Masks help protect the people wearing them from getting or spreading SARS-CoV-2, the virus that causes COVID-19, but now researchers from the National Institutes of Health have added evidence for yet another potential benefit for wearers: The humidity created inside the mask may help combat respiratory diseases such as COVID-19.
The study, led by researchers in the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), found that face masks substantially increase the humidity in the air that the mask-wearer breathes in. This higher level of humidity in inhaled air, the researchers suggest, could help explain why wearing masks has been linked to lower disease severity in people infected with SARS-CoV-2, because hydration of the respiratory tract is known to benefit the immune system. The study published in the Biophysical Journal.
“We found that face masks strongly increase the humidity in inhaled air and propose that the resulting hydration of the respiratory tract could be responsible for the documented finding that links lower COVID-19 disease severity to wearing a mask,” said the study’s lead author, Adriaan Bax, Ph.D., NIH Distinguished Investigator. “High levels of humidity have been shown to mitigate severity of the flu, and it may be applicable to severity of COVID-19 through a similar mechanism.”
A novel new study suggests that the behavior public officials are now mandating or recommending unequivocally to slow the spread of surging COVID-19–wearing a face covering–should come with a caveat. If not accompanied by proper public education, the practice could lead to more infections.
The finding is part of an unique study, published in JMIR Public Health and Surveillance, that was conducted by a team of health economists and public health faculty at the University of Vermont’s Larner College of Medicine in partnership with public health officials for the state of Vermont.
The study combines survey data gathered from adults living in northwestern Vermont with test results that showed whether a subset of them had contracted COVID-19, a dual research approach that few COVID studies have employed. By correlating the two data sets, researchers were able to determine what behaviors and circumstances increased respondents’ risk of becoming sick.
It’s been shown that when two people wearing masks interact, the chance of COVID-19 transmission is drastically reduced. This is why public health officials have pleaded for all people to wear masks: they not only protect the wearer from expelling particles that might carry SARS-CoV-2, the virus that causes coronavirus 2019 (COVID-19), but masks also protect the wearer from inhaling particles that carry the virus. Some people, though, still refuse to wear a mask. So UNC School of Medicine scientists, in collaboration with the Environmental Protection Agency, researched the protectiveness of various kinds of consumer-grade and modified masks, assuming the mask wearer was exposed to the virus, like when we interact with an unmasked infected person.
Published in the journal JAMA Internal Medicine, the research shows that some masks were as much as 79 percent effective at blocking particles that could carry the virus. These were masks made of two layers of woven nylon and fit snug against the wearer’s face. Unmodified medical procedure masks with ear loops – also known as surgical masks – offered 38.5 percent filtration efficacy, but when the ear loops were tied in a specific way to tighten the fit, the efficacy improved to 60.3 percent. And when a layer of nylon was added, these masks offered 80 percent effectiveness.