Everyone is saying this. I’m not buying it for a second.

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Dennis S
Everyone is saying this. I’m not buying it for a second.

Seriously?!

The virus spreads by aerosol transmission; when coughing, sneezing, speaking, even just breathing.
ANYTHING that restricts and lessens the distance that aerosol travels reduces the virus’s opportunity to infect another person.
Here’s a grade school demonstration: light a candle, put on a mask, and try to blow out the candle. Did the mask restrict how forceful and how far you could blow?

[youtu.be]

[youtu.be]

[youtu.be]


Mask use studies
[www.cdc.gov]

[files.fast.ai]

[www.nejm.org]

I may not have been clear. Of course they protect others FROM you. They protect you from others as well.

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Dennis S
I may not have been clear. Of course they protect others FROM you. They protect you from others as well.

Depends on the quality, capabilities and proper fit of your mask as to how much protection you will have.

That old, loose-fitting cotton bandanna, worn outlaw-style will not give anything close to the protection of a new, properly worn N95 mask.

What’s their point? Either way, mask-wearing is an attempt to interrupt transmission during a pandemic.

Quote
Dennis S
Everyone is saying this. I’m not buying it for a second.

My understanding is that there's no scientific consensus on the actual numbers, but a very rough ballpark/guesstimate that I've seen often is that when fitted properly, the numbers work out to about 80/20 with a N95 mask.

80% effective at protecting others from you.

20% effective at protecting you from others.

...For brief exposures. Locked in a small room with an infected person for a few hours, everyone there will probably get it regardless of the quality of the mask.

---

Quote
Tiangou

Quote
Dennis S
Everyone is saying this. I’m not buying it for a second.

My understanding is that there's no scientific consensus on the actual numbers, but a very rough ballpark/guesstimate that I've seen often is that when fitted properly, the numbers work out to about 80/20 with a N95 mask.

80% effective at protecting others from you.

20% effective at protecting you from others.

...For brief exposures. Locked in a small room with an infected person for a few hours, everyone there will probably get it regardless of the quality of the mask.

Not sure where you're getting those numbers from, and if it were true that an N95 were so ineffective at protecting you from others, then medical personnel wearing them would be getting corona left and right -- which they aren't.

As one example of a study:


From here: [www.cdc.gov]

Time it takes to infect, depending on who is wearing what type of mask:


From here: [www.wsj.com]

More published data:

[www.ncbi.nlm.nih.gov]
[www.pnas.org]
[www.ncbi.nlm.nih.gov]

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Freya says, 'Hello from NOLA, baby!' (Laissez bon temps rouler!)

Back when there was a new virus and a lot less information, it seemed plausible that having everybody wear a mask whenever interacting would slow the spread of the virus. And since it would not always be obvious that somebody was infectious, it made sense that we all wore the masks.

I don't think the logic has changed all that much, particularly considering that the newer variants can spread without our being particularly aware of carrying an asymptomatic infection.

But there is a separate kind of logic for people who were angrily uncaring about other people's safety.

Quote
PeterB
...

The WSJ story is paywalled.

I do appreciate that you managed to find an article that featured hamsters.

I may have been thinking of cloth mask studies, not N95.

[www.cdc.gov]

Source Control to Block Exhaled Virus

...Upwards of 80% blockage has been achieved in human experiments, with cloth masks in some studies performing on par with surgical masks as barriers for source control. In one study, conducted prior to widespread circulation of the Delta variant, masks worked equally well for blocking aerosolized particles containing both “wild-type” virus and the Alpha variant (a more infectious variant).

---

So what about the ubiquitous blue fabric masks? Certainly better than nothing, how much better?

BTW, I have appreciated PeterB’s knowledgeable input and background while we have waded through this thicket of misinformation/disinformation.

Quote
Don C
So what about the ubiquitous blue fabric masks? Certainly better than nothing, how much better?

Better than single layer masks made of regular woven cloth, and definitely better than knit neck gaiters pulled up over the mouth and nose. A cloth mask made from 2 or 3 layers of tight woven cloth and fit properly can do better, especially if one layer is made from polyester or cotton polyester. I saw some figures early on that the 3 layer version gave about 80-90% of the protection from aerosols as purpose made masks.

Quote
pdq
BTW, I have appreciated PeterB’s knowledgeable input and background while we have waded through this thicket of misinformation/disinformation.

I like the charts for easy reference.

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Saint Cloud, Minnesota, where the weather is wonderful even when it isn't.



Edited 1 time(s). Last edit at 05/20/2022 06:48AM by Speedy.

Quote
pdq
BTW, I have appreciated PeterB’s knowledgeable input and background while we have waded through this thicket of misinformation/disinformation.

Yes, and some others that have solid knowledge/expertise. I appreciate them sharing those with us.

---

e pluribus unum

Quote
Tiangou

Quote
PeterB
...

The WSJ story is paywalled.

I do appreciate that you managed to find an article that featured hamsters.

I may have been thinking of cloth mask studies, not N95.

[www.cdc.gov]

Source Control to Block Exhaled Virus

...Upwards of 80% blockage has been achieved in human experiments, with cloth masks in some studies performing on par with surgical masks as barriers for source control. In one study, conducted prior to widespread circulation of the Delta variant, masks worked equally well for blocking aerosolized particles containing both “wild-type” virus and the Alpha variant (a more infectious variant).

80% blockage doesn't translate into 20% protection though, right?

And it was unintentional that one of the articles mentioned hamsters as a model ... that's not surprising though, since they and other species like ferrets have been getting used as a model.

The WSJ article ... you can use the Bypass Paywalls extension for Firefox. If you can get access to it, it's actually a pretty nice article because of the infographics:

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Freya says, 'Hello from NOLA, baby!' (Laissez bon temps rouler!)

One of the biggest problems I've found with the blue/white surgical masks is the nose wire has been weak in several brands.

Weak, as in they don't hold their shape very well.

The means a bad seal which defeats the efficacy of the mask.

And it also fogs glasses.

I've been giving the ear loops of my masks a 180º twist to pull the nose and the chin portions closer to my face, making a much better seal, and leaves glasses almost completely fog-free.

I may try knotting the loops to see how that works.

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I am that Masked Man.

Your boos mean nothing to me, I've seen what you cheer for.

Insisting on your rights without acknowledging your responsibilities isn’t freedom, it’s adolescence.

I've been to the edge of the map, and there be monsters.

We are a government of laws, not men.

Everybody counts or nobody counts.

When a good man is hurt,
all who would be called good
must suffer with him.

You and I have memories longer than the road that stretches out ahead.

There is no safety for honest men except
by believing all possible evil of evil men.

We don’t do focus groups. They just ensure that you don’t offend anyone, and produce bland inoffensive products. —Sir Jonathan Ive

An armed society is a polite society.
And hope is a lousy defense.

You make me pull, I'll put you down.

I *love* SIGs. It's Glocks I hate.

I have and for a very long time used good KN95s. Short ear loops, good nose pieces and as I would breathe, the mask would inflate and deflate. But when things were bad before vaccines and I would have to physically interact with my daughter (like driving her to her monthly lab work), I would use white athletic tape to seal around the outer edge. I believe it helped and neither of us have gotten COVID45.

---

Saint Cloud, Minnesota, where the weather is wonderful even when it isn't.

No question that good fit is a very important aspect to the masking/N95 equation. I've found that really only the 3M Auras fit my face well, and aren't also super-uncomfortable. The metal clip plus the memory foam at the top makes all the difference in terms of comfort and fit, and really cuts down on eyeglass fogging. I don't find I usually need to seal around the edges, but if I were to want to do that, I would definitely again use memory foam strips (they're available at Bezosland) for that purpose.

I've seen so many folks here who are barely "masking" (when they are masking), since they're doing the nose thing, allowing the mask to droop down, having a completely loose fit, etc., etc.

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Freya says, 'Hello from NOLA, baby!' (Laissez bon temps rouler!)

[www.kcprofessional.com]



Thanks again to whomever mentioned these Kimberly Clark "Kimtech™ N95 Pouch Respirators." These are the only ones I have tried that do not fog my glasses and do not restrict breathing. Many dislike the duckbill look, I could care less. I find it reassuring that the "pouch" contracts and expands with my breathing, leads me to infer that I am inhaling and exhaling through the mask material instead of around the edges. Regular Size fits my size 8 head/oval face pretty well (could be a touch larger). USA made, NIOSH-Approved, I've bought two 50-packs via bald space enthusiast's store @ around $1 per mask. I think they were designed for production work in very dusty conditions.

Cons: Elastics somewhat flimsy but should last for the length of mask efficacy (8 hours?). Do not work well for double masking since it restricts the pouch. People give you funny looks, I'm already used to that. No beards allowed for a proper seal, sigh.

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=wr=

Way back in the beginning, there was a video of a surgeon with 6 stacked surgical masks doing a surgery, while wearing an oximeter. I don't believe he ever dropped below 100%.

Thus proving that they won't interfere with breathing or O2 saturation unless you are running on only half a diseased lung lobe. I have pretty bad asthma, and I can easily use an N95 as long as I am not running or carrying heavy loads.

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********************************************
“A sword never kills anybody; it is a tool in the killer's hand.” Seneca the Younger

The police have no duty to respond. See Castle Rock v. Gonzales, 545 U.S. 748 (2005) or Warren v. District of Columbia[1] (444 A.2d. 1, D.C. Ct. of Ap. 1981)

Judge Lee wrote that “we cannot jettison our constitutional rights, even if the goal behind a law is laudable." 9th Circuit Court of Appeals

[www.youtube.com]

I've become a fan of the 3M Aura 9205+ N95 masks.

They look better to my eye, but importantly, they have all the requisite safety features.

My favorite bits are the shape of the nose cheek area with a good wire bridge, and the extra bit that goes below the chin, with a tab for adjusting the mask.

The shape also lends itself to being covered with a second mask, surgical mask in my case.

The combination of the good nose wire and low profile of the mask reduce fogging of my glasses by a significant amount.

---

I am that Masked Man.

Your boos mean nothing to me, I've seen what you cheer for.

Insisting on your rights without acknowledging your responsibilities isn’t freedom, it’s adolescence.

I've been to the edge of the map, and there be monsters.

We are a government of laws, not men.

Everybody counts or nobody counts.

When a good man is hurt,
all who would be called good
must suffer with him.

You and I have memories longer than the road that stretches out ahead.

There is no safety for honest men except
by believing all possible evil of evil men.

We don’t do focus groups. They just ensure that you don’t offend anyone, and produce bland inoffensive products. —Sir Jonathan Ive

An armed society is a polite society.
And hope is a lousy defense.

You make me pull, I'll put you down.

I *love* SIGs. It's Glocks I hate.