What about the diameter of droplets of saliva leaving your mouth while speaking, that carry infectious loads of viruses?
droplets >5µm drop within 6 ft, aerosols <5µm float for hours. cloth & surgical masks leak 40-90 % around edges, stop mostly the big drops you can see, not the tiny ones that actually carry viral load. if someone’s sick the smart move is stay home or use a fit N95, not virtue-signal with a leaky rag.
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