Still, there is no evidence mask wearing helps in those situations.
I wore a well-fitted N95 the other day, I was mixing concrete for some deck footings — the masks work well for that.
They may not help that much with airborne diseases (as Covid turned out to be) but most diseases going around are droplet-borne. And, if they don’t help at all, why do medical personnel wear them?
Well, when the oncologist tells you that your wife’s immune system is going to be wrecked for a couple months and that you should wear a mask…guess what? You wear the mask. I love these people who challenge the immune system specialists. I gleefully wore a mask for a couple of months BEFORE Covid. And…I trust my board certified oncologist more than I trust FR docs.