As the Covid-19 coronavirus spreads across the world and sickens tens of thousands of people by the day, face masks have all of sudden become a scarce resource globally, selling out at pharmacies and on Amazon.com alike.
In China, where the novel virus has infected over 70,000 people and killed more than 2,000, wearing face masks is now a de-facto necessity for anyone to breathe in public space. Other countries recently seeing a spike in coronavirus cases, including Korea, Iran and Italy, have also rushed to urge the general public to put on face masks when going out.
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But do they really work? According to U.S. health experts and authorities, the answer largely depends on what type of face mask you wear. As a general guideline, though, per the U.S. Centers for Disease Control and Prevention (CDC), you are not recommended to wear a face mask unless told to do so by a doctor.
“CDC does not recommend that people who are well wear a face mask to protect themselves from respiratory diseases, including Covid-19,” the federal agency said on its website, noting that face masks are only recommended for those who show possible Covid-19 symptoms, such as coughing and fever, and their caretakers in close settings.
Instead, washing hands frequently is a far more effective method to keep the virus away, the CDC said.
“The data on the effectiveness of masks for preventing respiratory virus infections is not very clear,” Andrew Stanley Pekosz, a professor of Johns Hopkins’ Bloomberg School of Public Health, told CBS News on Thursday.
That said, face masks remain a popular choice for many due to concerns that the coronavirus could spread before a carrying person shows symptoms, which could take up to 14 days.
But health experts caution that not all face masks are equally effective in filtering out Covid-19 and that wearing one the wrong way could actually increase the risk of getting sick.
The generic surgical masks do very little in blocking small particles harboring the virus, Pekosz said. A special type of mask known as N95 respirators is much more effective, but only when worn properly.
“An N95 mask is the one that is most practical. It stops 95 percent of particles of a certain size,” Pekosz explained. “There is a N99 mask, which blocks 99 percent of particles, but that mask is difficult to wear for long periods of time because it is hard to breathe through it.”
“If [a face mask] is not fitted right, you’re going to fumble with it,” Health and Human Services Secretary Alex Azar said before a House Appropriations subcommittee on Wednesday. “You’re going to be touching your face, which is the No. 1 way you’re going to get disease, is unclean hands touching your face.