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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 wen
by glerk 4y ago
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 4y ago> 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/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724761/
- ceejayoz 4y agoThey've also got a substantially better seal around the edges.
- taf2 4y agoWhich makes them super comfortable
- nerfhammer 4y agominutephysics has a nice video https://www.youtube.com/watch?v=eAdanPfQdCA https://www.youtube.com/watch?v=eAdanPfQdCA
- AlexandrB 4y agoErrr, 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.
- ISL 4y agoI 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.
- dmix 4y agoThere 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 4y agoHow long can you wear an N95?
- bad416f1f5a2 4y agoNot 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 4y ago> 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.
- jvanderbot 4y agoI 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 4y agoThe 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.
- kurupt213 4y agoThey’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
- doktorhladnjak 4y agoIf 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.