Raleigh, North Carolina – The Centers for Disease Control and Prevention says you have to wear masks.
Researchers at the University of North Carolina tested this idea, testing to see what additional protection, if any, would provide double masking. On Friday morning they published their findings.
In a briefing, they shared their research on the effectiveness of masks in general, the importance of mask fit, and the added benefits of double masking.
Adjustment is the most important thing
“You really need to deal with the fit and make sure everything you carry fits you well,” said Dr. Phillip Clapp, assistant professor in the Department of Pediatrics.
According to Clapp, simply making sure a single mask fits can increase effectiveness by 20%.
A mask that does not fit allows air and aerosols to pass through any vacuum, which decreases protection against COVID.
Double masking provides increased protection
Tests indicated that double masking provides greater protection, as long as the masks are installed.
“With the double masking, we saw an increase of 15% [in protection], only through a double masking procedure or surgical masks, ”Clapp said.
In addition, double masking can provide additional protection, depending on how the wearer wears the masks.
For example, putting layers of a cloth mask on top of a surgical mask showed a 40% increase in efficiency. However, putting any surgical mask on top of a fabric mask did not provide similar protection.
Mask frames, which help ensure a good fit, also provide additional benefits.
However, even double masking is not compared to wearing an N-95 mask.
But wearing two surgical masks and adding a frame or brace around the face to prevent leaks and create a good fit, achieved 97% effectiveness in one test.
In short, the extra layers offer extra protection, but it’s very important to make sure it fits the mask or else the filtration will allow aerosols to pass through.
Finally, Dr. Emily Sickbert-Bennett, UNC’s director of infection prevention, addressed the most important type of “double masking.”
“The most important‘ double masking ’is when both you and the person you’re with are wearing a mask,” he said.
So whether you decide to mask yourself or not, one of the most effective ways to prevent the spread of COVID is simply for everyone to wear at least one mask.
Is it dangerous to wear a mask or a “double mask”?
Some people have been worried about whether wearing a mask can lower oxygen levels. So could double masking have a potential drawback?
Clapp and Sickbert-Bennett said they don’t think that’s a concern.
Clapp said what worries people is breathing their own air again, which increases carbon dioxide and decreases oxygen.
However, he said, these concerns are not backed by the science of how masks work.
“When you wear a mask, the volume of air inside that breathing space is very low. So when I breathe, I’m taking air out,” he said.
That’s the whole purpose of masks, he explained. They are meant to filter particles out of the outside air as you breathe air through the masks.
“So bring fresh air in addition to the small amount of air you exhaled earlier,” he said.
Sickbert-Bennett said, “Of all our medical colleagues who have reported this, this will not be a concern.”
When can we stop wearing masks?
Since COVID is transmitted by respiratory droplets, masks are key to preventing spread.
“If everyone wears masks constantly, I think this is the best way to end the pandemic,” Sickbert-Bennett said.
He said that when the transmission is reduced, the community can re-evaluate when it is time to finally hang our masks.
Until then, we can increase our protection by making sure our masks fit and, if we wish, by double masking.