@lagunaqueen @YouAreLobbyLud Sorry that's BS. Surgical masks are certified for PFE of 90%+ which is measured at 0.1 um, about the size of a virus, and droplets carrying virus are much bigger. The issue they have is often poor fit, not filtration.
Cloth masks were measured to filter about 70% of aerosols.
@lagunaqueen @YouAreLobbyLud 抱歉，这是废话。外科口罩的 PFE 为 90%，测量值为 0.1 微米，大约是病毒的大小，携带病毒的飞沫要大得多。他们遇到的问题通常是不合身，而不是过滤。
布口罩经测量可过滤约 70% 的气溶胶。