New England Journal Of Medicine On What Masks Can’t Do Regarding SARS-CoV-2
BY Herschel Smith
3 years, 10 months ago
Do you recall that I said this?
Next up, the wearing of masks. I have some experience in air filtration engineering from my early career testing and balancing HEPA filters and charcoal adsorbers. HEPA filters (of concern here) work by particle interception due to electrostatic force. Surgical masks, cloths, handkerchiefs, and other manner of cotton material (cotton is cellulose) do not have that.
My daughter wears one in surgery and the ER to prevent potential blood-borne pathogens from entering her mouth, not to prevent SARS-CoV-2, flu or the common cold (which is also a Coronavirus). N95 masks are just that, 95% efficient for particles down to a given size. Moreover, when a nuclear or chemical worker wears a full face respirator, if the wearer is a male and has a beard, he must shave. Workers have tried to create work-arounds for this by glazing their face with Vaseline, but the seal never works. The bulk of breathing air goes around the filtration media if there is no testable seal, not through it. This is true of full face respirators, and it is true in the superlative for these silly little masks half of America is wearing.
When you put an N95 mask on, the bulk of your breathing air is going under and over the top of the mask, not through it. Furthermore, every decontamination technique eventually destroys the electrostatic charge on the fibers, thus rendering the mask useless. It’s designed to be worn and then thrown away. It’s actually worse than useless, because we are now learning that there is a heavy viral and pathogenic loading on both the outside and the inside of the filter media, and we also now know that the degree to which a patient suffers from this disease is a function – at least partially – of the amount of inoculate that you breath.
Then I got a little more detailed and discussed particle sizes.
HEPA filters will remove particles down to 0.3 µm in size (to usually 99.95% efficiency, depending upon the filter – here I have used data for nuclear grade filters). The SARS-CoV-2 virus is 80 nm in diameter. A few viruses out of a million might be intercepted by electrostatic force, but that’s essentially zero.
If the particle you’re trying to intercept is spittle, stay away from coughing people anyway. But those particles drop by sedimentation, diffusiophoresis, etc.
0.3 µm versus 80 nm. A nanometer is 1E-9 meters, and 1 µm is 1E-6 meters. This means that a SARS-CoV-2 virus is 80E-9 / 0.3E-6 = 0.27 the minimum size necessary for even the most expensive nuclear grade HEPA filters to remove it from an air stream.
I need to caveat these statements and observe that because of the serpentine flow of air through a HEPA filter, it’s possible that there is some removal efficiency due to electrostatic force (i.e., that it’s not zero), assuming a charge on the shell of the virus. But it’s still low. While I’m not perfect, I won’t mislead readers. And while there is some small probability that there will be some small effect, any very small particulate eventually re-evolves into the air stream.
One of my major gripes with how America has turned to the medical bureaucracy during this pandemic is treating medical doctors like experts in every field of science. They’re not. A doctor isn’t an air flow and filtration engineer. A doctor isn’t an industrial hygienist. A doctor isn’t a physicist.
But it’s still nice to see that eventually they conform to the truth of what science tells us. This is straight from the New England Journal of Medicine (nejmp2006372).
We know that wearing a mask outside health care facilities offers little, if any, protection from infection. Public health authorities define a significant exposure to Covid-19 as face-to-face contact within 6 feet with a patient with symptomatic Covid-19 that is sustained for at least a few minutes (and some say more than 10 minutes or even 30 minutes). The chance of catching Covid-19 from a passing interaction in a public space is therefore minimal. In many cases, the desire for widespread masking is a reflexive reaction to anxiety over the pandemic.
You can read the rest for yourself. They eventually dive into a discussion concerning the use of masks by medical workers, and I think over-state their case (I still believe, along with my daughter, an NP, that she wears a mask for purposes of protecting herself from blood-borne diseases and spittle in the OR and ER).
However, nits here and there shouldn’t obfuscate the fact that at least they are being honest about this. Anxiety is the root of the problem, and reflexive fealty to the priesthood of the medical profession is a symptom of real problems in America concerning the lack of STEM education and knowledge.
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On May 29, 2020 at 6:19 am, Alex said:
“…reflexive fealty to the priesthood of the medical profession…”
Fear of death in the setting of collective godlessness has turned medical professionals into the anointed ones. Looking around one can easily see that “science” has become the new god, particularly among the younger generation. The irony here is that the majority ascribing to this new worldview don’t particularly understand the scientific method or critical thinking. They merely replaced the old, “outdated,” and “intolerant” religious dogma… with a new man-made dogma and refer to themselves as enlightened.
On May 29, 2020 at 7:24 am, Stan Erickson said:
What makes you think the virus particles travel isolated and not on droplets of salIva? You appear to be assuming that without proof. What makes you think only coughing people emit droplets? You appear to be assuming that without proof, in contradiction to what I have seen published from experimental data. What makes you think that saliva droplets follow the same path as air molecules around the boundaries of the mass – don’t they have a lot more momentum? You appear to be making that assumption without proof.
On May 29, 2020 at 8:38 am, scott s. said:
It drives me nuts when the local paper cites an “expert” and never provides any detail of just what the expertise is. I suspect often it is just the possession of a credential from some unknown authority.
How did the “six foot” rule come about? It sounds like kind of an arbitrary distance.
On May 29, 2020 at 8:56 am, Fred said:
Heresy:
“First do no harm? What kind of sin is this when it’s proclaimed in the name of Science? When a people make Science their god any abomination in the name of Science is called as some common good. Science is the observation of God’s creation or His created order. A nation properly run, and Christians themselves are not against Science but must be against Science as some kind of god lest you end up extracting wealth by way of carbon taxation to save the world from its own weather! Having evolved from monkeys, LORD help us, as this cult teaches, making us no better than the animals over which we have been gifted dominion, and the killing of children for expediency to later be proclaimed in the name of the god of science will lead to the harvesting of children as though a precious beautiful creation of Father God, known of Him before the foundation of the world, were simply any other planetary mineral resource to be devoured by a supposedly slightly smarter and more evolved troop of baboons. This is what happens when science is your god! I say again; we are not animals!”
https://civilizationsdoorstep.wordpress.com/2020/02/25/defense-of-the-heritable-line/
On May 29, 2020 at 9:05 am, MN Steel said:
Don’t know about the arbitrary 6 foot distance, but “social distancing” was a high schooler’s computer model project from the Bird Flu scare…
https://www.rt.com/op-ed/489710-social-distancing-bush-lockdown-covid/
On May 29, 2020 at 9:42 am, Dean said:
MD here. Just wanted to confirm that we are definitely NOT masters of every realm of knowledge. The good ones among us recognize that and rely on those who are experts in other fields when operating outside our wheelhouse.
My unsolicited thoughts re: masks in public… First, clearly N95 masks will not stop individual viral particles. However, larger aerosolized particulates would hopefully be filtered. Yes, clearly we should avoid people who are symptomatic. But these particulates can linger in the air after being aerosolized for an extended period of time. Meaning, if the lady three aisles over in the grocery store sneezes without a mask on and then you come walking down that aisle a minute or two after the sneeze, you’re going to be exposed to her aerosolized particles. Even though you are conscientiously avoiding sick people.
Second, the government should be able to mandate nothing with regards to masks. We as citizens should wear them if we feel so inclined. I do avoid being near unmasked individuals when in public, to the best of my ability. The onus should be on us to determine whether or not we wear a mask – and not the government nor Karens.
That’s all I’ve got. Great read, as usual.
On May 29, 2020 at 9:54 am, Fred said:
Oh, and something just occurred to me. Keeping in mind that everything evil does is a fraud of God, this new religious teaching of love for all is born of this; everybody who doesn’t love everybody else is evil. “Not I but Us” proclaims the bumper sticker. “We’re all in this together” from every commie outlet in the country. So, you pretend to love everybody no matter what or, of course, be hated and chastised by the deacons of the new high priests of Scienctism and socialist religious conformity.
But we must hate due to the sin of Adam and can only truly love in Christ Jesus. Upon no other foundation, no other Rock, can a man love his brother let alone his fellow man.
Even the pagans love within their clans but beyond that they do not.
It’s a fraud of the way and teaching of the Master, the true and only High Priest, Jesus Christ. There is only one way to truly love your fellows; that is to become a son of God, the temple of the Holy Spirit, through belief on the finished work of Jesus Christ on the cross being saved from the evil that is in every man’s heart through the remission of sins by the covering of the blood of Jesus Christ, the final sacrifice, once for all.
And remember; love includes hurting people with the truth to their own benefit. it’s not some hippy feelgoodism. “These six things doth the Lord hate: yea, seven are an abomination unto him: A proud look, a lying tongue, and hands that shed innocent blood, An heart that deviseth wicked imaginations, feet that be swift in running to mischief, A false witness that speaketh lies, and he that soweth discord among brethren.”
It is a heart that devises wicked imaginations that berates and belittles you into pretending to love, especially a phony love of those who mean you harm. And, listen good now; allowing people to continue in their sin is a grave wickedness. If you allow people to continue in sin you have not the love of God in you.
These feel good preachers telling you to make friends with the world are full of the devil. American Christians need to take this country back and the only way to do it is to get totally and ruthlessly ugly in the truth with everybody you know and meet, the Gospel is an offense.
“Unto you therefore which believe he is precious: but unto them which be disobedient, the stone which the builders disallowed, the same is made the head of the corner, And a stone of stumbling, and a rock of offence, even to them which stumble at the word, being disobedient: whereunto also they were appointed.”
Was a Christian America really that bad?
On May 29, 2020 at 9:57 am, Herschel Smith said:
@Stan,
I can see how you might think I’m assuming that given the nature of posts like this. It’s not a research paper – it has to be a 2.5 minute read (the usual duration of visits).
More reading is necessary, including coupling what I’m saying here with what I’ve said elsewhere.
For example, I claim, with good basis in the science, that aerosolized droplets fall to the earth. Sedimentation and diffisiophoresis act well on droplets. I know this because I’ve modeled spray environs before using this as a decontamination technique. Even without help, droplets don’t stay entrained in the air.
Entrainment in the air requires vaporization or being extremely fine, with a very small diameter and mass.
Sure, droplets produced from coughing could make their way to you, but you shouldn’t be around people who are coughing badly.
My main point is that the belief that a mask of any sort will protect you from people who are asymptomatic because there are free viruses floating in the air is just mythology. It’s fairy tales.
Modeling the trajectory and settling velocity of particles and droplets is HIGHLY complex (and I have done some of that). I make no claim to have done that as part of this analysis. Again, this is a two minute read.
On May 29, 2020 at 12:23 pm, Mack said:
Herschel, have you actually read through the NEJM ‘Perspective’ as it’s called? Here is the singles BEST pull-quote:
“One might argue that fear and anxiety are better countered with data and education than with a marginally beneficial mask, particularly in light of the worldwide mask shortage, but it is difficult to get clinicians to hear this message in the heat of the current crisis.
“Expanded masking protocols’ greatest contribution may be to reduce the transmission of anxiety, over and above whatever role they may play in reducing transmission of Covid-19.”
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After all, aren’t panic and phobia highly contagious?
On May 29, 2020 at 12:29 pm, Herschel Smith said:
@Mack,
An army of Karens trying to reduce anxiety. Cursing at you as you walk down the street without a mask or balloons around you to ensure social distancing.
On May 29, 2020 at 1:03 pm, Mack said:
“An army of Karens trying to reduce anxiety. Cursing at you as you walk down the street without a mask or balloons around you to ensure social distancing.”
Ah yes, welcome to ‘democracy’ 21st Century style.
No thank you.
On May 29, 2020 at 1:05 pm, Mack said:
Here is what I sent David:
Mandatory Masks Aren’t About Safety, They’re About Social Control
https://thefederalist.com/2020/05/27/mandatory-masks-arent-about-safety-theyre-about-social-control/
His response:
https://waronguns.blogspot.com/2020/05/behind-mask.html
On May 29, 2020 at 2:50 pm, Herschel Smith said:
@Dean,
Thanks for the visit. The language is terse, but I wanted my readers to understand my position. Doctors have enough of a background to get it without all of the explanations.
So doctors have to know an AWFUL lot of stuff: microbiology, zoology, chemistry, anatomy, etc., etc., etc.
Also, some doctors will go further and get an MS or PhD in other related disciplines, such as microbiology, epidemiology, toxicology, or do something related like get a MPH, where a lot of that stuff is covered.
Those folks tend to go into research, although I’ve seen some doctors who are in current practice who have not only their MD but a MPH and will thus know more than other doctors about toxicology (or at least they should if their school did their job).
But most folks are so slammed with debt after completing med school that they have to work. We all understand this.
Those folks simply cannot be relied upon to, for example, know the toxicology of isocyanates in the workplace. It’s not only unfair, but it relies on people other than the user to understand the risks.
All the time people use products that are unsafe, or use them in an unsafe manner. Right now, I’m evaluating types of full face respirators to recommend to my youngest son for treatment of his bee hives with Oxylic acid. A doctor can treat you if you did it wrong. That’s the use people should be making of doctors, not expecting them to know everything.
STEM is a waning discipline in America.
On May 30, 2020 at 8:31 am, JnotJ said:
I thought you might get to another point about how wearing a mask is to help others from catching any pathogens I might be carrying. Thoughts? I don’t go out much and keep my mouth shut at my quick trip to the store anyway.
It’s good to know why a mask doesn’t protect me. I save the n95 masks for use at home when I’m standing furniture or something.
Thanks
On May 30, 2020 at 10:43 am, Earl T said:
@Stan E.
Stan, did you even bother to read Herschel’s post with any understanding of what Herschel’s expertise is??? Based upon your totally emotional response, I’d guess not! I surmise you read the headlines, then rushed through it and couldn’t wait to post your hysterical “Karen”-like cross examination. Your fear and anxiety are clearly showing!
On May 30, 2020 at 11:24 am, Ed Hackie MD said:
Arrogant , silly comments, pontificating about known knowns and unknowns. Chicken soup May not help but doesnt hurt.
On May 30, 2020 at 11:54 am, Hal Dall MD said:
Excellent article, I’ll be sharing this with others.
I practice in an older rural town where most people dislike masking, but a few are very upset when others are unmasked. To the former I liken a surgical mask to a cartoon I saw of the effectiveness of a chain-link fence stopping mosquitoes. For the latter we wear masks at my office. I’ve also come to making a big show of my handwashing so that it is noticed.
On May 30, 2020 at 1:03 pm, Herschel Smith said:
To add a little to the conversation, an H2O molecule is 2.75 Angstroms in diameter. In a combination of a virus and H2O, the H2O adds unappreciably to the diameter of the particle, not enough to make a HEPA filter effective. A charcoal filter, impregnated with TEDA, is a different story since water is polar.
Water in air is in vapor form. Droplets sediment out of the air.
The main point remains. Free-floating viruses are not removed by masks that don’t contain charcoal.
On May 30, 2020 at 1:36 pm, Pretty Pink Pansy Mask said:
“By wearing a mask, the exhaled viruses will not be able to escape and will concentrate in the nasal passages, enter the olfactory nerves and travel into the brain.” — Russell Blaylock, MD
On May 30, 2020 at 1:37 pm, Karenocracy said:
Maybe mommygov will buy us all a biohazard suit to keep us safe in a sterile risk free bubble.
Oh…wait you can’t wear the suit 24-7 and the teevee looks funny when you are being told what to think.
On May 30, 2020 at 1:43 pm, Herschel Smith said:
@Mask,
I’ve noted the heavy viral and pathogenic loading on the inside and outside of masks in other articles. In particular, I would ask some folks the following question: “Have you thought about the buildup of Legionella on the inside of masks when you tell people to wear them all the time? If not, then your analysis is not complete.” Legionella is in the air anyway. It concentrates when condensation occurs. We learned this from the Bellevue-Stratford Hotel where the HVAC engineers had intake air directed right over condensation discharge. People died from it. We also saw Legionellosis in bathrooms at the border where immigrants took wet paper towels, threw them on the floor, and water pooled.
On May 30, 2020 at 4:01 pm, Nemo said:
@ Hershel May 29, 2:50
“That’s the use people should be making of doctors, not expecting them to know everything.”
Please explain then why most Doctors and 90+% of the ones I’ve dealt with over my 73 years on this rock come across as, and will sometimes even tell you, their patient, that they do know everything? God forbid you should ask them a question about some pronouncement they’ve made, which engenders either incredulity that you, the lowly patient, should deign to question the almighty doctor or outright anger and derision in their reply which generally ignores the question and instead belittles the patient?
On May 30, 2020 at 5:17 pm, Mack said:
To add a little to the conversation, here is Dr. No on CNN:
https://www.theblaze.com/news/fauci-second-covid-may-never-happen
[SNIP]
Fauci also said that Americans should wear face masks in public to protect themselves — but also to get into good practices.
“I want to protect myself and protect others [by mask-wearing], and also because I want to make it be a symbol for people to see that that’s the kind of thing you should be doing,” he added.
During the interview, the infections diseases expert also admitted that wearing a mask is not 100% effective, but says that it is a gesture that shows “respect” for other people.
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Kabuki theater!
On June 22, 2020 at 6:06 pm, Susan Linke said:
This is a great interview with the director of CIDRAP, Center for Infectious Disease Research and Policy. He systematically goes through all of the misinformation published about face masks. It’s a long but worthwhile read. Feel free to send to your elected officials.
https://www.cidrap.umn.edu/sites/default/files/public/downloads/special_episode_masks_6.2.20_0.pdf?fbclid=IwAR1rBikzoulzB2PGRxTY187OOLWDiUsvEnzZ_LhO9Adu0eJ54hn82TZNxsw
On June 22, 2020 at 9:10 pm, penses said:
“Feel free to send to your elected officials”
The (ballot box stuffed) elected officials don’t see anything beyond the buckets full of cash from the globalist banks. And what the usurers want is THE NEW NORMAL: masks, and spacing, and lockdowns, and come September it starts all over again because the elite have seen how easy it is to herd the sheep. The planneddemic is working beyond the globalists wildest dreams and the pols, supported by the MSM propaganda machine, will keep up the pressure, the facts be damned. This is corporate Amerikkas best chance to snuff out the free market and the competition it represents.
Trump is
On June 22, 2020 at 9:11 pm, penses said:
Sorry, booboo.
Trump is doing his part with billions in bailout money while the middle and lower classes become slaves.
On June 23, 2020 at 7:08 am, penses said:
“If Only Governments Were REALLY ‘Guided By The Science’”–principia-scientific.org
A good man attacked by corporate. The TRUTH is not welcome in the new normal society.