(Editor’s Note: The PV Student Publication has partnered with The Research Club to publish a series of research essays related to topics of COVID-19. All research essays are written and fact-checked by members of the Research Club, and The PV Student Publication is rolling out these essays as a service to our community. This essay explains the purpose of masks during the pandemic. This paper is written by senior Elise Schicker and fact-checked by seniors Daniel DeMilia and Madeleine Miller.)

A mask is a physical barrier between the wearer and their environment. It keeps respiratory droplets from crossing to either side as a means of preventing the transmission of harmful pathogens. There is a multitude of studies that prove wearing a mask lessens the transmission rate of pathogens[3] [5] [6] [7] [8] [10] [18] [20], including the virus that is causing the ongoing pandemic, SARS-CoV-2 (COVID-19).  

A mask is different from a respirator[1] [10]. Masks are not medical-grade and consequently do not fully protect one from pathogens. Surgical masks, cloth masks, and homemade masks fall under this category. A respirator is a medical-grade mask that is used by healthcare professionals. N95s fall under this category. Respirators provide a higher degree of protection to the wearer; however, they are not offered to the general public because of shortages[13] [14] [19]. 

#WearAMask to prevent getting and spreading #COVID19. If you use a disposable mask, the knot and tuck method can help your mask fit better against your face without gaps. Learn how to improve your mask’s fit. pic.twitter.com/BTgPDysxFO

— CDC (@CDCgov) April 13, 2021

The structure of a surgical mask is typically consistent between different brands: an outside layer of non-woven fabric (usually polyester) on either side with 2 filter layers in between[2] [7] [10]. These filter layers are successful in stopping particles above 1 micron[7] [2]. The structure of cloth masks is also relatively consistent between brands[16] [17]. Effective cloth masks are composed of a minimum of 2 layers of fabric. Some brands will add filter layers, but most brands do not.

The Centers for Disease Control and Prevention  (CDC) recommends that any cloth mask be composed of at least 2 layers of material. The World Health Organization (WHO) agrees, stating that 3 layers are ideal. Multiple layers are recommended because they provide extra protection to the wearer [3] [4] [10]. As the wearer inhales, the air is filtered through the material. The denser the material, or the more layers of material, the easier it is for a pathogen to get caught on the way in. 

 A mask may be composed of many different materials. They are typically composed of polymeric plastics such as polystyrene, polycarbonate, polyethylene, and polyester [2] [7] [9] [10] [12]. These synthetics are disposable, versatile, lightweight, and typically inert [7] [11] [15]. Some, like Polystyrene, are water-resistant [11]; however, they all are components of non-woven fabrics. Non-woven fabrics are made by being pressed together on a conveyor belt [12]. This means that their weave is tighter, so only very small particles can pass through.