4 ms·

Simple conclusion: "Masks make a huge difference indoors and rarely matter outdoors." The 10% estimate in question is perhaps orders of magnitude too conservati

Simple conclusion: "Masks make a huge difference indoors and rarely matter outdoors." The 10% estimate in question is perhaps orders of magnitude too conservative. Why would the CDC employ such a weak numeric argument? They could have left it at something like we see no strong evidence for outdoor transmission. Does there have to be a number attached to public health advice?

TehShrike 5y ago
I can sympathize with that, that would probably have been much more truthful. But the CDC recommendations have been so poorly thought out so far, it's hard to blame anyone who would say "screw your judgment of evidence, give us a number"
DebtDeflation 5y ago
>Simple conclusion: "Masks make a huge difference indoors and rarely matter outdoors." Also: For a disease that we now know is airborne/aerosol spread rather than airborne/droplet, N95 and KN95 masks are highly effective, a two layer cloth mask fit tightly over a surgical mask is moderately effective, and a cloth mask by itself is largely for show. I still see people saying you should NOT use N95 masks (they're cheaply and widely available now) while donning a neck gaiter pulled up over their mouth. It's another area where the initial messaging was terrible (in this case out of the good intention of reserving them for healthcare workers) and unfortunately has persisted.
- URSpider94 5y ago
  Cloth masks are largely for show in protecting you from other people. They are still highly effective in preventing your aerosols from getting out into the air. Even though COVID is airborne, it comes out of your mouth and nose in liquid droplets that then dehydrate and become airborne. If they hit a cloth mask on the way out, they'll be trapped.
- mcguire 5y ago
  By "N95 mask", do you mean this https://www.amazon.com/3M-8511HB1-C-PS-Sanding-Fiberglass-Respirator/dp/B002VMCHPG/ref=sr_1_5?dchild=1&keywords=n95+mask&qid=1620750854&sr=8-5 https://www.amazon.com/3M-8511HB1-C-PS-Sanding-Fiberglass-Re... or this? https://www.amazon.com/AccuMed-Respirator-Filtration-Disposable-Particulate/dp/B087QQV8WB/ref=sr_1_6?dchild=1&keywords=n95+mask&qid=1620750854&sr=8-6 https://www.amazon.com/AccuMed-Respirator-Filtration-Disposa... I've had a box of the former out in the garage for a couple of years; before 2020, if you looked for an "N95" mask, that's what you would find. But they're not terribly useful in a medical situation.
  - DebtDeflation 5y ago
    More the latter. They're both N95, but the valve in the former means outgoing air isn't being filtered.
  - raylad 5y ago
    You can wear another mask, like a surgical mask, to cover the exhale valve. Or tape over it (securely).
- generalizations 5y ago
  > For a disease that we now know is airborne/aerosol spread rather than airborne/droplet, N95 and KN95 masks are highly effective, a two layer cloth mask fit tightly over a surgical mask is moderately effective, and a cloth mask by itself is largely for show. I mean, who's "we"? I knew this back in January 2020.
- jaclaz 5y ago
  Actually, and just for the record, a N95 properly fitted works very, very well. But usually you cannot wear (properly) a N95 for more than two/three hours without having your face with deep signs (and of course you need to be clean shaven). A "generic" N95 used by untrained people and loosely worn, isn't that much better a protection for the person wearing it than a surgical mask, while both are quite good at protecting other people from the "emissions" of the person wearing the mask (of course only if it is valveless). Previous post with a link to a video of a proper "fit test" and some more info about valve and valveless: https://news.ycombinator.com/item?id=23957506 https://news.ycombinator.com/item?id=23957506

TehShrike 5y ago

I can sympathize with that, that would probably have been much more truthful. But the CDC recommendations have been so poorly thought out so far, it's hard to blame anyone who would say "screw your judgment of evidence, give us a number"

DebtDeflation 5y ago

>Simple conclusion: "Masks make a huge difference indoors and rarely matter outdoors." Also: For a disease that we now know is airborne/aerosol spread rather than airborne/droplet, N95 and KN95 masks are highly effective, a two layer cloth mask fit tightly over a surgical mask is moderately effective, and a cloth mask by itself is largely for show. I still see people saying you should NOT use N95 masks (they're cheaply and widely available now) while donning a neck gaiter pulled up over their mouth. It's another area where the initial messaging was terrible (in this case out of the good intention of reserving them for healthcare workers) and unfortunately has persisted.

URSpider94 5y ago
Cloth masks are largely for show in protecting you from other people. They are still highly effective in preventing your aerosols from getting out into the air. Even though COVID is airborne, it comes out of your mouth and nose in liquid droplets that then dehydrate and become airborne. If they hit a cloth mask on the way out, they'll be trapped.
mcguire 5y ago
By "N95 mask", do you mean this https://www.amazon.com/3M-8511HB1-C-PS-Sanding-Fiberglass-Respirator/dp/B002VMCHPG/ref=sr_1_5?dchild=1&keywords=n95+mask&qid=1620750854&sr=8-5 https://www.amazon.com/3M-8511HB1-C-PS-Sanding-Fiberglass-Re... or this? https://www.amazon.com/AccuMed-Respirator-Filtration-Disposable-Particulate/dp/B087QQV8WB/ref=sr_1_6?dchild=1&keywords=n95+mask&qid=1620750854&sr=8-6 https://www.amazon.com/AccuMed-Respirator-Filtration-Disposa... I've had a box of the former out in the garage for a couple of years; before 2020, if you looked for an "N95" mask, that's what you would find. But they're not terribly useful in a medical situation.
- DebtDeflation 5y ago
  More the latter. They're both N95, but the valve in the former means outgoing air isn't being filtered.
- raylad 5y ago
  You can wear another mask, like a surgical mask, to cover the exhale valve. Or tape over it (securely).
generalizations 5y ago
> For a disease that we now know is airborne/aerosol spread rather than airborne/droplet, N95 and KN95 masks are highly effective, a two layer cloth mask fit tightly over a surgical mask is moderately effective, and a cloth mask by itself is largely for show. I mean, who's "we"? I knew this back in January 2020.
jaclaz 5y ago
Actually, and just for the record, a N95 properly fitted works very, very well. But usually you cannot wear (properly) a N95 for more than two/three hours without having your face with deep signs (and of course you need to be clean shaven). A "generic" N95 used by untrained people and loosely worn, isn't that much better a protection for the person wearing it than a surgical mask, while both are quite good at protecting other people from the "emissions" of the person wearing the mask (of course only if it is valveless). Previous post with a link to a video of a proper "fit test" and some more info about valve and valveless: https://news.ycombinator.com/item?id=23957506 https://news.ycombinator.com/item?id=23957506