Coronavirus FAQ: I'm a one-way masker. With mask mandates going away, is that helpful?
Updated April 19, 20221:17 PM ET
WILL STONE
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It can be lonely out there as the solo masker in a sea of exposed chins and noses.
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But if you plan to continue wearing a mask, you can still get substantial protection as the sole mask-wearer if you do it right.
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Pick the best mask
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"The only thing I recommend is something like an N95 respirator," says Lisa Brosseau, a bioaerosol scientist and industrial hygienist who's a consultant for the University of Minnesota's Center for Infectious Disease Research and Policy.
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Of course, a
ny kind of protection is better than nothing at all. If you have no other options,
surgical masks are better than cloth masks because the material has electrostatic charge to trap incoming particles, says Abraar Karan, an infectious disease physician at Stanford University —
but if you're serious, don't count on them to keep you safe when most people nearby are unmasked.
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But
keep in mind that an N95 on its own isn't foolproof.
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Even with a solid choice like an N95,
you need to calculate the risks you'll face as a one-way masker.
"Just wearing a mask — it helps, but it is not going to turn being indoors into something that has no risk," says Jose-Luis Jimenez, a professor at the University of Colorado Boulder and an aerosols scientist.
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Poorly ventilated indoor spaces, especially where people are talking loudly, singing or exercising, carry the highest risk.
If you do go inside, the safest situation is an uncrowded venue. And the longer you spend indoors, the more you open yourself up to infection.
The final big risk consideration comes down to how many people are contagious in your community. Dr. Lisa Maragakis says you can look at
the number of new cases per capita in your community over the past week.
"That number needs to be in the single digits — somewhere between one to five cases per 100,000...
And remember:
There are no hard-and-fast rules.
For example, you can spend the same amount of time in similar indoor spaces, but the chance of infection can go up enormously depending on what people are doing.
"We've seen tons of outbreaks in choirs, none in libraries and movie theaters that I know of," says Jimenez, who has developed a tool that estimates risk in different scenarios.
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One recent modeling study found a
90% risk of being infected after 30 minutes when a person wears a surgical mask and is about 5 feet away from an infected unmasked person.
Switching to a respirator drops that risk to 20% over the course of an hour. And if both people are wearing a respirator, it's under 1% in an hour.
Brosseau has also analyzed this kind of scenario, although with a different approach that looks at how long it would take to get a big enough "dose" of the virus that you'd likely be infected.
She found it would be about an hour and 15 minutes for someone wearing an N95 (not fit tested) to get infected when in close contact with a contagious person.
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https://www.npr.org/sections/goatsan...imal-protectio