I-apLuN7sZc

This article feels like it’s months old or from an alternate universe. We “may” need masks indoors? I’m very confused what is being communicated here. It sounds like a bunch of experts fussing over the finer points of established theory without considering real data about this particular virus. Presumably because they don’t have enough data, but then the focus ought to be on collecting more, not arguing over theory.

The title while technically correct stokes fear more than anything else. The article goes into depth on how “airborne” is not terribly different than what we know now about aerosols hanging in the air. Most people will read the title and react at too large of a scale, while the only real insight should be that in crowded indoor places with poor ventilation (offices, restaurants), you may be able to get infected even when socially distancing.

That is much more reasonable and solvable. Airborne is a overused Hollywood term that makes most people think it floats on the wind and infects you anywhere, anytime.

What if masks give better protection against aerosol than droplets. So far it seems mask wearing has been unreasonably effective, eg Tokyo and Taiwan.

Some microbes really do float in the wind like that. But apparently viruses tend to get destroyed by sunlight or desiccated fairly easily. Bacteria are more complex, and become world travellers.

https://www.smithsonianmag.com/science-nature/living-bacteri...