COVID-19: 4 things to know about face masks
3. Is wearing a mask for an extended period harmful?
In the debate over wearing masks, some have claimed that continually wearing masks can be harmful to one’s health due to breathing in one’s own exhaled carbon dioxide.
Health and infectious disease experts have dismissed the claim that wearing a face mask would lead to hypercapnia (when there is too much CO2 in the bloodstream).
Prof. Keith Neal, an infectious disease expert who has experience controlling SARS, MERS and swine flu, among others, told BBC, “This simply won't happen unless there is an air-tight fit and you rebreathe your air.”
A CDC representative told Reuters that while the CO2 will slowly build up in the mask, “the level of CO2 likely to build up in the mask is mostly tolerable to people exposed to it. You might get a headache but you most likely [would] not suffer the symptoms observed at much higher levels of CO2.”
“It is unlikely that wearing a mask will cause hypercapnia,” the CDC representative said.
Carbon dioxide molecules are so small (smaller than respiratory droplets containing coronavirus) that they can easily pass through masks or out the perimeter of the masks.
A 2006 survey of healthcare workers who wear N95 face masks concluded that “healthcare providers may develop headaches following the use of the N95 face-mask. Shorter duration of face-mask wear may reduce the frequency and severity of these headaches.”
All in all, Reuters deemed it “partly false” that continually wearing a mask causes hypercapnia.