From the linked article:
A windowless public bathroom with high foot traffic is riskier than a bathroom with a window, or a bathroom that’s rarely used. A short outdoor conversation with a masked neighbor is much safer than either of those scenarios.
Recently, Dutch researchers used a special spray nozzle to simulate the expulsion of saliva droplets and then tracked their movement. The scientists found that just cracking open a door or a window can banish aerosols.
“Even the smallest breeze will do something,” said Daniel Bonn, a physicist at the University of Amsterdam who led the study.