[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.