This Marr article shows what a
lot of work she had to do to track it all down from scratch. The fact that Marr felt it necessary to do both her own research and learn everything that researchers did in the past did step by step in order to overturn their old theories is so wasteful of her very precious time.
Before I read the Marr article, I didn't know why the medical community used a 5 micron dividing line. But even in the very first of my zoom trainings in July 2020, I just told the participants it was obviously wrong and used the usual 0.1, 10, and 100 micron breakpoints throughout.
That was my fast and dirty opinion. However many IHs on one of the forums I monitor also were operating with the correct break points. Then a friend, Dave Newman, reposted something he'd sent us all at the beginning of the pandemic which clearly showed why the break point is not 5 based on Wells' work and others. Marr's work was already done and wrapped up by Mead from NIOSH in 2012. And since we had all read this, it was also common knowledge among the IH's on this particular forum.
see: Mead KR. et. al. Expedient methods for surge airborne isolation within healthcare settings during response to a natural or manmade epidemic. Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology Engineering and Physical Hazards Branch. EPHB Report No. 301-05f. April 2012. https://www.cdc.gov/niosh/surveyreports/pdfs/301-05f.pdf.
Monona
-----Original Message-----
From: ILPI Support <info**At_Symbol_Here**ILPI.COM>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Sat, May 15, 2021 8:28 pm
Subject: [DCHAS-L] The 60-Year-Old Scientific Screwup That Helped Covid Kill
Really good discussion of why there was all this initial confusion/debate about the aerosol transmission of Covid.
The 60-Year-Old Scientific Screwup That Helped Covid Kill
All pandemic long, scientists brawled over how the virus spreads. Droplets! No, aerosols! At the heart of the fight was a teensy error with huge consequences.
Turns out that 5 microns is like the =E2=80=98ole drink 8 glasses of water a day maxim or the one telling us not to eat before swimming. A widely accepted idea that is quite apocryphal.
Rob Toreki
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