[HN Gopher] Real-world data show that filters clean Covid-causin... ___________________________________________________________________ Real-world data show that filters clean Covid-causing virus from air Author : bruceb Score : 157 points Date : 2021-10-09 15:48 UTC (7 hours ago) (HTM) web link (www.nature.com) (TXT) w3m dump (www.nature.com) | dukeofdoom wrote: | In Canada, Many school, and public buildings still have asbestos | used throughout and very outdated ventilation systems. Schools in | smaller towns were built in the 60s and 70s. Asbestos was a town | in Quebec before they changed the name. | | Vaccines are pushed in part so hard, because its the cheapest | solution for government to implement. Not building extra | hospitals. Firing unvaccinated nurses, and hospital employees | during a pandemic is the other government solution. This of | course will blow back hard, should the vaccine efficiency wane | over winter. | jeeeb wrote: | Here in Australia states have been been putting portable air | filters in schools, age care homes and so on. | | Victoria for example ordered 51,000 filters recently to place | across all schools. | dboreham wrote: | Suspect that "These organisms are not typically thought to spread | through the air" was not evidence-based. | junon wrote: | "COVID-causing virus" | | So.. COVID. | _Microft wrote: | The disease that develops after being infected is called | _COVID-19_ which means _Co_ rona _Vi_ rus _D_ isease (first | seen in 20) _19_. The virus that causes it is _SARS-CoV-2_ , | the _S_ evere _A_ cute _R_ espiratory _S_ yndrom _Co_ rona _V_ | irus _2_ , which is one of many coronaviruses. The _2_ is there | because there was an earlier coronavirus caused disease (SARS) | in 2002 for which the pathogen was called SARS-CoV(-1). | dragontamer wrote: | > which is one of many coronaviruses. | | There's only like 7 coronaviruses that have been discovered | to infect a human. Three of which are SARS, MERS, and | COVID19. | | Its pretty novel, all else considered. | weaksauce wrote: | I mean you are dropping the whole colds are coronaviruses | too part though. though, the "cold" has a bunch of possible | viruses that cause it (something like 200 different | viruses) with the rhinovirus being one of the larger ways | since it's so resistant to being inactivated comparatively | to sars2 which only lasts for a day to three as a fomite | vector, is neutralized by soap and water or 70% IPA. If | covid had a viral vector like a rhinovirus that can last | for months on surfaces in wide variety of conditions on | surfaces and also spread via aerosolized particles it would | have been a completely different pandemic that would have | been far more deadly. | dragontamer wrote: | > I mean you are dropping the whole colds are | coronaviruses too part though. | | There's only 4 coronaviruses that causes a cold: HCoV- | OC43, HCoV-HKU1, HCoV-229E, and HCoV-NL63 | | The rest are rhinoviruses. | | ------- | | That's literally only 7 coronaviruses to care about | (including the 4 that cause "common cold"). | redis_mlc wrote: | 1) WIV took down their database, and a NIH version, in | 2019. | | Those listed around 30 corona sequences. | | 2) We don't know what corona viruses WIV is cultivating | in its humanized mice and lab monkeys. | selimthegrim wrote: | OC43 used to be a pandemic one itself in 1895. | makomk wrote: | Only 4 known coronaviruses that cause a cold, anyway. | While it'd be a bit surprising if there were more, HCoV- | HKU1 was only discovered surprisingly recently. | lovecg wrote: | "Coronavirus disease-causing virus" | umvi wrote: | HIV is to AIDS as SARS-CoV-2 is to COVID | est31 wrote: | Not entirely. AIDS is only the name for the final stage of | the disease, when your immune system is rendered totally | unable to defend your body. It usually takes years from an | HIV infection until AIDS develops. In the first viremic phase | of HIV you can even have fever but often people don't notice | it or put it off as some innocent cold. COVID-19 however is | used however to refer to all stages and forms of the disease. | | https://en.wikipedia.org/wiki/HIV/AIDS#Acquired_immunodefici. | .. | b1gz1m wrote: | Trump 2024! | | Trump 2024! | | Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! Trump 2024! | | Trump 2024! | dukeofdoom wrote: | So who makes a good room air filter? I have a dozen container | ships go by, a few hundred meters away from my window a day. | chmod600 wrote: | How effective would a mediocre filter be, just by physically | bouncing the virus around? Is the virus fragile enough to be | deateoyed that way? | peakaboo wrote: | How are they going to make billions of profit from air filters? | bradknowles wrote: | Have you looked at the prices of HEPA filter machines? | | Check out the cost of IQAir units. | cptskippy wrote: | Those are like the Louis Vuitton of air filters. I think most | people can get by with a Winx air filter. | azinman2 wrote: | I don't want a hospital I'm in to "just get by"... | sudosysgen wrote: | The machine is mostly just a question of convenience, as | long as the flow rate is right it's the filter that does | all the work, and those are relatively much cheaper. | throwaway984393 wrote: | You can build your own high-flow HEPA filter for about $45: | 1x 20-inch box fan ($20) 1x 20x20 MERV-13+ MPR-2400+ HVAC | air filter ($20) 1x roll of duct tape ($2.50) | | Air particle meters and other testing show they work just as well | as big expensive machines (it's just the filter doing all the | work). This is indeed a dirt cheap way to improve overall health. | 404mm wrote: | Go with MERV-17 - 20 to achieve HEPA-like filtration. | pkulak wrote: | I see people post this all the time, but I really don't think | an axial fan can pull air through a HEPA-like filter. You need | to spend $150 on a real solution. It's really not much, | includes the filters, and looks a hell of a lot better to boot. | xxpor wrote: | Plus mine has a sensor too, so the fan is only loud when it | needs to be. | tootie wrote: | This Old House has a really good breakdown on filtration and | air volume and have a pretty clever DIY box fan approach | using multiple filters. Still costs under $100. The | Wirecutter recommended Coway filter is $185 on Amazon. | | https://youtu.be/aw7fUMhNov8 | dragontamer wrote: | > 1x 20x20 MERV-13+ MPR-2400+ HVAC air filter ($20) | | That's a MERV-13 filter, not a HEPA filter. | | HEPA filters 99%+ of small (0.3um) particles per pass. A | MERV-13 filter only filters like 60% per pass IIRC. | | That means that a 1000 cu. feet of air through the HEPA filter | will result in 990+ cu. feet of clean air. While the MERV-13 | filter will only produce 600 cu. feet of clean air. | | -------- | | A MERV13 filter would be good enough to improve most air, but | its not HEPA and shouldn't be confused with it. | geoduck14 wrote: | This is fascinating! If MERV 13 filters 60% with each pass, | can we put 5 in a room to increase the circulation/filtration | and eventually get to 99% filtration? | | Also, I found this article which I found informative. Judge | it as you please: | | https://www.iso-aire.com/blog/what-are-the-differences- | betwe... | jph00 wrote: | Thanks to a higher CADR, it can actually be _better_ than | HEPA in practice, if you use 4 filters to create a corsi- | rosenthal box, as shown here: | | https://www.texairfilters.com/its-all-about-the-air-flow- | thr... | clairity wrote: | note that phrase like "600ft3 of clean air" are misleading. | filtration drops off rapidly with distance from the air | purifier, so the fan would need to be quite oversized for a | room to experience relatively even filtration. for most | rooms, that wouldn't be comfortable, for both noise and draft | reasons. | | i'm down with air purifiers for indoor particulate matter | (i.e., air pollution), but they're not really going to make a | dent in covid transmission rates. transmission happens mainly | during long face-to-face conversations, which mostly | precedes/bypasses room air filtration. | bsilvereagle wrote: | It's worth noting that filter efficiency is a function of | particulate size. A MERV13 and a HEPA filter are nearly | equivalent for filtering pollen, but have drastically | different performance for smoke and virus particles. | | There's a plot 1/3 of the way down the page that shows the | curves: | | https://frdmtoplay.com/nagivating-air-purification/ | diebeforei485 wrote: | "Virus particles" do not float free in the air to spread | disease. It's usually mostly salt water aerosols with a few | virus particles in them. | cottager2 wrote: | Is that known? I don't think it's been conclusively | decided whether or not the virus spreads via aerosolized | droplets or if it's truly airborne. | jcims wrote: | I thought they became airborne by being expelled in a | droplet ang the droplet evaporating. | epgui wrote: | It is known fairly well in the context of SARS-CoV-2, but | other viruses may have different distributions. | epgui wrote: | They certainly can free-float, generally speaking, but | SARS-CoV-2 in particular is indeed known to be mostly in | droplets and aerosols. | | Personally, I'd caution not to over-generalize this fact. | dragontamer wrote: | Yeah, it's actually pretty complicated. | | MERV13 also needs less pressure, and a box fan is bad with | pressure. If you stuck a HEPA filter on a box fan, it might | only do 100cu feet of airflow. MERV13 is maybe 200. | | HEPA is designed for higher pressure centrifugal fans. | MERV13 is likely the best balance for home made designs | hammock wrote: | There is a cubic design that people have been doing with | HEPA filters (4 sides and a cardboard bottom) that solves | the airflow issue. | geoduck14 wrote: | This is fascinating! If MERV 13 filters 60% with each pass, | can we put 9 in a room to increase the circulation/filtration | and eventually get to 99.7% filtration? Does it even work | like this? | | Also, I found this article which I found informative. Judge | it as you please: | | https://www.iso-aire.com/blog/what-are-the-differences- | betwe... | throwaway984393 wrote: | You're right, thanks for the clarification, this is a "DIY | air purifier" not a "HEPA" filter. (Apparently products today | even have to clarify if they are "true HEPA" due to | misleading marketing) | | According to this website | (https://freshairaustralia.blogspot.com/2020/01/how-does- | merv...) a study for underground mining filtration found a | MERV-16 filter superior to HEPA in terms of airflow and cost, | with a negligible difference in filtration efficiency. | | According to the study, the MERV-16 filters have higher flow | rates than a HEPA filter, which would both make the MERV | filter a better fit for an inefficient fan, and increase the | air filtration rate. The author of that site also finds that | the airflow rate can be more important than a filter's rated | efficiency: | https://freshairaustralia.blogspot.com/2020/01/why-air- | flow-... | | After some web searching, it seems you can buy smaller | replacement HEPA filters and MERV-16 filters starting at | ~$40. So I guess you can spend less if you only need "air | purifying", and more if you want the real deal. | DantesKite wrote: | Wouldn't be a bad idea to start having air filters in confined | spaces. | | Elevators, gyms, restaurants. | | Not saying it has to happen all at once, but it would help | decrease most respiratory diseases from spreading. | jonnycomputer wrote: | classrooms | sschueller wrote: | Classrooms where already an issue before Covid. Concentration | goes way down when the air starts to get thick and same goes | for meeting rooms. How many times have you entered a meeting | room where the air was so thick you felt it as soon as you | stepped in? | nradov wrote: | I'm skeptical that would be good for overall long term health. | There are only a limited number of endemic respiratory viruses. | Most of us will be exposed to them at multiple times in our | lives regardless of what protective steps we take. So I'd | rather get them while I'm still relatively young and healthy | because the resulting immunity will give me at least partial | protection later in life. | | Of course ideally it would be better to have effective | sterilizing vaccines for all those various respiratory viruses, | and perhaps someday we will. But those generally don't exist | today for the vast majority of viruses. | diebeforei485 wrote: | It's pretty standard in all office buildings, well before the | pandemic. I don't think expanding it to classrooms and gyms | is going to cause problems. | noodlesUK wrote: | There are significant health benefits to cleaner air, not | just from infectious disease, but also from particulate | pollution and various other harmful substances. I strongly | suspect that on the balance it would be a significant net | positive from that aspect alone, though I don't have | possession of any hard evidence to back that up. | throwawayboise wrote: | Not surprising? HEPA filters have been known to be able to filter | viruses for some time; it's maybe the main reason they were | invented? Not sure about that though. | auslegung wrote: | I have believed this for about a year, based on things I was | reading at that time. I thought this was widely known because | as you point out, that's kinda their purpose. This article | acknowledges that it was shown to be effective in lab settings | and this is mainly about seeing those results in real life | settings. | | But come on, if anyone finds something that's probably | effective based on science and isn't going to negatively affect | anyone, let's shout it from the rooftops. If schools had been | given funding to improve air circulation and filtration as well | as a local gym now does after a $500,000 upgrade, I'm sure many | would feel better about sending their children to school. | Gibbon1 wrote: | What bothers me is about 7-10 years ago there was a high | quality paper linking transmission of flu to temperature, | humidity, and air turn over. Depressingly the response was | 'oh well nothing we can do cause too expensive' | | We'd be in a lot better shape if we'd decided to actually do | something instead of falling back on the usual learned | helplessness. | Wowfunhappy wrote: | I'm student teaching in a third grade classroom, and I want | to add a least a small counter: | | We are required to have two HEPA filters always running in | the classroom. They are loud. Combined with the fact that (1) | children mumble, (2) the children have masks on, and (3) | everyone is supposed to stay 3+ feet apart, it's quite hard | to hear what a lot of kids are saying! | | I don't know what the right answer is, but what we have now | really sucks! | kadoban wrote: | There's quiet filters. I can barely hear the one(s) in my | house, and they're just cheapo ones. Typically the key is | to keep the fan speed reasonable, if you crank it up all | the way almost any fan is going to be loud. | ComputerGuru wrote: | The sound increases with the air pressure requirement. A | true HEPA filter requires much greater air pressure than | a typical air purifier filter. | kadoban wrote: | The ones I have are HEPA and the fan speed is still | variable, and very quiet on low. | gpm wrote: | Can you recommend the model you have? | | The one I have is loud enough on it's lowest setting that | I don't like leaving it on in the background :( | Gibbon1 wrote: | We have the Austin Air Healhmates at work. They are quiet. | | That said the real failure was the FDA not making getting | the vaccine approved for your 3rd graders by the start of | the school year. Frankly I don't know how those guys can | look themselves in the mirror while they are shaving in the | morning. | | I think vaccine approval for 5-11 year olds is coming in | early November. | nostrebored wrote: | Risk/reward here is absurd. This has never been about the | safety of the children. | Gibbon1 wrote: | Ending the pandemic is totally in the interest of the | children. | nostrebored wrote: | Aside from extremely poor studies about long covid in | kids: why? | Gibbon1 wrote: | In the US about 120,000 children lost a primary care | giver to covid. Is you are sane that counts for | something. | plorkyeran wrote: | The right answer is to buy better air purifiers, as good | ones are nearly silent. | im_down_w_otp wrote: | The point would be to have the central HVAC system be | renovated to boost circulation with HEPA filters in the | loop precisely so that you don't have to have two noisy | things doing a middling job of a similar task in the | classroom itself. | sokoloff wrote: | > have the central HVAC system be renovated | | Speaking for many schools in heating dominated climates: | renovate the what? (Many schools have forced water | radiators, which are obviously not able to be retrofitted | for effective air filtration.) | selimthegrim wrote: | They probably have those with windows that open, too, | thanks to the last pandemic. | roughly wrote: | Is that a thing? I hadn't heard that | [deleted] | amluto wrote: | Or upgrade to MERV 16, which is nearly as good, much | cheaper, and has much lower pressure loss. | nucleardog wrote: | The obvious answer would be for the school to not rely on | portable fans with filters on them, but instead actually | upgrade the building you're in. | clairity wrote: | using air purifiers like that for corona is mostly theater | anyway, since air purifiers don't filter the air evenly | (despite the misnomer metric "air changes per hour") in a | room. mostly, it filters really well near the purifiers and | poorly everywhere else. this of course depends on the | strength of the fan, but for most consumer air purifiers, | it's likely a few feet radius at best. that's not to say | that even that isn't worth having in an average bedroom, | but in a classroom, it's likely not doing much at all. | | also, you're already distancing (which is doing nearly all | the work there) and wearing masks (which is mostly theater | in a distanced classroom as well). the virus isn't free- | floating live in the classroom. most virus falls to the | ground directly. of what's aloft, it becomes inactivated | pretty quickly for all sorts of reasons (dessication, ph, | temperature, radiation, etc.) and most likely won't land | anywhere near a viable infection spot. so almost no active | virus is filtered out before it has a chance to reach a | moist, viable passageway in another person. | | even huge central commercial systems likely wouldn't filter | out coronavirus before they die off or land somewhere | harmlessly. it's another potential intervention that sounds | plausible on the surface, but is mostly useless against | covid. | roughly wrote: | With the added bonus that it would be better for the | students' health generally and would likely improve overall | educational outcomes. | | An awful lot of our handling of COVID has been farcical (a | year and a half in, we're still relying on cloth masks and | obsessively sanitizing surfaces), but in the case of schools | it's veered toward absurdist/tragic. | [deleted] | seventytwo wrote: | The authorities have long since stopped recommending cloth | masks and surface cleaning. Anyone still applying or | recommending those methods isn't up to date. | | There's nothing farcical about recommending cloth masks and | surface cleaning during the first few months of the | pandemic when nothing was known about how the virus spread | and when masks needed to be reserved for those on the front | lines. | | The only farcical piece is how our society reacted to the | recommendations of the experts. | roughly wrote: | > Anyone still applying or recommending those methods | isn't up to date. | | That's why it's farcical. In my area, you're required to | wear your mask when you enter a restaurant and keep it on | until you reach your table. Employees spend 8 hours | breathing in the building through a cloth mask. Many | places are still serving using single-use dishware to | "stop the spread". Many people are still walking around | with gloves on. | | I'm not saying these were bad recommendations at the | time, but they've turned into talismans and rituals we do | to ward off the evil spirit of COVID while people broadly | go about their lives as before. | | Meanwhile, things like updating and repairing HVAC | systems or restructuring buildings to maximize airflow, | which both actually address COVID and have actual | positive effects on health and wellbeing get short | shrift, because we're wearing masks, so we're safe, and | doing real work is expensive. | henrikschroder wrote: | > The authorities have long since stopped recommending | cloth masks | | That depends completely on where you live, there are | plenty of places that still have indoor or outdoor mask | mandates, despite them being completely useless. | seventytwo wrote: | Those local regulations may not be using the best | recommendations, either. There's been plenty of cases of | locales not using the best guidance. | | My point remains. | [deleted] | spqr0a1 wrote: | HEPA filters were developed for radioactive dust during the | Manhattan Project. Only several years later did the technology | get declassified and started being used in biology and | medicine. | jpe90 wrote: | It's not surprising if you understand how HEPA filters work, | the particulate sizes that they're effective for, and the | particulate sizes of viruses. Most people are not familiar with | one or more of those things, so these stories are worth | amplifying to the end of the earth and back, so that we can be | better prepared to deal with this pandemic and the next. | whiddershins wrote: | Obviously. | | So what would've happened if we had created a zillion jobs | installing air filtration to create healthier workplaces across | many dimensions (not just Covid) instead of paying people to stay | home? | AreYouSirius wrote: | WRONG ! | | You are force to think this way ! | | BUT | | What if you asked hospital staff if those ventilation unit in | ICUs do have filter inside or they just recycle indoor infected | hospital air and just add clean oxygen ??? | | so basically if you get into hospital and they hook you up onto | ventilation unit, you will increase virus load inside your | lungs because all those viruses you exhale are not filtered and | you will inhale them later. | | So just imagine how much is ventilation hookup in hospital good | and how much is bad for you !!! | | not talking about HVAC, im talking about medical equipment | directly pumping hospital air into your lungs. | smiley1437 wrote: | Do you have a time machine to bring this bit of information | back in time? | | And, would anyone have believed you? | | Many things are obvious in hindsight. | AreYouSirius wrote: | no hindsight needed, why are all those millions of people | wearing masks ? because WE ALL know filtration WORKS. | whiddershins wrote: | We had the information. It's why we didn't have huge | outbreaks related to planes. | | Anyone who looked into this, including me, knew this more | than a year ago. | nprz wrote: | Someone made an interesting point that we got rid of cholera by | drinking cleaner water and that we'll get rid of Covid by | breathing cleaner air. | felipellrocha wrote: | wut? | drzaiusapelord wrote: | You won't often catch covid from stray particles but from the | person breathing next to you, which these filters can't help. | This study was in a hospital where everyone is wearing serious | PPE, so its a super edge case to get rid of covid in the air | because the main use case of catching covid has been handle by | plain old PPE. | | This doesn't have sweeping applicability. It won't stop covid | among the general population. Its for maybe hospitals that are | on super covid lockdown that want a little more protection for | their most vulnerable patients. | | We get rid of covid through mass vaccination like any other | virus. There's no shortcuts for those who refuse masks and | vaccines. | dmix wrote: | > "This study suggests that HEPA air cleaners, which remain | little-used in Canadian hospitals, | | What, they are "little used"? I'd assume that's the first place | that would have adopted them. So strange how some hospitals | operate. | mmastrac wrote: | I suppose the cost of installation outweighed the minor | inconvenience of colds and flus spreading in the past. Only now | that we have a deadlier virus does it make sense. | trutannus wrote: | Most likely. Canada also has a habit of under-spending on | healthcare in general. The system is also hypersensitive to | political whims and can end up getting neglected as a result. | This is because the provinces have direct control over every | aspect of the healthcare system, and set the budget for them | directly. | | Unlike other nations like Germany and Estonia, Canada's | healthcare system is fully dependent on the provincial | government to exist and be funded. If I'm not mistaken, in | the two countries I mentioned, clinics can get private | funding while providing universal access in most cases, which | means they have a larger buffer between the political whims | of the state, and their ability to provide service. If the | state under-provides, the clinics can seek investors to cover | the new costs, all the while maintaining universal coverage. | | That's not something Canadians can do. Talk of any private | involvement, or restructuring in general, in Canada's | healthcare system is often very politically charged and not | particularly honest, so change is not happening any time | soon. | | I suspect the issue here is that the hospitals know that | having HEPA filters would be a good idea, but political will | isn't there to give them what they need. Canadian politics on | both sides lately has been more about the appearance of | progress through large gestures, rather than careful | consideration of long term solutions. It's very unfortunate. | jleyank wrote: | Have you lived any length of time in Canada? If so, where? | While I have been fortunate enough to not have needed to go | to hospital, my dental office reopened after the initial | lockdown last year with a HEPA filter, doorway screen and | other paraphernalia which made each workarea look like a | clean room. And they shifted from water to air-driven | cleaning and dressed like sci-fi actors. I would imagine | the hospitals were similar due to the stress put upon them. | Anecdotally, my wife had a breathing test in hospital a few | days ago and they checked vaccination status and accepted | the mask she walked in with. | | Given that the federal government is responsible for | funding much/most of the provincial health care system, | they have some input into how things operate. Most | provinces have a good handle on covid unless their | government went too deep into the "covid is over" bit | (Alberta, Saskatchewan). The covid response here was | delayed due to the need to secure vaccines from others, but | the end result has been quite good. | | I have lived all over N America, and the | freedom/flexibility of the Canadian health system has been | better than anywhere except St. Louis, MO when I was there | - and that required full-time employment. | trutannus wrote: | > Have you lived any length of time in Canada? | | Yes, I am a Canadian. I lived there for 25 years. I have | Canadian citizenship. Most of my family still lives | there. I also ended up stuck in Ontario for most of | COVID. I have family in Ontario, in Quebec, and elsewhere | in the country. I don't think Ontario had a very good | handle on COVID. It's also no secret that Canada is | suffering a major staffing, and funding shortage in the | healthcare sector right now. | | While most of your reply is about dentists (I'll get to | that later), I see you're comparing Canada's healthcare | system to the USA. I'm not. Compared to other systems in | NA, yes, it's much better since it's free and somewhat | fair. But that's the problem. Canadians should be looking | to other developed nations with public healthcare. Not to | the United States which operates on a completely | different paradigm. My comment that you're replying to is | entirely contrasting Canadian healthcare with EU systems, | not Americans. | | > dental office reopened | | The majority of dentists are private entities, and are | not subject to the same funding rules as hospitals. | They're not licensed through the same entities, funded, | or managed in the same way at all. Likely why they were | able to adapt so quickly. See: https://www.cda- | adc.ca/stateoforalhealth/servicescanada/ | | > [..] they checked vaccination status and accepted the | mask she walked in with. | | I'm not really sure what you're getting at here, this | does not really relate to funding, or anything I'm | talking about really. This is more about safety policy, | not funding, which is what I'm trying to discuss. | | Don't get me wrong, I've had some good experiences with | the system as well, but that does not mean it shouldn't | _significantly improved_. | jleyank wrote: | The masks might have been after seeing a different | comment, sorry. The problem with improving the system is | that 1/3 of the country seems to want the US system in | healthcare and probably (lots?) of other things. So it | goes. Re: Ontario, I was looking at Ottawa specifically, | the province generally and while it's "blessed" with a | Conservative premier he's taken more medical advice (or | indulged his populist leanings) more than other such | premiers. Canadians, for the most part, are willing to | play along which also helps. | overton wrote: | Early on in the pandemic, the Canadian IPAC (Infection Control | and Prevention) establishment came down hard against theories | of airborne COVID transmission, at first even going so far as | to not recommend masking. Even now that the science of airborne | transmission has been established, they're waging a rearguard | battle to obfuscate/deny it and airborne protections such as | better ventilation and masking. If you go to a Canadian | hospital wearing an N95 these days there's a good chance they | will insist you to take it off in favour of a "clean" surgical | mask with gaps around the sides and nose. | berberous wrote: | N95s often have exhaust filters which make a surgical mask | safer for everyone else around you. | coralreef wrote: | > If you go to a Canadian hospital wearing an N95 these days | there's a good chance they will insist you to take it off in | favour of a "clean" surgical mask with gaps around the sides | and nose. | | Wouldn't that just be because of protocol, ie. they don't | know if you, a member of the public, actually have a legit | N95 mask, or if you know how to correctly implement it, etc. | agustif wrote: | Is a surgical-mask better than a fake N95 mask? | Animats wrote: | _actually have a legit N95 mask_ | | Incidentally, if you want to validate 3M N95 masks, 3M has | a web site for that.[1] You type in the code on the bottom | of the box and 3M checks it. You can only do this once per | code; the site will tell you if a valid code has been used | before. They suggest signing and dating the box after doing | this, to indicate that check has been done. | | [1] https://www.3m.com/3M/en_US/worker-health-safety- | us/3m-safeg... | jbay808 wrote: | > If you go to a Canadian hospital wearing an N95 these days | there's a good chance they will insist you to take it off in | favour of a "clean" surgical mask with gaps around the sides | and nose. | | Happened to me many times. Sometimes they let me wear it over | my (certified) N95, sometimes they don't. | jdsully wrote: | Having some experience with hospitals and N95 they asked that | we put a surgical mask over the one we came with. Pointless | and unnecessary but I guess it's easier than having staff | validate the mask your wearing. | | They never required we remove a mask. | makomk wrote: | Airborne transmission and the usefulness of filters still | doesn't seem that clearly established - this study didn't | find that much virus in the air even without the filters, and | most of the real-world transmission seems to involve people | who were directly exposed to virus particles before they even | had a chance to go through a filter, via standing next to | someone or directly in an airflow path coming from their | direction. | clairity wrote: | thanks for pointing this out. it gets lost in the fervor of | trying to "fight the virus". most of our interventions are | useless, and yet, we still insist on doing them. the virus | just isn't aloft and active for very long. that's why the | most dangerous activity is _close conversation_ , something | we tend to do around people we know well (friends & | family), not strangers in public. ___________________________________________________________________ (page generated 2021-10-09 23:00 UTC)