(Adam Uren/BringMeTheNews) — A study at Duke University has determined which face masks are the most of effective at preventing the spread of droplets emitted by people when talking, a crucial aspect of limiting exposure to COVID-19.
The results of the low-cost study into 14 different styles of face mask were shared in Science Advances, and shows a significant disparity between the best performing and worst.
Unsurprisingly, the best at preventing droplets are the N-95 masks (without an exhalation valve) that are used heavily in medical settings, which the study found blocked more than 99.9% of droplets emitted by a person wearing the mask.
Also scoring highly with medical-grade 3-layer surgical masks, which only emit slightly more droplets than an N95 mask, followed by face masks made with polypropylene.
Cotton masks also fared pretty well, though there was variation based on the type of mask being worn. The best-performing homemade cotton mask, pictured below, is a “2-layer cotton, pleated style mask,” which over the course of 10 trials produced a result of blocking around 90% of droplet emissions. (…)