So why were "experts" hailing the Bangladesh mask study as proof that masks work? Because they were so desperate to point to something to support their belief system--even a study that was worthless.
The woman in the interview, Sandy, advocates for masks that have three layers: hydrophobic outer layer, polypropylene middle layer and water absorbant inner layer.
Friend of mine posted me that article to convince me eventually that masks (cloth or surgical) DO WORK. Could someone find a critical review of this publication?
Are there any RCTs about real N-95s worn properly (by professionals who know what they are doing when they put them on) against airborne respiratory viruses? I have anecdotal data about N-95s working to prevent respiratory infections, including Covid, while other masks clearly cannot work. You've mentioned multiple times that N-95s also don't work but I don't see any references. Thanks.
Most of the studies that the maskers use to justify mandates were theoretical studies on mask materials using lab equipment. That's fine, but then they make their conclusions based on best-case scenarios. As Tyson Gabriel points out, having a mask is just part of the equation.
For real-world scenarios, Daniel Horowitz hit the nail on the head when he published "Why Masks Don't Work In The Real World" (blaze.com, 2021-04-20). The reason masks are useless in the real world is the seal, or lack thereof.
Horowitz references an article by Drewnick, et al (2020-08-28, Aerosol Science and Technology, 55-1) which tested materials in a laboratory setup, much like other studies, but mask efficacy was also tested with increasing leak sizes as a percentage of the overall filtration area (0% to 2%). Additionally, testing was done with particle sizes roughly corresponding to those of influenza viruses (0.03um -- 2.5um).
Figure 8 in Drewnick, et al, shows that while perfectly sealed surgical masks may be effective filters, even a leak as small as 1% (one percent) is enough to reduce the filtration efficacy by half. In his article, Horowitz takes Drewnick's Figure 8 and extends the curve to show that at a 3% leak is enough to reduce the efficacy TO NEAR ZERO.
Take one trip to your local grocer and estimate the leak size for the average customer. Let's assume that the filtration area of a typical mask is roughly a 3in circle. A 1% leak would be a circular hole a bit over 1/4 inch (~6mm) in diameter. I'm tall and in most cases, I can see down past the noses on masked people. I'd estimate the average mask at the local Safeway has leaks between 5% and 15%.
But surgical masks were never designed to seal-- they were designed to protect the user from fluid splatter (aka "ick-foo"), and to blow out past the ears if the user sneezes. So, game over unless you use N95 respirators.
But is that good enough? N95 respirators are rated for 0.3um particles, i.e. they will trap 95% of particles 0.3um and larger. If you are going to work with tuberculosis patients, great! Your N95 respirator will filter out 99.5% of tuberculosis bacteria.
To filter out coronaviruses, which range from 0.1um to 0.5um, you'll need something a bit better. Like a fitted, full face (you have to protect your eyes!) P100 respirator. And you guys will have to be clean-shaven to effect a seal.
Hi Steve & other followers, has anyone explored the “American PNAS study” as all the mask lovers are referring to it as the perfect scientific study to justify masks and I am not sure if anyone has reviewed it yet?
Show me a physics study of the dynamics of masking showing that a 0.1 micron particle will be stopped from flowing on jets of air through 3 micron pores which you find in masks.
No, droplets don't count. Evaporation. In microseconds.
I don't know why we are surprised by garbage studies that support the narrative. You need only look at other areas in which "settled science" predicts grave catastrophe if we don't impoverish and enslave ourselves. “The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by an endless series of hobgoblins, most of them imaginary.” HL Mencken
When I try to post this to Facebook the thumbnail says, "A rigorous study finds that surgical masks are highly protective but cloth masks fall short." That made me question the wisdom of posting it lest people just read that headline.
I live in Australia. Love your work . When you look in the mirror of life the guy looking back at you is doing a great job for humanity in all parts of the Globe. Take care Steve
Masks keep you from picking your own nose and self-inoculating pathogens from your own dirty fingers. That is how they "work" - they prevent nose-picking.
What do you think of this?
https://m.youtube.com/watch?v=qgRv3_pp0FU
The woman in the interview, Sandy, advocates for masks that have three layers: hydrophobic outer layer, polypropylene middle layer and water absorbant inner layer.
https://chicago.suntimes.com/columnists/2022/2/26/22951392/covid-mask-mandates-chicago-column-laura-washington This just came out, smh.
Friend of mine posted me that article to convince me eventually that masks (cloth or surgical) DO WORK. Could someone find a critical review of this publication?
https://www.pnas.org/content/118/4/e2014564118#ref-32
Are there any RCTs about real N-95s worn properly (by professionals who know what they are doing when they put them on) against airborne respiratory viruses? I have anecdotal data about N-95s working to prevent respiratory infections, including Covid, while other masks clearly cannot work. You've mentioned multiple times that N-95s also don't work but I don't see any references. Thanks.
Most of the studies that the maskers use to justify mandates were theoretical studies on mask materials using lab equipment. That's fine, but then they make their conclusions based on best-case scenarios. As Tyson Gabriel points out, having a mask is just part of the equation.
For real-world scenarios, Daniel Horowitz hit the nail on the head when he published "Why Masks Don't Work In The Real World" (blaze.com, 2021-04-20). The reason masks are useless in the real world is the seal, or lack thereof.
Horowitz references an article by Drewnick, et al (2020-08-28, Aerosol Science and Technology, 55-1) which tested materials in a laboratory setup, much like other studies, but mask efficacy was also tested with increasing leak sizes as a percentage of the overall filtration area (0% to 2%). Additionally, testing was done with particle sizes roughly corresponding to those of influenza viruses (0.03um -- 2.5um).
Figure 8 in Drewnick, et al, shows that while perfectly sealed surgical masks may be effective filters, even a leak as small as 1% (one percent) is enough to reduce the filtration efficacy by half. In his article, Horowitz takes Drewnick's Figure 8 and extends the curve to show that at a 3% leak is enough to reduce the efficacy TO NEAR ZERO.
Take one trip to your local grocer and estimate the leak size for the average customer. Let's assume that the filtration area of a typical mask is roughly a 3in circle. A 1% leak would be a circular hole a bit over 1/4 inch (~6mm) in diameter. I'm tall and in most cases, I can see down past the noses on masked people. I'd estimate the average mask at the local Safeway has leaks between 5% and 15%.
But surgical masks were never designed to seal-- they were designed to protect the user from fluid splatter (aka "ick-foo"), and to blow out past the ears if the user sneezes. So, game over unless you use N95 respirators.
But is that good enough? N95 respirators are rated for 0.3um particles, i.e. they will trap 95% of particles 0.3um and larger. If you are going to work with tuberculosis patients, great! Your N95 respirator will filter out 99.5% of tuberculosis bacteria.
To filter out coronaviruses, which range from 0.1um to 0.5um, you'll need something a bit better. Like a fitted, full face (you have to protect your eyes!) P100 respirator. And you guys will have to be clean-shaven to effect a seal.
So, like Steve said, masks don't work.
Hi Steve & other followers, has anyone explored the “American PNAS study” as all the mask lovers are referring to it as the perfect scientific study to justify masks and I am not sure if anyone has reviewed it yet?
It was all right here, as early as April, 2019. https://www.nejm.org/doi/full/10.1056/NEJMp2006372
Show me a physics study of the dynamics of masking showing that a 0.1 micron particle will be stopped from flowing on jets of air through 3 micron pores which you find in masks.
No, droplets don't count. Evaporation. In microseconds.
Does this include n95 masks?
I don't know why we are surprised by garbage studies that support the narrative. You need only look at other areas in which "settled science" predicts grave catastrophe if we don't impoverish and enslave ourselves. “The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by an endless series of hobgoblins, most of them imaginary.” HL Mencken
When I try to post this to Facebook the thumbnail says, "A rigorous study finds that surgical masks are highly protective but cloth masks fall short." That made me question the wisdom of posting it lest people just read that headline.
I live in Australia. Love your work . When you look in the mirror of life the guy looking back at you is doing a great job for humanity in all parts of the Globe. Take care Steve
Hilarious! Thank you.
Now the latest from CA
What they say: wear a mask indoors unless you are fully vaxxed and have been wearing a mask all this time.
Read my lips
No new lies
Same old insanity
But let's flip it over now and then toake A real whopper
Masks keep you from picking your own nose and self-inoculating pathogens from your own dirty fingers. That is how they "work" - they prevent nose-picking.
I have a pediatrician sending me this (https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/masking-science-sars-cov2.html) when I asked her for proof that masks work. I know Steve's article here focuses on the Bangladesh study but is there another source I can send her which maybe addresses the other studies on the page she sent me from the CDC?