[AnthonBerg]

We also did not have data on the types of masks being worn or on masking adherence rates in the two school districts

It is known that this is an aerosolized pandemic. Airborne. Cloth and surgical masks do not work.

Source – there are many to choose from: https://www.sciencedirect.com/science/article/pii/S014067362...

The posted study on mandates has effectively no meaning. Closed FFP2/N95-style masks work. This is fact. A mandate does not make such masks magically appear on people’s faces. Therefore it is obvious that there is no effective correlation between the word “mandate” and what SARS-CoV-2 does.

[tzs]

That's awfully binary. With SARS-CoV-2 it is a probabilistic thing, where your chances of actually getting an infection depends on how much SARS-CoV-2 you are exposed to and for how long.

Even a cloth or surgical mask does lower that probability. Not enough that it is likely to make a difference if you are going to be exposed for a long time, such as spending hours in room with infected people like might happen at school.

But if you are say going to just do say a quick trip to the grocery store and you only have a surgical mask available, wearing it will lower your chances of getting COVID at the grocery store compared to going maskless.

Some sources: https://www.science.org/doi/10.1126/science.abg6296 , https://www.cdc.gov/mmwr/volumes/71/wr/mm7106e1.htm .

[tinus_hn]

Do note that at least that first source is just people theorizing it should work, not people checking if it actually does work.

[glerk]

This has been known since 2020. From the beginning, the public health message could have been "protect yourself using a N-95 mask", but for some reason they went with "protect others using a cloth/surgical mask".

The only reasonable explanation I can find for this is that N-95 masks were in short supply at the time and they had to be saved for medical professionals. We needed a distraction to prevent the general public from hoarding N-95 masks.

But here we are, 2 years later, still debating whether masks with holes orders of magnitude larger than the airborne virus particles they are supposed to stop are effective.

[bsilvereagle]

> whether masks with holes orders of magnitude larger than the airborne virus particles they are supposed to stop are effective

N95 masks work due to a dipole charge, not necessarily because of the mechanical filtration size.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724761/

[ceejayoz]

They've also got a substantially better seal around the edges.

[taf2]

Which makes them super comfortable

[AlexandrB]

Errr, the linked study directly contradicts your point:

> In both respirators, large decreases in the dipole charge density were observed after several heat treatments. However, there was no significant drop in filtration efficiency because multiple parameters (i.e., mechanical filtration) were involved in the filtration performance.

[nerfhammer]

minutephysics has a nice video https://www.youtube.com/watch?v=eAdanPfQdCA

[ISL]

I believe that you are entirely correct. One of the big lessons-learned is that the response should have been: "N95s work. They are very important. If you hoard them, healthcare professionals will die. Please donate your extras to your nearest hospital."

I saw firsthand, working with findthemasks.com, just how many people came to that conclusion on their own and rapidly aggregated and donated as many N95s as they could.

It is bonkers to me that we're not all wearing N95s by default until case-rates really come down, but I have accepted that our current state is the way of the world.

[creato]

I’m fully on board with “N95s work” but I still think this information is near useless from a public health point of view. They need to be fitted properly, which among other things, means being clean shaven. If you thought mask mandates were political trouble, just wait for the shaving mandate.

[jacobolus]

N95 masks still work (substantially reduce spread when worn by index patient and/or their contacts) when not fitted carefully. They then don’t live up to their rated specification, but are still a whole lot better than nothing or a lower-filtration mask.

[dmix]

There were major community backed PPE donation drives parked outside many hospitals providing nurses/doctors with quality gear as they walked into work.

This is the sort of thing gov will have years to solve but I’m sure many will fail to do it and a bunch of countries will be pushing surgical masks then next pandemic (or Covid 2.0).

[HKH2]

How long can you wear an N95?

[bad416f1f5a2]

Not sure how to parse the question; answering both ways.

How long can a person wear one? The few times I work in office I wear one all day, and don’t find it difficult.

How long can a single N95 be reused? I’d read research indicating the real limiting factor seems to be the quality of the seal, and the straps tend to fail before the mask loses efficacy. Basically, if it seals without air escape, you’re good.

[HKH2]

> How long can a person wear one? The few times I work in office I wear one all day, and don’t find it difficult.

I can't wear the 3M ones I have (with a decent seal) for longer than half an hour without getting lightheaded.

[bad416f1f5a2]

You might try to switch your respirator. The Aura series (3M 9210+ being the best Aura, IME) and VFlex (3M 9105) seem to be very comfortable and easy to breathe for me & others who I've shared them with. In general, a larger surface area makes it easier to breathe.

Another option is to look for a respirator with an exhalation valve. You give up a level of source control but any exhortations to "protect others!" is pretty silly when they come from people who aren't wearing anything to protect themselves. The Aura has a vented model (9211+) which I've not tried but have heard excellent things about.

You could also consider a half-face elastomeric respirator. You wouldn't expect it, but I've found the ones made with a quality silicone material (3m 75xx / Honeywell North 7700) to be far more comfortable than disposable N95s. They have far more breathable area, which is a major plus. When adjusted properly, they also do not "dig into your face" the same way disposable respirators do - you can keep the straps surprisingly loose & still maintain a seal. And they have a much lower TCO because the respirator media lasts for a long time. Muffled speech is the biggest problem, but speech diaphragms go a ways towards fixing that.

In general though, as you move up the ladder of protection you end up using tools that are both more effective & more comfortable. Pre-pandemic I had a crawlspace under my house spray foam insulated. A team of three guys crawled around under my house in mid-August while wearing full face respirators. They told me they were actually more comfortable than the old half-mask / goggles combination they used to use.

[vpilcx]

they were designed to be disposable, but when they were in short supply at the start of the pandemic, medical professionals were wearing them up to a month. There was a study that you could treat them with, I think, UV light, oh no wait, it was put them in the oven at a certain temperature, to extend their viability up to a certain point, but I think practically, most people switch off every week or so unless in extremely high risk situations.

[kurupt213]

They’ve known since SARS… like 15 years. There’s a paper about SARS burning through an apartment complex because a breeze blew contaminated air out one window and into the open window of a neighboring building

[jvanderbot]

I thought that "airborne" meant "could survive in water aerosols for long enough to get breathed in" not "sprouted little virus wings and flew through any hole it could fit through"

And I assumed water droplets were in fact several orders of magnitude larger than the virus, but would still be caught my masks. Otherwise what's the point for any virus?

[jacobolus]

The water droplets are several orders of magnitude larger than the virus, but still small enough for some of them to fit through the gaps in a cloth mask (but almost none make it past an N95 mask).

The cloth mask still stops the vast majority of such drops, cutting risk significantly compared to no mask.

[doktorhladnjak]

If spread was by large droplets, cloth and surgical masks worn as source control (by those infected) are effective. The problem is that it took a very long time before experts began to agree that spread is not just by droplets but by aerosols as well.

[gruez]

>Source – there are many to choose from: https://www.sciencedirect.com/science/article/pii/S014067362...

control-f for "mask": 1 match, and it's in a sentence talking about how mask quality and fit is important to preventing infection, but doesn't elaborate on the effectiveness of cloth/surgical vs n95 masks.

On the other hand there are also studies that show it working, eg. https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

>The surgical and N95 masks were both effective in significantly reducing the risk of infection, which together with the finding that 30% of non-infected staff did not use masks (table 2) supports that transmission is not airborne.

Do you have better a better study for this, preferably some sort of meta-study?

[senectus1]

>Cloth and surgical masks do not work.

this sort of statement really bugs me.

anything that slows the airspeed/spread is helpful. and there for "works". A cloth mask is definitely better than no mask... its has a much higher chance of catching larger droplets than no mask, it has a much higher chance of rate limiting even smaller droplets than no mask.

if 100% of the population worse cloth masks you would get a significant reduction of spread just because of the rate limiting.

N95 masks are not 100% effective.. so do we claim that they "Dont Work" as well? no we dont.

Nothing is black and white. nothing is works or doesn't work... every little step on the way every little effort all helps and by extension "Works".

[nathanaldensr]

Your argument, like many people made at the time this started, is purely technical. It only considers the virus itself to be the thing needing to be solved, rather than considering second-order effects.

[josephcsible]

If we banned all access to beaches, that would be helpful and "work" to reduce the number of people who get killed by sharks. If we should mandate cloth masks, then why shouldn't we do that too?

[throwoutway]

> Closed FFP2/N95-style masks work.

Schools are not going to mandate this, and even if they do kids will wear them loose/wrong. So knowing that, where do school boards go from here?

[amluto]

Now? Strongly encourage everyone to get vaccinated (to protect themselves, not others — the current vaccines don’t provide substantial protection to others any more). Encourage people who feel the need for extra personal protection to wear N95 masks and feel comfortable doing so. Encourage anyone who is sick to stay home (which was good sense before COVID anyway). Try to improve ventilation (which is also a good idea regardless of COVID). Encourage students to spend more time outside (again, a good idea regardless of COVID). And accept that outbreaks are going to happen.

There is, currently, no magic bullet available that will work in a school setting.

[ClumsyPilot]

ventillation, air purifiers and upper-room UV sterilisation are all cheap and practical solutions that shoukd be installed in every public building.

the fact thats uts still nit obvious, 2 years on us absurd

[chiefalchemist]

Source? How about the CDC? They came out on this as well and that science has been completely ignored. There's been no massive public health push, etc. Nothing.

Makes ya wonder.

[russellbeattie]

JFC. Masks stop your spit from flying. It's about protecting others, not you.

[MuchoMaas]

Setting aside for a moment the fact that chronic, day-in-day-out long term use of N95s has never been studied for potential ill effects, why is it so difficult to discern any reduction in community transmission from Germany's N95 mandates?

[ceejayoz]

> Setting aside for a moment the fact that chronic, day-in-day-out long term use of N95s has never been studied for potential ill effects...

There are professions that've been doing this for decades without any apparent negative impacts.

[GekkePrutser]

Yeah but not the same mask cumpled up in a pocket for so long it's become fluffy. I really wonder if that fine plastic material doesn't cause issues over time. The healthcare community is not a good benchmark for this because they have boxes full of fresh ones available everywhere and they change it every time they take it off. So they never wear a badly worn one.

[happyopossum]

Which profession requires constant 8-10hr a day use of an N95 mask?

[ceejayoz]

Some forms of mining, asbestos remediation, industrial work, etc.

They've been used extensively by enough people the burden of proof lies on the folks claiming they're somehow dangerous at this point.

[avar]

If you look at EU standards for asbestos removal [1] this really isn't the case. Ditto for the other examples you cite.

Almost nobody doing industrial work with comparable PPE doesn't spend at least 1-2 hours of a typical workday out of the PPE.

The linked PDF has an example of a typical workday when removing asbestos, note how many times it involves putting on or taking off the PPE.

I'm not making any claim about COVID mask mandates, other than your examples seeming irrelevant to "chronic, day-in-day-out long term use of N95s".

https://ec.europa.eu/social/BlobServlet?docId=7478&langId=en

[ceejayoz]

> Almost nobody doing industrial work with comparable PPE doesn't spend at least 1-2 hours of a typical workday out of the PPE.

Which leaves many thousands of hours in PPE, for many thousands of people. If the N95 masks caused health issues, we'd know. If someone can demonstrate a) a mechanism and b) any evidence for such an effect, I'm all ears.