Why the "Masks Cause Lung Damage" Excuse Doesn't Hold Up, According to a Pulmonologist

One antimask argument you hear a lot is that face masks — even the nonmedical-grade ones currently recommended for public use — will deprive you of oxygen, suffocate you with carbon dioxide, and generally cause damage to your lungs, particularly if you have underlying pulmonary conditions like asthma. It's gotten to the point that some people have started carrying around fake "mask exemption" cards that claim that wearing a mask poses a mental or physical risk to the bearer, while invoking the Americans With Disabilities Act and the "Freedom to Breathe Agency." (FYI, the FTBA is not a government agency and the official site of the ADA says these cards amount to fraud.)

Fraudulent exemption cards aside, it's true that wearing a face mask, especially for extended periods of time, is not particularly comfortable and can definitely make it feel like you're working harder to breathe. But does that actually lead to lung damage, and could masks actually be dangerous for those with or without preexisting lung conditions?

"There is no evidence that wearing a face mask is dangerous from a lung standpoint," said Kathryn Melamed, MD, a pulmonary critical care physician at UCLA. "There's no evidence to show that either you build up carbon dioxide or you don't get enough oxygen."

Dr. Melamed explained that the air won't flow as quickly when you're wearing a mask, which could make you feel like you're not getting enough to breathe, but it doesn't actually affect the amount of oxygen you inhale. "Masks are blocking some of the airflow, but they're not filtering out oxygen from the air," she said. Similarly, a mask won't interfere with the amount of carbon dioxide being exhaled from your lungs, and face masks aren't airtight to the point that it would cause a build up of carbon dioxide in front of your nose and mouth. "These masks are meant to filter air particles, but not filter oxygen and carbon dioxide," Dr. Melamed said. (Past studies on the N95 respirator, which is used by medical professionals but not recommended for the general public, have found that prolonged use of the N95 can lead to changes in oxygen and carbon dioxide levels, though evidence is mixed.)

The rules don't change when it comes to exercising with a face mask on, either. Feelings of discomfort might be "exacerbated and exaggerated" when you're exercising, Dr. Melamed said, but "there's no evidence to suggest that, at any point, you're not getting enough oxygen." (If you think there's a chance you'll come within 10 feet of another person while exercising, Dr. Melamed recommends wearing a mask. Here are more tips on exercising in a face mask and breathable styles to try.)

"There are no pulmonary conditions where wearing a face mask could be dangerous," Dr. Melamed told POPSUGAR. She pointed out that certain mental health conditions, such as severe claustrophobia, might make it difficult to wear a mask. Recent physical trauma to or surgery on your face could also cause issues with mask-wearing. From a lung standpoint, though, face masks should be safe to wear, even for people with conditions like asthma. "There is no reason that a patient with asthma should not be able to wear a mask," Dr. Melamed said.

In fact, it's the opposite. "If you feel like you have a lung condition that precludes you from wearing a mask," Dr. Melamed said, "then that condition is going to put you at higher risk of COVID." Asthma and chronic obstructive pulmonary disease are two lung conditions that the CDC says may make people more vulnerable to severe COVID-19. If anything, people with such conditions should be taking as many precautions as possible, including social distancing, staying home, and, yes, wearing a mask while they're out and about, Dr. Melamed explained. "There is no medical reason where, if you're going to be out in public, you cannot wear that mask."