Face mask or face shield? Experts weigh in on protection during coronavirus pandemic

Cities across the U.S. are requiring residents to don cloth face masks in public to help prevent coronavirus transmission, but the coverings aren’t always comfortable.

Masks can be hot, especially during summertime, and a literal pain due to the straps behind the ears.

Some people have made the change to plastic face shields and say they’re never going back.

“I hate wearing my face mask,” Hilary Brueck wrote for Business Insider.

She switched to a plastic face shield which sits on the bill of a baseball cap (others fit like headbands) and covers her eyes, nose and mouth, extending past her chin. It also has flaps that extend coverage to the sides of her face. She said the shield is easier to wear for long periods of time.

Face shields may be more comfortable, but are they safer than masks?

Experts say both have strengths and weaknesses.

Face shields

“I think face shields are a great option. One great advantage this time of year is that they aren’t as hot as a face mask is,” Dr. Michael Edmond, professor of infectious diseases at the University of Iowa, told KTRK. “For most people, it feels easier to breathe when you have on a face shield. You don’t get the fogging that you get with a mask if you’re a person like me who wears glasses.”

Face shields may also cause you to touch your face less.

With a mask, you may have to adjust it, meaning you could transfer the virus to your hands, Dr. Amesh Adalja, a pandemic preparedness expert at the Johns Hopkins Center for Health Security, told AARP.

Not so with the face shield, he said, as they’re easier to wear. They also don’t have to be removed when you eat or drink.

“They can also be taken off and cleaned,” he told Prevention. “In many ways, they’re a much more attractive option.”

But they aren’t foolproof.

Coronavirus is believed to spread through respiratory droplets and aerosolized particles. While face shields are beneficial at blocking droplets — they just land on the shield — smaller aerosolized particles can be more problematic as the shields aren’t air-tight, Dr. Rand McClain, chief medical officer of Live Cell Research, told Well and Good.

“With the aerosolized particles, though — because they’re light enough to float in the air — they could be drifting underneath, toward the mask. Someone inhales and you’d see the air pathway drop underneath the shield and then travel up toward the person within the shield,” he told the outlet.

A simulation study from 2014 found that face shields reduced inhalation exposure by 96% when worn by a medical professional within 18 inches of a cough. Once the cough dispersed around the room, however, the face shield was less effective, only reducing aerosol inhalation by 23%, the study said.

Still, Adalja told AARP the likelihood of getting viral particles under your shield is slim.

“Someone would have to stand underneath you and sneeze up into you,” he said. “It would be an odd circumstance that would cause that.”

Masks

N95 masks are the most effective at preventing infection, filtering out most particles and forming a tight seal across your nose and mouth, Prevention reported. Surgical masks are the second most effective followed by homemade masks, according to the outlet.

The Centers for Disease Control and Prevention recommends that people wear homemade cloth face masks when going out in public to help mitigate virus transmission.

The problem, experts said, is that respiratory droplets can land directly on masks and won’t completely deter particles from getting through the material. Masks also require you to remove them to eat and drink, Business Inside reported.

“We’ve seen studies showing that a 10 to 30% increase in protection is available with a standard bandana cotton mask,” McClain told Well and Good, adding that medical grade masks can protect against 60% to 80% of particles.

While the protection offered by homemade masks may not sound like much, one study found that protection from homemade masks is effective enough to drastically reduce transmission rates if they’re worn by enough people.

Masks are most effective at preventing the wearer’s germs from getting out into the world. Shields work in the reverse — they protect the wearer, Dr. Frank Esper, a pediatric infectious disease specialist at Cleveland Clinic Children’s Center, told Medical Express.

He said shields aren’t as effective as masks at keeping the wearer’s germs contained.

“If you cough, because this face shield is away from your face, those droplets can still get out better than if you have a mask on, where they basically get sucked up by the mask itself,” he told Medical Express.

What about wearing both?

Some doctors say the best way to use a face shield is to wear it in conjunction with a mask.

“Face shields are useful adjuncts,” Dr. Leong Hoe Nam, an infection disease expert told CGTN. “At the base of it, you definitely need a surgical mask, and wearing a face shield on top will be very, very helpful. The main reason is that the face shields only cover the face, and there are obvious gaps that are coming in from the sides and from the top and from the bottom.”

Wearing both a shield and mask is most common in health care settings, and other experts say it’s not necessary for people who are just out in public.

“I don’t think you get much added benefit to wearing a mask if you’ve already got a face shield on, for the average person,” Adalja told AARP.

This story was originally published June 30, 2020 at 11:54 AM with the headline "Face mask or face shield? Experts weigh in on protection during coronavirus pandemic."