Quote:
Originally Posted by chet2020
A. You link an article that is labeled "commentary," i.e. an opinion piece.
B. The article you link is dated April 1, 2020. That is ancient history. At that time, it was thought virus transmission was predominantly via surface contact, not airborne. Now we know transmission is predominantly airborne, not surface.
C. Martian linked 17 articles indicating cloth masks are useful. The phrase is "preponderance of the evidence."
|
LOL The two respiratory specialist Doctors who wrote that commentary looked at all the available studies that tested masks against virus particles. Coronavirus is no different than any virus that transmit thru cough and sneeze droplets or fine particle aerosols. There is no new magic cloth mask technology that can block fine aerosol particles, only N95 can do that.
Filter efficiency was measured across a wide range of small particle sizes (0.02 to 1 µm) at 33 and 99 L/min. N95 respirators had efficiencies greater than 95% (as expected). For the entire range of particles tested, t-shirts had 10% efficiency, scarves 10% to 20%, cloth masks 10% to 30%, sweatshirts 20% to 40%, and towels 40%. All of the cloth masks and materials had near zero efficiency at 0.3 µm, a particle size that easily penetrates into the lungs.
Near zero efficiency
If you think that cloth mask is protecting you from virus aerosols, go for it.