Scientists Tested 14 Different Face Masks To Determine Which Style Worked Best

With CDC guidelines now recommending we all wear masks to minimize the spread of COVID-19, the next question becomes what sort of mask we should wear. There are plenty on the market right now — from the stylish to the heavy duty — and sorting out what's right and what's effective and what's comfortable is a battle on its own.

However, one university's researchers set out to determine which face coverings work best — and which should be avoided — to help us figure it all out.

In the spring, face masks were hard to come by but now that summer is here, there are plenty of options.

Fischer et al., Science Advances, 2020

Almost too many to know which one to pick!

So researchers at Duke University set out to sort it all out for us, experimenting on 14 different styles of face coverings, from loose bandanas to home-sewn cotton masks to surgical masks and everything in between, to find out which ones are most effective at blocking droplets .

The idea from experts, of course, is that something should be better than nothing.

Unsplash | Zhang Kenny

But just how much better one is than another hasn't really been studied before.

"Surgical masks are commonly worn by medical personnel and have received a fair amount of testing in clinical settings," said lead researcher and molecular imaging specialist Martin Fischer at a press event, according to ScienceAlert. "But as far as we know, there was no quick, easy, and cost-effective way to demonstrate the effectiveness of such a wide variety of other mask types."

The researchers set up a fairly simple test.

YouTube | Duke Health

They attached a special lens to an optical laser that turned the light it emitted into a sheet and shone it into a dark enclosure. Then they donned a mask and spoke the phrase "Stay healthy, people," into the dark enclosure. Any droplets that made it through the mask would show up against the light sheet and be caught on video.

Even this much of the experiment showed something important. "We confirmed that when people speak, small droplets get expelled, so disease can be spread by talking, without coughing or sneezing," Fischer said in a press release.

Then it was simply a matter of reviewing the videos and counting the droplets that made it through the masks.

Fischer et al., Science Advances, 2020

No surprise, the fitted N95 masks worn by medical professionals working with COVID-19 patients provide the best protection and reduce the transfer of droplets most effectively.

However, somewhat surprisingly, many, many other masks, including cotton masks, showed a fair ability to block droplets as well.

One of the bigger surprises came at the bottom of the list.


While loose-fitting bandanas scored poorly at blocking droplets, they weren't the worst. That distinction went to fleece neck gaiters, the coverings that get pulled up around the face. They scored even worse than not wearing a mask at all.

"We believe that the material of our fleece breaks down large droplets emitted during speaking into several smaller ones," Fischer explained. "This could make wearing such a mask counterproductive, since smaller droplets have an easier time being carried away by air currents and endangering nearby persons."

The Duke team's findings were published in Science Advances.

h/t: ScienceAlert

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