How common is it to wear a mask?
My cousin and his wife came to visit me in NYC. Me and my cousin are Polish and his wife is Chinese (she's from Beijing - and my cousin and his wife were college sweethearts). Pretty much throughout their stay his wife wore a surgical mask - she said she has a weak immune system and asthma and also my cousin and his wife are expecting their first child (and she wants to keep herself and the child as healthy as possible). I respect that she's keeping herself healthy that way.
I'm just curious how common is to wear a mask?