In a review9 of observational studies, a global research team estimates that surgical and comparable cloth masks are 67% effective in protecting the wearer.In proof-of-principle studies, we compared various commonly available mask types and observed that some mask types approach the performance of normal surgical masks, even though some mask alternatives, for example neck gaiters or bandanas, offer hardly any protection. Our measurement setup is inexpensive and will be built and operated by nonexperts, allowing for rapid evaluation of mask performance during speech, sneezing, or coughing.
Still, determining mask efficacy is really a complex topic that is still an energetic field of research [see, for example, (9)], made even more complicated because the infection pathways for COVID-19 aren’t yet fully understood and therefore are complicated by many factors like the route of transmission, correct fit and using of face mask, and environmental variables. From a public policy perspective, shortages in supply for surgical markers and N95 respirators, as well as concerns about their unwanted effects and also the discomfort of prolonged use (10), have triggered public utilization of various solutions which can be generally less restrictive (for example homemade cotton masks or bandanas) but usually of unknown efficacy.(11), the performance of actual masks in a very practical setting must be considered. The work we report here describes a measurement method that may be used to improve evaluation to steer mask selection and buying decisions.
Eric Westman, a clinical researcher at Duke University School of Medicine in Durham, North Carolina, co-authored an August study11 that demonstrated a technique for testing mask effectiveness. His team used lasers and smartphone cameras to compare how well 14 different cloth and surgical face coverings stopped droplets while an individual spoke. “I was reassured that a lot of the masks we use did work,” he admits that, referring to the performance of cloth and surgical masks. But thin polyester-and-spandex neck gaiters — stretchable scarves that could be pulled up over the mouth and nose — seemed to actually lessen the height and width of droplets developing. “That could be worse than wearing very little,” Westman says.