The smaller aerosol particles go right through most masks. They don’t quickly fall to the ground and linger in the air.
“Covid-19 … is spread from person to person mainly through the droplets produced when an infected person speaks, coughs or sneezes. These droplets can land in the mouths or noses of people who are nearby.
These droplets are too heavy to travel far in the air. They only travel approximately one meter [39 inches], and quickly settle on surfaces. This is the reason person-to-person spread is happening mainly through close contacts.”
Video is also here.
How to protect yourself against COVID-19
Feb 28, 2020