Some Sensible Mask Research

Masking was a central flashpoint during the epidemic.  There was and still is no evidence that mandating face masks has any meaningful impact on community transmission of a respiratory virus.  I have reported on some mechanistic studies explaining why.  Now there is a new one.  The researchers used a setup of a mask on a human head replica to examine efficiency at stopping exhalation of particles in the size of virus particles.  The result was a finding that they aren’t very efficient.  Partly this is due to leakage but some particles appear to go through as well.  And what wasn’t evaluated was the effect of having virus collect on the mask, in terms of outward or inward transmission.  Even the vaunted N95 masks were found to have at best 82% efficiency, with a lower range of 52%.  I suspect you would find the same result in terms of inhalation.  Virus particles are very, very small, it doesn’t take much to infect a person and the mask itself after even a small amount of use is a source of more concentrated virus populations.

You might also want to read the explanation of the research from Emily Burns, found here.  While she focuses on the small number of virions needed to infect someone, I have also felt that the statistical odds were not great, given that a mask that stopped transmission in even 90% of encounters with the virus, would be useless when most people have tens or hundreds of encounters in a day or certainly a week.  And I don’t have any reason to believe that face masks are close to 90% effective even in that individual encounter.  They are, among other things, truly a virus collection device.   But I am also sure that next epidemic we will have mandates all over again.  (EB Post)