<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">It might give people a false sense of security... That said, my mask is a P200, but I got it for fire season years ago.<br><br><div dir="ltr"><div style="line-height: normal;"><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);">Regards,</span></div><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);"><br></span></div><div><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);">Dan</span></div><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);"> Sample my Kindle books at:</span></div><div style="line-height: normal;"><p style="margin: 0px; font-stretch: normal; font-size: 12px; line-height: normal; font-family: Helvetica;"><span style="font-size: 12pt;">http://author.to/DanUst</span></p></div></div></div><div><div style="line-height: normal;"></div></div></div><div dir="ltr"><br><blockquote type="cite">On Mar 11, 2020, at 12:04 PM, Stuart LaForge via extropy-chat <extropy-chat@lists.extropy.org> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><span></span><br><span>I don't understand this recommendation from the CDC for the public to NOT wear masks for COVID-19 prophylaxis. Is it based on any evidence or data? Or is it just because the supply shortage for healthcare workers? Maybe N-95 respirators are overkill for the general public that is not regularly face to face with infected patients or entering rooms with several patients. But why shouldn't somebody at risk not wear a surgical mask on the subway or bus?</span><br><span></span><br><span>Yes, the virus is small enough to go through the pores of a surgical mask but it will certainly stop many of the larger aerosol droplets. From the average cough or sneeze from three to six feet away. In fact according to this review of the literature, simple disposable surgical masks ARE effective in protecting the wearer according to 6 out of 7 studies. This is stronger than the evidence for the efficacy of hand washing which was also protective but in only 4 out 7 studies.</span><br><span></span><br><span>https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD006207.pub4/full</span><br><span></span><br><span>"These data suggest that wearing a surgical mask or a N95 mask is the measure with the most consistent and comprehensive supportive evidence. Seven out of eight studies included masks as a measure in their study and six out of seven of these studies found masks to be statistically significant in multivariable analysis. Handwashing was also included in seven of the studies with four studies showing handwashing to be statistically significant in multivariable analysis. All other measures were shown to be statistically significant in multivariable analysis on only one or two occasions."</span><br><span></span><br><span>What is going on here? Does the CDC just think everybody is too stupid to properly use a face mask properly? I have in the past been coughed on in public to my great annoyance so it certainly is a realistic risk. My professional opinion as a microbiologist is that at risk people should absolutely wear a mask in crowded conditions and safety glasses or goggles as well. And if you can't buy any because they are sold out or too expensive due to price gouging, then you should make your own:</span><br><span></span><br><span>https://www.youtube.com/watch?v=cZGU2vWHKC8</span><br><span></span><br><span>In my opinion ANY barrier to the aerosol from sick people is better than no barrier. Any insights from the other list members with biomed experience?</span><br><span></span><br><span>Stuart LaForge</span><br></div></blockquote></body></html>