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As the world rushes to surrender to covid-19, declaring it over even while case and death remain high or even rising, I feel the quixotic urge to remind people it doesn't have to be that way, and we could be cutting person-person transmission by 98%.
Getting high filtration material isn't hard now, any decent respirator or ASTM surgical mask qualifies; many respirators have tested as much better than their official certification of 94-95% at 0.3 microns, with over 99% filtration.
Getting good fit is much chancier, and most of us don't have access to professional fit testing, or even a DIY nebulizer test. But various results indicate that a reasonable attempt at fitting a respirator will be at least 88% protective, and using a surgical mask with a mask brace/fitter, even DIY with rubber bands, will get into the 90-95% range. And you can use mask braces with respirators too!
So you can get at least 88%, possibly close to 95%, if you want. And if everyone were wearing 88% masks, letting 12% through, what would get between two people would be 0.12^2, or 1.44%
This wouldn't stop all community transmission, if people go to restaurants/bars/gyms/parties a lot. Hell, if they do that, it probably wouldn't stop most community transmission, since being loud and unmasked is very very risky. But it would make other places safe, for the vulnerable and risk averse. And could crush covid if we masked and skipped dining out etc for a few weeks, far short of a full lockdown -- or as I put it, good masks are lockdowns for noses.
Getting high filtration material isn't hard now, any decent respirator or ASTM surgical mask qualifies; many respirators have tested as much better than their official certification of 94-95% at 0.3 microns, with over 99% filtration.
Getting good fit is much chancier, and most of us don't have access to professional fit testing, or even a DIY nebulizer test. But various results indicate that a reasonable attempt at fitting a respirator will be at least 88% protective, and using a surgical mask with a mask brace/fitter, even DIY with rubber bands, will get into the 90-95% range. And you can use mask braces with respirators too!
So you can get at least 88%, possibly close to 95%, if you want. And if everyone were wearing 88% masks, letting 12% through, what would get between two people would be 0.12^2, or 1.44%
This wouldn't stop all community transmission, if people go to restaurants/bars/gyms/parties a lot. Hell, if they do that, it probably wouldn't stop most community transmission, since being loud and unmasked is very very risky. But it would make other places safe, for the vulnerable and risk averse. And could crush covid if we masked and skipped dining out etc for a few weeks, far short of a full lockdown -- or as I put it, good masks are lockdowns for noses.