New England Journal Of Medicine On What Masks Can’t Do Regarding SARS-CoV-2

Via Herschel 

 We know that wearing a mask outside health care facilities offers little, if any, protection from infection. Public health authorities define a significant exposure to Covid-19 as face-to-face contact within 6 feet with a patient with symptomatic Covid-19 that is sustained for at least a few minutes (and some say more than 10 minutes or even 30 minutes). The chance of catching Covid-19 from a passing interaction in a public space is therefore minimal. In many cases, the desire for widespread masking is a reflexive reaction to anxiety over the pandemic.

Do you recall that I said this?

Next up, the wearing of masks.  I have some experience in air filtration engineering from my early career testing and balancing HEPA filters and charcoal adsorbers.  HEPA filters (of concern here) work by particle interception due to electrostatic force.  Surgical masks, cloths, handkerchiefs, and other manner of cotton material (cotton is cellulose) do not have that.

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