By Pat Carragher - March 08, 2021
Since the COVID-19 pandemic began there has been no shortage of myths and conspiracy theories circulating on social media. The latest batch of unfounded tales claim to have found a direct link between prolonged mask wearing and lung cancer. Some stories suggest that oxygen deficiency caused by masks can cause cancer. Others claim that dangerous bacteria in masks are breathed back into the lungs.
So, can prolonged mask use actually cause lung cancer? According to the American Lung Association (ALA), absolutely not.
Claims about masks causing low oxygen levels have been debunked over and over again since the beginning of the COVID-19 pandemic. Masks are designed to be breathed through and there is no evidence that low oxygen levels occur.
“Mask wearing aside, low oxygen levels don’t actually cause cancer,” Saltos said. “There are some similar factors between low oxygen and cancer in patients with chronic obstructive pulmonary disease, but the common denominator there is smoking.”
The ALA says there is some evidence, however, that prolonged use of N-95 masks in patients with preexisting lung disease could cause some build-up of carbon dioxide levels in the body. Oxygen deprivation, also known as hypoxia, is a known resistance factor in non-small cell lung cancer treatment. People with preexisting lung problems should discuss mask wearing concerns with their health care providers.
While it’s true that CO2 can be dangerous at high levels, experts don’t believe facemasks put you at risk. According to the Centers for Disease Control and Prevention, “the CO2 will slowly build up in the mask over time. However, the level of CO2 likely to build up in the mask is mostly tolerable to people exposed to it.”
Some articles go as far as to cite studies claiming the inhalation of harmful microbes into the lungs have been "cultivated through prolonged mask wearing.”
“The breathing that we do is not sterile to begin with,” said Saltos. “There’s bacteria all over. A lot of these are good bacteria that colonize in our bodies. Medical professionals have been wearing masks all day for a long time and there’s no connection between mask wearing and lung cancer.”
"Medical professionals have been wearing masks all day for a long time and there’s no connection between mask wearing and lung cancer."- Dr. Andreas Saltos
To support the claim that “masks are priming the lungs for inflammation and lung cancer pathology”, the article refers to a study published in the American Association for Cancer Research journal Cancer Discovery.
While that study does look at higher levels of certain oral bacteria in lung cancer patients, there is no mention of long-term mask wearing. The study was conducted between 2013 and 2018, before mask wearing was common.