Here’s yet another excellent reason to mask up: The Centers for Disease Control and Prevention (CDC) has announced that cloth face masks do help protect the wearer, not just the people around them.
Over the course of the pandemic, it’s become increasingly clear that wearing cloth masks helps protect other people. The SARS-CoV-2 virus that causes COVID-19 spreads mainly through respiratory droplets people spew into the air when they do things like cough, sneeze, sing, and even breathe. Other people can inhale these droplets, or the droplets can land on people’s eyes, mouth, or nose, thereby infecting them. Airborne transmission, which happens when smaller droplets linger in the air where other people can inhale them, is also possible, though much rarer. When you wear a mask, you curb how many of either kind of droplet you’re expelling into the air, which is why wearing a mask when you’re around people you don’t live with is so essential—it helps protect them from you accidentally spreading the virus. In their November 10 scientific brief, CDC cites studies that suggest multi-layered cloth masks block up to 50-70% of exhaled large and fine particles, while also slowing the forward propulsion of droplets that do get through.
One persistent question throughout this pandemic has been how much cloth masks actually protect the people wearing them by blocking coronavirus-containing droplets from others. Other types of masks, like surgical masks and N95s, are both shown to protect the wearer. But we’ve heard time and time again that the general public should reserve these types of masks for health care workers. Now, the CDC says, it’s clear that wearing cloth masks rewards you with some protective benefit for your own health.
The CDC came to this conclusion based on a slew of experimental and epidemiological research. In one illuminating case, two hair stylists with symptomatic COVID-19 who were experiencing symptoms saw 139 clients between them over eight days, with an average of 15 minutes with each client. The stylists and clients all wore masks, as was mandated by both the salon and local government. Once the stylists were diagnosed, public health officials did contact tracing and monitored all 139 clients for two weeks, ultimately reporting no COVID-19 symptoms in any of the clients or their secondary contacts. While asymptomatic cases could have been involved, 67 clients agreed to get tested, and none were positive for COVID-19.
Other studies the CDC cited found that, in cases where people wore masks in high-risk scenarios (like when around people who didn’t live in their households), they reduced their risk of infection by 70 percent or more. Research published in the Journal of General Internal Medicine in July suggested that wearing masks reduced infection risk and viral load, so that in the situations where people wearing a mask did become sick, they had a milder illness.
Exactly how much cloth masks filter out particles for the wearer varies from study to study, the CDC says, though it may be up to 50 percent of fine particles with some of the best cloth masks. What makes a good cloth mask? A high thread count, multi-layered cloth mask offers better protection than a single-layer mask with low thread count. The CDC also suggests that there may be some benefit in high thread count, multi-layered materials other than cotton, such as polypropylene, which might increase effectiveness by generating a type of static electricity that helps capture particles. Materials that repel moisture, like silk, may be useful in keeping masks comfortable during prolonged wear.
Even though some questions are still outstanding, this much is clear: Mask-wearing is one of the most crucially important public health tools we have against this virus. A recent study in Nature Medicine suggests that if everyone wore a mask in public, we could save 130,000 lives by February 2021. As SELF previously reported, experts believe we need a national mask mandate, and we need it now.
The CDC points to several studies showing that when government leaders directed people to wear masks, infection rates and deaths dropped significantly.
“Cloth face coverings are one of the most powerful weapons we have to slow and stop the spread of the virus—particularly when used universally within a community setting,” said CDC director Robert R. Redfield, M.D., back in July. It’s still true now.
As you mask up for yourself and others, remember that your mask is only going to be as protective as possible if it fits properly. Masks should snugly fit your face and always cover your mouth and nose, according to the CDC. The goal is to be breathing through the mask material, not around it.
As COVID-19 cases continue to skyrocket and we head into the winter and holiday season, the knowledge that masking is a clear defense against COVID-19 should be encouraging. We have a tool that works. We must use it.