Pro mask or anti mask?

Lots. While it might not stop you from inhaling a virus that is floating by it will reduce the number you cough into the air. Particles are collected by four methods. Diffusion, impaction, interception, and settling. Masks use the first three. Masks are really a team effort to reduce the transmission as no one knows for sure who is sick with Covid. If you don't wear a mask it just shows how selfish you are.