I strongly suspect those cheap little surgical masks most people wear are close to useless, as they are incredibly porous and allow completely unfiltered air to get in through the sides of the mask.
A P100 or at least an N95 respirator would be far more effective, but most people aren't going to wear those, unfortunately.
A P100 or at least an N95 respirator would be far more effective, but most people aren't going to wear those, unfortunately.