This article seems to make fantastic jumps from the believable -- mortality from overall air pollution (e.g. in Delhi) to the frankly unbelievable -- your ultrasonic humidifier supposedly reducing your life by nearly an hour each night, or that a daily commute between Newark and NYC takes half a year off your life.
According to this logic, anyone who works in the subway should be dying, what, 10 years earlier? Which is obviously not happening.
Similarly, it seems impossible to believe that the minerals in the air from humidifiers are equivalently dangerous to factory pollution or cigarette smoke. Different categories of particles are going to affect the body differently, no? I mean, our body requires minerals -- we're drinking them in our water all day long -- while certain factories may be belching out straight-up poison.
These statistics are just not passing the smell test. They seem to be extrapolations of extrapolations of extrapolations. This article's conclusions don't seem even remotely convincing.
"In a study on mice, researchers discovered that inhaling the dust from ultrasonic purifiers produces a cellular response, but this response lacks the inflammation and damage associated with other forms of particulate matter."
Myself, I got shocked when my air purifier suddenly started showing a huge amount of pollution (and yes, my eyes turned red). Only afterwards, I checked it was exactly because of my freshly-bought ultrasonic air purifier. Now I have an evaporative one - not as fast, not as spectacular, but better.
That's why you gotta use them with reverse osmosis filtered water. And not one that remineralizes, you can do that later on your own. I have a ultrasonic humidifier, reverse osmosis water filter and air quality sensor, it's all good.
Ultrasonic one is my first, only started paying attention to all this stuff because of 2020 and went all in, just trying to make my home a less crummy place.
This seems crazy to me. I have to dehumidify my home to keep it at 35%. Humidity is a constant battle. I couldn’t imagine paying to dump water in my air and promote mold.
Dry mucus membranes makes you more susceptible to a number of respiratory problems. If you have mold, everyone does to some extent, drying it out will just make the health problems worse as it aerosolizes the mold. Mold aside, for optimal health a level between 40-60% is advised. Allergy sufferers are especially sensitive to this.
The power draw at the humidifier will be larger, but the net power cost is about the same assuming a constant indoor air temperature. I always use filtered water for the US humidifier, but I'm reconsidering it now.
Are these humidifier particles bad at all? What does “cellular response” mean? Typically combustion particles are bad because they contain carcinogens and PM2.5 can deposit deep in the lungs.
This seems like a “PM2.5 bad no matter the source” theory which isn’t supported at all.
It's limescale, you don't want it in you lungs. Kidney stones also have some relation to it, probably not exactly caused by hard water, but they get their building material from somewhere.
I don’t think it’s generating anxiety, just creating a habit. Like washing your hands with soap after you go to the bathroom. Once upon a time that sentence might generate the response “if you’re worrying about how you wash your hands, then the worrying is what’s going to kill you!” (in actuality it was worse, the suggestion that a surgeon should wash his hands before surgery was considered offensive). But today it’s pretty automatic, not some laborious mental checklist. And if you’re in a situation without soap, generally you don’t freak out, you do your best with just water and move on.
Anyone whose health can be reasonably influenced by how you put out a candle has not been born yet. Everyone else has to deal with jobs and living circumstances that requires one to be inside all day, work strange hours, be outside in the sun all day, inhale fine dust from any kind of road nearby. There is a near endless list of similar/worse risk factors at play in one's life. Even though these risks might be provable in their damage to your functioning and there might be reasonable solutions to them, implementing them will still be insignificant. Just like how you should avoid apples because at least apples have killed people.
I have a cheap pm10 meter and ran it continuously for a few weeks. Next too cooking meat the other activity that stood out was blowing out the birthday candles. The pm10 rose to 300 and only was backs to healthy levels (below 50) several hours later. I was as surprised as you are. Next time I'll definitely open a window
Not all particles are equally toxic. If I had to guess, the smoke from a recently-extinguished candle is probably condensed wax vapor rather than PAHs and heavy metals.
I don't think condensed wax vapor has looks like the dark smoke that comes off a recently extinguished candle. I'm pretty sure it's carbon compounds from the wick.
The absolute values measured are not that high luckily. In the Netherlands at New years pm10 of greater than 1000 can be observed. I believe my outdoor sensor peaked at 900 in the first minutes of 2020. Glad fireworks were banned this year
My first thought on the candles was: If you're worried about paritculate emissions and air quality in your flat then maybe just don't burn anything in your flat.
I haven't researched that, but it always seemed entirely obvious to me that candles aren't exactly healthy in terms of air quality.
I think my follow on question would be which is better- a scented candle or a scented plug in like an Air Wick or Glade? Or are they similar and the only good choice is to have no perfumes floating in the air? I’ll gladly switch systems if there is a difference but I’d like to have something to make my house smell better.
Candle emissions have a low but known impact on your health. Plug in air fresheners don't have a known impact but they have god knows what chemicals in them. Maybe you'll get cancer at 60, maybe it would take three lifetimes of exposure to have any effect.
I genuinely can't be convinced there are people alive today that the risk of one scented candle in the home and/or plug in air fresheners are higher than the background danger of auto, industry, and just general pollution. This seems like an anxiety in search of a problem, or am I very underestimating it?
It just seems like the road in front of my house is probably more of a problem than my vanilla candle.
I once forgot to extinguish a candle before going to bed, it burned down, and produced a massive amount of soot. Their was a stripe of black suit on the wall where the candle was standing, a black spot on the ceiling, and my upper lip and nostrils were black from soot.
I'm not sure what effect on my health a one time event like this has, but if I can avoid it I will.
I think the particular bit about the subway may be informed by very recent news that the air pollution in the New York subway stations is far in excess of what anyone had inspected.
As for actual subway workers… I mean it’s not exactly a coal mine, but I would be pretty surprised if their mortality wasn’t at least somewhat measurably lower than, say, that of shepherds.
Just to point out how why this is a fairly nuanced topic, a shepherd may be breathing clean air but they're also exposed to UV radiation all day. They may have a higher morbidity due to increased skin cancer rates.
I'm no way an expert on the matter but by pure logic it's still amazes me how we survived (and evolved!) as a species for thousand of years without almost no shelter from direct sunlight and yet now (too much) sunlight exposure is seen as a cause of death. I know we lost almost all the body hair we used to have but still, we usually wear clothes when under the sun.
Maybe, if China would curtail their CFC usage perhaps.
...A recently reported slowdown in the decline of the atmospheric concentration of CFC-11 after 2012, however, suggests that global emissions have increased...
We show that emissions from eastern mainland China are 7.0 ± 3.0 (±1 standard deviation) gigagrams per year higher in 2014–2017 than in 2008–2012, and that the increase in emissions arises primarily around the northeastern provinces of Shandong and Hebei. This increase accounts for a substantial fraction (at least 40 to 60 per cent) of the global rise in CFC-11 emissions.
Moving to the country and being outside for 8+ hours of the day finally made it clear that cowboy hats, sombreros, etc. don't have wide brims just for fashion.
This was my thought. Traditional clothing for people who live and work outdoors in sunny climates generally does not feature a lot of exposed skin. I'm pretty sure that the "shorts and a t-shirt" summer wear is a fairly modern phenomenon.
Evolution (and survival) only cares about if you survive to reproduce. So human evolution (and survival) matters only until 14-40, and humans aren't dying of skin cancer at exceedingly large numbers at those ages.
If we pushed back the reproductive age we'd eventually evolve to live longer (though would have more people dying without reproducing first). This experiment has been successfully shown in fruit flies.
> So human evolution (and survival) matters only until 14-40
Not necessarily. I'd imagine it helps the survival chances of your grandchildren if you're around when they're growing up (though it probably mattered less back when children were raised by communities than in the nuclear families we have nowadays).
Sure, it would have helped homo sapiens even more if more of their children had lived to childbearing ages (if, say, they'd discovered antibiotics a few millenia earlier or evolved more natural immunities). But the infant survival rates back then were enough to ensure the species survived, just like the smaller fraction of the population struck down by skin cancer every year wasn't enough to put evolutionary pressure on us to develop resistance to it or develop sunlight avoidance traits. Evolution doesn't guarantee that every possible beneficial adaptation takes place.
> I'd imagine it helps the survival chances of your grandchildren if you're around when they're growing up
Keeping toddlers from walking off a cliff (and the other things unsupervised toddlers will do to kill themselves) is probably why he said 14-40 and not 14-30.
> human evolution (and survival) matters only until 14-40
I just don't think that's true. I think grand parents being around was important for human survival.
If it wasn't, if all that mattered was having the most kids, then why would women go through menopause? Wouldn't it be better if women continued having children until they die?
I think it makes sense that young people have kids (the sooner the better, faster evolution and less chance of DNA degradation)
Then they should live as long as possible to help raise their grandkids to ensure their genes survive.
> If it wasn't, if all that mattered was having the most kids, then why would women go through menopause? Wouldn't it be better if women continued having children until they die?
Given that the risk of birth defects goes up significantly the older a woman is, menopause is probably evolutionarily advantageous.
I may be overly cautious given where I live has an 11+/Extreme UV rating all year round.
Though I do want to point out that clothing doesn't protect against UV as much as you might think, and a sunburn or lack thereof doesn't tell you all that much about your UV exposure for the day. You could have exceeded your healthy exposure for the day without getting a sunburn.
Skin cancer probably plays no role for your ability to reproduce. By the time you die from skin cancer you already had children and probably even grandchildren.
The longer you live as a male the more children you can have. Also grandparents helping raise grandkids is a factor in their survival in the village ..
Shepherds (like all folks) wear and wore clothes, long sleeves and often hats also in the summer. Also if skin is exposed to sun regularly, often, its much less sensitive compared to usual office worker seeing almost no sunlight and then having 2 weeks of mega exposure and sunburns on vacation.
The last time I looked in to this, enough sun exposure to tan is also enough sun exposure for folk of northern European discent to badly increase skin cancer risks.
This is why tanning studios have been banned in Australia.
I don't know about that. My memory of shepherds from when I was a kid in my grandparents' village was of a guy being covered head to toe in what looked like terribly hot clothing for the summer. And this wasn't some high-altitude village, either.
I figure I was getting much more sun exposure as a kid running around in t-shirt and shorts then the local shepherds did.
I'm sure their skin cancer morbidity is higher but the studies I've seen seem to show that sun exposure overall correlates with lower mortality and morbidity overall. There may be confounders like exercise at play but shepherds are probably getting more than most subway workers.
I put together a monster air quality monitor with just about every sensor I could cram into it. Dust sensors, geiger counters, the whole works.
One of the biggest problems I found was indoor CO2 levels. High CO2 levels (much less than dangerous CO2 levels) make you groggy, sleepy, and can induce headaches. I now get notifications to open my windows when CO2 levels pass a certain threshold.
> According to this logic, anyone who works in the subway should be dying, what, 10 years earlier?
Just two more nuances:
1) The article is measuring loss in "DALYs" = disability-adjusted life years. 10 DALYs lost may not mean dying 10 years earlier, but could also mean suffering from Alzheimer's for 16 years (Alzheimer's has a weight of 0.66 [1]), or any combination thereof (e.g. 10 years of Alzheimer's + dying 3.3 years earlier).
2) The cited number is for the "worst offender" on the NYC metro. The pollution levels on the London underground are less than a 10th of that.
Statistical evidence for high BMI's effect on quality of life and morbidity is more compelling, at least in the developed world. Author's thesis does stand insofar as AQ often being overlooked as a causative agent behind cardiovascular disease.
BMI is known to be a bad measure for outliers (e.g. bodybuilders) and just a ballpark rather than exact but for most people there's a pretty decent correlation between BMI and body fat percentage or whatever you prefer.
BMI is a fairly decent measure for folks who don't work out or otherwise build excess muscle. And since that's _most_ Americans, BMI is a good starting point to use when judging health fitness.
Great now let's figure out how to measure BFP across the entire population the way we can with BMI. Every guide i've seen either uses expensive displacement equipment or trained professionals with calipers. That doesn't scale nearly as well as a height / weight calculation
This. (Warning: light-weight argument incoming, but it’s intriguing) Is anyone seriously looking into this? How do we know that (for example) subway workers don’t have shorter lifespans that can’t be accounted for any other way? Just taking a superficial, devils-advocate stance makes me wonder what other broad correlations may exist that aren’t known just because they’re not being investigated rigorously? In some ways this also intersects with the bias against publishing negative results - what if a good study of this has been done but wasn’t published because it wasn’t headline-grabbing?
Is there a fundamental reason why the subway must be like that? I assume it's not as bad in say Hong Kong? Copenhagen metro for example is automated and there's a wall and automatic doors separating the tracks from the platform. I assume it's quite clean.
Subways are dusty because they use mechanical brakes that produce metal dust particles.
For $50 per carriage, dust collecting sponges, fans or filters could be fitted, but train companies don't care. By doing anything about the dust they might be opening themselves up to lawsuits claiming they didn't do enough about a risk they knew about... There are also political issues - often the train company bought the trains 50 years ago and will pay extortionate prices to the original manufacturer for any modifications, and if they make modifications themselves the manufacturer will drop all support.
Many modern trains are starting to have electric braking, and that produces far less dust.
> Is there a fundamental reason why the subway must be like that?
1) Dust from brakes, as noted by other comments.
2) Tunnels, and stations in underground spaces, therefor hard to ventilate.
> I assume it's not as bad in say Hong Kong?
No idea, but air quality in the London underground is very bad indeed. I mean you can sometimes see a visible brown haze looking down the length of the platform.
Having lived in Manhattan for 7 years, and Hong Kong for 9, I'm pretty sure the air quality inside the Hong Kong MTR is better than the NYC subway. Air in the stations in Hong Kong is air conditioned and filtered. Not that feeling is the best measure, but the feeling of the air in a lot of the NYC stations is just not great.
Outdoor air quality in Hong Kong was pretty rough a few years on either side of 2014, but it has either gotten better lately or I've stopped noticing the bad days.
I was surprised about the actual driving too. Vancouver's Skytrain is automated and largely outdoors, with the exception of occasionally needing to take a train over manually
> These statistics are just not passing the smell test.
These numbers are derived from estimations, for sure. But they are sophisticated estimations and serve to rank other health risks in life. In rich countries we usually obsesses about things like pesticides in food or „small particulate matter“ to an extent that it is absurd. Air quality is a real threat in many countries but not anymore in the US or most of Europe for sure.
As the article shows obesity is the killer number 1 in the US. A healthy diet is something which is totally under our control. And for sure smoke generated at a BBQ for example is not very healthy and can be avoided by using a gas grill.
These are things usually ignored and thus underestimated in our health obsession.
“Air quality is a real threat in many countries but not anymore in the US”
Couldn’t be more wrong.
As the author casually admits, we know nothing without experiments. End of story.
What makes your statement so wrong is that it takes decades for the consequences to show up, if they are measurable at all, in non experimental studies. That is exactly the same reason that cigarettes were considered safe for so long. Health consequences take decades to show up and without experiments all we get are loose correlations. Air quality in many places in America is getting worse, the size of the population in these areas is massive. To declare to potential health consequences 60 years in the future without any solid experimental evidence is the same as the doctors of the 50’s telling patients to smoke up, there’s no evidence cigarettes are bad. Exactly the same.
> What makes your statement so wrong is that it takes decades for the consequences to show up, if they are measurable at all, in non experimental studies.
So, you're telling me the air quality is getting worse despite this trend not being observed, yet? There is a logical fallacy somewhere. Furthermore, the link between lung cancer and cigarette smoking was well observed already in the 50s but the tobacco industry naturally downplayed the risks.
BTW: It is an established fact that air quality in the cities of 19th century was way worse -- mainly due to the fact that people cooked and heated their places with open fires and coal. For some insight on the UK: https://theconversation.com/air-pollution-in-victorian-era-b...
Define “air quality” as a single metric is crude at best, but arguably dishonest. The nature of pollution and the pollutants themselves have changed have they not?
Edit: To illustrate the point, assume that getting regular physical is more important now than 100 years ago, due to on average more sedentary contemporary lifestyles. Assume heavy air pollution decreases outdoor activity, which seems plausible if not certain. How long would it take for a body of scientific literature to develop to document the problem? Given measurement problems and the difficulty of doing simulation heavy research, we might never be able to prove such a linkage exists, even if it did.
> According to this logic, anyone who works in the subway should be dying, what, 10 years earlier? Which is obviously not happening.
I don't think you're being honest here, it obviously isn't try to make the point that each commute = 1 year, that's why it's in the "lifestyle" category and not in the "single event" one
> it obviously isn't try to make the point that each commute = 1 year
They aren't saying one commute takes a year off the life. They're saying that people who's job is riding the public commute infrastructure spend roughly 20 times as much time breathing the air in the commuter infrastructure as people who commute to/from work, so if the effect is linear... that's roughly a 10 year reduction in lifespan.
Or, are you trying to say that some underlying common factor between commuting and home/office air quality is present, and so the commute is just a proxy for that common factor? If that's the case, if that common factor is identifiable, it should be named. If that common factor isn't identifiable, how are we confident in attributing it to air quality?
Or, are you claiming that the air quality in the commute infrastructure is the culprit, but the effect is dramatically sublinear?
> or that a daily commute between Newark and NYC takes half a year off your life.
As compared to an "average" US city taking off a quarter-year. I think the commuting thing is a red herring, and they just mean living/working in the NYC metro area, which as a densely populated area likely has slightly worse air than an average US location.
> According to this logic, anyone who works in the subway should be dying, what, 10 years earlier? Which is obviously not happening.
Are you sure this isn't happening? I could easily imagine people working in dusty places for example dying earlier due to health related issues that could be traced back to the lifestyle.
Yeah, it is not at all obvious to me that this isn't happening. Is anyone even collecting the data you would need to tell whether or not it's happening? I'm sure the transit authorities would rather not know.
Oh I read their allegedly "humidifiers kill" snippet, so tl;dr:
> but ultrasonic humidifiers produce huge numbers of particles. They turn any minerals in the water become airborne particles. got the following steady-state increases over background levels.
> Mineral water: ~265
> Tap water (Seoul): ~260
> Purified water: ~50
> Distilled water: ~0
So what you mean is that if I follow the instructions on the manual and use distilled (or at least purified water) for mineral and biological reasons, the issue is smaller to non-existent?
Reverse osmosis filtered water is mainly what I have in mind, companies sell that. 6-14 PPM is what I measured personally and I think it falls into this category.
That's some crappy RO water. My home system takes 45 ppm water and reduces it to <2 ppm (~500 kΩ). For all intents and purposes, it's not conductive on its own.
Distilled water is made by steam condensation, and nearly ultra-pure but still contains dissolved gases.
DI water should be made from some distilled water to be the highest possible purity, but it's usually made from RO or simply filtered tap water.
There are some things DI can do that steam distillation can't, and vice-versa. The two processes are entirely different and NOT interchangeable.
> My home system takes 45 ppm water and reduces it to <2 ppm
My tap water is around 227 and filter is just recently installed, there's still some air in the system. I don't think it will go that low ever, but it's good enough for me. I plan to remineralize it a bit for drinking anyway, so it's all a bit moot.
I don't need it to remove air from water, I need it to stop mixing air that was in the empty spaces around filters when they were installed into said water. Tap water doesn't have much air in it I don't think, it will sort itself out eventually. Right now I have very small air bubbles that are still visible when filling up a glass, they are created when air and water pass through RO membrane. After you let it sit for a while PPM number drops.
Because you would see all the time commercials on tv letting you know that if you, or a late loved one, worked in the subway you may be entitled to financial compensation.
Not unless data has first been collected and analyzed. There was a long period of time between people suspecting cigarettes were unhealthy and actual data showing it
I find it hugely suspicious that huge claims are made but the methodology behind the numbers presented in the first figure is not explained at all.
Further down, correlation plots are shown but no analysis of potential confounders that could affect life expectancy as well, like access to medical care, education, wealth.
People are dying from air pollution it's just that we like to ignore it because what are you realistically going to do about it... Move to your villa in the countryside?
Thankfully as a human being I'm perfectly able to ignore and suppress inconvenient information.
"According to this logic, anyone who works in the subway should be dying, what, 10 years earlier? Which is obviously not happening." And you know this how?, Where YOUR numbers and conclusions come from?
As for humidifiers, specifically ultrasonic ones - we bought one for our baby, but immediately with it also the best water purifier we could find (Zero water) that produces demineralized water practically absent from other molecules than H2O. There is no dust the next morning on the floor (or anywhere), there is no buildup of calc in the machine.
I do believe that breathing that fine dust isn't very healthy long term, but that article outright lies about using it = taking 50 minutes out of every 1440 minutes of everybody's lives.
We would see this effect in dusty (ie Saharan) regions already, there are hundreds of millions of people living in those conditions. What is dust if not small particles of stones and organic compounds flying around.
Completely untrue. The US spends the most per capita and gets worse outcomes than other countries. This fact was even highlighted in Michael Moore's Where To Invade Next?
do you know of mortality statistics specifically for subway workers? Because it may very well surprise you and it can't be grounds for dismissing the hypothesis.
a bit off topic, but i can logically guarantee you that smoking takes at least 5 minutes off your life. It takes that long to smoke a cigarette...
You have to put things into perspective, why should you care less about living now then in 40 years in the future? Chances are your quality of life will only get worse etc.
Also, the suggestion to make products more deadly so that they are used less seems like bad policy. Reduction of harms usually does not mean killing the patient.
Thank you for this extensive resource on air quality. Yes, it needs to get more attention as it is one of the main drivers of mortality of environmental risks.
One thing one has to bear in mind is that often when you optmize your home for low PM (e.g. with air purifiers and fixing of air leackage) your CO2 will get very high causing headaches and reduce cognitive performance.
So it always makes sense for indoor air quality monitoring to measure PM and CO2 in parallel.
We have open source, open hardware build instructions for a very reliable Air quality sensor that can be used to measure PM2.5 and also CO2 [1]. It is very accurate for the fraction of the costs of commercial sensors. You can build it for less than USD 20 (or with CO2 for less than USD 50) and send the data to our cloud server or any other backend.
I am more than happy to send you some free PCBs (you just paypal me the cost of the postage) and you can build your own sensor and log the data. Contact me if you are interested.
I have an AirVisual Pro, which is quite expensive, but my half finished air quality monitor project had been on the bench for much too long.
I have windows open all the time, air conditioning on too often, and dehumidifiers and HEPA filters as well. It is not efficient or particularly environmentally friendly... but I want a CO2 level < 800 ppm and a PM2.5 level under 10... so here we are.
My next half baked idea is figuring out a way to have a sealed home and an appliance (or messy bench-top device) to remove CO2 from the room continuously and exhale outside -- current ideas revolve around using a carbonate (lithium? sodium?) in water in an electrolysis cell and an aquarium bubbler to collect CO2 and expel it outside. The best I've been able to accomplish so far is baking CO2 out of baking soda (sodium bicarbonate) and sealing it in about a cubic foot container and achieving ~300 ppm CO2 (lower than outside which is ~400-450).
From my armchair-research, there are scale challenges with plants.
Algae is commonly the go-to for CO2 scrubbing for it's relative efficiencies. Algae might scrub 1-3 grams of CO2 per liter per day (https://www.osti.gov/servlets/purl/1485133).
Humans exhale approximately 1kg CO2 per day.
I consider 300-1000 L of algae scrubber tanks per person a lot of volume.
Bubbling air through quicklime slush is an easy way of removing CO2. You can turn the calcium carbonate that forms back into quicklime by applying heat.
But it's probably better if you invested into a counterflow heat exchanger for ventilating your home. You can recover a large part of the heating/cooling energy.
The question is how much CO2 can I fix with a reasonably sized apparatus and really I would prefer a continuous system (which is why electrolysis) rather than a batch system.
Also I would prefer levels lower than outside, obviously air exchangers will necessarily be worse than just being outside.
You might try using oxygen conentrator with high throughput to concentrate oxygen from outside and pump it into your home.
With small device I could drop CO2 levels to zero in volume of a gargabe bag in few minutes.
But that would give you oxygen rich atmosphere. You'd probably want to add some inert gas to that. Nitrogen preferably. Are there nitrogen concentrators?
Also all of that is probably really dangerous because human body doesn't detect oxygen level, just CO2 level. So you might easily pass out and suffocate without any warning if your oxygen supply unit get damaged but your nitrogen supply unit doesn't.
I'd assume that some chemist or other has already published a paper about that. But you could probably figure it out yourself experimentally by weighing quicklime, letting it react and weighing it again. Start a youtube channel to finance the project :)
Well I've gotten as far as purchasing 20 pounds of baking soda... my experiments thus far haven't been able to remove a detectable amount of CO2 from a room.
My literature searches haven't had much success thus far, lacking a chemistry degree hasn't helped. I have found some things but not enough to come to any sort of engineering designs. I'm assuming it's one of those things that's almost too simple for anyone to have bothered writing a paper about unless they had the exact sort of ideas I did. (OR they're using terms that I haven't been able to come up with yet)
Try buying 20 lbs of calcium hydroxide, it is sometimes used for soap making iirc, so it should be available on amazon. Bubbling air through a concentrated solution should do something. At least at the CO2 concentrations of exhaled air you get visible amounts of insoluble carbonate: https://www.youtube.com/watch?v=Vl9A8Iyc_LY
I don't know for sure, but there are certain things I notice which I think may have been improved when I started keeping track of CO2 and keeping my windows open. (I don't spend most of my time outside and I certainly don't sleep outside; outside levels might be 450 but inside levels even with my mitigations are usually around 700)
Like so many things I think it is a small effect; it's not like I can go anywhere for a week to experience 300ppm air.
I haven't gone to the levels of designing experiments and data tracking on myself. The fact that I've lived with allergies and a broken nose most of my life probably hasn't helped my personal respiration characteristics.
You are describing an anaesthesia circle breathing system, otherwise known as a rebreather scuba set. :-)
You would need to consider the occupant oxygen consumption. A typical human respiratory quotient is 0.8 (0.8 mole of CO2 produced for every 1 mole of O2 consumed). You’ll get a net inward movement of gas into house all things being considered.
Anyway, don’t do if. If you do it ‘right’ the argon will slowly build up and you’ll asphyxiate. Thankfully achieving that level of seal is very difficult.
If you are really worried about PM2.5, just wear a PAPR.
Oh I'm not interested in hermetically sealing my apartment, there are no worries of normally constructed buildings being able to withstand a meaningful difference in oxygen pressure between inside and outside. CO2 pressure though can easily be increased by a large factor (5x is easy) and maintained with humans inside and closed doors and windows.
PM2.5 is easy to maintain with HEPA filters.
CO2 is not easy to maintain without forced ventilation, and really I would like to try inside levels lower than outside levels. (say 300 ppm)
I’m intrigued by the idea of chemically scrubbing co2 at home as well. Hepa filters are easier to use than I’d expected. The next big step is co2 reduction.
Don’t those requirements conflict? Maintaining a partial pressure difference between inside and out for CO2 but simultaneously preventing a partial pressure difference in O2? I guess with a large enough scrubber running constantly it might work but it will be highly inefficient - a bit like running AC at full blast with open windows.
They do to a degree but overall composition of the atmosphere has so much oxygen and so little co2 that the dynamics are quite different.
There’s something like 50x as much oxygen in the atmosphere as co2 so a relative change of 1% nominal value will correct itself fifty times faster for oxygen than for co2 between outside and inside (ok a wild simplification, but still)
The result is that without really intense sealing it’s basically impossible to make a difference in indoor oxygen levels whereas with even a cracked window i can maintain co2 levels two to three times outdoor concentrations in my apartment.
Running a co2 fixer with the place shut up would be more like... running the air conditioner full blast with the place shut up. Yes there would be losses but they would be relatively contained.
Could you get a few more plants around the house? Plants can remove things like benzene, formaldehyde, xylene, and toluene. Maybe not the fastest but certainly don't cost much once you have them.
Unfortunately this myth, which I also once believed, has been debunked. You just need waaaay too many plants to actually have an effect. The tests the myth were based on all assumed a closed system, which just isn't realistic.
From one randomly googled article on the myth of house plants cleaning the air:
"To remove toxins, you would need at least 10 plants per square foot."
To remove how many "toxins" exactly? Like, let's say I actually have a shitload of plants, like my ceiling is just lined with peace lilies. Presumably there is some % of something being removed, I'd be curious to hear what that is.
But CO2... to simplify imagine being a vegetarian, how much plant matter would you eat in a day? How much plant matter grew in one day in your houseplants? The only way plants are going to fix carbon is by adding it to their own mass. Just think about a conservation of carbon atoms. There's no way any plants in your apartment are going to make a dent in the carbon cycle of your personal environment.
There are arguments to be made for lots of things sticking to or getting sucked into the leaves of plants... maybe if there were a whole lot of plants a meaningful amount of VOCs or other pollutants could be removed... maybe.
If you think about it you have to grow an amount of plant matter comparable to the amount of food you eat in order to maintain levels (considerably less of course because a lot of carbon goes down the toilet, but still a fixed fraction, this would take full sun an a considerable area, like a fraction of an acre)
Block of flats. Apartment is fairly well sealed. If I seal the windows I can drive up CO2 levels to 1500. I have plastic windows with seals that have "unsealed" mode. In this mode window is just barely opened. Like 1mm gap between a window and a frame.
And one window cracked like that is enough to drop CO2 levels below 800 while there's one person in the apartment.
note that the effects of periodically higher co2 concentrations on overall health is inconclusive at best (life evolved with significant co2 around). particulate matter and atmospheric pollutants (like voc’s), however, are most assuredly detrimental to our health, so it makes sense to act mainly on the latter (with air filters/purifiers) over the former.
the point is that humans (and life in general) have entirely evolved with varying levels of co2, so the excess levels found in a fairly closed room is unlikely to be a really serious risk (vs. a sealed room with much higher concentrations, where it's obviously a serious asphyxiation risk). this risk, according to research, is currently inconclusive at best.
the concentrations and types of particulate matter, however, is unprecedented, and as such, presents a higher inate risk, something that scientific research is really only starting to grapple with but so far is showing to be likely a serious risk to many (most?) species on earth.
with that said, i'm not trying to discourage your project in any way, just saying that for most people, addressing particulate (plus voc) risk is likely going to be the overwhelming majority of the benefits to be found in relation to indoor air quality. reducing co2 could be worthwhile if you have an especially airtight room/house, but nearly no houses are that airtight (passiv houses are meant to be so, however).
I've seen a study or two that claim that the bulk of some PM, like brake dust for example, is much smaller than 2.5um. Having exposure to the industry, do you have hopes for sensors that can identify smaller particles than .3um (that's the smallest Purple Air goes).
In practice, how does one try to achieve a balance between CO2 and PM? Do you open the windows for a while when CO2 is up and PM is down, and then close them and run your purifiers when CO2 starts to go back down? Is it possible to keep both low with HEPA filters on the windows?
A solution that one of our customers uses (Prem Tinsulanonda International School) is the installation of a positive pressure system. They are able to achieve near zero AQI in their classrooms when you have more than 300 US AQI outside.
I keep my HEPA filters on with the windows always open.
If the air quality is decent outside, it is easy to maintain a PM2.5 rating of near <10 like this.
In California fire season I have a box fan on high in the window pushing air in (and sealing the areas around the window) through an MPR 2800 furnace filter (which is better than the 99.97% rated hepa filters, would be marked as a ULPA filter I believe in different contexts) with this I can maintain the ~0 PM2.5 rating inside even when the AQI outside is >300 while keeping CO2 in check.
It's been quite surprising how easily the CO2 spikes with closed windows and doors in the bedroom with just one person... I essentially always have a window in each room open several inches, cracked isn't enough, usually with at least one fan pushing air through a window.
The best case solution would be a passive house with MVHR (Mechanical Ventilation with Heat Recovery) and incoming air filtration. This means your home has a steady flow of fresh, low-CO2 air that is filtered for pollen and other particles (depending on the air filter chosen).
Another solution is to install a positive pressure system with high performance HEPA filters. This is especially recommended if you live in areas with very high air pollution.
i put my air purifiers on low when the windows are open to deal with the particles i throw up by moving around and doing stuff indoors. with the windows closed (usually only at night), i put the air purifiers on medium/high.
> co2 and pm should both go down with windows open.
Very much depends on where you live. I have a few DIY air quality stations with data being piped to Grafana. I just looked at the latest data, the average outside PM level for the past 5 months has been around 100 µg/m³, while inside it's around 10 µg/m³.
This spring happens to be pretty windy and this skews the outside levels down, otherwise the ratio would be much worse.
i live in LA on a relatively busy neighborhood street and according to my air quality meter, it’s true. concentrations go down during the day (windows open) and up at night (windows closed).
edit: i mentioned the road to note that outdoor pollution is higher during the day, yet opening the windows despite that lowers overall particulate levels indoors. it may be different in indian cities or cities like beijing with much higher pollution levels.
The crazy thing is there are no nearby cars. There is a highway about 1.5km away which I assume it must all blow from. There is nothing else within 1.5km
That's a great resource, thank you. As a tinkerer who is already quite far down the ESP8266 rabbit hole, are you able to tell me if your software distribution has any particular "special sauce" around the interpretation of the data from these sensors? Or is it predominantly glue between the sensors and the OLED display / your cloud service?
I am interested in replicating your hardware stack but implementing the software stack using the esphome framework which supports all of the components used in your DIY solution.
There is no secret sauce needed. The Plantower sensors tell you the PM2.5 in micrograms directly and we just display it to the OLED display or send it to a server. It is all open source so you can check the code.
Thank you for all of you interested in getting the PCBs. To send me a message please go to https://www.airgradient.com/diy/ and send me a message with the orange chat button. Thanks!
There was a bit of interest last time I remember you posting on here as well - have you thought about putting up a batch on something like crowd supply? I think it would sell well enough to make it worth your time, and fire season is coming up again soon.
Yes that might be a good idea but I am very happy that so many people are interested in building one and that we can increase the awareness on air quality so I am happy to do the work ;)
Yeah, this is an interesting enough problem to me that I recently started researching how to build an arduino version of what this person is offering - in my head, I basically reinvented the product they're offering, without all of the nasty bits of actually having any idea how it works. I would definitely pay a reasonable amount of money for a set of sensors that Just Worked that would collect data in my house.
I understand how fixing leakages, or more generally, not properly ventilating your place, would increase CO₂ levels, but where do air purifiers come into the picture? Is it just because someone who has an air purifier is also more likely to not ventilate (to keep PM2.5 down?), or are air purifiers themselves somehow bad for CO₂ levels?
I can't guess why they would be, and searching around a bit doesn't seem to suggest that's the case either.
How should someone contact you? I looked into setting up something on an Arduino last year, and the CO2 sensor I ended up purchasing was not very good, so it's cool to see someone thinking about this problem domain.
We use the Senseair S8 CO2 sensor which is very accurate and of high quality.
Some of the TVOC sensors give an estimated CO2 level (eCO2) which is not recommended because these values are not very accurate.
Yes the Senseair S8 is very good. Only problem is that the automatic baseline calibration sometimes needs 7-10 days to kick in. But you can also do a manual calibration.
I'm definitely interested to build one of these. Located in Vancouver Canada. Maybe you can mention in a reply to your own post how people can contact you (if you can't still edit your post)?
Yes, sometimes some components are not available for all countries. Just search for the same sensor on aliexpress. There are many vendors for the same sensor. Some will ship to the US.
Also in Canada and interested in getting some PCBs. Not sure if OP is selling if not i would be into splitting the cost of getting a batch made if its economical
I don't know the answer to that specific question, but I do know it's an NDIR sensor. The Wikipedia page on that sensor type likely answers your question—
The biggest pitfall I see with this is we’re extrapolating from large doses of air pollution to very tiny ones.
Clearly we have enough evidence to say that smoking a pack a day or living in a smog-filled city will cut years off your life. But we would need truly gigantic samples to show that blowing birthday candles or broiling fish once a week will cut weeks off your life.
Instead these conclusions are being derived on linear extrapolations from large air particulate doses. Yet many things in biology follow the principal of hormesis, where a small dose or a toxin may be harmless or even helpful.
Similar models have been used for years and are still the gold standard when predicting the health effects of radiation exposure. Yet mountains of evidence show that radiation workers, who are regularly exposed to small dosages of otherwise harmful regulation do not have anywhere near the cancer rates we’d expect from the linear extrapolation models.
Sorry for the pendantry: it sounds like you mean linear interpolation, rather than extrapolation. Extrapolation is where you project outside the range of previously collected data, and is particularly likely to result in false conclusions. Interpolation is where you estimate a value inside the range of collected data from points around it, and is usually a lot less dangerous. But I agree with your point that, in this case, it does seem pretty baseless.
But the article is extrapolating, not interpolating.
Extrapolation is when you're extending to outside of the measured data range. In this case, the measurements were all of large values, and it's extrapolating (linearly) to small values. Just because the values being extrapolated to are smaller, rather than larger, doesn't make it interpolation.
Which is precisely why this has the risk of false conclusions, like you say.
Could you give some citations for studies on radiation workers? The permissible doses in most countries are extremely low and there are not that many people working in the industry. This makes me wonder they manage to achieve statistically significant results.
EVs reduce tailpipe exhaust near roads but it's worth noting that brake abrasion dust isn't going away anytime soon and it's considered very bad to breathe, possibly in the same league as diesel emission particles.[1] I guess regenerative braking on an EV reduces this somewhat.
Most EVs indeed use regenerative braking. Which means your brake pads last a lot longer as you barely use them. Tire particles are a bigger problem. Just think of the mass of tires that you erode away before you replace them (routinely) and compare that to the brake pads you replace much less often. And it's not just the tires that erode but also the road. Asphalt particles are nasty as well. Though most of that dust is quite coarse and doesn't stay in the air as long. But then, tire and road dust is apparently the biggest source of microplastics in our oceans. It washes away, enters our sewers, rivers, and eventually the oceans. It's bad for different reasons as well.
Anecdotal, but since recently getting a plug-in hybrid I've only been using regenerative braking except for the most abrupt stops. Whenever you approach a red light or junction it's not hard to stay within the regen braking zone.
I’ve always made it a game to see how little I can use my brakes, whether in bumper-to-bumper traffic or more wide open suburban roads. I never understand why people need to race up to red lights just to do a hard brake. I take solace thinking they probably replace their brakes 20% more frequently.
Yes, I have owned a Prius and Corolla Hybrid and on both vehicles the front rotors always go very rusty because I only ever press the brake down enough to activate the regenerative braking (for better fuel economy). The regenerative braking power of these vehicles is about 20-30kW.
And as a side effect, I haven't needed to replace the brake pads for about 150,000 kms on the Prius. Actually the mechanic told me that they look brand new. I haven't experienced any problems from the rust yet. The front rotor on the Corolla (2020) seems to be a much better, newer design, and doesn't rust nearly as much as the Prius (2014).
endnote. For anyone considering the new Corolla Hybrid ... I rate it very highly as perhaps the best car ever designed.
That’s a bummer to hear, and I saw other folks mentioning that on this thread too. Could you describe the climate in which you’re located? Maybe a humid, salty coastal climate will affect that differently than a dry, dusty climate.
I drive a 12yo hybrid and my annecdotal experience suggests that isn't correct.
I drive mainly around the city and had to replace brake pads recently as they became rusty (salt during winter). The pads had been on for 80,000km and were less than half worn. On regular ICE cars (which have bigger brake pads) you'd usually have to replace them well before that point as they'd be worn down. I'd imagine they last even longer on newer hybrid and EVs.
What? I am driving EVs multiple times a week in a European city and regenerative breaking is always happening at every brake action until mechanical brakes kick in.
That must reduce appliance of mechanical brakes at least by half.
You can turn regen braking off, but why would you unless maybe the EV model feels like shit when switching between regenerative and mechanical brakes.
Most definitely in the city. Regen handles the vast majority of braking for me. Depends on how strong the regen is in your vehicle I guess, but it's definitely possible to make it strong enough.
Another reason why we should not be making this big push for EVs but instead try to shift our infrastructure away from personal vehicles and towards mass transit and micromobility.
EVs will still make this picture look the same and are thus inherently an inefficient form of transport:
A lot of people don't know how to use engine braking, I guess teaching them that is going to significantly increased your brake pad life on existing vehicles in circulation.
Remember there are 3 brakes in your car, handbrake, foot brake and engine braking.
Foot brake and handbrake are effectively the same thing because they operate on shared friction components using mechanical wires instead of hydraulic lines. There maybe a different mechanism but it ultimately uses the same drum or disc.
Engine braking (jake braking) by trucks is illegal by statue in many cities and towns because it's very loud. Also, engine braking is riskier in terms of costs (stresses to drivetrain, torque converter, transmission, engine) than brake pads, so people aren't going to do it. Furthermore, they rarely have the skills or transmission to be able to do it conveniently. In addition, if it were more efficient or safer, it would likely be a feature, but I've never seen it in a standard transmission passenger vehicle.
I'm completely not a car mechanic, so the following is essentially a question phrased as a statement. But I'm a bit skeptical about this idea.
I assume you mean the engine break in a manual tranmission car (AKA stick shift in the US). But that relies on your clutch, which is still a friction based mechanism. Admittedly if you're breaking you're probably going to change gear either way, but the amount of friction depends on the difference in revs between the two parts coming into contact, which is presumably going to be larger if you're using it to engine break. So it seems to me that you're reducing wear on your brake pad but just switching that to increase wear on your clutch - with similar effects on air quality.
The clutch is only actuated when changing between gears. Engine braking happens when in gear, and at that point the clutch plates are compressed together and spin as one unit - no dust being generated. Any significant slipping of the clutch would make it burn up very quickly, since cars use dry clutches which cool down by radiating heat into the air.
Engine braking happens because engines have very high internal resistance - with motorcycles for example, there's no parking brake, you just leave it in 1st gear and it will not roll. So when you're not on the throttle, the inertia of the wheels/drivetrain will keep the car moving and the engine RPMs from dropping to idle instantly, but over time the engine will drain that inertial energy and slow down the car.
Also, engine braking is pretty weak on modern manual cars AFAIK. At least in my Honda Civic it basically doesn't engine brake, compared to my motorcycle. The effect is there but very minor.
Actually EVs are much worse than ICEs for tire dust and road abrasion, as they tend to be much heavier than an equivalent ICE car, with much more torque.
Depends on how much your drive. Drive only now and then and brake only the bare minimum, you can get really rusty brakes. I ended up having to get towed with brakes being seized due to rust and lack of use.
Well yes, weather will cause rust. Good use of brakes can clean it up and keep the mechanism from seizing. Lack of braking = lack of use as far as the brakes are concerned.
I could run my errands without braking at all (except when stopping at a parking lot). Anticipate lights and traffic flow, downshift to slow down.. that's how I used to drive. At home I could even park without braking to slow down, thanks to a small incline at my parking spot.
My previous car, which had automatic transmission, didn't have really show any issues with rust because I actually had to brake when driving around town. Same weather, same locale.
Having lived in Central America, I can tell you that almost none of the recommendations[1] here are relevant, at least in relation to the kind of air pollution that kills the numbers of people shown in those graphs. Smoky fires (mostly for cooking) inside small huts are everywhere in much of the world, and very few of the affected people understand the risks. Even if they did, they rarely have any viable alternatives.
If you tried to tell those people about particle counters or HEPA filters, you might as well tell them about cold fusion while you're at it. Sure, all the things mentioned might help, but for anyone with the means to follow the recommendations in this article (and with the ability to read an article), I can almost guarantee that air quality is not going to be a major factor in your life expectancy.
[1] With the exception of "Be careful about smoke when cooking."
Even here in Poland. People burn anything to stay warm, oil even. The unhealthy pollution starts in November then ends in March. The entire time everyone, including children, are outside, pretending like it's not a problem. People running in the streets. And when you bring it up to people they get angry. Schools don't close, everyone continues like it's normal.
I'm moving back to the west coast USA soon. I could live in a shack and my family would be better off. People complain about the wildfires, but in Poland they get it every year, and for longer. Try forbidding your kids to go out(too young to wear a mask) the entire winter... Even if you somehow make the perfect environment at home, those kids will eventually have to physically go to school and brave pollution. Before the pandemic I was the only crazy one with a mask during high pollution days. If kids wore a mask because of pollution then I was told they would be ostracized.
So, other than that elephant in the room, it's a perfect country.
Thank you. I thought I was the only one in Poland with this view! My Polish wife gets angry when I mention it. I'm trying to rescue us (we have a young child) but she is resistant. Well done for escaping.
Thank you. As a native Polish dweller I'm fully with you on this one. Fortunalelly I have no kids so I just spend winters at home with my air purifier and laugh brutally at anyone concerned if their kale is exactly organic.
Pandemic, making wearing mask socially acceptable really did me a solid.
It's not just about life expectancy, but life quality. I think we'll one day be surprised just how many mental health and chronic illnesses are significantly attributable to air pollution, in all its forms.
That's a fair point, though I'd still wager that for those of us not cooking over open fires, those effects are likely very minimal - at least in contrast to the people mentioned earlier.
Everything's relative, sure, but pay close attention to your sense of well being the next time you're in a car with an air freshener, or someone sprays febreeze in a room. You'll probably start to feel uneasy and/or have dulled senses very quickly. Do that often enough, and the abuse adds up.
I'm surprised "having a bonfire" isn't on this list, but I'm afraid to see how detrimental it might be.
The nostalgia factor is sort of wearing off now that I'm 40 and don't want my clothes to smell bad or have a low-key asthma attack. The last time I went camping in a campground and everyone had a fire going, the whole park was completely choked with smoke that it made going for a walk really crappy. It's such a weird activity, driving cars out to the woods to pay to burn dead trees.
Pretty close to being on the list. "Have a really smoky fire at home. Life cost: 1 day"
Considering the close association of food, warmth, security and socialization with the habitual use of fire for at the very least several hundred thousand years of human history, is it really any surprise that some people still enjoy the practice?
I'm surprised this doesn't mention gas stoves and ovens. Gas is the "high end" option, yet creates totally unnecessary PM2.5 pollution in your home. Children growing up with gas stoves have higher rates of asthma.
Very interesting to me that gas is considered the 'high end'-option, I presume in the U.S?
Where I live, the high end-option is to get an induction stove. I have one, and it's extremely pleasant to cook on. Granted, I've never cooked on gas because that alternative is mostly not used, in my experience.
I believe part of the perception of gas as 'high end' is the observation that many restaurants use gas. However, from what I understand, many restaurants use gas because it is the cheapest way to get BTUs into pans - gas is CHEAP, and restaurants use a lot of it.
That said, certain types of high temp cooking like wok cooking require jet-burner gas stoves to get the right sort of flavor, but I think induction is superior in most cases.
Also, high-heat wok cooking, while delicious, is terrible for air quality.
Gas is popular for the instant and fine grained control over temperature. You get much of the same advantages by using induction. I've had a cheap electrical furnace for ages and it is a bit limiting but you get used to it. Asian wok cooking uses gas burners to get the wok up to high temperature. High temperatures are important for that type of cooking. Another trick they use is to use thin metal for the wok so it conducts heat quickly. That's much harder to do with an electrical furnace but not impossible. If you use cast iron pans, they hold the heat much better and longer. It takes ages for them to heat up though. For flavor, cook over wood or charcoal. That's why outdoor grills are popular and why the gas variety of that is a bit frowned upon by grilling enthusiasts. Cooking on an open fire also is quite nice. But of course living next to a place where that is done is not great for your lungs.
Heat is not equally intense or similarly distributed between different stove types. Gas cooking delivers intense heat along a trajectory that follows the curve of the pan, and allows for thin pan materials with low heat capacity. The natural result of this is the wok, which cooks the best over a gas flame on high settings.
Want a restaurant-quality stir-fry? Your only choice is a wok on an intense gas plume. The thin material of the wok gives it low heat capacity, meaning that when you turn on the heat it rises in temperature very fast, and cools relatively fast when you turn it off. This allows very precise control necessary to get the best flavor. The wok is curved, which is critical to mixing ingredients correctly while cooking, but the gas flame does a fine job of following the form of the pan to give adequate heating throughout. Electric or induction stoves come short on both aspects: you need thicker pans (higher heat capacity) with flatter resistive elements built-in. You simply can't get the same flavor with those setups.
So no, it's not so simple as "heat is heat."
Pay attention to the kitchen next time you're in a Chinese or Thai restaurant. They really make use of the industrial gas-powered ranges that are universally equipped in their kitchens.
Few years ago I moved from a little apartment with an electric range to an SFH with gas everything.
"Good for you," my gas-enthusiast family said, "now you have a REAL stove"
It still takes forever to boil water in a pot. The food tastes the same. I wonder why furnaces have these fancy high-efficiency heat exchangers and stoves don't? Cost?
I wouldn't mind going back to electric. I just assumed it cost more, but maybe cooking isn't significant compared to running a furnace.
> I wonder why furnaces have these fancy high-efficiency heat exchangers and stoves don't? Cost?
I don't see how a design like that would work for a range. The purpose of a range is to heat small, movable objects (pots) to high temperatures (~500°F) with good responsiveness (= short time constants). The purpose of a furnace or water heater is to heat fluids contained in large spaces or tanks to modest temperatures (~100°F) with very limited responsiveness (= long time constants).
The heat exchanger really helps the case of heating a stream of fluid, as that's where the exchange is most useful. The physical and thermal mass of the heat exchanger and flue condenser are both considerable.
I'm not seeing how to make a gas rangetop significantly more thermally responsive without making it no longer practical. For people who can't abide gas for whatever reason, induction units are supposedly excellent these days. (I've never tried one. They can't possibly be worse than an electric smoothtop range, though!)
Induction stoves are pretty good for dumping watts into water. However, it's very hard to get a good mid-range temperature. Gas makes it really straightforward to get something cooking at exactly the heat you want.
I think I have tried 5 different models in the last few years, from the very cheap, to the relatively pricey, and all were relatively lacking when it came to fine control.
I don't think there's any real reason why they shouldn't have fine temperature control - presumably the temperature is controlled by the switching speed of the mosfets in the coils?
I imagine this will change, though. I would have thought induction hobs are cheaper to produce, since it's just a copper coil and a bunch of power mosfets.
I think it used to boil faster? My grandma replaced her stove and noticed it took forever to boil. The service guy said regulations around the volume of gas have increased the time it takes to boil water.
No idea if that's true or not, but I'd believe it.
It does take a while to boil water (although not nearly as long in my experience), and food tastes the same, but there's essentially zero time waiting for the heating element to heat up. For me that's the big difference -- near-instant control over the amount of heat being applied.
Why would someone downvote that? Pretty lame. I'm sharing my personal, relevant experience. Make a comment if you somehow disagree or thing I missed the mark... Like.. what?
It really depends where you live, where I live in Asia electric (induction) is the high end option and gas is the standard. Electric also doesn't work great with a wok.
I don't think we should do domestic cooking with gas for reasons that include respiratory health, but it's worth noting that the link between modern domestic gas ovens and childhood asthma is very weak relative to other risk factors, which might be why it's not mentioned in the article.
"When the meta-analysis puts everything together, they come to the conclusion that gas cooking produces a small increase in asthma risk for children, perhaps a 1.5 percentage point increase in risk." (https://emilyoster.substack.com/p/gas-stoves-finally)
The study in question: "Our meta-analyses suggest that children living in a home with gas cooking have a 42% increased risk of having current asthma, a 24% increased risk of lifetime asthma and an overall 32% increased risk of having current and lifetime asthma."
To me, a 24% increase in risk of lifetime asthma is significant and well worth avoiding both at an individual level and a societal level, given that good alternatives are readily available.
Given this 24% number, I guess the "1.5 percentage points" you quoted must be the absolute increase in asthma prevalence across the population, i.e. gas stoves in every home would cause 1.5% of people to develop asthma (when they otherwise wouldn't have it). That seems quite bad actually. If true, not using gas stoves (currently in 35% of households) could have prevented over a million cases of asthma in the US alone.
Two years ago, I participated in a rocis.org study cohort. It was very informative. Participants are given a collection of monitors (particulate, CO2, radon, and one other I can't remember). We are given three air particulate monitors. participants collect the data and send it back to rocis.org. Here were some of the main takeaways personally. Note that I live in Pittsburgh which doesn't have great air.
A. The idea that you should "open your window to let in fresh air" is false. The outdoor air is 10x worse at my house and I don't live it a "polluted" neighborhood but in the burbs.
B. Monitoring is very insightful. I put one monitor outside, one in the living room, and one in my bedroom. The outdoor air like I said was 10x worse than indoors. Indoors wasn't so great either. I replaced my furnace electrostatic filters with quality HEPA filters (they make box filters the same size as electrostatic panels and they are beasts). The indoor air quality improved by about 30%. I added a Blue HEPA filter to the bedroom. It runs continuously at the middle fan setting. Bedroom air quality improved by about 50%.
C. Cooking is the biggest contributor to indoor pollution. When you monitor in real-time this becomes obvious. Induction is the way to go. Of course, the high-end appliance manufacturers are going to continue to make you covet that gas range. But if you're building or renovating a kitchen, go inductive.
US with worse physical activity... I think this is car culture taking its toll. So many spend so much time in their car, and forget that you're really just sitting down. This means that in order to get the most value out of a car, you have to sit more. More hours on the road, less hours moving around. I'm not prescribing anything for anyone... it's fine if people want to spend most of their day in their car, I'm just saying some people are looking like their body has been molded by a car seat, and can't walk for a few blocks without getting tired.
In addition to lost life, there is also a cost to quality of life. Air quality is one of the biggest contributors to the risk of senile dementia. But also the gas composition is known to affect cognition in the short run as well, with a measurable difference in cognitive tests when indoor CO2 is elevated.
I think it’s highly likely that in 20 years we will view diesel cars like we do leaded fuel. An insanely bad idea that we knew was bad at the time but continued to use.
No need to bring in effects to cognition, even. It just sucks to live in a place where “(tonight’s run|tomorrow’s hike) is canceled because the air quality is shit” is a thing.
> On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day (p < 0.0001). VOCs [volatile organic compounds] and CO2 were independently associated with cognitive scores.
> Relative to 600 ppm, at 1,000 ppm CO2, moderate and statistically significant decrements occurred in six of nine scales of decision-making performance. At 2,500 ppm, large and statistically significant reductions occurred in seven scales of decision-making performance (raw score ratios, 0.06–0.56), but performance on the focused activity scale increased.
We recommend to our new parent friends that they get a room air purifier for their new babies.
It simultaneously generates white noise and the accompanying deep bass rumble that is calming like a car ride, and it gives peace of mind knowing that they spend a third of their life with ultra clean air.
Micro-managing your life to this extent is probably why all dystopian books/movies involve some well-meaning technical person who thinks we should be doing XYZ to prolong our lives.
While these things may (anecdotally) prolong your life, does anybody really want to be 102 and having to be nursed for all the basic needs like bathing yourself?
Combine this article with the many(many) others that tell you how to micro-manage all aspects of your life(to be "super productive") and you instantly find that once you start to deviate from your steady-state of micro-management, your worry skyrockets.
I never understood perspectives akin to "why would I want to add years to my life when I'll just be old anyways?". I think many people don't realize that if you take care of your body (especially eating well and movement) you not only extend your lifespan but your quality of life as well in the later years.
Anecdotally, my parents exercise regularly and take decent care of themselves compared to their friends (I even got them juicing regularly). You can tell the difference because most of their friends of the same age are dying or living a severely reduced quality of life while my dad still plays hockey regularly and my mom exercises daily. Both have very few health issues (other than a bit of high blood pressure).
I guess what I'm getting at is that it's kind of sad to me that we've become so used to the idea that old age automatically = shitty when I think there is so much that we could be doing that would mean we could live long lives AND still have autonomy and comfort. I definitely agree that if you micromanage things to a level where you are just stressing or orthorexic that's not good, but I don't think that's the only approach if you want to live a long, healthy life.
What age are your parents? I find it hard to believe that you can live past 80 years with a high quality of life, barring having 1 in 100 age-related genetics
My great aunt golfed until about 95, danced, read books, went to a cafe every day. She bad a wonderful life and was very happy right until the end.
80 is way too young for the kind of physical and mental degeneration you’re envisioning to happen automatically.
Now most people don’t eat well, aren’t especially mobile, will be quite overweight by 60+ with multiple chronic health conditions, lots of muscle loss, etc. This is obviously common. My point is most of those conditions are lifestyle conditions and are not automatic features of aging.
they are almost 70. I think the Blue Zones[1] make a pretty strong case for groups of people living with similarly healthy lifestyles all living longer than the average and with better quality of life. I just think it's pretty reasonable to conclude that there will be a difference between the bodies of people who take care of themselves over their lifetime vs. those who don't.
We have people living longer and longer (I think the last person was 122?!) and it doesn't really make sense that you reach an age like 80 and everybody, no matter their choices, all end up similarly unhealthy and in pain with reduced mobility.
I lived in BKK for over a year and I checked the AQI like weather. I bought a reliable pm2 reader. Air filtering system for my house and wore a mask religiously outside. The air was so bad that I began to get very ill before i started to employ these 'Micro-managements'
I'm not understanding why you feel this is micro-management. People constantly "micro-manage" their life in far more detailed ways than this - what you eat, what you wear, where you sit, all kinds of trivial decisions made minute-by-minute as you live. Being aware of one more environmental factor and making some decisions based on it hardly feels like a huge additional burden on my life.
Yes, if anything, we should be macro-managing. The environmental air quality that we incur on ourselves is the largest factor we will have to deal with in life, why not start there? Why are we tolerating a society predicated on burning fuel to push two tonnes of steel around for almost any kind of human travel when there are so many cleaner alternatives?
In this specific instance, the solution is very low cost and low effort, so the ROI is probably good.
Also, in general, the later years of your life when you've gained experience and wisdom are quite valuable to the world, it's not a bad idea to maximize those.
I'm curious whether the issue the author identifies (real or not) with ultrasonic humidifiers applies also to humidifiers that simply blow air through a wet membrane..
I've got an ultrasonic humidifier. I found that running it for a few hours with Brita filtered water made my whole room full of white dust. So I started using only distilled water. Since getting distilled water means I have to walk a few blocks and refill a 10 liter container every two days, I'll probably not buy an ultrasonic humidifier in the future.
I have both a humidifier and purifier working 24/7, several meters apart and I've noticed that tap water in any form does make the purifier work harder, but demineralized doesn't.
> Nothing else is so important while also being so easy to address.
It's actually not that easy to address if you don't have extra cash laying around. Most people in the world will not do the things on this list.
Other things it leaves out, like frying food (edit: I'm a moron, it does mention it down the line), or buying furniture or clothes that off-gas VOCs, or living or working in a place with fiberglass-lined air ducts, or using a gas range or oven.
Years ago I read scientists saying that indoor air pollution was one of the largest causes of death, disease, and decreased quality of life. So I decided to take it seriously. This is one of my biggest eccentricities, as people find it very hard to believe anything invisible matters.
My biggest hack in this regard: living somewhere with low enough ambient pollution that you can open a window. Say less than 50 pm 2.5 outdoors. This reliably leads to a pm 2.5 of 4 indoors, even with windows shut, as long as I am not cooking poorly.
Then the open window will vent VOCs and CO2. Even a tiny crack of an open window in winter is sufficient. In summer you need more open.
That’s pretty much it, and the rest is making sure not to burn stuff when cooking, which mostly involves keeping the stove clean and not letting anything fall on the burners, and putting hot water in warm pans after cooking.
I measure all of this with an awair, a laseregg, and a co2 monitor. It’s pretty low effort and I feel confident the air quality is good.
If I do mess up while cooking I open windows to vent and put on a mask until it has dissipated. It’s all mostly just background habit now.
This is a good list. One other important thing to do if you can help it is to never live near a road. Any road, even infrequently driven on ones. If there's only one car per day on a road, but you live ten feet from it, and occasionally the wind blows the exhaust in your direction, you're breathing that in. Walls don't help. Live at least one mile in a straight line from highways.
I mean, the article only provides individual tips to fight the global problem of air solution. Extinguishing candles with a lid and avoiding incense won't do shit in the grand scheme of things. It's like putting a bandaid on an open leg fracture.
> IMO, cities should just ban almost all car traffic from the centres so people can live car free without being poisoned.
This would have a much greater impact on the problem for sure, but sadly nobody likes that, some people think owning a car is freedom while it's slavery.
put urban roads (and parking) underground, and use industrial scrubbers at air exchange. expensive but worth it. tax fossil fuels/carbon to subsidize this and internalize the environmental costs.
Where I live it takes several years to paint a pedestrian crossing. Even if we decided to put all traffic underground, nobody alive today would see that project finished.
Often things are said to the effect of it being weird that we're capable of spaceflight, but infrastructure is too hard and expensive. The lack of fluidity in the labor market, i.e. pinning people to a field or worse, a company, for a lifetime creates a lot of that inefficiency, I think.
I know the idea is that specialization is good for everyone, and people doing certain kinds of work should be good at it, but I think allowing more diversity in the types of work people do, more intermingling, and more fluidity are realistic goals with a lot of advantages. We already have a big problem in matching qualified people with jobs efficiently. If we get substantially better at that, we can do it more rapidly, and allocate resources much more intelligently, since demands change in every profession as things develop. I would actively welcome breaks in my knowledge work to do the many types of "dumb labor" I can do when it's useful. It's something to ponder.
i’ve had streets near me repaved twice, many repainted more than twice, and a water main under a street replaced/repaired twice, in the past 10 years, while other pothole-riddled streets nearby are still waiting their turn. it’s inscrutable why that is.
yes, but this way, we could have our (expensive) cake and eat it too. we could free up the above ground streets for electric buses, pedestrians, bikes, malls/parks, and the like, make cities denser/more walkable, remove asphalt/concrete to lower the heat island effect, add trees/plants everywhere, and all sorts of human centered stuff. it’s not so realistic (though the boring company may help with that), but what a vision it is!
To some extent yes. I remember one of my first experiences in Chicago taking the Metra Electric from Hyde Park to downtown and getting out at the north entrance which dumps you out at Lower Water Street, which is very disorienting if you are not familiar with the area.
That's a more ideal solution, but it's probably faster to move than for a city to make changes like that. You can try to stock up on food and grow crops to minimize driving.
I was thinking the same thing. All this time I had been living near a busy thoroughfare because I assumed it was good for me. I'll have my realtor on the phone this afternoon. How bad could the Texas market be?
It will take time for exhaust particles to be significantly reduced as a result of EVs, plus, the increased weight of EVs will create more tire and asphalt wear, which is also quite bad (possibly worse).
Regenerative braking largely solves the brake pad issue. Some EVs are efficient enough that brake rotors rusting over from not being used is a concern.
How is it possible to separate DALYs lost from high BMI from DALYs lost from low vegetables and/or low physical activity? The author never fully explains the methodology behind the graph.
I don't understand how the author arrives at the conclusion that "[air quality] is often the most effective health intervention, period".
How do you take that away from the plots? If you're in the US my prime take-away would be to keep your BMI in check.
The first graph shows ~2 deaths per 1000 people per year. Surely more than 2 persons/1000/year die in those countries. What are the causes for the other ~10-15 deaths/1000/year?
Given the information in the article, I don't see anything to support the central thesis about air quality. The reasoning for it is so thin that I have no idea whether it's true or not.
Most of the world lives outside the US, so "often" would seem to apply to the potential improvement in DALYs.
BMI reductions are also notoriously difficult, while many of the mitigations listed in the article are low effort and relatively low cost. You could plausibly include this in your comparison of effectiveness.
I'm dubious that water soluble 'particles' from water hardness are a major concern. The meters can just distinguish sizes, but I expect that particles of a given size can radically differ in how harmful they are if nothing else based just on the body's ability to clear them.
The people's fear of dying is creating too many problems on this earth. Instead of wasting your energy trying not to die, accept that you will be dying one day, later or sooner, and you will be much happier. You will be using your time on earth much more wisely.
Laundry and clothes by far creates the most dust and particles in my home, probably yours too.
At night, with the lights off and the room dark, turn on your phone LED pointed at the ceiling. Look closely at the air just above the light, you'll see tiny little material threads and speckles. I do not like the idea of constantly breathing that in.
I've used an expensive HEPA air filter in my room and did some testing, lo and behold: when I checked the air with my phone LED it was absolutely teeming with material particulates (probably cotton, which I mostly wear).
The air filter creates a circulation in the room disturbing dormant dust and kicking it up into the air, but the filter doesn't seem to catch and contain this dust.
Alternatively, when I left my room window open without any filter and allow fresh outside air in, the phone LED test later reveals almost pristine air quality probably a 100x decrease in particulates.
I'm now trying out a water-based air scrubber, one that looks like a fish bowl. It agitates the water, non-ultrasonically, just using rotation, and sends air through the wash. Doesn't seem to be more effective than just letting fresh air in through the window though.
Most particles by total mass, but not by total health risk. Your phone LED test only detects large particles that your lungs can remove (see https://en.wikipedia.org/wiki/Mucociliary_clearance ). PM2.5 particles are more dangerous because they can make it past the lungs' self-cleaning system, and the very smallest ones can penetrate the lungs and end up in the bloodstream. You need a laser sensor to measure small particles.
I had a lot of issues with an allergic-like reaction to my old bedroom when temporarily moving back to my parent's house while switching apartments. It was a bit dusty there, but visibly it didn't look too bad.
I had noticed this before while crashing there every now and then, but hadn't thought much of it. But since I had to stay there for a while I had to do something.
So I bought an air purifier with HEPA filter and let it work at full blast while I was at work. The first few days had a very noticeable improvement, and after five days I had no issues at all anymore.
It's weird that people get alergic to stuff they grew up with.
I grew up with cats. Never had a problem with them. My last cat died when I was 21. I moved out. I didn't have any contact with a cat for about 4 years. Bam, now I'm alergic to cats.
Air purifier does wonderful thing for people with allergies. Thanks to it I could pretty much stayed off meds last year.
This seems pretty poorly researched, or at least poorly presented.
The numbers the author uses to quantify "life cost", as far as I can tell, come entirely from one graph in the section "A heuristic to quantify harms". The author examined the life-years lost from exposure to ambient particles in multiple countries around the world, concluding that
>being exposed to 2500 PM2.5 for one year costs 1 DALY
But that line comes from a chart with a range of about 10-100 describing constant exposure to ambient particles. Even if we assume the author's line is correct, identifies a real effect, and correctly ascribes causality, it is not reasonable to draw the conclusions they do.
The author speculates burning a cone of incense, which will produce a concentration of about 4000 for a few hours. This is forty times the largest value on the graph and is some 100,000 times shorter in duration. It is ludicrous to try to extrapolate without a great deal more evidence.
And, obviously, the types of particles found in the air outside are not the same as the ones found inside.
It's a shame that there is some good information on this page ruined by this one bit of shoddy statistics.
It’s interesting that installing an ERV system (energy recovery ventilation) in the home wasn't mentioned. These are devices that bring in fresh air from outside but retain much of the inside temperature.
Many things in the home offgas harmful chemicals or particulates. Continually cycling the air is a good way to reduce the amount you are breathing, especially in highly efficient homes that are close to air tight.
"Exposure to fine particulate matter (PM2.5) has been associated with increased risk of heart disease,1 insulin resistance (IR),2 and diabetes,3 all conditions that are characterized by inflammation"
Being rich gives you an extra 14.6 years: more money usually correlates to better food, better environment, better healthcare, etc.
Owning a Tesla Model Y, indirect marker of wealth would be good for you otherwise.
I think this is a bit handwavy. There is a lot of evidence to show that air quality has an impact on health. How much might be harder to quantify, but I don't think it's unreasonable to think we might be underestimating its impact.
> It's not just about life expectancy, but life quality. I think we'll one day be surprised just how many mental health and chronic illnesses are significantly attributable to air pollution, in all its forms.
Also any idea what the VOCs pollution or particulate matter is being released in the air from heated electronics e.g. lcd TV panel getting hit, computer monitors getting hot (WFH running it all day),hot laptops, hot charging bricks for electronics, etc.
I tend to smell the bad chemical smells from these hot electronics in plastic casing, what about furniture and other stuff indoors imparting VOCs e.g. formaldehyde? Surely these things are additive to the things mentioned in the article and bad for our health?
This very dubious text is a good example of why scientists need to go through some basic training, and articles need to be reviewed (even by your officemate!) before going online.
I have a random question for those who survived the smoke in 2020 california: California homes have horrible insulation.. did having an air filter indoors make a difference?
Our body should have >0 capacity to cleanup the toxins absorbed. Considering we shed billions of cells every day and generate replacement for them. So the smoke absorbed from blowing the candle may be exhaled/shit/farted sometime before next candle.
Also, one thing these stats miss/don't bring out is the quality of life. e.g. living in Delhi may reduce your life only by 3 years, but may substantially impact health in the last 15 years of your life.
Skimming the comments (i.e., those missing the lede)...the arc of the article is this: breathing is another form of eating. It's how your body consumes additional resources and persists. You breathe all day. Every day.
One breath probably won't kill you. But take enough breaths of the wrong micro-substance and that aggregation will likely shorten your life. Perhaps significantly.
Conclusion: If watching your (food) diet is important so is you gases (i.e., air) diet.
I have a Dylos air quality monitor. It's a great combination of sensitivity and price, and it's led me to dramatically change my habits.
I no longer simmer things with my gas range all day (I use an induction cooker instead). I stopped using any candles/incense. I run a HEPA filter in my bedroom 24/7, and I always keep that door shut.
I stumbled across this and coincidentally, I've just moved to Tasmania. Supposedly, it has the world's cleanest air. There is an air pollution monitoring station on the west coast which sets a baseline measurement for the rest of the world. I can definitely tell the difference vs Sydney where I used to live.
We are at that point from a technology perspective - look up passive houses - but it's still far too niche an area. For new construction, it's actually not that much more expensive, and is also far more comfortable and energy efficient also.
In the USA yes, especially the west coast. In Poland I was about to get a condo constructed but not doing that anymore, but the process was quite interesting. The insulation blew most everything in the USA out of the water. Mostly because they have no choice given the really cold winters. During the winter pollution gets really bad and if you shut the windows, pollution goes down indoors, but so does CO2. Ideally you have a hepa filter + outdoor A/C that brings in warm filtered air during the winter.
Noise dampening is still an issue. Where I'm living, the whole flat is subject to resonance, when old buses drive by. It's like living inside the throat of a bass vocalist. That, and I hear every laugh a child has outside, even though I'm on 7th floor (8th, if you count like USA-ians do). It's terrible.
Anybody that lives somewhere with heavy PM doesn’t need to fit test a mask. You instantly feel the difference when you put one on. They don’t block many types of pollution, but for heavy wildfire smoke they will instantly decrease the migraines when pm are above 200 or so.
Anyone know the particulate exposure levels of being around your car in the garage and starting and stopping the engine multiple times a day (garage door open), how much is this going to effectively reduce your lifespan from being around combustion engines daily.
Did you know that the world trade center debris in the air were actually carried many miles away. Some of us are still suffering from the pollution it caused. I read that in a research article.
Lucky we're getting a Clean Air Tax in Victoria, Australia - to keep the pesky, potentially solar powered EVs off the road - before we reach 1% market rate. Should help keep the diesels safe.
I thoroughly enjoyed reading this in-depth article.
As we're working on air quality at Airica, it's great to see that this topic is getting more attention lately.
We focus on easy to deploy air quality monitoring for schools and offices. In these spaces it's just as much about CO2 as PM as high CO2 levels reduce cognitive performance significantly. This 2016 study shows 61-101% better cognitive scores in well ventilated buildings:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4892924/
can i point out that mortality isn't the only statistic. Health is just as important. I know 70 year olds who are sick and weak, and 90 year olds who are fit and healthy
> I have discovered that when I make this case, even to highly intelligent and health-conscious men and women, a psychological truth quickly becomes as visible as a pair of clenched fists: They do not want to believe any of it.
LOL this happens whenever I talk about this issue with people here in Poland. Part of it is their family is here, it's hard to immigrate, deep down they know it is a problem. It was upsetting to tell my Polish wife that we need to move out of Poland and to scary USA but... she agreed with me and we're doing it. For us, the risk of death is far higher here with all the smoke. Even the California wildfires are relatively harmless in comparison, we get that every year in Poland and no one cares, at least in Calfornia everyone recognizes that it's a problem and people stay at home.
But here, wood burning(or even coal burning), is a part of the culture, giving warm fuzzy memories at granny's house burning horrid things in the furnace for others to enjoy.
I think some people are so afraid of dangers to their health that they are even afraid to acknowledge them. I think I've seen a lot of this during the pandemic. When you try make people acknowledge the dangers they are facing they are going to panick and defend their peace of mind furiously.
Anyways, good luck in the US. Avoid getting shot, having a pool, drinking sugared water instead of water, any medical issue and getting on the bad side of the law in any way. ;-)
You realize your risk of death of air pollution in polish cities is 160/10,000 people? In the US the risk is 5 in 100,000 people.
sugar water will be a problem, I did not like this about the USA.
medical issue - with FAANG you're fine
bad side of the law: in the communities we live in faang, again, not a problem, you're on the right side of the law. Unless you're black, then that is quite a problem unfortunately.
Man, that article is a bummer! I grew up in a house with an open fireplace and for long periods we literally used it to cook on (out of poverty, not choice). Those are some of my happiest memories. And now some crazy "rationalist" wants to take away my open fire? IT'S ALL LIES I SAY.
There is also the issue of brake dust and rubber from tires on asphalt close to highways and major roads that are not good to breathe in when exercising outdoors.
for anyone interested, we have terrible air quality in the "steel city" Gary, Indiana. I track the air quality and industry https://millerbeach.community in/around my lil community using a PurpleAir II
A simple 20 x 20 Box fan with a furnace HEPA filter placed against it (just turn on fan and place filter behind it) will do wonders for your indoor air quality. The 3M 2200 Series Filtrete Filters are amazing. You also always want to cook with the Hood Fan going. The particulate that is created during cooking is so small it can pass through the lungs into your blood stream causing havoc.
I have 3 running in my home and they haven't been turned off for over 1.5 years, still going strong. The filters I buy at Costco when on sale (3 for $29).
This one has been on the fan 24x7 for the last 2 months and is still good for a couple of more.
As another commenter noted, it depends on your air, but a decent HEPA filter (H13/H14 etc.) will last a very long time if you remove the coarse dust first with a prefilter.
The prefilter is typically a lot cheaper and is replaced more often. Even some non-woven filter fabric (like that used in vacuum cleaner filters) will dramatically increase the HEPA filter life, is super cheap, and can be washed for reuse.
My purifiers use an F8 prefilter and H13 HEPA filter, and the HEPA filter will last about 2 years.
We run box-fan filters during wildfire season here in the PNW and change them out after the season ends. Last year they were quite gray after all of the fires. We run Honeywell HEPA cleaners year round and bring the box fans out to supplement as needed.
I never realized that ultrasonic humidifiers would also aerosolize minerals or other contaminants in the water, but it makes sense. I wonder if running a HEPA filter in the same room as the humidifier mitigates the health impact significantly.
and doesn't filter CO2 in any way measurable. You would need your entire place filled with the right plants to make a difference. I tried, and failed at this when I realized I'd have to get way more plants.
The other issue with plants is that having them in any decent numbers means you’re likely to have at least some with a mold/fungus/pollen issue, so they actually reduce air quality. Outdoors that’s not so much of an issue because there’s airflow and the mold/fungus/pollen is dispersed, while inside your room it’s limited to a very small amount of still air.
Wish I could remember where I read it but the conclusion was that having indoor plants solely to increase air quality isn't a good idea. Obviously it's somewhat better than nothing but so minor as to be largely insignificant given how much air exchange there is with the outside world when you aren't on a shuttle
HEPA filters cannot remove nanoparticles and ionizing filters ionize the air, and well, ozone is not good for us. So plants are far superior in this regard to air purifiers, which are useless
According to this logic, anyone who works in the subway should be dying, what, 10 years earlier? Which is obviously not happening.
Similarly, it seems impossible to believe that the minerals in the air from humidifiers are equivalently dangerous to factory pollution or cigarette smoke. Different categories of particles are going to affect the body differently, no? I mean, our body requires minerals -- we're drinking them in our water all day long -- while certain factories may be belching out straight-up poison.
These statistics are just not passing the smell test. They seem to be extrapolations of extrapolations of extrapolations. This article's conclusions don't seem even remotely convincing.