Wearing three-layer masks blocks 90% of infectious particles, experts say

[السياسي]

A study from Virginia Tech University found that three-layer masks - with two outer layers of fabric and a filer in between - blocked out at least 90% of potentially infectious particles.

https://www.dailymail.co.uk/health/article-9193611/Wearing-three-layer-masks-blocks-90-infectious-particles-experts-say.html?ns_mchannel=rss&ito=1490&ns_campaign=1490 ]قرااء المزيد ..... [/url]