the opening 'Abstract' which closed with this statement...(Page 1)
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"Case studies are presented for classrooms and nursing homes, and a spreadsheet and online app are provided to facilitate use of our guideline. Implications for contact tracing and quarantining are considered, and appropriate caveats enumerated. Particular consideration is given to respiratory jets, which may substantially elevate risk WHEN FACE MASKS ARE NOT WORN." (emphasis mine)
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Here's another...from the body of the report...(Page 5)
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"Since the rate of inhalation of contagion depends on the volume flux of both the exhalation of the infected individual and the inhalation of the susceptible person, the risk of infection increases as Qb2. Likewise, masks worn by both infected and susceptible persons will reduce the risk of transmission by a factor pm2 , a dramatic effect given that pm ≤ 0.1 for MODERATELY HIGH QUALITY MASKS (74, 75)." (emphasis mine)
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And finally, this one...(Page 8)
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"In both examples, the benefit of face masks is immediately apparent, since the CET limit is enhanced by a factor p−2, the
inverse square of the mask penetration factor. Standard surgical masks are characterized by pm = 1 to 5% (73, 74), and so allow the CET to be extended by 400 to 10,000 times. EVEN CLOTH FACE COVERINGS WOULD EXTEND THE CET LIMIT BY 6 TO 100 TIMES for hybrid fabrics (pm = 10 to 40%) or 1.5 to 6 times for single-layer fabrics (pm = 40 to 80%) (75). Our inference of the efficacy of face masks in mitigating airborne transmission is roughly consistent with studies showing the benefits of mask use on COVID-19 transmission at the scales of both cities and countries (22, 33, 83)" (emphasis mine)
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So...Baron's own contribution to this topic shows him to be totally wrong about the value of face masks usage....'THEY WORK'...and now that KN95 masks are readily available, the medical community (except for Baron) is strongly recommending them.
Don't be stupid like Baron...use those face masks...like the medical "Pros" do.
Link: https://www.pnas.org/doi/pdf/10.1073/pnas.2018995118