The Centers for Disease Control and Prevention have been encouraging Americans to wear masks in public in order to protect themselves and others from COVID-19. However, some people argue that certain types of masks don’t do much good since the virus particles are small enough to get through.
While that is true, health experts say it is about how the particles travel and not just their size.
“It’s one of the most common, incorrect pieces of information that’s being spread on the internet, that cloth masks don’t work because the virus is so small it can go right through it,” said Dr. Dale Bratzler, Oklahoma University Chief COVID officer.
Officials say that while carbon dioxide can escape from cloth masks, the COVID-19 virus typically cannot. That’s because the respiratory droplets that carry the virus are much larger than the virus or CO2, so they cannot pass through a mask.
“The virus comes out on droplets. So I’ve seen that in so many different presentations. ‘You know, the virus is 50 to 150 nanometers, that can go through a cloth mask.’ Absolutely, that’s true. It can go through a KN95, it can go through a surgical mask. But that’s not how the virus comes out of your mouth. It comes out riding droplets, aerosols and droplets. And cloth masks are incredibly effective at preventing droplets and aerosols from coming out of your mouth. They’re not perfect but they’re very good,” Dr. Bratzler said.
“While each utterance generated hundreds of droplets ranging in size from 20 to 500 micrometers, the researchers showed that covering the speaker’s mouth with a damp washcloth blocked nearly all of them,” according to MIT analysis.
To prove it yourself, Dr. Bratzler says you should wear a mask for a couple of hours at a time.
“Just wear a mask for a few hours and feel the inside of it. You’ll feel the moisture on the inside of the mask. That’s why we ask you to wash the mask frequently,” Dr. Bratzler said.
MIT analysis suggests a number of real-world studies that reinforce the value of mask use.
“A recent study, for example, used publicly available data to calculate the COVID-19 growth rate before and after mask mandates in 15 states and the District of Columbia between the end of March and late May of 2020. Researchers found that mask mandates led to a marked slowdown in the daily growth rate, estimating that mask mandates may have prevented up to 450,000 cases of COVID-19,” author Kim Schive writes.
Though masks are not 100 percent effective, doctors say they dramatically reduce the risk of infecting others.
“They’re very effective and multiple studies have shown when both people are wearing a mask, even a simple two-layer cloth mask, it dramatically reduces droplets and aerosols that come out of your mouth. It reduces that zone of contamination that’s around you and protects both parties,” he said.