Been saying it for a long time...
https://www.ctvnews.ca/health/coronavirus/scientists-warn-of-overlooked-danger-from-coronavirus-spreading-airborne-microdroplets-1.5012340
Physical distancing and frequent handwashing are not enough to fully protect against airborne transmission of the novel coronavirus, hundreds of scientists say.
Virus-carrying microdroplets pose more of a danger than is currently being communicated, the scientists argue in a new medical commentary, and the result is that poor ventilation is easing the path of the pandemic. The commentary has been accepted for publication in the journal Clinical Infectious Diseases. It is signed by 239 scientists from 32 countries and a wide variety of science and engineering disciplines, according to a statement from the Queensland University of Technology (QUT) in Australia.
“We are concerned that people may think they are fully protected by following the current recommendations, but in fact, additional airborne precautions are needed to further reduce the spread of the virus," lead author and QUT air quality expert Lidia Morawska said in the statement.
Stay out of smaller / poorly ventilated buildings. (masks don't protect against microdroplets)
There are signs that the smallest microdroplets can travel beyond the two-metre limit. One American study found that they can move three metres in 12 seconds, and a fourth metre as they linger in the air for up to a minute. Morawska said that there is significant evidence that microdroplets can travel even farther – into the tens of metres – especially when indoors.
“Studies by the signatories and other scientists have demonstrated beyond any reasonable doubt that viruses are exhaled in microdroplets small enough to remain aloft in the air and pose a risk of exposure beyond [one to two metres] by an infected person,” she said.
Earlier studies already found that Sars-Cov-2 can stay alive for over 3 hours in aerosol form.
REDUCING THE RISK
Morawska said that effective ventilation systems are the best way to reduce the spread of microdroplets. She said the most effective systems minimize the use of recirculated air by bringing in as much clean air from outdoors as possible, and that even opening doors and windows can make a major difference.
These ventilation techniques can be augmented with the use of air filtration and exhaust devices, as well as ultraviolet (UV) lights that kill germs. Another way to lessen the risk of microdroplet transmission is to avoid situations of overcrowding, especially on public transport and in public buildings, Morawka said.
Furness agreed with the suggestion to use UV lights in air filtration systems, saying that there could be a "renaissance" in this practice because the light can be effective against the virus in a way that physical filters cannot.
"I think we will probably see a resurgence in the use of UV light within air circulation systems, because UV light will kill viruses and it doesn't really matter how small they are," he said.
Face masks do not play a role in protecting against microdroplets, Furness said, because the droplets are so small that they can fit through the holes in most masks.
It's been known since April 16th...
https://www.nejm.org/doi/10.1056/NEJMc2004973
Something to ponder while restrictions on crowding are being reduced more and more.
Essay Pro