Scientists published a study where they had people wear masks, after which they tested for bacteria. They found no evidence of bacteria growing in the mask. They only found bacteria that came from people’s faces! So that bacteria was already on people. The article’s title is “Study of the micro-climate and
bacterial distribution in the dead space of N95 filtering face respirators” published on Scientific Reports.
According to Thomas’ experience, he has been wearing masks every day for years in Beijing, Delhi, and Shanghai, even on hot summer days, while biking across town. Throughout his years of experience, he has never once seen evidence of bacteria on the mask or bacteria smells on the masks. However, he always follow two rules:
1. Avoid always putting the masks in bags or pockets, where they could get musty
2. Always put the mask out where it can dry, with the interior part facing up
And of course, if your mask ever smells like it’s got gross bacteria growing on it, get a new one!