While wearing a mask has evolved from a question of personal protection into a politically divisive symbol, the consensus among the medical community is that the science behind wearing face coverings to prevent the spread of viral infection has long been settled.
In March, the Mayo Clinic reported that experts did not yet know the extent to which people with COVID-19 could spread the virus before symptoms appeared early in the pandemic. Additionally, experts did not know that someone who was seemingly asymptomatic could spread the virus.
The medical community has a better understanding of the virus six months into the pandemic than they did early on.
The growing consensus, said Dr. Raffaella Betza, chief of staff at Blue Mountain Hospital, is that COVID-19 is spread when people talk, cough, laugh, sneeze, sing and eject viral particles into the air.
Betza said the epidemiological evidence is “ample.” Along with anecdotal data, she said, wearing a mask cuts the spread of COVID-19.
A study published in May in BMJ Global Health showed transmission was cut by roughly 80% in households where one person in a family was confirmed to have COVID-19, and the rest of the family wore masks indoors as a precaution.
Raina MacIntyre, a co-author of the study, said the study showed that wearing a mask protected the whole family.
Betza pointed to another instance in Missouri where two hairstylists who had tested positive with the virus came into contact with 140 of their clients, but because both of the stylists wore a mask, none of the clients tested positive.
Different types of masks offer different levels of protection. Surgical-grade N95 respirators are the most effective in protecting against the coronavirus, Betza said.
She said it is important to remember that they need to be fitted to be maximally effective.
“The way we do this in the health care setting is that you actually put on an N95 and then a hood, and they spray a chemical under the hood that tastes bitter if it makes it past the mask,” she said. “If you can taste bitter, then the mask is not fitted.”
Conversely, she said, if one cannot taste the bitterness after a minute, then they are cleared to wear the mask when needed.
She said wearing an N95 mask that does not fit properly is no more effective than wearing the lesser protective cloth or surgical masks.
Betza said surgical masks offer more protection than cloth masks. However, she said an actual comparative number between the two is not known.
“Both masks certainly decrease the spread considerably,” she said.
Surgical and cloth masks, she said, are key in preventing the wearer from spreading the virus through respiratory droplets. It has become clear both masks do provide some protection from catching the virus as well, she said.
Researchers have lumped both cloth and surgical masks together in studies that have looked at how effective communities have been at stemming the spread of COVID-19.
“We know that surgical masks are more effective than cloth masks, but we absolutely know that both help stop the spread of COVID-19,” she said.
The top two complaints she hears from patients are discomfort and difficulty breathing.
Most of the time, she said, if someone is having a hard time breathing with a mask on, it’s because the mask doesn’t fit right.
“People sometimes wear the mask too tight or wear masks that are not stiff enough so that the mask sucks in when you take a breath,” she said.
Betza said she recommends a face shield for those who have tried different types of masks but are unable to find the right fit.
“This would meet the face-covering requirement and provide some protection, though possibly not as much as a mask,” she said.
She said people with asthma, chronic obstructive pulmonary disease and other respiratory diseases can wear a mask without any problems.
“Doctors and nurses with those medical problems wear masks all day in the operating room without incident,” she said.
The Centers for Disease Control and Prevention recommends using the same make, model and size respirator that is the proper fit each time a mask is worn and to thoroughly wash hands before taking the mask off and putting it on.
When putting the mask on, one should hold the respirator in their hands with the nose piece at their fingertips, then cup the respirator in their hands allowing the headbands to hang below their hand and hold the respirator under their chin and point the nose piece upwards.
The top strap goes over and rests at the top backside of the head while the bottom strap gets positioned around the neck, under the ears. Do not cross the straps.
Place fingertips on the metal clips to mold the nose area. Check the seals, either using the Betza method or by placing both hands over the respirator, taking a quick breath and ensuring the respirator seals tightly to the face.
For cloth masks, wash hands thoroughly.
Ensure the mask covers the nose and mouth and make sure to secure it under the chin. Additionally, be sure to fit it snugly on each side of the face. Lastly, make sure the mask breathes easily.
Despite the abundance of medical studies and epidemiological evidence, Betza said, “the best evidence comes from the real world.”