I'm not sure what to think about the face masks. The common dust masks everyone is buying up surely won't do much good... and they're rather uncomfortable. I went through some training about proper respiratory protection when I worked for an industrial cleaning place. The paper dust mask helps protect against most dust, but it's rather uncomfortable and not as effective as some other things. On the other hand, you have half-face or full-face respirators, which are more comfortable and do a better job against dust with the basic dust filter, but there are also other filters designed to guard against serious chemicals that can be deadly in high amounts.
My last job at a recycling place was really,
really dusty and I became concerned enough about it to buy one of
these on my own. It worked great and I wasn't coughing up black shit anymore, but I'm not sure how well it would protect against the virus... viruses aren't dust, after all. On the other hand, I see some flawed logic behind the statement that masks only help if the person wearing the mask is sick, as it reduces the chance they might infect someone else. If that's the case, surely if a healthy person wears one, it can also cut down on their chance of being infected, yeah?