I heard something interesting from an OSHA employee a while back that basically said all of the recommended masks are garbage for these purposes. Like N95 masks are made for already-contaminated environments, so they only filter what comes in but not what goes out. He also said surgical masks are designed for sterile environments where surgeries are performed - they do nothing in regular places where dust and debris and all kinds of bugs and germs are swirling around.
Which is part of the reason I'm like "to hell with masks". They don't do anything, and I think pleading with or forcing people to wear them is just some kind of weird facet of this new religion that's sprung on to the scene. Masks are one of it's shame rituals.
If someone is serious about filtration and protection, they would need to walk around in HAZMAT or MOPP gear.