Face masks: To wear or not to wear during an outbreak?

Siva Kumar (US)

Masks protect from only particulate matter in the air you breathe but they can't filter out microbes. Well, you won't be breathing in microbes sitting on dust particles or such but a free-floating microbe is too small to be stopped by a mask.

How does a mask help you? Say someone nearby sneezes or coughs -- the droplets thrown out by them will be stopped by the mask, that is all.