I read a report that said forget the masks, they do nothing. However, leave your shoes outside and treat them like you’re handling a kidney from an Aides patient. Handle them very carefully then washing your hands for a full minute afterwords. They know something, Coronavirus is living on the concrete and the ground
I used to work on contaminated sites. A pain in the butt to get in and out of them. Upon leaving you would have several stations to go through. At real bad sites somebody was at each station to help you. Clean the boots. Clean the suit. Help take the boots off. Help take the suit off. Etc.
There was a video of somebody in China going through a similar procedure to get back into their apartment building. But the guys monitoring him only had him change out his surgeon’s mask and rub his hands quickly with sanitizer.
In between the ineffective hand sanitizing he used a common pen sitting on the table to sign in.
It is REALLY difficult and time-consuming to make sure you are decontaminated. Hence the disposable Tyvek suits. At $15 each they are disposable when charging $150 an hour at a haz-waste site. Going to the grocery store - not so much.
Most masks are to prevent the wearer of the mask spreading what he has to others. They don’t have any real filtering abilities. Probably special ones do.
Masks are a waste of time and money for a disease that’s likely BL4. You’d need a full decon procedure when you got home and eye protection as well. Masks DO prevent your spreading it as much, which is why they’re mandated in China and elsewhere right now. A mask will keep your germy breath and snot to yourself ;)
Leaving shoes outside isn’t a bad idea. When I lived in the city I left mine just inside the dooor.
And yes, your shoes are usually filthy.