The Importance of Face Masks: Fact Sheet

By: Andrew Koh

  • Wearing protective face masks have been shown to reduce the amount of respiratory droplets in the air that could spread Covid-19

According to a study conducted by the New England Journal of Medicine (2020), “respiratory aerosols and droplets generated from speech have been shown to transmit Covid-19.” By conducting an experiment “using high-speed video and recording someone repeating a phrase without a face mask, the study found hundreds of droplets ranging from 20 to 500 micrometers were generated. However, when the subject repeated the phrase again while wearing a damp washcloth, the study discovered nearly all these droplets were blocked when the mouth was covered” (Bai, 2020).

In another study conducted by researchers at Brigham Young University found that “there is clear evidence that face coverings reduce the spray of droplets produced during speaking, coughing, and sneezing. This is why masks have long been recommended for individuals with respiratory infections. Furthermore, home-made cloth masks are similar in effectiveness to surgical masks in diffusing the “jets” of droplets that could spread Covid – 19” (Abbott et al., 2020).

  • Mandatory mask wearing can lead to a slowdown in daily COVID-19 growth rate

The guidance of the CDC and WHO to wear protective face coverings have been largely implemented through legislation and protocols provided by officials within the state level. In a natural experiment utilizing the state government mandates, a study found evidence of the effectiveness of mandatory mask wearing in preventing the transmission of Covid-19. By analyzing “the effects of state government mandates for face mask use in public issued by fifteen states plus Washington, D.C., between April 8 and May 15, 2020, the research discovered changes in the daily county-level COVID-19 growth rates between March 31 and May 22, 2020” (Lyu & Wehby, 2020).

“The first five days after a mandate, the daily growth rate slowed by 0.9 percentage-points compared to the five days prior to the mandate; at three weeks, the daily growth rate had slowed by 2 percentage-points” (Bai, 2020). This study “estimates that as a result of the implementation of these mandates, more than 200,000 COVID-19 cases were averted by May 22, 2020” (Lyu & Wehby, 2020).

  • The more layers your mask has, the better!

In a study conducted by Duke University (2020),” researchers compared 14 different types of protective face masks and found that the N95 masks used by medical professionals and a 3-layer surgical mask were the top two protectors in an experiment similar to the one conducted by the New England Journal of Medicine in assessing the amount of droplets transmitted in the air after repeating a phrase.” The conclusion found all of the mask coverings to be beneficial in blocking out harmful droplets suspending in the air in some way. The only mask not recommended was the neck gaiter as it was deemed “too thin to offer much protection” (Elassar, 2020).

In a time where there has been over 8.2 million cases and 220,000 deaths in the U.S. and over 40.2 million cases and 1.1 million deaths worldwide, there is an incredible moral, societal, and human responsibility to do anything we can to reduce the transmission of Covid-19 and to hopefully minimize the risks of receiving the disease when we try to continue our daily lives. The scientific evidence supporting the wearing of face masks gets clearer and clearer as Covid studies continue and as time goes on. If we can all participate and protect the people and community around us, we can start seeing some progress and allow for the greater medical resources to maintain and contain this Covid-19 pandemic.


Abbott, B., Greenhalgh, M., St. Clair, S. and Bush, J., 2020. Making Sense Of The Research On COVID-19 And Masks. [online] Available at: <; [Accessed 20 October 2020].

Bai, N. (2020, October 16). Still Confused About Masks? Here’s the Science Behind How Face Masks Prevent Coronavirus. Retrieved October 20, 2020, from

Elassar, A. (2020, August 09). Researchers created a test to determine which masks are the least effective. Retrieved October 21, 2020, from

Lyu, W., Wehby, G. L., NW, F., K, M., ES, R., Al., E., . . . LH, S. (2020, June 16). Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US. Retrieved October 21, 2020, from

New England Journal of Medicine. (2020, October 08). Visualizing Speech-Generated Oral Fluid Droplets with Laser Light Scattering: NEJM. Retrieved October 20, 2020, from

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