Ask Dr. Nandi: 2 masks may be better than 1, CDC study finds

COVID-19 mask generic
Posted at 4:22 PM, Feb 10, 2021
and last updated 2021-02-10 17:18:58-05

(WXYZ) — A new study from the CDC has found that two masks are better than one. And when fitted correctly, they can provide a very high level of protection against the coronavirus.

I’m excited to share the details of this study because it really demonstrates how effective masks can be. So here’s what the CDC did. They simulated breathing experiments using mannequin-like forms. And they put to the test both cloth masks and surgical masks. And what they found, was that the risk of spreading the virus fell more than 95% when everyone wore a properly fitted surgical mask with a cloth mask over top of it.

The protection level was found to be 80% if only one person wore a properly fitted surgical mask with a cloth mask over it. Which is still really good protection from viral particles. But that number dropped down again, to 60% if only one person wore a properly fitted surgical mask.

How the mask fits is really the key. When you look at common surgical masks, which are often the color of blue, the sides are loose if you just slip it over your ears without fitting it first.

Now, surgical masks are made of polypropylene, which uses a tiny electric charge to capture any viral particles in the air. But if the sides are not properly fitted, then particles can sneak in or escape out. So to get a tighter fit, you need to knot the straps and tuck the mask. And that will help the mask fit tighter to your face and get rid of those gaps.

We’re not expecting new mask recommendations from the CDC. But they did update their webpage called “Improve How Your Mask Protects You”.

They have several good suggestions which now include wearing a disposable mask underneath a cloth mask. But to me, the main takeaway with this new CDC study is that while two layers are important, the research showed that how a mask fit is really the key. And that wearing two well-fitting masks performs the best and provides higher protection from the coronavirus.

This is especially important now that we have new variants circulating.

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