Installing air filters in classrooms has surprisingly large educational benefits (2020)
145 comments
·March 31, 2025Aurornis
AngryData
I would also think there is a bias of schools spending extra money and effort towards student improvements if they are willing to go so far as allocate funding for air filtration systems. A better method would be to just give some schools air filtration for free and see if things help without any other major changes.
To me its like looking at schools that buy newer buses and trying to show new buses improve test scores. When in practice the only schools that are buying any significant number of new buses have far more money coming in than in the past and have a lot more to spend on students compared to other schools, which is way more relevant than what year a kid's bus is made. Maybe better buses would improve scores too, but there is no way to tell if 95% of an improvement is due to other unrelated factors based on funding.
Aurornis
> A better method would be to just give some schools air filtration for free and see if things help without any other major changes.
This is what the study looked at.
The problem was that it wasn’t randomized within schools or across teachers. They also looked at a very limited time window. They also note that some teachers weren’t using the air filters. They also found that the VOCs they were trying to filter weren’t even detected before the filters were used. They also used some questionable regressions to imply larger trends.
The list of problems goes on and on. It’s fascinating how easily people are tricked into pivoting around this one study, though, simply because it’s the one introduced by the headline.
jancsika
> They also looked at a very limited time window. They also note that some teachers weren’t using the air filters.
To correct and clarify:
They also looked at a very limited time window. They also note that-- after this very limited time window-- some teachers stopped using the air filters. In the words of the authors, this made long-run results "difficult to interpret."
stdbrouw
I would also expect the estimated magnitude of the effect to go down over time, but that's just my general attitude to these kinds of things, the fact is that the discontinuity design that they use already accounts for variations between classes, teachers, schools, years. The way it works is that some unexpected event that applies to some people but not others is taken to represent a natural experiment, and then variation between groups before the event is compared to variation between groups after the event. The comparison is never against no variation.
The smoking gun is really in Table 3 and Table 4, where you can see that the effects that were observed are compatible with a population effect of 0, or alternatively you can look at Figure 2 and note that you could draw a straight line (no effect) within the confidence bands. Doesn't mean the effect is not there, but that there's insufficient evidence that it is, and that we should indeed be very careful about taking the estimates at face value.
mmooss
Based on your comment, the effect could be larger as well as smaller.
All research is met on HN by people who know better and will tell you why it's flawed. There isn't a greater collection of expertise in the history of the world than on HN.
Edit: I meant to add: What value can we find in this research? It wasn't published as scripture, the perfect answer to all our problems. It's one study of some interesting events and data; what can we get out of it?
Aurornis
> Based on your comment, the effect could be larger as well as smaller.
The reality of any underpowered study could always be “larger as well as smaller”. This statement doesn’t add anything to the conversation.
The mistake is pivoting around poorly structured and underpowered research.
> All research is met on HN by people who know better and will tell you why it's flawed.
This is a misunderstanding. People who know how to read studies will always be aware of the limitations.
There’s a difference between saying “everything is flawed” and pointing out the limitations. Most early research comes with significant limitations like small sample sizes or large cofounders. You have to understand these in conjunction with the results to know how to interpret it.
There’s a cynical approach where people see discussion of limitations, don’t understand it, and instead go into a mode where they think it’s smarter to ignore all criticisms equally because every paper attracts criticisms.
This is just lazy cynicism, though. There are different degrees of criticisms and you have to be able to see the difference between something like a slightly underpowered study, and something like this paper where the authors threw a lot of regressions at a lot of numbers and kind of sort of claimed to have found a trend.
TheOtherHobbes
In this case, it only takes a few seconds to find multiple studies confirming the effect.
For example
https://onlinelibrary.wiley.com/doi/10.1111/ina.12042
https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0668.2010...
mmooss
[flagged]
conformist
Conditional on “the study being published and getting attention” the real effect is likely smaller and not larger.
Eg if you assume there is a real effect plus a lot of noise, given the study has been published etc the noise will have more likely acted in the favourable direction.
IMHO given the relatively large size of the effect it seems quite likely that the noise part is in fact potentially large (this is much more subjective) which makes is less clear that there is measurable signal at all here. I’d have to see a lot of replication or a very strong explanation of the underlying mechanism to believe the magnitude of the effect, but will very easily believe the sign (with a small magnitude).
graemep
> All research is met on HN by people who know better and will tell you why it's flawed
It is almost certainly flawed, and it is probably wrong: https://journals.plos.org/plosmedicine/article?id=10.1371/jo...
If you are discussing research at all it is important to discuss the flaws too. The alternative I can see would be to take every published paper as proven true even though we know this is not the case.
bawolff
Science succeeds when people lean towards the side of cynicism instead of optimism. Scientific research should be read critically.
mmooss
Critical thinking and skepticism are good, but much of what happens on HN is not that.
Thinking critically includes, most of all, finding value - you need to think critically (and skeptically) to avoid assigning value to things that don't have it, but you must find value. The goal is to build knowledge - just like the study author needs to find knowledge among flawed data, you must find knowledge among flawed studies - and they are all flawed, of course.
Focusing on the flaws and trying to shoot down everything is just craven recreation.
LorenPechtel
Things which reach the level of getting on here are basically always outliers. And is the outlier real or a false positive? There's a huge selection bias towards the false positives.
robertlagrant
> All research is met on HN by people who know better and will tell you why it's flawed. There isn't a greater collection of expertise in the history of the world than on HN.
It seemed like a pretty valid criticism. These studies should be taken with a massive pinch of salt because they're fairly uncontrolled.
eru
> Based on your comment, the effect could be larger as well as smaller.
Yes, but since we know that there's a huge bias to publish and publicise larger results, you know what way to bet.
im3w1l
Installing air filters is an intervention that has a cost and thus needs to be verified and proven. You don't roll such a thing out on a broad scale based on "the effect could be large".
dzhiurgis
I find it bonkers we have better regulation around growing battery chickens than growing kids.
You don’t need massive study to find out that kids don’t like suffocating in classrooms.
It’s a bit like mandating reversing cameras on cars. Study says economically they do not make sense, but not squishing your kids trumps that.
7thaccount
I'm a big fan of air filters and have many in my own home that have made a big difference in quality of life as I live in a high pollen area. They can help with a lot more irritants as well that some students may be sensitive to (i.e., some students may study better if their immune system isn't in overdrive for half the school year like mine was). I'm not sure how these would help with natural gas though. I can't read the article due to paywall. Some VOCs can be filtered out (at least I think) with a baking soda filter ...those have to be changed more often than the HEPA filters (at least on my model that has one). Again, that should help with some scents (a major issue for me - even the dishwasher running can cause problems for me), but it isn't going to help if there is a gas leak (not sure if that is what the article is suggesting).
pizzly
I'm not sure what it was but I remember learning where with a continuous runny noise in certain classes (buildings) with AC. Outside and different buildings were fine at least for me. In those effected buildings I estimate that 5% were also effected by hearing people sniff every minute or so. This definitely caused distraction while learning. A good filter on the AC would properly have solved this.
LorenPechtel
The gas was long gone, it wasn't being filtered.
However, I don't see that it proves pollution is the cause. What about infection? Air filtration can reduce the spread of pathogens. Schools throw together a large pool of people, the bug of the day will go around. Less if there are good filters.
maxerickson
The article and study are both explicit that natural gas wouldn't have been an issue (the leak was fixed and the gas was gone). The impact from the filters would be from other indoor air pollutants.
7thaccount
Thank you!
evil-olive
> but I also think the extreme results from this study aren't going to hold up to further research.
there already is further research. and the results do seem to be holding up.
the study you're quoting from is the one linked in the 2nd paragraph of the article. this is from the 3rd paragraph:
> But it’s consistent with a growing literature on the cognitive impact of air pollution, which finds that everyone from chess players to baseball umpires to workers in a pear-packing factory suffer deteriorations in performance when the air is more polluted.
that paragraph links to an earlier Vox article [0] which goes into more detail, and well as linking to all of the various studies:
> A wide range of studies about the impact of pollution on cognitive functioning have been published in recent years, showing impacts across a strikingly wide range of endeavors. Stripe CEO Patrick Collison has taken an interest in this subject and compiled much of the key research on his personal blog. Among the findings he’s highlighted include:
> - Exposure to fine particulates over the long term leads to increased incidences of dementia and Alzheimer’s disease in the elderly (a second study confirms this).
> - A study of 20,000 older women found that 10 micrograms of additional long-term particulate exposure is equivalent, across the board, to about two additional years of aging.
> - The impacts are not limited to the elderly, however, nor are they exclusively long-term. A range of specialized professionals also seem to suffer short-term impairment due to air pollution. Skilled chess players, for example, make more mistakes on more polluted days. Baseball umpires are also more likely to make erroneous calls on days with poor air quality. Politicians’ statements become less verbally complex on high-pollution days, too.
> - Ordinary office workers also exhibit these impacts, showing higher scores on cognitive tests when working in low-pollution ( or “green”) office environments. Individual stock traders become less productive on high-pollution days.
> - The same also appears to be true for blue collar work. A study of a pear-packing factory found that higher levels of outdoor particulate pollution “leads to a statistically and economically significant decrease in packing speeds inside the factory, with effects arising at levels well below current air quality standards.”
> - Last but by no means least, the cognitive impacts appear to be present in children, with a Georgia study that looked at retrofits of school buses showing large increases in English test scores and smaller ones in math driven by reduced exposure to diesel emissions.
0: https://www.vox.com/future-perfect/2019/12/11/20996968/air-p...
Aurornis
> there already is further research. and the results do seem to be holding up.
You’re conflating different results.
The results of the headline study are dramatic in ways that aren’t holding up. The test score increase happened after a single year of putting air filters in class rooms. That’s minimal exposure to purified air for a fraction of the day, 5 days a week, for less than a year of classes.
The other studies are much longe term and look at things like decades of exposure at city scale.
Do you see the difference? The study tried to claim that purifying air immediately improved test scores by dramatic amounts.
There are other serious limitations in the study, like the fact that they can’t even identify which air purifiers were installed or how effective they were. There’s a footnote that says many weren’t even used. There’s a section on air quality monitoring that says they didn’t even detect the VOCs they were trying to filter before they started filtering.
This is the type of study that people implicitly believe because it makes logical sense, but when you read the details you realize that there isn’t much substance in it.
fc417fc802
> The other studies are much longe term and look at things like decades of exposure at city scale.
Are they? Several towards the end of the list are specifically about short term day-to-day effects across a range of situations.
> There’s a footnote that says many weren’t even used.
Quite damning if true.
> they didn’t even detect the VOCs they were trying to filter before they started filtering
That is confusing the reasoning that led to the company footing the bill versus what was being looked at here. The lack of VOCs is actually in the author's favor as it eliminates "exposure to atypical VOCs" as an otherwise fairly severe confounding factor.
facile3232
> but expecting test scores to improve dramatically like this is not realistic
That seems like a problem for the reader, not a problem with the text. Why would the reader expect this? Is it the use of present tense in the title rather than past tense?
Aurornis
What do you mean? The article implies it from the title through the text.
They hedge by saying “could” but like most articles in this vein it goes on to pivot around the outlier study.
facile3232
Ah! I just skipped the article. The paper is much more straightforward.
xattt
If anything, schools able to implement air filtration and fresh air exchanges systems are likely those flush with cash and supportive parents.
permo-w
in this case the filtration systems were installed on the dime of a local natural gas company after a leak, although that was as a result of the interference of interested parents
dzhiurgis
These systems are not that expensive and save money.
If parents would be allowed to contribute towards it like a 10year bond it would pay for itself…
xwolfi
And the resulting backlash 10 years down the line ? I don't think science should be used that way: who would trust it eventually ?
Would you support a small study saying a medicine or a vaccine produces a 20 year life expectancy increase, all that to end up 20 years later with no improvement, everyone on that medicine, and the anti-everything yelling on every platform that the big pharma lobby poisoned our children ?
Even when the studies are on large samples, double-blind, long time range with a clear explanation as to why there's an effect, we have people trying to kill the resulting health campaigns. Don't encourage fake ones !
eru
> I don't think science should be used that way: who would trust it eventually?
There's no single party controlling 'science'. It's all just individuals many of them under 'publish or perish' rules.
calvinmorrison
only ycombinator would have a hard time with the concept of 'open the window' and instead expect a capital installment of $2B to retrofit classrooms
do_not_redeem
Do you think everyone lives in California where there's comfortable sunny temperatures and no rain 360 days a year? Classic ycombinator post
lazyasciiart
Yes, silly gas company, should just tell the local schools to open the windows and let the natural gas in.
You have heard of air pollution, I assume. Some schools are in places that regularly have polluted air.
ajb
In many areas the source of air pollution is outside. Opening windows helps with house dust and mold spores, but not with particulates from diesel, tyres or with pollen.
fasthands9
It also seems possible that students do better on tests when the air is cleaner, but that doesn't necessarily mean the students learned more.
Imagine if some schools installed air conditioning in their gym one year. Running times around an indoor track would improve considerably, but mostly because conditions at the point of testing improved. Not necessarily because the air conditioning made the students actually improve their stamina or speed.
rayiner
Someone writes whether the data actually shows what it purports to show: https://statmodeling.stat.columbia.edu/2020/01/09/filters-be...
> The whole thing is driven by one data point and a linear trend which makes no theoretical sense in the context of the paper (from the abstract: “Air testing conducted inside schools during the leak (but before air filters were installed) showed no presence of natural gas pollutants, implying that the effectiveness of air filters came from removing common air pollutants”) but does serve to create a background trend to allow a big discontinuity with some statistical significance.
I’m reminded of the walkback of scientific studies showing massive benefits from giving kids in third world countries deworming medications: https://www.theguardian.com/society/2015/jul/23/research-glo....
My beef with Matt Y.’s worldview of “scientifically driven public policy” is that the costs and benefits of public policy interventions are so devilishly difficult to study that you can’t meaningfully use them on realistic time scales to drive policy. This is an exceedingly simple hypothesis—filtering air improves test scores—that can easily be tested while controlling for confounding factors. But even then it’s hard!
rnjailamba
Andrew Gelman: "No, I don’t think that this study offers good evidence that installing air filters in classrooms has surprisingly large educational benefits." https://statmodeling.stat.columbia.edu/2020/01/09/no-i-dont-... (Adding this older link here for cross reference)
A thread on Gelman's article is here: https://news.ycombinator.com/item?id=22006595.
sudoshred
The material impacts associated with the recommendations a study makes can influence the results in a way that does not favor objectivity.
Analemma_
The study itself is pretty explicit that it is just one encouraging case study which the authors believe merits follow-up research, rather than something conclusive. Matt Y's reporting isn't as forthcoming about this as it probably should've been, but he does also say the same thing at the end. He sort of buried the lede but didn't lie or anything.
rayiner
I'm not accusing Matt Y. of lying. I like him and subscribe to his Substack. I'm just saying that the article illustrates the shortcoming of his approach to public policy. His data-driven approach to public policy is based on an overly optimistic view of reliability of the data.
amluto
I wish there was more data on the effects of gasses in the air on people.
We seem to know:
- Elevated CO2 in rooms impairs cognitive performance.
- Elevated CO2 in submarines, at levels far higher than you would see in a normal room does not appear to impact cognitive performance.
- Installing carbon filters (what this study actually looked at) might improve classroom performance.
- People don’t like stuffy rooms.
All this is consistent with multiple hypotheses. It could be that we just don’t know anything about it. Or maybe there is some gas or gasses emitted by people that isn’t CO2 that makes people mildly uncomfortable and have worse cognitive performance.
CO2 is certainly a good proxy for ventilation quality in a space where air is exchanged with outdoors but where the gasses in the air are not otherwise changed. Carbon-filtered classrooms and submarines are not examples of this.
jedc
(Former submariner here.)
Elevated CO2 in submarines absolutely impairs performance. One example: there was a guy on my boat who got migraines when CO2 got too high - he was useless. Luckily the fix is simple - just turn on another CO2 scrubber.
There's nothing special about a submarine that makes CO2 somehow different than anywhere else.
amluto
I recall this study and maybe another one:
https://pubmed.ncbi.nlm.nih.gov/29789085/
I’m definitely not an expert.
4gotunameagain
What if you're low on sorbent and can't turn on another scrubber ?
I wonder if sorbent quantity correlates with performance
frognumber
CO2 is a proxy for many other gasses. Cheap CO2 sensors sense volatile organic compounds (VOCs), and use those to estimate CO2.
Many of those gasses do impact cognitive performance. It's not obvious to me why CO2 would, but if CO2 is going up, so is everything else we breathe out. CO2 where I am is somewhere in the ≈400ppm-1000ppm range -- 0.04% or 0.1% -- and it's pretty inert. I'm not sure what harm it does.
If it does to harm, rising CO2 levels should be much more concerning than "just" climate change.
But I suspect it's other gasses.
vlovich123
Rising co2 levels I believe are nowhere near the differential inside vs outside when windows are closed. There’s lots of reason to believe that rising co2 specifically lowers cognitive performance - our brains work on o2 and our body actively works to expel co2 as a waste product - increasing co2 levels means the body has less O2 available and has to work harder on co2 expulsion for survival instead of powering the brain.
LorenPechtel
Crowding out O2 isn't going to be meaningful, the amount of CO2 is simply too small. If there's an effect it's from reducing the rate at which the body can expel the CO2.
If crowding out O2 was relevant why do I feel the same on our local mountain at 10,000'+ vs 0'- in Death Valley? To crowd out that much O2 with CO2 would be lethal. (That's not to say that my performance is the same. There's a big difference in the heart rate I can sustain.) What we feel is the CO2 level in our blood rising because it isn't diffusing into the lungs. Lowering O2 is only detectable with training and that's based on noting the symptoms of oxygen deficiency on brain function. (Such training is relevant in the world of aviation where it might give warning that you need to grab that oxygen mask. The average person will never encounter such conditions, nor have the resources at hand to make use of the knowledge even if they did realize it.)
frognumber
This is not quite correct.
1) CO2 levels have risen from under 300PPM in 1860 to over 400PPM right now -- by around 150PPM -- with a rise of about 25PPM per decade for the past four decades.
The difference in CO2 levels in my bedroom with windows open and closed is a couple hundred PPM (500-800ppm range in my bedroom, with windows open and closed, respectively). I can definitely feel a difference in performance if I don't let in fresh air. It's more than climate change (300ppm versus 150ppm range), but not big-O more, and climate change is on-track to get there in another few decades. Conference rooms might be over 1000ppm, but it still big-O similar.
2) CO2 levels are measured in parts-per-MILLION. That argument simply doesn't make sense. The atmosphere is 21% oxygen. Crowding out oxygen is simply not an issue. Critically, from personal experience, if I have some dry ice in a room, I generally don't suffer.
People run into problems when CO2 levels reach a out 5000 ppm over many hours. Even the most dense conference rooms don't hit that.
jwpapi
Personal anecdote getting an airthings that reminds me to open the window (along with a pushover api setup) has probably been the biggest productivity improvement in 10 years.
Cthulhu_
It's kinda worrying you need an app / appliance to remember to open the window. Rule of thumb is to have the windows open at least 10 minutes a day, every day.
LorenPechtel
You realize a lot of us live in places where that would be very expensive? Not to mention that the HVAC plants are usually not sized with that in mind.
socksy
Why is opening the window expensive? Climate control?
tangjurine
>For a sense of scale, Mathematica Policy Research’s best evidence on the effectiveness of the highly touted KIPP charter school network finds that after three years at KIPP there is significant improvement on three out of four test metrics — up 0.25 standard deviations on one English test, 0.22 standard deviations on another, and 0.28 standard deviations on one of two math tests.
I wasn't sure what .22 std deviations meant, so I looked stuff up a bit. For a normal distribution, going from the average to 1 standard deviation above is going from the 50th percentile to the 84th percentile. Going up .22 standard deviations from the average is going from the 50th percentile to about the 55th percentile.
aetherspawn
I’m so confused why they installed HEPA filters to filter out LNG and methane.
And HEPA filters don’t really scrub CO2 that effectively, even with a carbon membrane, so can we really expect lower CO2 levels?
Considering this, what’s the actual takeaway here? Cleaner air (dust/virus free?) is better for productivity?
I am asking because I want to buy the same filter for work, but I am doubtful that the $700 HEPA filter sounds like the same filter they used, even though the article mentions they used readily accessible 5 stage filters.
amluto
Having tried to dig into this a while ago, they installed carbon filters.
Most of the stuff for sale as “carbon” filters has too little carbon to do much. You want quite a lot, and, for some gasses, you can get special impregnated carbon or other media.
aitchnyu
Tangential, are there DIY methods of activated carbon? I got pellets, impregnated sheets and a packaged one for my air purifier, but I dont know when they are helping and when they are exhausted.
schiffern
To tell when carbon filters are exhausted, the best way is to use an indoor VOC monitor.
Air filter AC is specially prepared, so making your own DIY charcoal (while possible) isn't nearly as effective. You can mostly regenerate/desorb the carbon by heating it to 400F. Never use your regular oven though, not least of which because it reeks. Get a cheap toaster oven and disposable foil pans and do it outside, in a location where it can't possibly catch anything on fire.
tangjurine
I'm guessing someone had a hunch and wanted to buy some HEPA filters. Also, all HEPA filters should filter air similarly, the price should be based on the rate at which air is filtered. I bought a HEPA air filter for $150 for my room.
sokoloff
There are ratings spanning H10, H11, H12, and H13 for HEPA filters.
craigdalton
There are well established hierarchies of evidence in health studies and this study would rank as low quality evidence due to inability to control for other factors. See https://gdt.gradepro.org/app/handbook/handbook.html#h.3183vu... for background.
In studies of pollution and impacts on health, the confounding factors often have a larger impact on the health outcome than the pollutant, such as particulate level, and therefore significant control of confounders is required to estimate any impact on the health outcome. The strong effect in this study is highly suggestive of a confounder rather than a real effect from particles or other pollutants and therefore would require a much better study design to support tacking action at a policy level with an expectation of a huge impact.
Fine to put filters into improve overall air quality but just not with the benefit rationale suggested in this study.
fifteenforty
Also, turns out preventing kids from getting sick improves educational outcomes.
sheepscreek
My dad made a similar observation, assuming the children were young. However, upon reviewing the article, I noticed it doesn’t explicitly mention the grade level. Considering younger children have weaker immune systems, this could potentially lead to fewer missed classes and improved grades. Personally, my first grader misses out on a considerable number of classes.
However, if these results were observed in grades 3 or higher, it could suggest a more substantial phenomenon. I randomly picked the third grade, but perhaps there’s a specific age after which the medical community considers a child’s immunity to be significantly enhanced.
fifteenforty
Ventilation and air purification have a strongly theoretical basis and there have been real-world studies showing a clear benefit.
permo-w
do younger children have weaker immune systems?
LorenPechtel
It's not that they are weaker, but that many things actually confer long term immunity. The "common cold" is actually many viruses, once you've beaten one it's not likely to get you again but it's cousins will.
Balgair
Not as much as their immune systems haven't been around very long and seen as many diseases.
xwolfi
But then, what about being protected from sickness from a young age, to end up sick all the time as an adult ? You had a better education, we can agree, but your body got weaker as a result and now you can't be as productive as an adult.
I exaggerate a bit, but I found that during covid, where the mask was mandatory in my place, I was never sick. The only few years in my life where I was actually healthy continuously for YEARS, I and my friends could not believe the impact of the mask. But then we were stuck at home, living in constant misery and stress.
Once the masks disappeared, finally we could live again, and got extremely sick the first few years... Maybe a more normal balance would have been better ? Sick a bit continuously ? I think trying to avoid sickness is like trying to swim against the current, nature just works that way.
fifteenforty
I just keep wearing an N95. I've had maybe 3 infections in 5 years.
tehjoker
getting sick is bad for us. we should clean the air. i’ve been wearing n95 indoors for years, 1 cold (neg for c19) in 5 years
Balgair
Anecdote: Our daycare was a plague ship right after covid 'ended'. None of the kids had any immunities, and they made up for it in a hurry. Man, what a terrible year.
As a result, the daycare got a grant to get N-95 air filters installed and those UV lights that Chinese restaurants tend to have in the bathrooms. One per room.
What. A. Difference.
The infants and kids coming up are not nearly as sick, and when they do get sick, it's not nearly as terrible. The RSV vaccine has also been a godsend.
I can't really tell/feel what what the silver bullet here, but the combinations have been amazing. So much so that we got them for the house.
HPsquared
I wonder how much of the improvement was due to reversion to the mean. When bringing everyone back, you would expect a sharp peak of infections which would decay to normal levels after a while - filters or not. I'm sure they do still have some positive effect though.
Balgair
Anecdotally: it was a big effect.
Rigorously: no way to tell now, the time has passed.
Likely: you're right. But what little staff is there from pre-covid says that they have helped a lot too.
Reality: here's $500/wk and my kid, in return I get really sick for a year no matter what.
LorenPechtel
What lights are you talking about? UV capable of disinfecting isn't something you want to be looking at. (Are you perhaps thinking of the bug-zapper lamps that are sometimes described as UV? Way up at the top of the visual spectrum, a lot of bugs go for them. But they're just a lure to get the bug between the high voltage wires that actually kill it.)
The only disinfecting UV lights I've heard of for use in occupied areas are hanging things that only point up where nobody's going to be exposed. I have heard of some research for safe UV lights that are high up in the UV, they actually still burn but without enough penetration to get through the dead skin layer.
throwaway2037
Nice story. I can believe it. I was surprised that you mentioned the RSV vaccine. Last I checked, they were still working on it. I was wrong: There are three competitors now: (1) Arexvy (GSK), (2) Abrysvo (Pfizer), and (3) Mresvia (Moderna)
Ref: https://en.wikipedia.org/wiki/Respiratory_syncytial_virus_va...
Normally, I use this clinic in Thailand to compare prices for vaccines: https://www.thaitravelclinic.com/cost.html
The RSV vaccine is crazy expensive, even more than the HPV one. Over 200 USD is incredibly expensive in a developing country (like Thailand).
> those UV lights that Chinese restaurants tend to have in the bathrooms
theoreticalmal
Only marginally relevant, this is one reason I use swamp coolers in my home. My windows are open 24/7, 4 months of the year. I hear the birds in the morning and it’s so much more pleasant than shutting in an air conditioned box, in my opinion
meroes
Do you not get massive amounts of dust?
mmooss
Why would opening the windows result in dust, except where there a lot of dust outside (near a construction site)?
wahnfrieden
Having any roads/cars around is a major problem. Brake and tire dust. Many people live near roads and traffic.
bluGill
swamp coolers work - imples desert - implies dust
Mistletoe
Does the humidity not cause problems? What is the relative humidity in your home?
SoftTalker
I'd guess somewhere dry. Swamp coolers don't really work in humid climates.
IneffablePigeon
Unlikely to be a problem if the windows are open, in most climates.
amai
Many air filters are generating annoying sounds. You get better air, but the distraction by the constant noise of the filter might be more than counter productive.
brody_hamer
My first thought was the exact opposite. Ambient noise in classroom (from other students) can be very distracting, and I wonder if adding white noise helps kids to focus (in the same way that accoustic dampening would)
yoshuaw
A study published just yesterday [1] showed that just two airborne diseases [2] were responsible for approximately 85% of all sicks days in Greece during 2023-2024. Disregarding the common-sense argument that reducing collective suffering is a good thing overall - even by the cold hard logic of capital, being able to reduce company sick days by up to 85% is a huge opportunity.
Imo we're way overdue standards and controls for clean indoor air that are on par with standards for drinking water and food. Like this article shows, we have the tech to provide clean air today. All we're missing is policy to uniformly deploy it.
[1]: https://www.sciencedirect.com/science/article/abs/pii/S01966...
[2]: SARS-CoV-19: ~75% of sick days, Influenza: ~10% of sick days
socksy
Might this be related to the fact that Greeks tend not to take sick days compared to other European countries[1]? Not coming to work because you have covid is far more culturally accepted (and maybe expected) than a common cold.
[1]: https://www.ekathimerini.com/economy/1255154/greek-work-ethi...
I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research.
From the paper:
> To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles of the leak (but not beyond). This variation allows me to compare student achievement in schools receiving air filters relative to those that did not using a spatial regression discontinuity design.
In other words, the paper looked at test scores at different schools in different areas on different years and assumed that the only change was the air filters. Anyone who has worked with school kids knows that the variations between classes from year to year can be extreme, as can differences produced by different teachers or even school policies.
Again, I think air filtration is great indoors, but expecting test scores to improve dramatically like this is not realistic. This feels like another extremely exaggerated health claim, like past claims made about fish oil supplements. Fish oil was briefly thought to have extreme positive health benefits from a number of very small studies like this, but as sample sizes became larger and studies became higher quality, most of the beneficial effects disappeared.