Face masks: Which are most, and least, effective
For three months, I proudly wore my Steelers bandanna over my mouth and nose when around others to do my part to prevent the coronavirus from spreading. I ditched it recently, switching to a cotton mask that is easier to put on and take off quickly.
Now I know the swap is beneficial for another reason: Cotton masks scored better on a recent study of how well various face coverings do in stopping the potential spread of the disease.
Duke University researchers examined how effective 14 types of face coverings are at blocking respiratory droplets that are sprayed when someone is talking. They found “stark differences.”
“Some mask types approach the performance of standard surgical masks, while some mask alternatives, such as neck fleece or bandannas, offer very little protection,” concluded the study, published Friday.
When baseball started a few weeks ago, I thought it was cool that some players wore neck gaiters, or fleeces, so they could pull them up over their mouth and nose when around opponents on the field.
This study shows that while the players’ intentions are good, the results may not be.
The type of neck gaiter that was tested, a polyester spandex material, resulted in more droplets being sprayed than by someone not wearing a mask. That’s because the fabric broke large droplets into multiple smaller ones.
“They tend to hang around longer in the air, they can get carried away easier in the air. So this might actually be counterproductive to wear such a mask,” researcher Martin Fischer said in a video produced by Duke about its testing.
“So it’s not the case that any mask is better than nothing. There are some masks that actually hurt rather than do good.”
Knitted masks also were ranked as low-performing. N95 masks with valves were flagged because the exhalation valve allows “strong outwards airflow,” which can decrease protections for people nearby.
It wasn’t a surprise that the mostprotective face coverings were fitted N95 masks, the hospital-grade coverings used by health care workers.
They did not allow any respiratory droplets through. Multilayered cotton masks and three-layer surgical masks scored well, too.
The analysis was done using a cellphone to record video of someone wearing the masks as they spoke into a box. Inside the box was a laser beam, which illuminated the spray of droplets that came through the masks, so they could be counted by a computer algorithm.
The counts were compared against the amount that came from a speaker not wearing a mask.
The study was prompted by a request from a Duke doctor who was working with a nonprofit to provide masks to at-risk and under-served populations in Durham, North Carolina, where Duke is located. He wanted to make sure the masks that were handed out were effective.
“We were trying to make a decision on what type of face covering to purchase in volume and little information was available on these new materials that were being used,” Dr. Eric Westman said in a Duke news release.
The research prompted the community outreach project to change the type of mask it initially planned to buy.
“They were no good,” Westman said. “The notion that ‘anything is better than nothing’ didn’t hold true.”
I can already hear the snickering from the anti-mask crowd about this research. They’ll latch on to the fact that bandannas and neck gaiters aren’t so effective, after public health officials had suggested people wear them.
What I hope most people will learn is that many of the masks do a good job of blocking respiratory droplets, which can spread the virus. And even bandannas block some droplets.
The findings offer deeper insight into a situation I wrote about a few weeks ago, how two hairdressers who were infected with the coronavirus didn’t pass it on to any of their customers because they wore masks. They wore a double-layered cotton or surgical mask, both of which ranked high in the study.
It’s not only the people who know they are sick who should be concerned about spreading COVID-19. Many infected people feel fine and show no symptoms, so they don’t realize they’re contagious. That’s why it’s necessary for everyone to wear a mask when they are around others.
Sadly, not everyone ever will be convinced of their value. The worst malcontents aren’t satisfied with just flouting the rules. They will punch you in the face or even shoot at you if you dare suggest they comply.
The latest incident happened Sunday at Sesame Place in Bucks County. A 17-year-old employee underwent jaw surgery after a park visitor punched him because the worker did his job and reminded the man and his female companion they had to wear masks in the amusement park, according to The Philadelphia Inquirer.
Mask requirements aren’t going away soon. Those of us smart enough and civic-minded enough to comply might as well wear ones that work the best.