There’s so much we still don’t know about the new coronavirus. It’s understandable that people are scared and have questions, one of the most pressing being: Are masks safe? The short and extremely reassuring answer is that, yes, it’s not only safe to wear masks to curb the spread of this dangerous disease—it’s essential. “Research suggests that wearing masks is highly effective at preventing the spread of COVID-19,” Mary Elizabeth Sexton, M.D., an assistant professor of infectious diseases at Emory University School of Medicine in Atlanta, tells SELF.
The good news is that the vast majority of people in the U.S. have gotten on board with wearing masks. In a nationally representative Pew Research survey released in June, 80% of 9,654 respondents said they wore a mask in stores or other businesses at least some of the time, and 65% said they did so “all or most of the time.” Also, 75% of people actually support requiring face masks in public, according to another nationally representative poll, this one published in July after the Associated Press-NORC Center for Public Affairs Research interviewed 1,057 U.S. adults.
If you or your loved ones still have questions about why wearing a mask is helpful, not harmful, here’s what you need to know.
It’s not true that masks will cut off your oxygen or make you breathe in carbon dioxide.
As all the experts interviewed tell SELF, wearing a mask isn’t going to increase your chances of breathing issues such as hypoxemia (low blood oxygen levels) or hypercapnia (elevated blood carbon dioxide levels). Masks prevent you from dispersing as many respiratory droplets and aerosols into the air as normal, which can greatly curb the spread of COVID-19—we’ll explain how this works in detail in just a bit. But what’s key to know from the start is that masks still allow for the free flow of oxygen and carbon dioxide that you need in order to stay alive, Enid Neptune, M.D., an associate professor of medicine and a pulmonary and critical care physician at Johns Hopkins Hospital in Baltimore, tells SELF. It’s completely understandable that people might worry about this because wearing masks can make breathing feel harder. But that doesn’t mean that wearing a mask is dangerously restricting your oxygen intake or carbon dioxide output, even if you have to huff and puff while wearing it.
An oxygen molecule is made up of just two atoms, while a carbon dioxide molecule is composed of three atoms, making both of these gases drastically smaller than respiratory droplets or aerosols containing SARS-CoV-2, the virus that causes COVID-19. “Viral particles are several hundred times bigger than oxygen and carbon dioxide molecules to begin with, but that still underestimates the size difference,” Mary Elizabeth Sexton, M.D., an assistant professor of infectious diseases at Emory University School of Medicine in Atlanta, tells SELF. Viruses in the coronavirus family are typically between 120 and 160 nanometers in diameter, compared with oxygen molecules, which are around 0.35 nanometers, and carbon dioxide molecules, which are around 0.33 nanometers. What’s more, these viruses are contained in respiratory droplets or aerosols, both of which are significantly larger than the virus itself, Neptune explains. Translation: Oxygen and carbon dioxide molecules are small enough that even the tightest cloth and surgical mask weaves shouldn’t significantly affect their passage, says Sexton.
There’s another solid piece of evidence showing you don’t need to be scared that wearing a mask will cause intense breathing issues: “Both hypercapnia and hypoxemia make people sleepy and confused, but surgeons operate on very small, critical areas of the body with great skill while wearing masks, sometimes for 8 to 12 hours at a time. If people truly experienced negative effects on oxygen or carbon dioxide levels while wearing a mask, it wouldn’t be possible for surgeons to do their jobs,” says Sexton.?
The only evidence we have of masks potentially interfering with oxygen and carbon dioxide flow when worn for long periods is limited to N95 masks, which have special filters to block at least 95% of airborne particles—and finer weaves than surgical or homemade masks. Even then, it’s not definitive. A small 2006 study in Acta Neurologica Scandinavica suggested that health care workers who continuously wore N95 masks for more than four hours at a time developed headaches. This could theoretically indicate hypercapnia or hypoxemia but could also simply be due to the physical stress an N95 puts on a person’s face and head, the study authors wrote.