The science of face masks

@metal-brain said
Multi-layer cloth masks? What are those?

Do you not understand what the word "Multi" means or do you not understand what "layer" means or what, exactly?

@humy said
Do you not understand what the word "Multi" means or do you not understand what "layer" means or what, exactly?

Do you wear a multi layer mask?

@metal-brain said
Do you wear a multi layer mask?

Yes.

@humy said
Yes.

How many layers does it have? Is it a cloth mask or a surgical mask? Who made it?

@metal-brain said
How many layers does it have? Is it a cloth mask or a surgical mask? Who made it?

I made it i.e. it is home made.
I could be wrong but, I would guess that, because its home made, it wouldn't be formally defined as a surgical mask. But I when I googled "surgical mask" I got conflicting definitions that made it unclear whether it would be correctly defined as a surgical mask in particular so I'm a bit unsure about that one.
I made it taking account some limited expert advice of making home made ones I saw over the internet and also as an improvisation during lockdown when I didn't have the means of simply going out to buy one.
It has 3 layers; each of which are cotton cloth from an old throw-away shirt I had. -certainly not ideal but certainly a lot better than nothing.

What about it?

@metal-brain said
Multi-layer cloth masks? What are those? Is that another name for a surgical mask? Most people wear single layer cloth masks. You need test what most people are wearing.

Cloth masks leak. That is why they fog up my glasses. The belief that all exhaled air goes through the fabric of the mask is false.

The US surgeon general explained why face masks can increase the ...[text shortened]... -explains-masks-public-coronavirus


https://www.rt.com/news/507374-facebook-censor-oxford-masks/

A leak, though, is preferable to an open faucet. Mask wearing is a personal hygiene issue.

The US surgeon general - in March - said “It's important to understand that we are looking at the data every single day and we make the best recommendations to the American people we can based on what we know."

Based on these studies and many others, recommendations have changed since March.

* One conspiracy theory I'll entertain is that the "DON'T BUY MASKS" message coming from the CDC in March was related to the shortage of supply in hospitals and nursing homes, and had nothing to do with their efficacy at limiting spread.

@wildgrass said
A leak, though, is preferable to an open faucet. Mask wearing is a personal hygiene issue.

The US surgeon general - in March - said “It's important to understand that we are looking at the data every single day and we make the best recommendations to the American people we can based on what we know."

Based on these studies and many others, recommendations have changed ...[text shortened]... supply in hospitals and nursing homes, and had nothing to do with their efficacy at limiting spread.

"Based on these studies and many others, recommendations have changed since March."

Yes, but were the recommendations based on science?
The US surgeon general gave very specific reasons wearing face masks could do more harm than good. Those reasons have NOT been proven wrong.

@metal-brain said

The US surgeon general gave very specific reasons wearing face masks could do more harm than good. Those reasons have NOT been proven wrong.

I take it that above "could do" as opposed to the words 'will do' means even ignorant you knows face masks generally do more good than harm?
We have already showed numerous studies conducted by experts showing how face masks generally do more good than harm.


And now I have answered all your questions about my face mask to the best of my ability, what about it? What is your point?

@metal-brain said
Those reasons have NOT been proven wrong.

Yes, they have.

@wildgrass said
Yes, they have.

What is your source of information?

@metal-brain said
What is your source of information?

Are you kidding? I posted 100 articles.

@wildgrass said
Are you kidding? I posted 100 articles.

That is not true. You didn't post a single article on this page.

You don't have any evidence face masks are effective. It really comes down to common sense. If you can smell a person's fart being filtered through 2 layers of clothing, including denim jeans, how safe do you feel wearing that mask?

Think about it.

@metal-brain said


You don't have any evidence face masks are effective.

https://www.nature.com/articles/d41586-020-02801-8
Face masks: what the data say
The science supports that face coverings are saving lives during the coronavirus pandemic,
https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html
Evidence for Effectiveness of Masks
...emerging evidence from clinical and laboratory studies that shows masks reduce the spray of droplets when worn over the nose and mouth.
https://theconversation.com/masks-help-stop-the-spread-of-coronavirus-the-science-is-simple-and-im-one-of-100-experts-urging-governors-to-require-public-mask-wearing-138507
The evidence
...There are numerous studies that suggest if 80% of people wear a mask in public, then COVID-19 transmission could be halted.
...laboratory and epidemiological evidence...
https://www.europeanscientist.com/en/public-health/how-effective-are-face-masks-at-slowing-spread-of-coronavirus/
By far, the strongest evidence for mask-wearing can be found in real-world data or so-called epidemiologic data. Leffler and colleagues analysed data on demographics, testing, lockdowns, and the public wearing of masks from 196 countries and found that countries with cultural norms or government policies supporting public mask-wearing had much lower per-capita mortality rates (1)
...
Another study from Germany reported that face masks reduced the number of newly registered SARS‐CoV‐2 infections by between 15 and 75 per cent over a 20-day period after their mandatory introduction (2). Overall, the authors estimate that face masks reduce the daily growth rate of reported infections by around 47 per cent.
...
The general consensus seems to be that masks – even, simple cloth ones – while clearly not foolproof can significantly slow the spread of the virus and reduce deaths

(1) Leffler, C.T. et al. Association of country-wide coronavirus mortality with demographics, testing, lockdowns, and public wearing of masks. Update August 4, 2020. medRxiv (2020). DOI: 10.1101/2020.05.22.20109231

(2) Mitze, T. et al. Face Masks Considerably Reduce Covid-19 Cases in Germany: A Synthetic Control Method Approach. IZA Discussion Paper No. 13319 (2020). Available at SSRN: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3620634

(3) Fischer, E.P. et al. Low-cost measurement of facemask efficacy for filtering expelled droplets during speech. Science Advancese (2020). DOI: 10.1126/sciadv.abd3083

(4) Simha, P.P. and Rao, P.S.M. Universal trends in human cough airflows at large distances featured. Physics of Fluids (2020). DOI: 10.1063/5.0021666

(5) Sickbert-Bennett, E.E. et al. Filtration Efficiency of Hospital Face Mask Alternatives Available for Use During the COVID-19 Pandemic. JAMA Internal Medicine (2020). DOI:
..."
https://www.wsj.com/articles/face-masks-really-do-matter-the-scientific-evidence-is-growing-11595083298
Face Masks Really Do Matter. The Scientific Evidence Is Growing.
Face masks are emerging as one of the most powerful weapons to fight the new coronavirus, with growing evidence that facial coverings help prevent transmission
The research Dr. Redfield cited included a recently published study suggesting that universal use of surgical masks helped reduce rates of confirmed coronavirus infections among health-care workers at the Mass General Brigham health-care system in Massachusetts.
Researchers from around the world have found many different kinds of masks can significantly reduce the spread of coronavirus,
Their findings largely align with other recently published research.

https://www.thetimes.co.uk/article/facemasks-shown-to-cut-spread-of-covid-19-9r92zfpb8
Facemasks slow spread of coronavirus by 40 per cent, study shows

If you can smell a person's fart being filtered through 2 layers of clothing, including denim jeans, how safe do you feel wearing that mask?

Smells are generally from the direct sensing of particles many times smaller than airborne virus infected droplets so it is unsurprising that the tiny gaps through cloth don't block smells but do at least block some of those virus infected droplets getting through. So you are just being completely stupid here. Water runs straight through a kitchen sieve so a kitchen sieve doesn't block peas from going through it? -Your same moronic 'logic'.

@humy said
https://www.nature.com/articles/d41586-020-02801-8
Face masks: what the data say
The science supports that face coverings are saving lives during the coronavirus pandemic,
https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html
Evidence for Effectiveness of Masks
...emerging evidence from clinical and laboratory studies that shows masks ...[text shortened]... tchen sieve so a kitchen sieve doesn't block peas from going through it? -Your same moronic 'logic'.

"Smells are generally made by particles many times smaller than airborne virus infected droplets so it is unsurprising that the tiny gaps through cloth don't block smells but does at least block some of those virus infected droplets getting though. So you are just being completely stupid here. Water runs straight through a kitchen sieve so a kitchen sieve doesn't block peas from going through it? -Your same moronic 'logic'."

The irony is that is the real moronic logic. Another lie, really. It isn't at all true. If it is, you can surely provide your source of information.

@metal-brain said


Another lie, really. It isn't at all true.

which part? The part about the kitchen sieve? If not, specify exactly WHAT you claim isn't true... Molecules of smell being many times smaller than those virus-infected airborne droplets? The virus alone is much larger than most smell molecules so logic dictates if those droplets contain virus then they must generally be even larger.