The air transports viruses and other pathogens. Since viruses are smaller than other bioaerosols, they have the potential to travel further distances. In one simulation, a virus and a fungal spore were simultaneously released from the top of a building; the spore traveled only 150 meters while the virus traveled almost 200,000 horizontal kilometers.
In one study, aerosols (<5 μm) containing SARS-CoV-1 and SARS-CoV-2 were generated by an atomizer and fed into a Goldberg drum to create an aerosolized environment. The inoculum yielded cycle thresholds between 20 and 22, similar to those observed in human upper and lower respiratory tract samples. SARS-CoV-2 remained viable in aerosols for 3 hours, with a decrease in infection titre similar to SARS-CoV-1. The half-life of both viruses in aerosols was 1.1 to 1.2 hours on average. The results suggest that the transmission of both viruses by aerosols is plausible, as they can remain viable and infectious in suspended aerosols for hours and on surfaces for up to days.