Surgical, N95 masks block most particles, homemade cloth masks release their own

Medical Xpress ^ | SEPTEMBER 25, 2020 | Andy Fell, UC Davis

[conservative98]

Laboratory tests of surgical and N95 masks by researchers at the University of California, Davis, show that they do cut down the amount of aerosolized particles emitted during breathing, talking and coughing. Tests of homemade cloth face coverings, however, show that the fabric itself releases a large amount of fibers into the air, underscoring the importance of washing them. The work is published today (Sept. 24) in Scientific Reports.

[cut]

Without a mask, talking (reading a passage of text) gave off about 10 times more particles than simple breathing. Forced coughing produced a variable amount of particles. One of the volunteers in the study was a superemitter who consistently produced nearly 100 times as many particles as the others when coughing.

In all the test scenarios, surgical and N95 masks blocked as much as 90 percent of particles, compared to not wearing a mask. Face coverings also reduced airborne particles from the superemitter.

Homemade cotton masks actually produced more particles than not wearing a mask. These appeared to be tiny fibers released from the fabric. Because the cotton masks produced particles themselves, it's difficult to tell if they also blocked exhaled particles. They did seem to at least reduce the number of larger particles.

[smokingfrog]

Where are the UV lights?

[monkeyshine]

That’s gonna be the next hysteria. Common flu symptoms are very similar to CV19 symptoms. So as flu season comes upon us, we are going to have a lot of nervous nellies, and demands on the HC system, and demand for testing. There are couple of instant (or near instant) tests in final stages of testing, including the one from Abbot but that still needs a clinic. An at home test would be best, if it could be developed and approved quickly.

And another thing, you will have people who are positive and asymptomatic for covid, but also have the flu - and it will be impossible to know the symptoms are unrelated to covid.

[alabama_heart]

Yes he is....BS particles.

[Jane Long]

I sewed our masks out of a lightweight gauze fabric.

How many particles do you suppose they block?

:-)

[monkeyshine]

I knitted a sportscar out of steel wool.

(Stolen from an old Mad Magazine cartoon I read as a kid more decades ago than I care to admit)

[DugwayDuke]

monkeyshine wrote: “Well I suppose someone needed to research this scientifically. But some things are just self evident.”

What has been ‘self-evident’ for sometime is this: masks are highly effective as a virtue signalling device that says “I wear so you know I care.” Secondarily, mask mandates allow politicians to demonstrate that they are ‘doing something’.

[Jane Long]

😂

[monkeyshine]

You are right about that. And I’d add, for politicians to try to shame and divide and lord over the citizens... as if they didn’t do enough of that already.

[roadcat]

True, and both go right around and through any mask that isn’t sealed to the face. It’s science.

Half the people I see with cloth masks have large openings around the bridge of the nose, or are under the nose. Science tells me that this is a problem.

[Pearls Before Swine]

N95 masks stop viruses like screen doors on submarines stop water.

Don't screen doors slow down water flow at least a little?

[Daniel Ramsey]

Dontcha just love articles about slave muzzles?

[Paladin2]

Getting more Fiber is a Bad Thing?

[semimojo]

Masks like Fauci likes to wear don't work.

"Face coverings also reduced airborne particles from the superemitter."

[mass55th]

Jerry Nadler released a large amount of particles in his pants yesterday.

[Mom MD]

installed at the ceiling level shielded from the kids

[logi_cal869]

Sham study designed to buttress the mask mandates. The devil is in the details (i.e. the vague terminology of 'particles', with nary a mention of attempt or ability to measure "particles" in the sub 3 micron range, to state nothing of 120nm).

This passing statement is rather telling:

"Indeed, recent work by Liu et al. demonstrated that some of the highest counts of airborne SARS-CoV-2 (the virus responsible for COVID-19) occurred in hospital rooms where health care workers doffed their PPE, suggesting that virus was potentially being aerosolized from virus-contaminated clothing or PPE, or resuspended from virus-contaminated dust on the floor47. It remains unknown what role aerosolized fomites play in transmission of infectious respiratory disease between humans, and it is unclear whether certain types of masks are simultaneously effective at blocking emission of respiratory particles while minimizing emission of non-expiratory (cellulosic) particles."

The best evidence of it being a sham study is this passage:

"Here, we measured outward emissions of micron-scale aerosol particles by healthy humans performing various expiratory activities while wearing different types of medical-grade or homemade masks."

Cited references for "particles" in the "micron range" all refer to particles in the >2 micron range except one.

In consideration that SARS-CoV-2 is approximately Images below for reference to all:

N95 Outer Layer

N95 Fine layer

Disposable surgical mask (medical grade):

T-shirt

Note: The small dot to the immediate right of all 4 of the Coronavirus graphical representations us the virus to the SAME SCALE (you may need to zoom in; the enlarged representation is provided for visual effect to locate the properly-scaled virus, which is smaller than a decimal point at that scale).

[smokingfrog]

I would hope they’re well shielded. UV light will damage your eyes.

[Shethink13]

Thank you! Exactly. You can’t spread what you don’t have.

[Bulwyf]

No mask will work for a virus. Zero. Full hazmat suit with supplied oxygen or bust.

[Bulwyf]

*facepalm * wow.