I feel that there is so much misinformation going around on this that for the benefit of this Community I should repost what I've been posting elsewhere on this topic
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People should understand how bad this new face mask policy is.People are being told to wear any kind of cloth material so that surgical masks and N95 masks are available for medical workers.
First, the shortage of surgical and N95 masks may be largely artificial in the United States.
Until this week, there appears to have been a ban or restriction on KN95 masks because although those are used around the world, they weren't certified by the FDA and the FDA refused to even consider certifying. That has just changed, so at the moment there is a massive run on KN95 masks, presumably by those who never considered them an option before. When the panic buying subsides, we'll have a clearer picture of world-wide supply and demand.
As for regular cloth coverings,
People should know that only N95 is going to give you practically 100% protection.
Surgical masks are never worn by healthcare workers in a critical Covid19 situation because they're only about 60% effective.
Cloth coverings and home made masks are estimated to provide no better than 40% protection and depending on material and fit, likely a lot less.
So, bottom line is that if you're wearing your cloth covering in public and encounter 3 situations where you were at high risk of infection, in <two> of those encounters it would be as though you were wearing no mask at all, and that's "best odds"
Those kinds of odds sucks.
Stay Home.
Isolate.
Don't believe cloth coverings are going to protect you from Covid19
Based on a clinical study in 2018 in China which measured particulate penetration of types of facial coverings and masks by blowing diesel exhaust through the masks worn by subjects and taking readings outside and inside the masks. Although the purpose obviously was to measure air pollution, is completely applicable to anti-viral use as well.
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PS.
I'll include here a comment on another recommendation that's being widely circulated...
Everyone should wear a mask, it'll prevent transmission because even if not all masks will protect the wearer, it'll do a good job of preventing anyone who is infectious (knowingly or not) from spreading to any others.
Well,
That ignores the fact that many N95 and other masks have "rubber flapper" vents which make exhalation easier.
Problem is that those vents also bypass any filtering
Which means that if the wearer is contagious, there is nothing to prevent that person from transmitting to others.
Consider what this means, in the recently published New England Journal of Medicine study of the King County, WA Assisted Living Home where the first major outbreak in the US happened, a single person caused over 160 infections(residents, doctors, nurses, visitors), of which almost 1/3 died. Granted, the conditions for this outbreak were practically a laundry list of worst possible but it does illustrate what may be a worst possible case of transmission even in the outside world if people didn't isolate and relied only on masks.
And, consider that today there is emerging suspicion that up to 75% of infections take place from asymptomatic people(people who appear normal). So, you can't really tell if the person wearing the vented mask is a potential spreader or not.
Therefor,
There would be a long list of caveats if you're to believe that simply wearing masks is sufficient without first killing off the virus as much as possible first... enough that IMO it's unworkable.
TSU
********************************************
People should understand how bad this new face mask policy is.People are being told to wear any kind of cloth material so that surgical masks and N95 masks are available for medical workers.
First, the shortage of surgical and N95 masks may be largely artificial in the United States.
Until this week, there appears to have been a ban or restriction on KN95 masks because although those are used around the world, they weren't certified by the FDA and the FDA refused to even consider certifying. That has just changed, so at the moment there is a massive run on KN95 masks, presumably by those who never considered them an option before. When the panic buying subsides, we'll have a clearer picture of world-wide supply and demand.
As for regular cloth coverings,
People should know that only N95 is going to give you practically 100% protection.
Surgical masks are never worn by healthcare workers in a critical Covid19 situation because they're only about 60% effective.
Cloth coverings and home made masks are estimated to provide no better than 40% protection and depending on material and fit, likely a lot less.
So, bottom line is that if you're wearing your cloth covering in public and encounter 3 situations where you were at high risk of infection, in <two> of those encounters it would be as though you were wearing no mask at all, and that's "best odds"
Those kinds of odds sucks.
Stay Home.
Isolate.
Don't believe cloth coverings are going to protect you from Covid19
Based on a clinical study in 2018 in China which measured particulate penetration of types of facial coverings and masks by blowing diesel exhaust through the masks worn by subjects and taking readings outside and inside the masks. Although the purpose obviously was to measure air pollution, is completely applicable to anti-viral use as well.
====================================
PS.
I'll include here a comment on another recommendation that's being widely circulated...
Everyone should wear a mask, it'll prevent transmission because even if not all masks will protect the wearer, it'll do a good job of preventing anyone who is infectious (knowingly or not) from spreading to any others.
Well,
That ignores the fact that many N95 and other masks have "rubber flapper" vents which make exhalation easier.
Problem is that those vents also bypass any filtering
Which means that if the wearer is contagious, there is nothing to prevent that person from transmitting to others.
Consider what this means, in the recently published New England Journal of Medicine study of the King County, WA Assisted Living Home where the first major outbreak in the US happened, a single person caused over 160 infections(residents, doctors, nurses, visitors), of which almost 1/3 died. Granted, the conditions for this outbreak were practically a laundry list of worst possible but it does illustrate what may be a worst possible case of transmission even in the outside world if people didn't isolate and relied only on masks.
And, consider that today there is emerging suspicion that up to 75% of infections take place from asymptomatic people(people who appear normal). So, you can't really tell if the person wearing the vented mask is a potential spreader or not.
Therefor,
There would be a long list of caveats if you're to believe that simply wearing masks is sufficient without first killing off the virus as much as possible first... enough that IMO it's unworkable.
TSU