Asklemmy

This is somewhat misleading. Here’s a section from near the beginning of a scientific review I linked in my reply to @[email protected]:

To reduce spread of respiratory diseases, we need to understand the mechanisms of spread. There is strong and consistent evidence that respiratory pathogens including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respiratory syncytial virus (RSV), influenza, tuberculosis, and other coronaviruses such as MERS and SARS-1, are transmitted predominantly via aerosols. Infected individuals, whether symptomatic or not, continuously shed particles containing pathogens, which remain viable for several hours and can travel long distances. [Emphasis mine.] SARS-CoV-2 is shed mainly from deep in the lungs, not the upper respiratory tract, and the viral load is higher in small aerosols (generated in the lower airways) than in larger droplets (generated in upper airways). Whereas large respiratory droplets emitted when people cough or sneeze fall quickly by force of gravity without much evaporation, those below 100 µm in diameter become (bio)aerosols. Even particles tens of microns in diameter at release will shrink almost immediately by evaporation to the point that under typical conditions they can remain airborne for many minutes. In contrast with droplet transmission, which is generally assumed to occur via a single ballistic hit, the risk of airborne transmission increases incrementally with the amount of time the lung lining is exposed to pathogen-laden air, in other words, with time spent indoors inhaling contaminated air.

Respiratory infections may theoretically also be transmitted by droplets, by direct contact, and possibly by fomites (objects that have been contaminated by droplets), but the dominant route is via respiratory aerosols. The multiple streams of evidence to support this claim for SARS-CoV-2 include the patterning of spread (mostly indoors and especially during mass indoor activities involving singing, shouting, or heavy breathing), direct isolation of viable virus from the air and in air ducts in ventilation systems, transmission between cages of animals connected by air ducts, the high rate of asymptomatic transmission (i.e., passing on the virus when not coughing or sneezing), and transmission in quarantine hotels when individuals in different rooms shared corridor air but did not meet or touch any common surface.