Is COVID-19 transmitted by aerosols or by droplets?

[ElliotSmith]

TL;DR

Is COVID-19 aerosolized?

Is COVID-19 aerosolized like the flu and common cold? Or is it only transmitted through sneeze and cough droplets?

 

[jim mcnamara]

It is not a simple either/or choice.
This link is meant to be readable by most folks:
https://www.asm.org/Articles/2020/April/COVID-19-Transmission-Dynamics

 

[lflournoy]

New research (topic is 'masks', but Means is aerosolization):

Seeing is Believing: Researchers Test Effectiveness of Facemasks and Soc... https://youtu.be/evATiHUejxg via
@YouTube

 

[Astronuc]

The headline is sensational, but the article content is important regarding the experimental results and their interpretation and extension to related phenomenon, or in this case aerial transmission of viruses and other communicable diseases.
https://www.wired.com/story/the-teeny-tiny-scientific-screwup-that-helped-covid-kill/

Marr is an aerosol scientist at Virginia Tech and one of the few in the world who also studies infectious diseases. To her, the new coronavirus looked as if it could hang in the air, infecting anyone who breathed in enough of it. For people indoors, that posed a considerable risk. But the WHO didn’t seem to have caught on. Just days before, the organization had tweeted “FACT: #COVID19 is NOT airborne.” That’s why Marr was skipping her usual morning workout to join 35 other aerosol scientists. They were trying to warn the WHO it was making a big mistake.

. . . the WHO’s advisers seemed to be saying those same laws didn’t apply to virus-laced respiratory particles. To them, the word airborne only applied to particles smaller than 5 microns. Trapped in their group-specific jargon, the two camps on Zoom literally couldn’t understand one another.

Linsey Marr installed air samplers in places such as day cares and airplanes, she frequently found the flu virus where the textbooks said it shouldn’t be—hiding in the air, most often in particles small enough to stay aloft for hours. And there was enough of it to make people sick.

In 2011, this should have been major news. Instead, the major medical journals rejected her manuscript. Even as she ran new experiments that added evidence to the idea that influenza was infecting people via aerosols, only one niche publisher, The Journal of the Royal Society Interface, was consistently receptive to her work. In the siloed world of academia, aerosols had always been the domain of engineers and physicists, and pathogens purely a medical concern; Marr was one of the rare people who tried to straddle the divide. “I was definitely fringe,” she says.

Besides Linsey Marr, the other hero in this effort is graduate student Katie Randall, who found an out-of-print book written by a Harvard engineer named William Firth Wells. Published in 1955, it was called Airborne Contagion and Air Hygiene.

Thresholds for phenomena in science and engineering can be problematic, or even dangerous, if misunderstood or misapplied. The story in the Wired article is similar to patterns I've seen in certain aspects of science and engineering.