3 ms·
There’s probably all kinds of confounding factors here, but on high pollution days (code purple air quality) when I’m bicycling I need to take my N95 mask off e
by jdavis703 7y ago
There’s probably all kinds of confounding factors here, but on high pollution days (code purple air quality) when I’m bicycling I need to take my N95 mask off every few minutes for “fresh air.”