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How effective are face masks in polluted areas?(r/askscience)
it all depends on the mask.
the flimsy little white dust masks that you see a lot of people using? completely useless. they are for “comfort only,” not NIOSH approved or rated or certified; basically, they’re designed to make you “feel” better when sanding or working around dust, but the mask isn’t proven to actually filter anything from the air or improve your safety.
if you get a respirator that is certified and capable of actually filtering particulate matter or gases, then you’re in better shape.
here’s a link from the CDC and NIOSH (National Institute for Occupational Safety and Health) that explains all about respirators:
here’s a more general link from the same source with tons of information regarding respirators: