Does your coronavirus mask work? New study separates the worthy from the worthless

https://www.sfchronicle.com/bayarea/article/Does-your-coronavirus-mask-work-New-study-15473251.php?utm_source=Nature+Briefing&utm_campaign=400aa96402-briefing-dy-20200811&utm_medium=email&utm_term=0_c9dfd39373-400aa96402-44992633

Surgical masks work, fleece gaiters not so much

Fitted N95 masks without valves and three-layer surgical masks came out on top in a study of which face coverings are best at stopping transmission of respiratory droplets. Researchers used lasers to illuminate the droplets expelled by a person saying “Stay healthy, people” 5 times while wearing one of 14 different types of mask. They found that folded bandannas and knitted masks did not offer much protection. Fleece neck gaiters seemed to break up the largest droplets into smaller ones and so might actually be worse than wearing nothing. The authors hope their simple, inexpensive experimental setup will encourage more testing to help people to choose the best mask.
San Francisco Chronicle | 6 min read
Reference: Science Advances paper