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Bacteria inside masks and oxygen deficiency from masks causes lung cancer

What you may have heard

Mask-wearing increases the risk of cancer.

What science tells us

There is a vast amount of evidence showing that long-term mask-wearing has no effect on cancer risk. The first study to make this false accusation about masks has been discredited by many other studies (Moffitt Cancer Center). The American Lung Association also states that there is no shred of truth to the statement (ALA).

Epidemiological Evidence

The Centers for Disease Control and Prevention has also responded, stating that mask-wearing does not pose any additional health risks and is essential to protect individuals from COVID-19. Wearing a facial covering helps protect others when you cough, sneeze, or talk and spray viral droplets into the air (ALA). Many people are not aware they have become infected and unknowingly spread COVID-19 to others. As a result, wearing a mask is important to lessen the spread of disease. There is no evidence from epidemiological studies that conclude that mask wearing is associated with cancer.

Laboratory Evidence

There is no evidence from laboratory studies that connect mask wearing to cancer development.

IARC Carcinogen Classification: Not Classified

How to reduce your risk

When selecting your mask, it is important that the mask not be so thick as to make breathing uncomfortable. Filters are probably unnecessary and may make masks more uncomfortable. The gold standard is the N-95 mask, which is 95% effective at protecting the wearer from inhaling viral particles (ALA). Surgical masks are less effective and cloth masks are even less so. Regardless, even a 50% reduction in transmission is essential to reduce the spread of COVID-19 (ALA).

Whenever you wear a mask, make sure it is new and sterile. If wearing a mask does give you breathing difficulties, try going to a space outdoors and away from people to regain your breath (CDC).

Bottom line

Mask usage does not cause cancer and using masks to prevent the spread of infectious diseases (such as COVID-19) is crucial.

Centers for Disease Control and Prevention (CDC): Masks
Moffitt Cancer Center: Mask wearing
American Lung Association (ALA): Masks


Published: July 7, 2021
Verified/updated: August 22, 2022