Face masks effectively limit the probability of SARS-CoV-2 transmission
This isn&#x27;t a study; it is a mathematical model [1].<p>&gt; Here, we develop a quantitative model of airborne virus exposure that can explain these contrasting results and provide a basis for quantifying the efficacy of face masks. We show that mask efficacy strongly depends on airborne virus abundance. Based on direct measurements of SARS-CoV-2 in air samples and population-level infection probabilities, we find that the virus abundance in most environments is sufficiently low for masks to be effective in reducing airborne transmission.<p>Meanwhile, they ignore the dozens of studies showing masks are ineffective, or even counterproductive:<p><a href="https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC4420971&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC4420971&#x2F;</a><p><a href="https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;29395560&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;29395560&#x2F;</a><p><a href="https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;32590322&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;32590322&#x2F;</a><p><a href="https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;15340662&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;15340662&#x2F;</a><p><a href="https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;26579222&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;26579222&#x2F;</a><p><a href="https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;31159777&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;31159777&#x2F;</a><p><a href="https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC5779801&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC5779801&#x2F;</a><p><a href="https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;19216002&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;19216002&#x2F;</a><p><a href="https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC4420971&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC4420971&#x2F;</a><p><a href="https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC2493952&#x2F;pdf&#x2F;annrcse01509-0009.pdf" rel="nofollow">https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC2493952&#x2F;pdf&#x2F;ann...</a><p><a href="https:&#x2F;&#x2F;www.nap.edu&#x2F;catalog&#x2F;25776&#x2F;rapid-expert-consultation-on-the-effectiveness-of-fabric-masks-for-the-covid-19-pandemic-april-8-2020" rel="nofollow">https:&#x2F;&#x2F;www.nap.edu&#x2F;catalog&#x2F;25776&#x2F;rapid-expert-consultation-...</a><p><a href="https:&#x2F;&#x2F;www.nap.edu&#x2F;read&#x2F;25776&#x2F;chapter&#x2F;1#6" rel="nofollow">https:&#x2F;&#x2F;www.nap.edu&#x2F;read&#x2F;25776&#x2F;chapter&#x2F;1#6</a><p><a href="https:&#x2F;&#x2F;wwwnc.cdc.gov&#x2F;eid&#x2F;article&#x2F;26&#x2F;5&#x2F;19-0994_article" rel="nofollow">https:&#x2F;&#x2F;wwwnc.cdc.gov&#x2F;eid&#x2F;article&#x2F;26&#x2F;5&#x2F;19-0994_article</a><p><a href="https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC6599448&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC6599448&#x2F;</a><p><a href="https:&#x2F;&#x2F;www.acpjournals.org&#x2F;doi&#x2F;10.7326&#x2F;M20-1342" rel="nofollow">https:&#x2F;&#x2F;www.acpjournals.org&#x2F;doi&#x2F;10.7326&#x2F;M20-1342</a><p><a href="https:&#x2F;&#x2F;link.springer.com&#x2F;article&#x2F;10.1007&#x2F;s00392-020-01704-y" rel="nofollow">https:&#x2F;&#x2F;link.springer.com&#x2F;article&#x2F;10.1007&#x2F;s00392-020-01704-y</a>