Face masks

Shotclog
Posts: 17
Joined: Mon Feb 15, 2021 11:37 am

Face masks

Post by Shotclog »

I met a friend for lunch over the weekend (outside in the chilly air) and he was adamantly pro-masks, asserting that the weight of scientific evidence now showed that they were net beneficial. In particular, he pointed me to the work done by Linsey Marr, an American scientist at Virginia Tech.

I blustered a bit about the Danish study (widely reported on forum) which I thought (actually, still believe) to be the only concerted and controlled study of their effectiveness. I have researched Linsey Marr's work a bit, but I quickly get bogged down in the scientific terminology. It looks as though she has done a lot of useful work on aerosols, although it is not clear whether her work has been peer reviewed.

I remain sceptical that the enforced wearing of masks in a non-clinical setting, in circumstances where people (generally) do not rigorously apply clinical standards to their wearing of masks, is unlikely to be sufficiently beneficial to be justified. However, I am always ready to have my views challenged by different and/or better evidence.

I'd be grateful to tap in to the collective wisdom of members here, and to be guided to the latest peer reviewed work on this question.

Many thanks.

Sir Gus
Posts: 39
Joined: Wed Jun 17, 2020 3:25 pm
Location: Cotswolds

Re: Face masks

Post by Sir Gus »

To be honest Shotclog, whilst I sympathise, I would give up on this now if I were you.

The mask true believers are unlikely to change their minds, and even if a few of them do and go as far as finally admitting they have been conned, most won't, and will for years ahead bang on about all this being necessary.

Here's my approach; I don't personally care whether masks work or not. I think mask mandates and evil, immoral and wrong and I don't wear one on that basis, not on the basis that I don't think they work.

thinksaboutit
Posts: 529
Joined: Wed Jan 06, 2021 11:38 am

Re: Face masks

Post by thinksaboutit »

Shotclog wrote: Mon Apr 19, 2021 8:30 am I met a friend for lunch over the weekend (outside in the chilly air) and he was adamantly pro-masks, asserting that the weight of scientific evidence now showed that they were net beneficial. In particular, he pointed me to the work done by Linsey Marr, an American scientist at Virginia Tech.

I blustered a bit about the Danish study (widely reported on forum) which I thought (actually, still believe) to be the only concerted and controlled study of their effectiveness. I have researched Linsey Marr's work a bit, but I quickly get bogged down in the scientific terminology. It looks as though she has done a lot of useful work on aerosols, although it is not clear whether her work has been peer reviewed.

I remain sceptical that the enforced wearing of masks in a non-clinical setting, in circumstances where people (generally) do not rigorously apply clinical standards to their wearing of masks, is unlikely to be sufficiently beneficial to be justified. However, I am always ready to have my views challenged by different and/or better evidence.

I'd be grateful to tap in to the collective wisdom of members here, and to be guided to the latest peer reviewed work on this question.

Many thanks.
If you are after wisdom, you are in the wrong place.
All you will get is biased opinion!

There are many here who will tell you there is no evidence that masks work. The reality is that there have been many studies, which have been poorly designed so their results cannot be taken as proof. They tend to make the mistake of not having a large enough sample size, controlling/monitoring the participants or isolating the other infection mechanisms.

So looking through the list of studies often posted on here, most say something like "no significant difference", which generally means that there was an observed difference, but it was not large enough to be certain that the result didn't just happen by accident (generally that certainty must exceed 95%)

But when they nearly all say the same thing (difference, but not statistically significant) , it is one hell of a coincidence!
They obviously stop some transfer.. just try blowing through the fabric.

The Danmask study has such a conclusion, which means they should have run a bigger trial.

The study you post shows some good evidence that masks are helpful, as everyone must know to some extent.

https://vtnews.vt.edu/articles/2020/11/ ... -1123.html

If a proportion of droplets are trapped by a mask, it must impact the probability of an infection, or the viral load of that infection.

Of course, most sceptics have bias against all government measures, so consider "lack of evidence" to be proof of the opposite.

jmc
Posts: 390
Joined: Mon Sep 21, 2020 9:01 am

Re: Face masks

Post by jmc »

Shotclog wrote: Mon Apr 19, 2021 8:30 am I met a friend for lunch over the weekend (outside in the chilly air) and he was adamantly pro-masks, asserting that the weight of scientific evidence now showed that they were net beneficial. In particular, he pointed me to the work done by Linsey Marr, an American scientist at Virginia Tech.

I blustered a bit about the Danish study (widely reported on forum) which I thought (actually, still believe) to be the only concerted and controlled study of their effectiveness. I have researched Linsey Marr's work a bit, but I quickly get bogged down in the scientific terminology. It looks as though she has done a lot of useful work on aerosols, although it is not clear whether her work has been peer reviewed.

I remain sceptical that the enforced wearing of masks in a non-clinical setting, in circumstances where people (generally) do not rigorously apply clinical standards to their wearing of masks, is unlikely to be sufficiently beneficial to be justified. However, I am always ready to have my views challenged by different and/or better evidence.

I'd be grateful to tap in to the collective wisdom of members here, and to be guided to the latest peer reviewed work on this question.

Many thanks.
My one observation is that all studies after March 2020 should be ignored. Once a scientific subject becomes politicized almost all published papers after that date are worthless. Paleoclimatology after the mid 1990's being a perfect example.

There are lots of Far Eastern studies on the subject over the decades. Pre 2020. As wearing facemasks by people with symptoms of colds or flu is deeply embedded in the cultures of some of those countries. If you have lived in a western city with a large Chinese / Japanese population facemasks in public would have already been very familiar. It a courtesy and good manners thing.

So it has been studied and the results confirm the basic physics of transmission. If the infection is transmitted by wet coughs and sneezing then casual facemasks worn by those with infections do reduce a small amount the transmission rate. But not much. As a barrier to preventing getting an infection. No effect. Now the N95/N99 (FFP2/3) respirator masks do make a big enough difference to show an effect in the studies. But those are not the masks people are wearing. I have seen less than 5 people in the last year actually wearing masks that provide any possible protection. Everyone else is wearing a placebo mask.

The simplest way of thinking about it is the physics of the particles that transmit SARs Cov2. Very small particle of water droplets less than 2 microns. What you see when you breath out on a very cold day. That "mist" is the main transmission route. N95/99 masks filter out at least 95/99% of those very small particles. Thats what they are designed to do. Face mask and surgical masks filter out none of those very small particles. Surgical masks are designed to protect the patient from any larger salivary particles, sneeze, coughs etc of the medical staff. Not protect the medical staff from airborne particles from the patient. When medical staff need physical protection from infectious agents in the air they wear N95/N99 respiratory masks. Thats part of the regulatory testing process for these respirator masks. Do they keep very small airborne particles out. With surgical masks its purely whether they are an efficient outward barrier of air-borne emissions from the wearers mouth.

So facemasks dont work as a airborne infectious disease control measure because of basic physics. Now if everyone wore N95/N99 masks, especially at home around people with symptoms, that might make a difference. But only in the first 4 to 6 weeks of break out. Before it goes community spread. So late January to early March 2020 in the UK. By April 2020 even largescale use of N95/99 masks would not have changed the short to mid term trajectory of infection. The long term outcome was never in doubt.

So N95/99 masks do work to a certain degree, but thats not what people are wearing. So as I said, the facemasks people are wearing in public are purely a placebo. No scientific basis to their use.

Cheesyrider
Posts: 48
Joined: Tue Oct 20, 2020 3:07 pm

Re: Face masks

Post by Cheesyrider »

Any discussion of this kind of thing invariably ends up in a "my expert is better than yours" type of stalemate, and is basically pointless.

I try to avoid talking about it but if I am forced, I just say something like "There is a lot of data, especially before 2020 showing masks aren't particularly useful, and the government and WHO have flip flopped repeatedly on them which doesn't engender trust, and even if they do work, 99.99% of people don't wear them properly, and you can't apply studies from controlled hospital environments to the whole country wearing it daily" and I just leave it at that.

Honestly, this argument won't be won by logic or arguments, it will be won by action - when most people just choose to ignore it and nobody cares.

The more people who simply stop wearing masks, the more likely that is to happen. To that end, I've simply stopped wearing my mask on public transport (if someone challenges me, I take it out and put it on, but that happens very very rarely - usually some busybody goons from the local Council if they are around). I firmly believe doing that does much more good than trying to persuade my mask wearing friends with logic.

I still wear it in shops and taxis but I'm thinking of stopping that too.

Just wait - if they actually make outdoor mask wearing compulsory I expect to see 25% of the population become mask-exempt overnight.

User avatar
MikeAustin
Posts: 1032
Joined: Thu Aug 27, 2020 2:27 pm

Re: Face masks

Post by MikeAustin »

You could always pose the the question to mask wearers that, if they think their masks are effective, why should you wear one to protect them?

The sheep accept, without question, what they are told by chosen sources. Unless you can stimulate questions, discussion may be fruitless.

One question that can often be posed is that of consequences. If a certain view and/or action is followed, where will it eventually lead? That can stimulate a questioning imagination. I modified a whiterose sticker to print my own:
--- IMAGINE ---
A pandemic so widespread you need to be reminded that it’s there.
A virus so deadly you have to be tested to even know you have it.
A ‘vaccine’ so safe you have to be blackmailed into taking it.

Splatt
Posts: 1498
Joined: Thu Oct 29, 2020 12:46 am

Re: Face masks

Post by Splatt »

Ultimately they love quoting either models or meta studies.

The never ever go to the actual gold standard of science - peer reviewed, randomised controlled studies measuring community mask usage on actual infections.
Mainly because what little research is out there shows no reduction.

You have people analysing analysis of studies comparing states etc which make no attempt to separate out variables such as distancing, hands, mask, lockdowns etc.

Just suggest to them you'll give the topic consideration once some actual peer reviewed RCTs on actual measured infections come out.

Shotclog
Posts: 17
Joined: Mon Feb 15, 2021 11:37 am

Re: Face masks

Post by Shotclog »

Thanks Sir Gus. I suspect you are right about it not being worth the effort to discuss the point with lockdown zealots-certainly it does my blood pressure no good! As Mark Twain (possibly) said: "It is easier to fool someone, than to convince them they have been fooled."

But at the end of the day, the only way I can see this madness being prevented again is for the sceptics to marshal the best scientific evidence we can in support of our case, whilst recognising, and dealing with, the evidence that is adverse to that case.

Teebs
Posts: 227
Joined: Fri Oct 30, 2020 10:20 am

Re: Face masks

Post by Teebs »

It is time to slay this dragon (again).

However, I agree with Sir Gus: we are in hysteria mode and few people will be swayed by evidence, one way or the other.

At the outset, I should say something about myself: I did post-doctoral work in theoretical physics at the Ecole Normale in Paris, and a place called Imperial College in London. Before becoming a theoretical physicist I trained and worked as an engineer. So, I can understand the mindset of scientists/engineers and can read technical and scientific papers.

I got out of science some years ago because I wanted to afford a country estate (work in progress).

Now, on to masks:

There are two ways of looking at the efficacity of something like face masks:

1. Laboratory experiments like Ms Linsey Marr has been doing (and I have just been reading her material);

2. "Field" work to see if they have impact.

The two may appear to be very different, but in the case of face masks I am glad to report there is no contradiction. You just need to read carefully.

In case (1), a face mask is subjected to carefully measured circumstances in a laboratory. The material is precisely defined and so are the circumstances. You will find the terms "optimal conditions" in the work published by Marr. That means tight seals etc. Little to do with real life.

The work by Marr looks at N95 respirators (not the stuff most people wear) and tightly fitted not allowing for any escape around the edges - something that is almost impossible to achieve. Even nurses and surgeons in operating theatres do not achieve that. This is an ideal laboratory situation.

Under these ideal situations, N95 respirators block up to 90%. Once you lose these ideal conditions, the number tumbles very low, very quickly.

When extrapolating to the fabric and blue patches people put on their faces, Marr concedes these do NOT stop the virus, which is a particle around 0.1 microns. However, she then tests if they can block particles as large as 1,000 to 10,000 microns (that is 1mm to 1cm) and then she says, surprise surprise, they stop that.

How can she justify going so large? Because she assumes the virus is transmitted in liquid aerosol and not in a pure form. The open question she avoids is: when do people exhale droplets of between 1mm and up to 1cm? Answer: That happens when people are ill and coughing and sputtering.

Even then, she has to make further assumptions to come up with decent numbers, at one point going for "triple layer" masks. She is getting close to military grade gas masks!

So, simply put, the work of Ms Marr confirms what has always been known: masks do not stop virus particles. They only stop the virus if it is carried in larger liquid droplets, but that only happens when people are very sick.

Marr has not done anything new. The same thing has been known for ages, ever since the silly things were invented. And they were invented to stop larger particles accidentally emitted by surgeons etc from entering an open wound in an operating theatre. That is the limit of their efficacity. Nothing has changed.

(The word "accidental" is important. If a surgeon is sick and coughing or sneezing, he/she does not go to work. Surgical masks are only there for "accidents" like an unexpected cough or choke. They do not allow sick nurses and surgeons, who are shedding disease, to carry on working.)

Here is a good recent thread that debunks a lot of recent theorising about masks:
https://twitter.com/Emily_Burns_V/statu ... 5764576259

Now on to part (2): "field" work.

The Danish Study Shotclog mentions was a "field trial". They did not put a mask in a lab and shoot particles at it and measure what comes out of the other side. Instead, they monitored several thousand people, half of whom wore the masks and half did not, and at the end found a dead heat between the two groups. Those who wore the masks did no better than those who did not.

There are much larger field trials all around us, though not described in those words:

Look at the curves for covid cases (and deaths - which are far more important than +ve pcr tests) and look at the points in time when mask mandates were declared and lifted. You will find absolutely no impact. To make this even more explicit, compare the curves between territories where mask mandates were declared, and those that did not have them. Again, you will find zero impact. It is as if the silly things never existed. (The USA has plenty of valuable data because some states issued mandates and others did not. No discenible differences found.)

As I said at the beginning, there is no conflict between lab tests and real world results because if you read the lab reports accurately you will see that (a) they describe ideal conditions that do not exist in the real world and then (b) to extend those ideal conditions to the real world they make sweeping assumptions about particle size. Both (a) and (b) undermine the arguments for mask mandates, and they are in line with what we see in the real world (and the Danish study): masks make no difference.

No medical difference, that is.

However, they are an extremely powerful tool for spreading fear. That is where they have a genuine impact. Psychology.

Sir Gus
Posts: 39
Joined: Wed Jun 17, 2020 3:25 pm
Location: Cotswolds

Re: Face masks

Post by Sir Gus »

Teebs - great stuff.

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