Are there any dangers of long-term mask use as this viral picture claims?

A meme shared thousands of times on Facebook claims people can suffer from reduced oxygen to their blood and brain, possibly leading to death, if they wear a disposable mask for too long.

This is misleading; only a marginal decrease in oxygen saturation can sometimes be measured in people wearing a disposable mask, and several experts agree there is no evidence of long-term effects from breathing through a mask.

“Danger of Facemask, Mask is supposed to be used for limited time,” the text at the top of the image says before listing four side effects, including possible death, of wearing the face-covering for an extended period.

A similar visual has also circulated on Facebook and other social media sites.

During the novel coronavirus pandemic, which has killed more than 450,000 people globally, the official advice from the US Centers for Disease Control and Prevention (CDC) remains that wearing a mask or face covering is recommended where social distancing is difficult.

AFP Fact Check asked medical experts to break down the claims presented in the image.

Claim: If you wear a surgical mask for a long time, the oxygen in your blood and brain reduces

“It is true that masks may cause trivial changes to oxygen and carbon dioxide levels, but this is mainly seen with N95, not surgical or cloth face masks,” Hallie Prescott, Assistant Professor in the Division of Pulmonary & Critical Care Medicine at the University of Michigan Health System, said to AFP by email.

The CDC does not recommend the use of N-95 masks to the general public.

Prescott, who is also a staff physician at the Veterans Affairs Ann Arbor Health Care System, referred to a report published in 2008 which studied deoxygenation induced by surgical masks during major surgeries. The report found a “decrease” in oxygen saturation in surgeons, “either due to the facial mask or the operational stress.”

“My interpretation is that—for 99.9 percent of the population without severe underlying lung disease—there are at most only trivial decreases in blood oxygen levels with surgical or cloth masks,” she said.

If the person wearing a mask is experiencing headaches, “they can result from a variety of things – such as uncomfortable ear loops on masks – so I would not assume that headaches are a reflection of low oxygen,” Prescott added.

Josh Mugele, Emergency Department Physician at Northeast Georgia Medical Center in Gainesville, Georgia, says there are “zero adverse effects to long-term mask usage.”

“Not only is there absolutely no credible evidence to the contrary, but many professions wear masks for long periods of time on a regular basis with no adverse effects, including surgeons, lab technicians, and painters,” he told AFP in a direct message on Twitter.

Prolonged use of a well-made mask is unlikely to cause hypercapnia, a build-up of carbon dioxide in the blood, AFP found in another fact-check.

Claim: If you wear a surgical mask for a long time, you will start feeling weak

“It is hard to refute someone’s subjective feelings,” Prescott said, but “objective data suggests that surgical and fabric face masks are safe for the vast majority of the population who don’t have severe underlying lung disease.”

Jonathan Karn, virologist and director of the Cleveland COVID Task Force, told AFP by email that people should not “start feeling weak or die” while wearing “a light surgical mask or homemade cloth mask.”

Claims that the use of masks worsens the immune system are also false, AFP USA found in another fact-check. 

Claim: Wearing a mask for an extended time may lead to death

“Nobody has ever died as a direct result of wearing a surgical mask. If people can transplant an organ or perform brain surgery while wearing a mask, it is reasonable to ask people to wear them in public to reduce transmission of novel coronavirus,” Ryan Marino, an emergency medicine physician at University Hospitals Cleveland Medical Center, told AFP via a direct message on Twitter.

AFP Canada debunked a video of a nurse warning against continuously wearing face masks, claiming they can harm the body.

Claim: Pull off your mask when you are alone

“If you are alone in a car there is no reason to wear a mask, but it should be put on when leaving the car if other people are being encountered. The general idea behind face masks is to break the chain of infection in the population,” Karn explained.

Caution is, however, advised when putting on and removing a face mask to avoid further contamination, as explained in a WHO graphic.