> do masks inhibit production of and exposure to aerosols carrying SARS-COV-2? This seems (to me) to me clearly established, and essentially irrefutable. Aero

> do masks inhibit production of and exposure to aerosols carrying SARS-COV-2? This seems (to me) to me clearly established, and essentially irrefutable. Aerosols? It's far from established. In fact, it's a dubious claim, unless you're far more specific about what you mean by "masks". The best laboratory studies show that properly fitted respirators (i.e. as used in hospitals), can reduce aerosol emissions. But few people are wearing respirators, and essentially nobody is fitting them correctly. Cloth masks? Surgical masks? Cup masks? About the only claim you can make is that they might reduce heavy droplets and then, only by about 30% or so. There's no reason to believe they have any effect on aerosol emission. Michael Osterholm covered this extensively: https://www.cidrap.umn.edu/covid-19/podcasts-webinars/special-ep-masks https://www.cidrap.umn.edu/covid-19/podcasts-webinars/specia... Anyone who has done a mask fitting -- where they put you in a room with vaporized stuff that you can taste to detect leaks -- will tell you how difficult it is to get an aerosol-resistant seal on a mask. The chances that the general public is doing it is 0%.