COVID-19: Most Efficacious Face Masks /NEW ENGLAND JOURNAL OF MEDICINE
By Amy Orciari Herman
Edited by André Sofair, MD, MPH
Most efficacious face masks: N95, surgical, polypropylene, and handmade cotton face masks all appear efficacious for blocking respiratory droplets, while bandanas and fleeces seem to offer little protection, according to a study in Science Advances. Researchers tested the efficacy of 14 different mask types as follows: A male wearing each mask repeatedly spoke the words “Stay healthy, people” toward a laser beam inside a dark box. Droplets that passed through the laser scattered light, which was recorded with a cell phone camera, and a computer program then counted the droplets in the video. For reference, the speaker did the same while not wearing a mask. N95 masks were most efficacious, followed by surgical masks, then polypropylene masks and handmade cotton face coverings. Other masks were less efficacious. In particular, gaiter-type fleece coverings seemed to spread larger respiratory droplets into numerous smaller droplets. Of this, the researchers write, “Considering that smaller particles are airborne longer than large droplets … the use of such a mask might be counterproductive.”
FROM SCIENCE ADVANCES
Original Blogger URL: https://medicoanthropologist.blogspot.com/2020/08/how-protective-are-different-types-of.html