Masks protect [from Covid] better than distancing, [MaxPlank] study finds
&gt; <i>[Even at] 3 meters of social distancing ... it takes less than five minutes for an unvaccinated person standing in the breath of a person with Covid-19 to become infected with almost… certainty ... if the infected persons have the high viral load of the delta variant of the Sars-CoV-2 &#x2F;&#x2F; Even so ... if both the infected and the non-infected person wear well-fitting FFP2 masks, the maximum risk of infection after 20 minutes is hardly more than one per 1,000, even at the shortest distance. If their masks fit poorly, the probability of infection increases to about 4%. If both wear well-fitting medical masks, the virus is likely to be transmitted within 20 minutes with a maximum probability of 10%. [Such] infection probabilities ... indicate the upper limit of the risk [in the extreme assumption the expired is undiluted: i]n daily life, the actual probability of infection is certainly 10 to 100 times smaller</i><p>FFP2, both, fitting: max 0.1% at 20min; FFP2, both, loose: 4% at 20min; surgical, both, fitting, 10% at 20min - exaggerated theoretical values.<p>The study is accompanied by a video demonstration showing the motion of expired vapour from a dummy in thte different cases (no mask, surgical, FFP2 loose, FFP2 tight) at <a href="https:&#x2F;&#x2F;youtu.be&#x2F;uuvruHuob7s" rel="nofollow">https:&#x2F;&#x2F;youtu.be&#x2F;uuvruHuob7s</a><p>There is also an article on MedicalXpress, <a href="https:&#x2F;&#x2F;medicalxpress.com&#x2F;news&#x2F;2021-12-maximum-covid-infection-masks.html" rel="nofollow">https:&#x2F;&#x2F;medicalxpress.com&#x2F;news&#x2F;2021-12-maximum-covid-infecti...</a><p>&gt; <i>In their calculations of the risk of infection, the Göttingen team considered a number of factors that had not previously been included in comparable studies ... The team also considered that droplets that people spread when they breathe or speak dry while in the air and become lighter. This means that they remain in the air longer but also have an increased virus concentration as equal size droplets directly after release. When inhaled, the opposite happens: the particles take up water again, grow like a drop in the cloud and therefore deposit more easily in the respiratory tract</i><p>Original research article: Gholamhossein Bagheri et al, <i>An upper bound on one-to-one exposure to infectious human respiratory particles</i>, Proceedings of the National Academy of Sciences (2021) <a href="http:&#x2F;&#x2F;dx.doi.org&#x2F;10.1073&#x2F;pnas.2110117118" rel="nofollow">http:&#x2F;&#x2F;dx.doi.org&#x2F;10.1073&#x2F;pnas.2110117118</a><p>@Dan: title: the specification &#x27;from COVID&#x27; is required to make the title meaningful (&quot;protection&quot; from what); that of &#x27;MaxPlank&#x27; is to discriminate this study (also through the timeframe of this post) from assumedly a large number of others on this very general topic.