The use of face masks has been a part of daily life since the early days of the pandemic. Unfortunately, donning PPE has taken on a renewed importance ever since the highly transmissible Delta variant has become the dominant strain of the virus in the U.S., with some local health officials reviving mask mandates in public places. But covering up with just any type of mask doesn't necessarily mean you're safe: A new study has found that you may need to wear more than a basic cloth or surgical mask to protect yourself from COVID or stop you from spreading it to others.
The latest research on the matter, published in the journal Physics of Fluids on July 21, comes from the University of Waterloo in Canada. To test their effectiveness, a team of researchers simulated breathing using CPR mannequins in a large, unventilated room while wearing different types of masks, including three-ply cloth masks, surgical masks, N95 masks, and KN95 masks.
Results found that commonly worn cloth masks and basic surgical masks were only capable of filtering exhaled particles "at apparent efficiencies of only 12.4 percent and 9.8 percent, respectively." On the other hand, results also found that N95 and KN95 masks saw "substantially higher apparent filtration efficiencies" of 60 percent and 46 percent, respectively. This led the study's authors to conclude that the two premium masks "are still the recommended choice in mitigating airborne disease transmission indoors."
The team believes that the poor fit of most cloth and surgical masks is to blame for the major decrease in filtration capabilities. Photographic evidence from the study showed that spaces between the face and PPE allow particles to escape into the ambient air, most often redirecting particles out the top of the mask over where it touches the nose.
Ultimately, the research team concluded that a combination of improved ventilation systems and higher quality face masks could go a long way in slowing the spread of COVID-19. "There is no question it is beneficial to wear any face covering, both for protection in close proximity and at a distance in a room," Serhiy Yarusevych, PhD, a professor of mechanical and mechatronics engineering and the leader of the study, said in a statement. "However, there is a very serious difference in the effectiveness of different masks when it comes to controlling aerosols."
"A lot of this may seem like common sense," he admitted. "There is a reason, for instance, that medical practitioners wear N95 masks—they work much better. The novelty here is that we have provided solid numbers and rigorous analysis to support that assumption."
The study comes after some top health experts have begun suggesting higher quality face masks during the surge of the Delta variant. During an interview with CNN on August 2, Michael Osterholm, PhD, epidemiologist and director of the University of Minnesota Center for Infectious Disease Research and Policy, made the case that it was time for people to upgrade from the cloth masks, bandanas, and gators that do very little to protect against virus transmission.
"We need to talk about better masking," he argued. "We need to talk about N95 respirators, which would do a lot for both people who are not yet vaccinated or are not previously infected. Protecting them as well as keeping others who might become infected having been vaccinated from breathing out the virus."
Osterholm wasn't the first expert to advocate for upgrading PPE. During an appearance on CBS' Face the Nation on July 25, Scott Gottlieb, MD, former Food&Drug Administration (FDA) commissioner, argued that on top of focusing on vaccinations, the right quality mask was necessary to protect against the virus. "I think, though, if you're going to consider wearing a mask, the quality of the mask does matter. So if you can get your hands on a KN95 mask or an N95 mask, that's going to afford you a lot more protection," he said.