Preprint that I commented on last month about SARS-CoV-2 viral RNA in air is now published at nature.com/articles/s4158… See thread for key take-homes /1
Concentrations are higher in fine (<2.5 micron) droplets than in larger ones (>2.5 microns). This size droplet can remain floating in air for 2+ hours. /2
Concentrations are highest in hospital room where staff removed PPE, so resuspension probably important. Levels much lower after they reduce number of people and cleaned better. /3
Also high (19 copies/m3) in small patient toilet room that lacked ventilation. /4
Concentrations undetectable or low in public areas, except crowded areas outside hospital (7 copies/m3) and department store (11 copies/m3). /5
At these levels, it would take 15 minutes of exposure to inhale 1 viral RNA copy, on average. And we might expect <1% of them to be infectious. Chances of transmission are very low, but we should continue to avoid crowds. /6
They did find virus deposited on surfaces 2-3 m from patient's bed, so it does travel more than 1 m and can contaminate surfaces >1 m away. /7
