Fact check: Masks worn during COVID-19 response do not cause fungal lung infections

Posts shared on Facebook claim that “people are starting to enter ER’s with fungal lung infections from wearing masks,” advising users to take breaks from wearing them. This claim, however, is false.

Reuters Fact Check. REUTERS/Axel Schmidt

Examples of such posts can be found here ,  here , and here .  

Dr. Thomas Nash, an internist, pulmonologist, and infectious disease specialist at New York Presbyterian Hospital in New York City ( here ), told Reuters, “The only thing that hits the mask is what you breathe out,” explaining that healthy people “don’t exhale fungus.” 

Nash said that someone who already has a fungal infection in their lungs could possibly contaminate their own mask, but not the other way around.

According to the Centers for Disease Control and Prevention (CDC), “fungi are common in the environment, and people breathe in or come in contact with fungal spores every day without getting sick. However, in people with weak immune systems, these fungi are more likely to cause an infection” (  here  ). 

“A fungus can infect the lung and cause a variety of problems ranging from an abscess to pneumonia to an asthmatic reaction,” Dr. Nash said.

Aspergillosis, an infection caused by a type of mold, is one example. The CDC says that “most strains of this mold are harmless, but a few can cause serious illnesses when people with weakened immune systems, underlying lung disease or asthma inhale their fungal spores” (  here  ). Illnesses resulting from aspergillosis typically affect the respiratory system, but symptoms vary widely. 

Fungal infections Valley fever ( here  ) and histoplasmosis (  here  ) can infect the lungs of people living in or visiting certain areas (  ). 

“If I had a mask and left it out in an old shed and I put it back on after a month, maybe it would contain fungus,” Dr. Nash said, calling the trail of logic “a series of impossibilities.”

Still, he advises that people clean reusable masks regularly in order to reduce the risk of spreading the new coronavirus or other germs. Johns Hopkins Medicine provides tips for cleaning a variety of different face masks here .  

As for claims that wearing a face mask causes other health complications, Nash said that “some of the masks are a little too tight” and therefore uncomfortable. But they still “allow in plenty of oxygen.”

The Cleveland Clinic has debunked the myth that “wearing a mask will make me sick” here . The site says that although “there’s been some speculation on social media that wearing a mask can cause you to rebreathe the carbon dioxide you exhale and make you sick,” it is “very unlikely” that you will inhale high levels of carbon dioxide from wearing a cloth face mask.  

Reuters Fact Check debunked a claim that wearing a mask would cause hypercapnia here . 


False. Wearing a face mask to protect from COVID-19 does not cause fungal lung infections.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts  here  .