Is it Worth Wearing Masks to Prevent Coronavirus?

There has been a rush to purchase surgical masks to prevent Coronavirus.  In short, it is not going to do much and thus not worth the effort.  Surgical masks prevent the wearer from spewing out droplets, but are not overly efficient at the reverse.    So it would be recommended for someone who may have been exposed, but not for someone who is just trying to prevent illness, especially in places like the US where it is a low risk.

Healthcare workers working with potentially ill person from Coronavirus are advised to wear a heavy-duty mask called an N95 respirator.   "These respirators are designed to fit tightly around the nose and mouth, and, when worn correctly, block out at least 95% of small airborne particles, according to the CDC."  But these are not something recommended for the general public.

https://www.businessinsider.com/wuhan-coronavirus-face-masks-not-entirely-effective-2020-1
People are racing to buy face masks amid the coronavirus outbreak, but they probably won't protect you from illness
Holly Secon Feb 26, 2020, 2:45 PM

Of the many preventative measures you can take to protect yourself from the new coronavirus, wearing a face mask is one of the most visible. But for members of the general public, health experts don't think it'll help much.

"There's little harm in it," Eric Toner, a scientist at Johns Hopkins Center for Health Security, told Business Insider. "But it's not likely to be very effective in preventing it."
Since the coronavirus outbreak started Wuhan, China, in December, more than 81,000 people have been infected and at least 2,760 have died. Cases have been recorded in 40 other countries. (For the latest case total and death toll, see Business Insider's live updates here.)

According to the Centers for Disease Control and Prevention (CDC), the best precautions for the public are the standard, everyday ways to avoid all germs: wash your hands frequently, try not to touch your face, and avoid close contact with sick people.

In healthcare settings, however, the CDC has issued stronger directives: Any patients that present flu-like symptoms or have recently traveled to China's Hubei province should wear surgical masks. That lowers the risk that a potentially infected person could spread the coronavirus to others via saliva or phlegm.

The agency also directed doctors and nurses treating potentially infected patients to wear N95 respirator masks and goggles.

US healthcare providers are preparing for the coronavirus' potential spread in the US. The CDC said on Tuesday that the prevalence of the disease could worsen and that it "might be bad."
Health and Human Services Secretary Alex Azar said yesterday that the US needs at least 300 million N95 respirator face masks for healthcare workers as the country braces for a potentially rapid spread of the coronavirus. The US currently has 30 million masks.

But for the average person, a mask is still probably not necessary. And as mask shortages continue, buying them up can take them away from medical workers that need them.

Two types of face masks

Face masks are designed to catch large contaminants and particles. There are two common kinds: surgical masks and N95 respirators.

N95 respirators filter out most airborne particles from the surrounding air, preventing wearers from breathing in particles down to 0.3 microns in diameter. These types of masks are often used when air quality is poor due to wildfire smoke or pollution, and they're designed to fit tightly against one's face.

When worn correctly, N95 respirators block out at least 95% of small airborne particles. So the respirators can filter out some droplets carrying coronavirus. The coronavirus itself measures between .05 and 0.2 microns in diameter, according to a recent article in The Lancet.
Healthcare workers are required by law to undergo a "fit test" every year to ensure they know how to use N95 respirators properly.

"While you're wearing this mask, somebody sprays something really nasty around you — it's a chemical that makes everybody cough their brains out if it gets in their mouth, and it's a test to see if that mask is really working," Robert Amler, a former medical officer at the CDC and a dean at New York Medical College, told Business Insider.
More than 3,000 medical workers in China — the epicenter of the outbreak — have gotten infected by the virus.


No health agencies in the US have issued recommendations for the public to wear N95 respirators.

Surgical masks, meanwhile, are designed to keep droplets and splatter from passing from a person's mouth to nearby surfaces or people. So they're primarily meant as a physical barrier to keep healthcare providers or sick people from spreading their own mouth-borne germs to patients.

The fit of a surgical mask is far looser than an N95 respirator, with openings around the edges.

Many people do not wear either type of face mask properly, however — wearers often move the masks to the side to touch their faces throughout the day, breaking the barrier that the mask is supposed to create. This makes the protection ineffective. Extended facial hair, as well, can break the seal.