While most of the bacteria and fungi cultured from the masks were not harmful to humans, some were opportunist pathogens, while others were found to cause diseases like bacteria that cause food poisoning and staph infections, and a fungus that causes ringworm, athlete’s foot, and jock itch.
From their findings, the authors of the study suggest that people with a weakened immune system should “avoid repeated use of masks to prevent microbial infection.”
The CDC says that immunocompromised people or those at high risk for severe disease should wear a mask or respirator when there is a high community level of COVID-19.
The health agency did not respond to The Epoch Times’ request for comment on the findings of the Japanese study.
Supporters of universal masking during the pandemic say that masks help to prevent or reduce transmission of SARS-CoV-2 infection.