Droplet and Airborne particles?

Question

how much time do droplet aerosols suspend in air? how about airborne aerosols?

Answer 1

That really depends on the medium of the droplets. Are they respiratory (cough, sneeze) or GI (diarrhea or vomit -- yes, these things can and will aerosolize)? Respiratory droplets can be much smaller than the GI droplets. Larger droplets of course settle faster than smaller droplets because of air resistance.

For example, norovirus (the virus that causes the stomach flu) can suspend itself in droplets in the air for up to TWO HOURS following a violent bout of vomiting.

Then you have to account for the pathogen itself. Fragile pathogens will die quickly even if suspended. But there are hardier things like measles that can hang for a good long time, as in the case of the kids in San Diego who got measles from being in a clinic waiting room AFTER measles-infected kids were in there.