Why Should We Wear Masks?

The specter of Americans wearing face masks on a routine basis during the current COVID-19 pandemic has divided communities, sparking fear, anger, and at times violence. Misinformation is rampant. It is almost impossible to do controlled ethical studies exposing either healthy people to the virus with and without masks, or with and without an infected person wearing a mask. That being said, what do we know?

One study using high speed video showed that hundreds of various size droplets, both large and small were generated just by speaking a simple phrase. These droplets can carry the virus in an infected person. This study found that a large portion of these droplets were blocked by covering the nose and mouth with a damp washcloth. While most people think of themselves and their own risk, mask wear is foremost to help prevent asymptomatic individuals infected with COVID-19 from passing the virus to others. It is estimated that 40-50% of those infected with COVID-19 may not experience significant symptoms, and those that do develop symptoms can be contagious for up to nine days before symptoms develop. That being said, there is some evidence that wearing a mask may also help keep you from getting infected. While a mask does form somewhat of a barrier to prevent someone else’s droplets from reaching your nose and mouth, it also helps prevent a healthy person from touching a contaminated surface and then transferring the virus to their own nose or mouth.

No masks are not perfect. They do not filter all of the droplets, or smaller particles known aerosols, however the fewer to which you are exposed, the less likely you are to become infected. Face masks need to be medical grade or if fabric, consist of at least two layers. There should not be big gaps around the edges where droplets can easily escape and both the nose and mouth need to be covered. They need to be washed or disinfected frequently. The more you touch or adjust your mask, the less likely you are to benefit from it. Particles can still enter the body through the mucous membranes in the eyes. This is why masks alone don’t work. They need to be combined with frequent hand washing or sanitization, social distancing of at least 6 feet, and good ventilation whenever possible. Small children and those with breathing problems may not be able to wear a mask. It presents issues for people with hearing problems. Plastic face shields, plastic barriers at businesses, limiting social interaction outside your home, ventilating closed spaces, and of course attentive hand hygiene, still provide some protection. There are masks with clear panels to aid in lip reading.

Perhaps anecdotal experience speaks as loud as anything else. In May, two symptomatic hair stylists in the same Missouri town exposed 140 clients to COVID-19. Following the salon’s policy, the two stylists and 98% of the clients wore masks during their entire encounter. None of their clients contracted Covid-19. The is also the case of a COVID-19 positive male with a cough who flew from China to Toronto. He wore a mask the whole time. None of the twenty-five people in his section became positive for COVID-19.

Masks are an important component in the fight against the spread of COVID-19, but they need to be part of a comprehensive approach that includes hand washing, social distancing, ventilation and spatial barriers, as well as rapid and diligent contact tracing. It is important not just for you, but your family and neighbors as well.