Unmasking the Truth

BY KATE SAGE, D.O.

Remember when wearing a mask was associated with Batman, Spiderman, and  e Incredibles? Well, we may feel like we’re living in an alternate universe or Gotham City, but we can all save lives if we wear a facemask. Recently, it has become mandatory to wear a mask in any public place where social distancing is not possible.  ere’s understandably some confusion about what type of mask to wear, why the rules have changed, and whether mask wearing really stops the spread of COVID-19. Here are some facts.

What are the Di erent Mask Types? Overall, there are three main types of masks: N95 respirators, paper/medical masks, and cloth masks.

N95 respirators are used in medicine and other places to  lter out very small particles. Often the particles being  ltered can cause infection or cancer, so N95s are used to prevent a human from inhaling them.  ey’re named because they can  lter out 95% of very small (0.3 micron) particles.  is type of mask has to be “ t-tested,” which means that a person puts on an N95 and then goes through a speci c screening process to make sure that the appropriate particles are  ltered. A typical  t test goes something like this: A person puts on an N95 and then puts a full face hood (think something like a beekeeper hood but made entirely of plastic) over the head. A second person then sprays a chemical inside the hood. If the person wearing the N95 can smell or taste the spray, then they fail the  t test and they need a di erent size N95. At this time, N95s are not recommended to the general public, and are reserved for health care professionals taking care of COVID-19 patients. Before COVID-19, healthcare professionals generally only wore N95s in speci c situations, so there was not a need for a large stockpile. Because of COVID-19, there is a shortage.  is is part of the reason why the general public was told not to wear a mask in the early stages of the pandemic. O cials believed that if the general public wore N95s then the front line health care workers wouldn’t have enough because of low supply. N95s are meant to be used one time, and then thrown away.

Surgical masks and paper masks are similar, but do not necessarily function in the same way. A surgical or medical mask is a product that undergoes extensive testing and is meant to be used during medical procedures.  ere are varying degrees of how much a medical mask can  lter, with some  ltering up to 60% of small particles.  ese masks do not need to be  t tested.  ey  lter particles by containing large droplets that can be released while sneezing, coughing, breathing or talking. Medical masks are meant to be used one time and then thrown away. Paper masks are di erent.  ey have not necessarily been tested or approved for medical use.  ey often are meant to be used once and then thrown away.  eir e ciency depends on how the mask is manufactured, the number of layers, and the material.

Fabric or homemade masks are usually made from cotton or polyester.  ey function in the same way as paper or medical masks in that they usually can  lter out larger particles like droplets from a sneeze.  ere are so many varieties and no uniformity.  ere have been studies published to see what percentage of very small particles are  ltered when using a vacuum  lter, or other over-the-counter type  lter, but there is no de nitive answer regarding  ltration on a fabric mask.

Why Wear a Mask? It does protect you. It also protects others. Many people are asymptomatic or not symptomatic yet. If a person is around an asymptomatic COVID-19 infected person, and breaths in viral particles, that person can get sick and infect others. It’s di cult to predict how many people one positive COVID-19 patient can infect. Some people appear to be “superspreaders,” which are people who infect more people in a smaller amount of time than the average infected person.

Do Masks Work for Slowing the Spread of COVID-19?  ere are several studies that show wearing a mask has slowed the spread of COVID-19. One study looked at countries where wearing a mask is the cultural norm, and compared it to countries that resist wearing masks.  e countries where mask wearing is more socially acceptable had slower rates of COVID-19 spread. It’s here.

Looking locally here in the USA, another study showed the rate of COVID-19 decreased rapidly after states made masks mandatory.  at study is here.  ere are also several case-reports of how COVID-19 has spread from one carrier to other people. In case-report after case-report, if the person infected with COVID-19 wore a mask, the carrier did not spread it to people around him or her, even in enclosed spaces like in an international airplane  ight. Read about that one here.

Dr. Katherine Sage is an Orthopaedic surgeon. She likes to write about medicine, science, and women’s place in the universe.