Over the past few months, social distancing, contact tracing, quarantining, and mask wearing have all become new vital habits to slow the spread of COVID-19. New Yorkers have already demonstrated great adherence to these rules, and have been doing a fantastic job at wearing their masks while outside at all times. It is important that they continue to do so in order that the positive effects of this change endure. Wearing a mask in public spaces has become the new normal, but how effective is this practice? And with so many options, what factors should you consider when picking a mask to wear?
Types of Masks
Masks work by creating a physical barrier between you and others, thus reducing the chances of respiratory droplets containing the virus infecting others through coughing, sneezing, and talking. There are various pros and cons that come along with each type of mask that are important to consider when deciding which one to wear.
Cloth masks use loops that go around the head or ears to secure it onto the face and can be homemade from any tightly woven material such as a cotton t-shirt, or even a dish towel. As long as they efficiently cover your mouth, nose, and below your chin while remaining breathable, cloth masks are safe to use. The thicker the material, or more layers used when making the mask, the higher its effectiveness. A huge benefit to cloth masks is that they can be washed and reused, which lessens waste and also ensures that you won’t run out of available masks to wear when needed. Cloth masks provide adequate protection for the average person on public transport or in stores, without taking away scarce PPE from healthcare professionals working with patients.
Some people have experimented with adding filters in their cloth masks, such as coffee filters or vacuum bags. This, to a certain extent, can make them more effective but also adds the risk of inhalation of harmful fibres, and can create difficulty breathing. The homemade aspect of many cloth masks can expose the wearer to the risks that the material used is not thick enough, or that it does not fit the face properly.
Surgical masks are disposable masks made of a mixture of paper and plastic synthetic fabrics. These masks are protective against larger respiratory droplets produced during coughing or sneezing. They are usually worn by medical professionals as PPE during surgeries or in sterile hospital environments.
While these masks are relatively cheap to buy, they don’t protect as well against smaller droplets as other masks. Under lab conditions, surgical masks prevented 60 to 80 percent of small droplets from getting through. The generally larger fit of these masks could be one of the reasons why. The most significant downside to wearing surgical masks is that they cannot be washed and reused, thus contributing to waste, as well as taking away from the PPE supply available to medical professionals.
N95 or Professional-Grade Medical Masks
N95 masks are designed for professional healthcare workers to create a very tight seal between the outside and the wearer’s face. These masks get their name because they protect against 95% of small droplets when fitted properly, making them highly effective.
N95 masks are made for a single use and cannot be washed. Furthermore, they will not give a proper fit to someone with facial hair, or to small children. Healthcare workers who use these masks have regular professional fitting tests to ensure the masks fit perfectly. These tests are not available to the public which means the masks may not fit properly and therefore may not give adequate protection. Very important to note is that some N95 masks come with a valve on the front to make breathing easier. These are often used in environments such as construction sites. These introduce the possibility of droplets getting through and spreading to others. Masks with valves on the front should not be worn in public spaces as they do not protect others as well. Reports have also been made of companies selling fake N95 masks that do not actually protect wearers so buyers should be wary when purchasing.
Face shields are large pieces of plastic that hang down from a headband which cover the entire front of the face. In normal circumstances face shields are worn to protect medical workers during procedures that may involve splatter of bodily fluids. These shields do not provide the same protection as a face mask, as respiratory droplets are still able to go in or out from under the face shield.
Face shields should only be used as an extra layer of protection in addition to another type of face mask when working in close proximity to others.
Putting On and Taking Off Your Mask
Before putting on your mask it is important to wash your hands, or use hand sanitizer if it is the only thing available. Avoid touching your face as much as possible when putting on your face mask, and make sure it is on and fitted properly, as you do not want to be adjusting it once it is on your face. When taking off your face mask it is important to also wash or sanitize your hands and try to not touch your face as you take it off. You can also store your reusable mask in a small paper or plastic bag to ensure it doesn’t contaminate any of your other belongings. Always wash your hands after handling your mask.
The Effectiveness of Mask Wearing
Although wearing a mask is primarily to prevent a sick person from spreading disease to others, it still provides the wearer with protection from infection. The effectiveness of mask wearing increases as more members of the population do so.
A study published in PNAS: The Proceedings of the National Academy of Sciences of the USA (https://www.pnas.org/content/117/26/14857) has shown that airborne transmission of COVID-19 is the most significant mode of transmission, but that mask-wearing has significantly decreased spread in this way. Research in this same study shows that between April 17th (when mask wearing in New York City was first mandated) and May 9th, the number of COVID-19 infections in NYC were reduced by about 66,000. Furthermore, The Institute of Health Metrics and Evaluation predicts that almost 33,000 deaths in the United States could be prevented by October 1st if 95% of the population were to wear masks.(http://www.healthdata.org/news-release/new-ihme-covid-19-model-projects-nearly-180000-us-deaths) In another simulation, a group of scientific researchers estimated that 80% of the population participating in mask wearing would reduce COVID-19 spread more effectively than a full lockdown. (https://arxiv.org/pdf/2004.13553.pdf)
There are lots of things to consider when choosing a mask to wear, but the bottom line is that any mask is better than no mask at all. At a time when reducing the spread of COVID-19 is saving lives and allowing some of life to return to normal it is vital that we all participate in wearing one.