Yup, especially on the older lines (Northern, Victoria, Jubilee, Bakerloo). Particulate pollution can be two orders of magnitude higher than at street level. This tends to be glossed over when trumpeting the success of ULEZ measures pushing people away from cars and onto public transport, and I say that as a non-car-owner.
People tend to walk 10-15 mins at either end when taking the tube, and more walking through the day to get lunch, etc. My understanding is this activity is net positive despite the extra particulates while on the tube. I might be misremembering this with a study I read on cycling in road pollution though
Whenever my best mate goes on about having access to "cultural experiences" that I don't have for living in the sticks I remind him it comes at the cost of massive tube bogeys. :P
ULEZ massively reduced the amount of NO2, which is a trigger for asthma. It also seems to have reduced the hospital admissions for heart related emergencies.
Anecdotal, but similar situation here for me (I don't need an inhaler, but visiting London around 2015 meant blowing my nose to black snot for a week, and then back in 2024 it was completely fine)!
Anecdata I was living very close to a busy highway, and my young daughter was wheazing when she had a cold, we had to give her medicine via a nebulizer. When we moved out to the country more, far away from any major roads, these issues all disappeared within a couple months.
A friend of mine does research on air pollution from cars - the TL;DR is you should not live within a third of a mile of a highway. The falloff is pretty sharp, but you don't want to be in that zone.
Notably, most major cities have been building tons of housing (especially ‘affordable housing’) right next to highways, as it is the only areas that aren’t already built out with tons of high value houses.
I'm not able to find exact statistics on the composition of traffic pollution but I've read its a complex mixture of particles, including lots of non-exhaust emissions like tire and brake dust.
I wanted to long for the time when people hated "Malaria" and wanted to move to "Beunos Aires". But they believed the arrows chase us at daytime and the plague engulf us at night, like in the Psalm.
Since Eastern Europe is relatively poor and sensitive to energy prices a lot of households invested into insulation, new windows, etc. Last 20 years there was also a huge boom for heat recovery ventilation. Such a simple and inexpensive device that provides so much. Should be first item in every household to invest into.
> Funny part is that locals here are absolutely scared of any sign of draft or direct aircon
I have always been and am still baffled by this. My whole family loses their minds if there is even a slight draft or AC, whether in the house or car. When my brother visits he incessantly closes car vents and windows. Parents constantly nag to put on warm clothes and avoid drafts etc., and when we inevitably get sick a few times a year mostly from school transmitted cold viruses they gloat about it.
Maybe it's a cultural thing from times without good heat/insulation where drafts meant an actual freezing house, which, yes that would actually have an impact on health.
I was in Sarajevo during COVID, I'm sure a reason the numbers were so bad there is from everyone being in enclosed spaces with no ventilation. Smoking without ventilation was bad enough, now add a virus on top of it.
Living very close to busy highways is known to generate poor air quality. I recommend anyone in those locations buy an air purifier for their kids' rooms.
I bought a couple reasonably priced HEPA purifiers and I change the filters on schedule. Replacement HEPA filters are very cheap.
Also watch out for things that we do indoors that can generate bad air quality. I had a friend who bought a VOC meter and noticed very high readings in his kid's room. He traced the source to his chemical and paint cabinet nearby, which he never considered because he couldn't smell anything. Throwing out a lot of the old containers dropped the measurements to the unmeasurable range.
Agreed, just buy air purifiers with HEPA filters and change them regularly. The main expense is buying one for every room, but it's one of those expenses you wish you had made sooner.
If you’re so inclined, you can build your own air purifier with laser cut panels or 3d printed panels and use a cheap ikea air filter and standard PC fans. All the parts are readily available, and user repairable.
If you pair if with an Apollo AIR-1 you can have home assistant ramp up and down the fans with a PC fan controller based on live readings of PM2.5 in your home. I did this with the help of Claude code.
I really wish the DIY folks would measure the airflow and sound levels on this sort of thing. CADR and decibels are going to vary wildly with fan choice
I came across this site which has pretty comprehensive data about PQ curves (the chart for determining CADR given filter impedance) at different noise and power levels: https://www.cybenetics.com/evaluations/fans/204/ (many other fans tested as well but I've been liking the value of P14 Pro PST)
However they look somewhat commercial and I'm not sure the funding/incentives so definitely corroborate with other sources.
DIY folks are not a commercial outfit with access to testing equipment.
Having said that, there are reviews of some DIY models reviewing CADR[1], and it's bizarre to complain about testing decibles since Arctic P14 fans, the most commonly recommended fans, are a thouroughly tested product. Running them at around 25% based on lower PM2.5 readings is almost inaudible from experience.
Didn’t the Apollo 13 crew make an air scrubber out of duct tape and hope? Surely a cardboard box, a box fan and a hepa filter covered in tape gets you 90% there
You are referring to a Corsi–Rosenthal Box. You are correct that they will get you 90% of the way there, but they also tend to be large, loud, and ugly. We can build better things now that we have time and resources.
Looks like a cool project, but the 99.97% HEPA filters are the expensive part. Building yourself only makes sense if you want to choose your own aesthetics or enjoy doing it.
It also makes sense if you're worried that a proprietary filter will be yanked off the market, leaving you with an unusable item. Also, for the money, you cannot get that kind of smart functionality from my research.
My $50 (without the HEPA filter) air purifier can detect particles and change fan speed accordingly. It also has a light sensor to go into really quiet mode during the night.
Though, looking it up it seems that prices for the Winix Zero (including one set of filters) have doubled since I last bought one.
HEPA filters are counterproductive in standard air purifiers. Air purifiers pump their cleaned air directly into the dirty air of the room. It doesn't matter if that cleaned air is extremely clean, because it's immediately mixed with dirty air. What actually matters is how much clean air you produce: the "clean air delivery rate" (CADR).
The more effective the filter the more it restricts airflow. If a filter is only 99% effective instead of 99.99% but allows double the airflow, it provides nearly double the CADR. To benefit from HEPA you need a clean side and dirty side, like in a clean-room setup.
If the purifier can filter the air more quickly than air leaves the room it'll still reduce the amount of pollutants in the air. Most people aren't going to create a "clean side" and "dirty side" setup for filtering the air in a room.
I think that is what they're saying: the point is that if you're doing this, you don't want to optimize for the cleanest air leaving the filter, but more for throughput.
A reasonable compromise is achieved by an air purifier that has the outlet on top because it’s blowing the filtered air well away from the inlet side and generally circulates the air in the room.
I used to work in the cleanest room in the state, that wasn’t a lab, back when I lived in Adelaide, and top-inlet button-outlet in a raised floor data centre is how the air handling units in the main data hall worked, so you can simulate that to a certain extent.
> The more effective the filter the more it restricts airflow.
This isn’t the whole story. Surface area and flow rate are factors.
A residential home is aiming to improve air quality, rather than grow flawless silicon ingots etc.
The point isn’t that the HEPA filter won’t work under those conditions, it’s that if you can get away with not separating the clean and dirty air, you can achieve better filtration overall with a higher flow, lower resistance filter at a lower noise level. HEPA filters shine in use cases where you need single-pass filtration, like vacuum cleaner output filters or clean room air filters. If you don’t separate clean and dirty air, the filter will still work, but you aren’t taking advantage of its main distinguishing quality, which is its single-pass filtration performance.
If you get to recycle the air through the filter several times, MERV-13 offers much better performance tradeoffs for a residential air purifier because you can recycle the air through it much faster at acceptable noise levels. My home air purifier recycles the volume of my home every 15 minutes or so, vs HEPA filters which produce totally clean air, but since it just mixes with the dirty air that doesn’t matter as much as the rate at which it cleans air.
And guess what 98% of consumer air filtering systems utilize a hepa filter. You’re really over optimizing a non problem. Unless you are constantly producing more contaminants than the system can keep up with it’s totally a fine solution.
If you only use 99% it means there are small particles you can't catch. Being faster is meaningless if you can never clean the air.
Air purifiers are designed to run 24/7 and all they do is catch particles. Eventually all the particles will be caught. The one I got also detects if there is a lot of particles and will spin faster accordingly.
I am specifically talking about particles in the 0.3 to 1.0 micron range which according to the graph from your link are the most difficult to filter out. Can a 99% filter catch these? My understanding of this is that they cannot.
According to hepacart [1] 99% HEPA filters do not even exist, since HEPA seems to be clearly defined:
> HEPA filter definition, which requires a filtration efficiency of 99.97% for particles as small as 0.3 microns. "HEPA-type" filters may capture larger particles but are not effective against the finer particulates that true HEPA filters excel at removing.
> It doesn't matter if that cleaned air is extremely clean, because it's immediately mixed with dirty air
What matters is the gradual removal of particles from the air.
The HEPA purifiers I have move enough air that everything gets scrubbed. It works.
My house has a separate central air system with a non-HEPA air filter with a decent MERV rating for the bulk filtering. The HEPA air purifiers do the scrubbing of finer particles.
Don’t overthink this. This looks like knowing just enough to be dangerous but missing the big picture.
Maybe overthink it a bit? I'm skeptical about the big picture.
You have an air purifier in your kid's room. If this is a fairly large apartment or a house, and you have central air running, how much purer is the air in that room? If your central air system is modern and continuously circulates air throughout the house at a low fan speed, you're effectively trying to purify your whole house with that low-output room-sized HEPA filter. Have you done measurements to see if it does anything?
(Not the person you replied to, but offering an anecdote)
There are ton of variables here. One is where the return air intake is. My house only has a single return air vent in the hallway on a 10' ceiling (the furnace is directly above that in the attic). I think this is not-uncommon in the western US.
I have a room-sized purifier in each room on the floor, and they accumulate considerable dust. What I don't know is how much of that would have been successfully pulled out into the hallway, if I didn't have the vacuum of the purifier.
This is impossible for me to A/B test meaningfully given all the environmental variables - wind (house isn't airtight, wind pushes into leaks harder), wind direction (wind from the desert brings sand and other small particles), humidity, etc.
If anyone has reading material on properly controlled experiments in this regard it'd be really interesting to see. I honestly don't know if they're more effective than disabling them and allowing the central HVAC a chance to pick it up sans airflow-tug-of-war. My hunch is it's not worse, though I have no expertise here.
Long-winded post but I'll close with an anecdote: when we had those wildfires in the Bay Area back during covid, they were absolutely more effective at getting the soot and smell out of all of our rooms than the status quo.
edit: One thing to be aware of if someone is evaluating these, all of the claimed numbers from manufacturers are based on you running the air purifier on the absolute highest speed it offers. Almost no one actually does this in on these consumer grade freestanding ones, especially in bedrooms, because they're quite loud.
I can buy a HEPA filter machine off the shelf. What I can't buy off the shelf is any other non-HEPA filter machine like you're describing. So while you might be right, there's no products readily available that meet the spec you're providing. We've got to work with what we have available and what time we're able to make for this stuff.
This reads as being overly confident and wrong. Optimizing for CADR is right but saying HEPA is counterproductive is simply wrong. We are not trying to filter out asbestos and consumer air purifiers are meant to mix the air. So long as over some acceptable period of time the air quality improves it’s a success.
The average person isn't going to have a clean-room setup and we're not looking for perfect here just marginally better when it comes to a bedroom.
If you put a standard sized air purifier with a HEPA filter in it into a room it will absolutely lower the dirty air of the room. Because over time you're lowering the particle count.
If I turn my air purifier on in my room even with the door open the air quality sensors improve their readings quite dramatically.
What’s your suggestion? Just sit there and be angry that transportation exists?
You don’t think the parent commenter is also using transportation?
The pollution from transport also occurs with trains, buses, and any other vehicle that has wheels, brakes, or moves fast enough to stir up the air and kick particulates into the air.
People do what they can and control what’s within their reach.
So to give you other example. You live and nearby opens a chemical plant and starts smelling, so you just buy gas mask and hazmat suit or start complaining?
And yes other means of transport also does pollute, but amount is is critical here. You need much less public transport than you need individual cars.
I drive the car, you buy/rent cheap place because its shitty polluted noisy place, so compensate that with air purifier. There is no free lunch in healthy society, there are good reasons for rent for same amount of m2 do wildly differ across same city and its not just sunset views or distance to work
I got tired of that sort of argument when I realized that a great many of the people who argued that they have the right to tear down the side streets of walkable downtown neighbourhoods lived in unwalkable suburban neighbourhoods. Those unwalkable neighbourhoods were usually designed with a single access road to ensure there was no through traffic, so they would never have to deal with that problem. Then those same people had the audacity to ask everyone to pay for additional access roads when they realized that a single access road was a disaster when their neighbourhood needed emergency services and had to be evacuated (because it was burning to the ground). Of course, those additional access roads had to be designed to discourage through traffic.
Am I bitter about that? Yes. There is nothing wrong with wanting the best for you. There is something dearly wrong with using what's best for you to make life worse for others.
buying a new house will have $40k in reltor fees alone, $2k for movers, plus the, you know, hundreds of thousands for the new house. and what if I like my current house, it's in a busy hip area?
or should I launch a multi-year lobbying campaign in the city and/or state and/or national level to have roads moved?
NO2 is a very hazardous air pollutant which doesn’t get a ton of attention. The main sources are combustion engines and gas stoves. Asthma looks to be mostly caused by gas stoves.
I’ve got a sensor that can detect no2 and it noticeably spikes when using gas. Switched to induction after that.
I’ve never once been in a property that had an exhaust fan sufficient. I’ve had the exhaust on full blast and the spike on the air quality sensor on another floor of the house is rapid and massive.
I suspect a sufficient ventilation would require something more like a lab fume hood that can pull a negative pressure on the area around the stove.
And from what I have seen, a good number of exhaust fans are straight up fake and just ventilate back in to the room rather than ducted outside.
You can't filter out carbon monoxide and nitrogen and sulfur compounds with those recirculating filters. They are more for trapping volatilized oils so they don't stain the walls. If you're cooking with gas you really want proper ventilation.
They contain a feels good filter to make you think something is happening. But to actually filter the pollution you'd need a activated carbon filter for the n02 and a hepa filter for the smoke. Which none of them contain and would clog rapidly.
It's massively easier to just not create the no2 by replacing gas with induction, and to vent the smoke outside rather than trying to trap it in a filter. I think the introduction of cheap consumer air quality sensors like from IKEA will start to make this problem a lot more visible to people.
That’s a good point, and obvious now you point it out.
On the other hand, when water turns into steam at standard atmospheric pressure, it expands in volume by about 1,700 times.
Whereas the gas in your stove is already a vapour, mostly methane, turning in to mostly water vapour and carbon dioxide. So the expansion ratio isn’t going to be anywhere near as high as that.
I’d say you’re still right.
Still, I wonder to what extent an exhaust fan does help.
If the exhaust fan can vent x cubic feet per minute and the room is y cubic feet in volume then it takes z minutes to full ventilate the room, etc etc.
It squeezes me with approximately the weight of an elephant sitting on my chest. But humans are adapted to this and don't notice. It helps that the insides of my lungs are being squeezed outwards by the same force. Otherwise I surely couldn't breathe.
I am indeed wrong. Air pressure is about 100kPa, which is to say 100 kilonewtons per square meter, which is about the weight of 10 kilokilograms or tonnes per square meter, and the surface area of a human is about a square meter, so the air pressure force acting on a human is about 10 tonnes, and an elephant weighs about 5 tonnes, so it's actually the weight of two elephants.
Do you have a source for that? Because as far as I can see, asthma isn't _that_ less common in countries where gas stoves are barely used, such as germany. Still has like 60-70% of the asthma cases the US has. There's also a ton of other pollutants the US hasn't yet forbidden, but the EU has, which could also explain a lot of the difference in rates.
Don't get me wrong, it's certainly a good idea to get rid of gas stoves. I just think it's a bit much to declare them the primary cause of asthma.
> N02 is a very hazardous air pollutant which doesn’t get a ton of attention. The main sources are combustion engines and gas stoves. Asthma looks to be mostly caused by gas stoves
That makes sense but the unverified claim is that gas stoves are the main contributors to asthma.
I don't understand why we keep on building right next to highways which are some of the worst things for our health. You don't need to live in the countryside for that. Just stay roughly 1km away from them and the situation is significantly better.
There is evidence of a lot of ugly diseases caused by this, without even mentioning the constant 40+ dB background noise.
Are we classing A-roads as "highways" now? If not, I have no idea what you mean when you say you're never far from a highway in London. There are no motorways through London.
I'd like to imagine the stunned scientist is a scientist from another field, they show some medical findings to a guy who looks at snail butts all day and he's the one "stunned" by the findings
Smokers don't magically undo the damage they did to their lungs after they stop smoking. Stunned might be hyperbole, but it is at least a little bit surprising.
"Stunned" isn't really a scientific term. It's the sort of editorializing you should expect to come from people who aren't the scientists themselves. More than hyperbole, it is classic click bait.
Also, quitting smoking definitely eases a number of symptoms, especially if you're not at the point of chronic emphysema. The reduction of inflammation triggers alone after a bit of time is fairly significant. Less coughing, less mucus buildup, etc.
But this isn't that at all. "Stunned" is used here because it's the word one of the study's authors actually used.
'"I was absolutely stunned when I first saw the results," Prof Chris Griffiths, a senior author on the study, at Queen Mary University of London, told the BBC.'
The lifetime risk is approximately 1.3% for women and 1.8% for men. For regular smokers: 11.2% for women and 14.8% for men. So about 15 to 30 more likely to get lung cancer. Bringing that down to 4x is close to "almost the same".
Might be that I am not reading probabilities correctly, but how do 1.3% -> 11.2% and 1.8% -> 15% become "15 to 30 times more likely"? Sounds like less then ten times?
“ Thus, those who quit smoking at ages 15 to 34, 35 to 44, 45 to 54, and 55 to 64 years avoided an estimated 100%, 89%, 78%, and 56% of the excess cancer mortality risk associated with continued smoking, respectively”
They absolutely do! Not all the way, but if you'd have smoked a pack a day for 15 years and then have given up for the last 15, there's absolutely no way you'd be saying this!
'"I was absolutely stunned when I first saw the results," Prof Chris Griffiths, a senior author on the study, at Queen Mary University of London, told the BBC."'
I agree. Though they did at least put it in quotes in the first sentence, which I hope doesn't indicate how far people are generally getting through an article before commenting on it on Hacker News.
I'm obviously supportive of less pollution etc etc but looking at the actual graph results I wouldn't describe them as 'stunning', the needle barely moved. But of course, they have to have something to make headlines after spending so many million on the study and who knows how many billion on ulez.
I'm not one of these anti ulez people I think it's good. But you can imagine the pressure to spin tepid results into headlines.
The entities with a ton of money tied up in the ULEZ are, perhaps with a layer or two of indirection, are likely the same ones funding this research, or if not this research then the guy across the hall in the same lab.
Yes, and I really don't care if they've got a direct quote from a scientist. Far too likely that word was coaxed out of the scientist by a reporter or PR hack. Or he thought he needed to use that word to get enough attention to keep his research funding. Or he was a relatively closed-minded scientist.
HN needs a 's/^scientists stunned by/Scientists notice/i' filter for Titles.
EVs use regenerative braking. So they hardly produce any brake particulates. And the tire particulates are heavy so they don't stay airborn for nearly as long. At low speeds, tires don't wear out as quickly.
Europe has quite a few cities where traffic is increasingly discouraged from going to the inner cities. Cities like Paris and London are much transformed from what they used to be and it shows in the health statistics.
It's not just the particulates but also nitrous oxides (nox) produced by combustion engines. Nox is correlated with lots of health issues. Take it away and you see lower rates of chronic lung issues, cancer, development issues with kids, etc.
But yes, tires are also an issue. But a fairly minor one to anything coming out of a combustion engine.
Mass transit indeed is nice in big cities. Removes the need for taking the car.
There is a generator at the end of my street in a shipping container sized metal box, it also has a mini office and loo, and is used by the construction workers digging holes in the road. It has company spiel written on the side, promoting the box's environmental credentials, including the punchline: 'Zero NOX when generator not in use'.
During the 90s "Fat is evil" craze, all yogurt was replaced with "Fat free" yogurt that had 100 extra calories worth of sugar.
The yogurt aisle in the US is still primarily made up of this garbage product category which exists based on utter falsehoods pushed by the sugar industry. 30 years later and we are still constrained by what ignorant fad chasers in the 90s did.
Might instead refer to a start-stop / battery backup kind of system, where idling-but-on doesn't burn any fuel, but sudden loads can still be serviced.
Regens braking means significantly less brake dust, especially at city speeds and with blended braking.
> Although…rail might solve those?
Trains still have brakes. Some can regen brake but because they usually don’t have batteries they need the rail or overhead gantry to support inputs.
But on a passenger-mile basis, I expect an electric train produces essentially no particulates compared to a car, even a light rail on tyres. I do not however have numbers.
For all that I did not care for them originally this is probably something full-height platform screen doors help with, assuming the trains themselves are also filtered that would keep the pollutants clear of drivers and users, although it does not exactly resolve the question of managing their presence in the tunnels themselves, and I could see things get pretty dire in case of breakdowns.
Impossible to retrofit, of course, but what helps more are big tunnels. Modern ~9m diameter single tunnel systems are a lot better for this than old 3.5m diameter double tunnel systems.
City dwellers are the ones that use public land to store their cars.
Of the three
Villages I know well (my sisters, the one I lived in until moving to a larger 8000 person town, and the one with the primary school) I can’t think of any
Likewise the tiny hamlets I drove through on the way to school didn’t have people parking on the road, there’s simply no room. You occasionally get delivery vehicles stop and it causes chaos.
I'm thinking mostly of eg terraced streets in villages and towns. Similar to cities in that there tends to be a single space for parking on the street but multiple car owners per house on average.
Different to cities in that there isn't remotely the public transport infrastructure to support getting rid of cars, or the private facility to support electric overnight charging for the longer distance car-commuting etc that isn't generally needed if you live in cities.
Things are improving with technological advance but - again - not everybody can afford those advances and the latest models.
It's a completely different lifestyle living in those sorts of places in some respects.
Not at all. You're quoting from a report based on data from a Net Zero campaign. But let's give it the benefit of the doubt and assume it's accurate, 60-70% having access to electric overnight.
That's still leaves millions (?) of households with on street parking.
Most commuters outside cities get on quite ok with normal cars - because they have to - and a third of them is hardly "niche".
The average mpy is 7k, so let's say a weekly charge is more accurate.
You can probably get away with that in most cases with on-street parking with a mix of commercial chargers and work if you're lucky.
That "probably" is the point. Your average normal car user (especially in financially challenged times) fighting for a car space on their street is not motivated to take on that higher risk at higher cost in a less competitive market to keep the equivalent of HN demographics happy.
Very small number in the U.K. outside of big cities and towns. In England 65% have off-road parking outside of London, and most of that 35% will be in cities and towns.
I can’t think of a single house in my sisters village without parking. The village hall also has a carpark with two 7kW chargers.
100%,
and not just due to no emissions / minimal break dust.
The noise reduction is a massive dividend. I used to live in london 10+ years ago, and when I come back I’m stunned by the noise difference, it really is so much quieter especially in central london. EVs everywhere especially replacing the horribly noisy diesel black cabs and buses. Very noticeably different and much more pleasant, and improving all the time as EV adoption continues to accelerate, hooray
A lot of jurisdictions have laws that say electric cars must emit thatbnoise while driving. Which is basically because you might not be able to hear them over the louder sound of gas cars. I hope that that requirement can go away if we get to near 100% electric.
Noise reduction benefit is marginal. Most of the noise comes from tires rather than the engine. At 30 km/h tires are louder than the engine, so an EV driving at 50 km/h, which is the typical city speed limit, isn't any quieter than an ICE car.
Noise benefit isn’t marginal. Central London average speed is 7 to 10 mph (11 to 16 km/h) so engine noise is significant. There is lots of idling traffic: traffic lights, taxis at cab ranks, buses at bus stops, everyone in a jam - removal of idle noise is particularly significant.
Too bad the tire particulates likely get worse, both because EVs are heavy, and because they have more low-end torque and encourage driving that leads to more tire wear. I don't have sources but it's my educated guess from recent experience with a few EVs
But I'll take it if diesels and two-strokes will die in a fire
There’s a massive confound around vehicle size, too: EV buyers are less likely to get massive trucks and SUVs because that extra bulk drives cost up and range down, and when you’re comparing tire particulates the numbers will be more favorable for a EV sedan compared to an ICE SUV.
Electric vehicles are stills cars. But better than gasoline and especially diesel cars.
So yeah.
That said not clear to me about PM2.5 is I've never seen anything legit seeming that tries to characterize the harm based on the type/source. Though it seems agreed diesel is especially bad.
In some areas of London the ULEZ has been so successful that the measured NOx is now coming mostly from gas boilers used for heating, probably mostly old large commerical units.
So shifting from gas boilers to heat pumps and from gas ovens and stoves to electric/indusction is also beneficial.
London's also been putting effort into improving safe bicycle routes lately. I visit London every few weeks and if I'm going somewhere in central, I'll often just grab one of the Santander hire bikes instead of the tube. Well, most of London (looking at you, Royal Borough of Kensington and Chelsea)
I use air purifiers mounted on my windows, running continuously except in the deep summer and deep winter. This makes my air contain 50-100x fewer particulates than the outdoor air. In contrast, the best I can achieve with floor air purifiers as people have them is a 5-10x reduction. The window purifiers also keep excess CO2 and VOCs out.
Yes, the filter absolutely has an activated carbon layer in it in addition to a HEPA layer. I understand that activated carbon doesn't last long. I have been changing the filter every two months.
Note that because this purifier is mounted at the window, it filters incoming air from outside, not the indoor VOCs that are already in the residence. The indoor VOCs will simply have to get exhausted from elsewhere due to the air pressure.
What I am suggesting is that my need for activated carbon is slightly less because I am rapidly pushing the VOCs out in the resulting exhaust.
Health improvements are not measurable any more if you go below 5 mcg/m2 average level of PM2.5 particulates. For 50x reduction to be beneficial, you need to live in an area where the pollution is 250 mcg/m2, which is an extreme level found only in a few unfortunate places on Earth. 5-10x reduction is reasonable almost everywhere.
I know precisely the subjective difference between a 5x reduction and a 50x reduction. Only the latter feels sufficiently good to me, and my brain operates better with it. You will know it when you experience it. Maybe it's my middle-aged brain that needs the extra support. I live in an urban area near traffic. Lately there intermittently also has been wildfire smoke coming down from Canada.
> strongest evidence yet that local clean air zones could help reduce some of the harm caused by pollution during childhood.
It's incredible this is even in debate. It's one of those intuitive things well known since the reduction of coal burning and smog during the industrial revolution in London?
Conservatives flipped on multiple of their policies after Reform's success on local election in 2025 and started to copy Reform UK. Even the Labour shifter right after 2025.
They dropped a few points in pools but for Conservatives they likely will be the main competitor - among Reform UK voters there are much more former Tory voters than former Labour voters.
The amount of wailing about this was unbelievable. London is a terrible city for driving in in the first place, and the idea of 10% of them having to change cars provoked totally absurd responses.
We're going to see the same when EV-only mandates, true zero emissions zones, start appearing across the next decade.
It's madness but I hope abolishing ULEZ will have little impact at least for London - people who already drive modern cars will not start suddenly replacing them with older more polluting ones.
Surely you're talking about all those people who voted the dirty heavy industry across the oceans where they can't even regulate them, as if we don't all share the same space rock.
Asthma is so common that this is not only easy to test, but has been. That's what the article was about.
Anyway, by your own reasoning, wouldn't sensitive lungs be an advantage? The incentive to find cleaner air is also breaking away from the pack. Every civilization in history has started out that way. It takes more than mere brute force to beat the competition.
Are you suggesting that it would be advantageous for humanity to evolve to live in London circa 2000?
Larry Niven played with this in one of his stories; a time traveller from the far (and highly polluted) future has to use mechanical breathing assistance, because the levels of CO2 in the air in the past weren't high enough to prompt the breathing response properly (human breathing is controlled largely by blood CO2 levels).
Anything you can do externally will tend to evolve out. That's why humans can't make their own Vitamin C and half of them need glasses. Keeping a trait in the population does require keeping up the selective prrssure, which is eugenics.
completely anecdotal. my earliest childhood memories in india were of asthma, sinusitis and constant cold. this was consistent until i was 26 and since then I've moved to the US and lived in New York with 0 days of sinusitis or breathing trouble. and i fallback to trouble breathing when i go home again.
even New York is so much more better than Bangalore or my small village in the middle of coffee farms
I just made a comment about having good air quality but with summer fires we were getting smoke for weeks at a time so I got an air purifier. My kid wasn't struggling horribly but I did notice right away after putting one in his room that he slept better and his breathing seemed so much more relaxed at night and it just felt like it made a noticeable improvement to me.
During my childhood, I lived across the street from a brewery. I suffered from chronic sinusitis for years, and no one understood the cause.
When I moved to a different part of town, the problem immediately stopped.
The same thing happened to one of my classmates who lived in the apartments next to me.
Bangalore has historically (over decades) been known to have a high incidence of asthma due to the high pollen in the air. It's been made worse in recent years due to pollution. The pollen is present for a significant portion of the year while other pollen regions in the world tend to have it for a smaller duration.
I live in British Columbia so we have fairly good air quality. But with the yearly fires lately summer air some years is poor. So one year with the fires smoking and air quality getting poor I got an air purifier for my kids room and the living room.
It is only anecdotal but right away if felt like he had better sleeps. The smoke wasn't thick as it was from fires hundreds of miles away and it wasn't like any of us were hacking or coughing crazy but in hindsight I felt that my young son who would have been effected the most slept better and his breathing at night seemed quieter and easier.
I've been meaning to do some data mining on how much PM2.5 differs with even a few hundred feet of elevation. I have a theory that even around Silicon Valley, living even up a little bit in the foothills would have you breathing massively cleaner air most of your life vs living in the pits of the valley. I see it all the time when I'm out there for recreation or just driving, the smoggy haze all over that just sits in the valley and the Bay. It's probably not too tough of a data processing challenge to compare the stats on Purple Air AQI sensors in reasonably close geo proximity vs elevation to get some statistically-significant data on this.
When I talk about health implications I often end up saying "but it's less bad than living next to a street" which statistically many things we spend time optimizing about are.
However most people live next to a busy street ...
There is a big difference between believing something is true, and demonstrating it is true and measuring the effect. One is a vibe. The other can drive policy.
There is a big difference between believing something is true, and demonstrating it is true and measuring the effect. One is a vibe. The other can drive policy.
It's not pointless anti-intellectualism, it's pro-humanism.
History holds enough examples of intellectuals who out of absolute lack of any human compassion subjected fellow human beings to anti-humane conditions, hoping to find and push the limits of their bodies and psyches in order to maximize profits, ahem, sorry, optimize spending.
And those who you hope to be able to set "policies" on further cramming of people into the machine are exactly those who profit off that.
Yet there are always heart/right hemisphere dead morons who need precise numbers and conclusions written in blood instead of simply relying on common sense.
It was news to me that the lung damage from pollution isn't necessarily permanent in children, if a change in environment happens early enough. Up until reading this, I was under the impression it would be.
We had a lot of construction work in the neighborhood, our house covered in fine dust particles each day. My kid got asthma in the same period, keeps asking when she can stop taking the medicines, and I say "I don't know" thinking "probably never". But maybe now the construction work is over, there is hope? (And if construction starts again, we know that it is better to move, because there is hope.)
While having something done at Stanford's hospitals, at one point I was placed in a room with signs indicating it was on a heavily filtered ventilation system rated for COVID, etc. It was striking to be in an environment with air almost to clean room quality.
What is more amazing to me is I thought this wouldn't be localized. I thought we have on earth and one atmosphere but clearly not? Like the standard of living can wildly change if we change our own local area. We don't need people in Montreal or Paris to come up with a plan?
So unlike greenhouse gases, which can last in the atmosphere for years, seems like NO2 and particulates only stay in the air for less than a day or a few days. This is an amazing little fact because we can start small and call for meaningful reform where we live without requiring a global coordination. Maybe there will be a global consensus later but it doesn't matter because we can start making improvements today within our own local context. The bonus is we will likely also lower our own carbon footprint as we reduce our other emissions. I think this is the "selfish" breakthrough we need to convince people.
When I say it doesn't matter, I don't mean like cross border contamination does not happen but rather that we can improve our own lives with our own action regardless of what others do.
The obvious actionable thing that you can do for your own life is to stop using or being around gasoline or petrol powered two stroke engines such as in a leaf blower. But we can do more. We can completely ban these two stroke engines from being sold at all and that will bring meaningful improvements in weeks, not years.
The problem is to make more impact, we will need to actually get people to give up or retrofit their existing equipment. We will need to educate people about the harms that these things cause and why the change is good. However, in today's siloed world, I don't think it will be easy at all. So perhaps the most difficult part ironically in a very connected and yet siloed world is the marketing of this idea and connecting the required change in behavior with the benefits.
As we saw with the leaf blower example, the costs are concentrated, yes but so are the benefits! The benefits are NOT at all diffuse because guess who benefits the most from not inhaling in gasoline fumes? The person operating the leaf blower!
The localisation of it struck me when I read an Irish EPA report on traffic-related air pollution a few years ago that recommended carrying your child if you were walking regularly near heavy traffic. The air at 0.8m (their breathing height) has 5-15% more NOx in it than the air at 2m (the height they would breath at being carried by you).
I remember reading something similar about walking on the part of the pavement furthest from the road, because being an extra meter or so away makes a big difference
This is a reminder that getting an air purifier with high airflow filters (NOT HEPA!) is lifechanging in cities with high pollution levels.
I recommend getting one of these https://www.youtube.com/watch?v=sQGfO4hNb60 and just slapping a MERV 12 to 16 filter on it, you can get a whole roll off aliexpress for cheap and replace them monthly if you wanted to and it would be cheaper than 1 hepa filter replacement. They can also filter vastly more air, while you can keep hepa for 6 to 12 months MERV will filter a lot more air.
The sad thing is... when the ULEZ went into effect, there were some wild conspiracy theories about it. Suddenly even my father was an expert and viewed it as sinister government intervention - all because of youtube crackpots. I couldn't get him to relate to my view that cleaner air must be a good thing.
I bet if some youtube weirdos pushed out videos against "big soap" for making us unnecessarily clean our hands after pooping... we'd have a growing following of angry "freedom from big soap" people.
My anecdata: I have a Japanese friend who was born in 1964. She grew up in Yokohama for the first ten years. Japan didn't pass its first (serious) environmental protection law until 1967. She said many, many of her friends had asthma. Fast forward 50 years, very few children have asthma in Yokohama.
I will never forget watching this documentary about a Canadian man, Doug Rogers, who went to Japan in 1964 to train martial arts at a dojo. This YouTube video[1], watch it from 1:00 to 1:10. The air pollution is simply stunning. It shows you just how terrible the air pollution was in Tokyo in 1964. Today, it is night and day. The same is true for most large cities in highly industrialised nations.
Link to the original study below, free to access [0]. The key data appear to be this:
>At baseline, 184 (14%) of 1280 children with successful FEV1 measurement in London had a clinically low FEV1 (pre-bronchodilator FEV1 <80% of predicted value) compared with 126 (9%) of 1339 children in Luton (appendix p 8). At the end of the study, these values had dropped to 51 (9%) of 585 children in London and 41 (7%) of 606 children in Luton (appendix p 8).
So the proportion of children with low lung function dropped from 14% to 9% in London, and from 9% to 7% at the comparator site in Luton. It's not that much different, though any improvement is welcome.
349 comments
[ 0.23 ms ] story [ 46.9 ms ] threadVisiting London used to mean blowing your nose to black snot for a week afterwards, these days living in London it's pretty good.
https://www.theguardian.com/uk-news/2026/jul/18/london-under...
Whenever my best mate goes on about having access to "cultural experiences" that I don't have for living in the sticks I remind him it comes at the cost of massive tube bogeys. :P
Sources:
https://www.bbc.com/news/articles/c75q9d2pqyeo https://www.theguardian.com/environment/2026/jun/12/emergenc...
Rising natural gas prices due to the Ukraine war also made even more people install fireplaces (as if that was cheaper).
Surprise surprise.
https://en.wikipedia.org/wiki/Sanatorium
I guess the modern descendants are the health retreat, the rural airbnb, and the day spa that offers oxygen therapy.
I have always been and am still baffled by this. My whole family loses their minds if there is even a slight draft or AC, whether in the house or car. When my brother visits he incessantly closes car vents and windows. Parents constantly nag to put on warm clothes and avoid drafts etc., and when we inevitably get sick a few times a year mostly from school transmitted cold viruses they gloat about it.
Maybe it's a cultural thing from times without good heat/insulation where drafts meant an actual freezing house, which, yes that would actually have an impact on health.
I bought a couple reasonably priced HEPA purifiers and I change the filters on schedule. Replacement HEPA filters are very cheap.
Also watch out for things that we do indoors that can generate bad air quality. I had a friend who bought a VOC meter and noticed very high readings in his kid's room. He traced the source to his chemical and paint cabinet nearby, which he never considered because he couldn't smell anything. Throwing out a lot of the old containers dropped the measurements to the unmeasurable range.
DHH is also a fan (pun not intended?): https://world.hey.com/dhh/air-purifiers-are-a-simple-answer-...
If you pair if with an Apollo AIR-1 you can have home assistant ramp up and down the fans with a PC fan controller based on live readings of PM2.5 in your home. I did this with the help of Claude code.
https://www.thingiverse.com/thing:6826527
https://makerworld.com/en/models/2470181-nukit-tempest-euro-...
However they look somewhat commercial and I'm not sure the funding/incentives so definitely corroborate with other sources.
Having said that, there are reviews of some DIY models reviewing CADR[1], and it's bizarre to complain about testing decibles since Arctic P14 fans, the most commonly recommended fans, are a thouroughly tested product. Running them at around 25% based on lower PM2.5 readings is almost inaudible from experience.
[1] https://www.youtube.com/watch?v=ZjGJN57DgA8
Though, looking it up it seems that prices for the Winix Zero (including one set of filters) have doubled since I last bought one.
The more effective the filter the more it restricts airflow. If a filter is only 99% effective instead of 99.99% but allows double the airflow, it provides nearly double the CADR. To benefit from HEPA you need a clean side and dirty side, like in a clean-room setup.
https://en.wikipedia.org/wiki/Clean_air_delivery_rate
I used to work in the cleanest room in the state, that wasn’t a lab, back when I lived in Adelaide, and top-inlet button-outlet in a raised floor data centre is how the air handling units in the main data hall worked, so you can simulate that to a certain extent.
> The more effective the filter the more it restricts airflow.
This isn’t the whole story. Surface area and flow rate are factors.
A residential home is aiming to improve air quality, rather than grow flawless silicon ingots etc.
But a HEPA filter is better than no filter. Even if would be more effective with another.
(Also depends on size of hepa filter and room to clean. Large enough filter and small enough space and Hepa can clean all the air)
If you get to recycle the air through the filter several times, MERV-13 offers much better performance tradeoffs for a residential air purifier because you can recycle the air through it much faster at acceptable noise levels. My home air purifier recycles the volume of my home every 15 minutes or so, vs HEPA filters which produce totally clean air, but since it just mixes with the dirty air that doesn’t matter as much as the rate at which it cleans air.
This level of filter goes in the central air system.
The HEPA purifiers are for scrubbing the finer particles.
Air purifiers are designed to run 24/7 and all they do is catch particles. Eventually all the particles will be caught. The one I got also detects if there is a lot of particles and will spin faster accordingly.
Air filters don't work like sieves. The smallest particles are easier to block than the mid-sized particles. See:
https://en.wikipedia.org/wiki/Mechanical_filter_(respirator)
Clean Air Delivery Rate is often specified for specific pollutants. One is smoke, which is mostly small particles.
According to hepacart [1] 99% HEPA filters do not even exist, since HEPA seems to be clearly defined:
> HEPA filter definition, which requires a filtration efficiency of 99.97% for particles as small as 0.3 microns. "HEPA-type" filters may capture larger particles but are not effective against the finer particulates that true HEPA filters excel at removing.
[1] https://www.hepacart.com/blog/dont-be-fooled-by-hepa-filter-...
What matters is the gradual removal of particles from the air.
The HEPA purifiers I have move enough air that everything gets scrubbed. It works.
My house has a separate central air system with a non-HEPA air filter with a decent MERV rating for the bulk filtering. The HEPA air purifiers do the scrubbing of finer particles.
Don’t overthink this. This looks like knowing just enough to be dangerous but missing the big picture.
You have an air purifier in your kid's room. If this is a fairly large apartment or a house, and you have central air running, how much purer is the air in that room? If your central air system is modern and continuously circulates air throughout the house at a low fan speed, you're effectively trying to purify your whole house with that low-output room-sized HEPA filter. Have you done measurements to see if it does anything?
There are ton of variables here. One is where the return air intake is. My house only has a single return air vent in the hallway on a 10' ceiling (the furnace is directly above that in the attic). I think this is not-uncommon in the western US.
I have a room-sized purifier in each room on the floor, and they accumulate considerable dust. What I don't know is how much of that would have been successfully pulled out into the hallway, if I didn't have the vacuum of the purifier.
This is impossible for me to A/B test meaningfully given all the environmental variables - wind (house isn't airtight, wind pushes into leaks harder), wind direction (wind from the desert brings sand and other small particles), humidity, etc.
If anyone has reading material on properly controlled experiments in this regard it'd be really interesting to see. I honestly don't know if they're more effective than disabling them and allowing the central HVAC a chance to pick it up sans airflow-tug-of-war. My hunch is it's not worse, though I have no expertise here.
Long-winded post but I'll close with an anecdote: when we had those wildfires in the Bay Area back during covid, they were absolutely more effective at getting the soot and smell out of all of our rooms than the status quo.
edit: One thing to be aware of if someone is evaluating these, all of the claimed numbers from manufacturers are based on you running the air purifier on the absolute highest speed it offers. Almost no one actually does this in on these consumer grade freestanding ones, especially in bedrooms, because they're quite loud.
If you put a standard sized air purifier with a HEPA filter in it into a room it will absolutely lower the dirty air of the room. Because over time you're lowering the particle count.
If I turn my air purifier on in my room even with the door open the air quality sensors improve their readings quite dramatically.
I drive the car, you buy the purifier.
You don’t think the parent commenter is also using transportation?
The pollution from transport also occurs with trains, buses, and any other vehicle that has wheels, brakes, or moves fast enough to stir up the air and kick particulates into the air.
People do what they can and control what’s within their reach.
And yes other means of transport also does pollute, but amount is is critical here. You need much less public transport than you need individual cars.
Am I bitter about that? Yes. There is nothing wrong with wanting the best for you. There is something dearly wrong with using what's best for you to make life worse for others.
buying a new house will have $40k in reltor fees alone, $2k for movers, plus the, you know, hundreds of thousands for the new house. and what if I like my current house, it's in a busy hip area?
or should I launch a multi-year lobbying campaign in the city and/or state and/or national level to have roads moved?
Living in the country gave me bad hay fever/asthma in the city much less asthma.
Not exactly the same thing.
the only plants that survive these days are the ones that spam a ton of pollen, so it gets selected for aggressively.
I’ve got a sensor that can detect no2 and it noticeably spikes when using gas. Switched to induction after that.
Does the area immediately above where the gas stove was have an exhaust fan that vents to atmosphere?
I would have assumed a properly specced exhaust fan would capture and remove combustion products from a gas stove?
I suspect a sufficient ventilation would require something more like a lab fume hood that can pull a negative pressure on the area around the stove.
And from what I have seen, a good number of exhaust fans are straight up fake and just ventilate back in to the room rather than ducted outside.
Culinary Cargo Cult.
It's massively easier to just not create the no2 by replacing gas with induction, and to vent the smoke outside rather than trying to trap it in a filter. I think the introduction of cheap consumer air quality sensors like from IKEA will start to make this problem a lot more visible to people.
On the other hand, when water turns into steam at standard atmospheric pressure, it expands in volume by about 1,700 times.
Whereas the gas in your stove is already a vapour, mostly methane, turning in to mostly water vapour and carbon dioxide. So the expansion ratio isn’t going to be anywhere near as high as that.
I’d say you’re still right.
Still, I wonder to what extent an exhaust fan does help.
If the exhaust fan can vent x cubic feet per minute and the room is y cubic feet in volume then it takes z minutes to full ventilate the room, etc etc.
You’d sure notice if the air in your kitchen was swooshing about 671 miles per hour.
Nope.
> It helps that the insides of my lungs are being squeezed outwards by the same force.
So you agree your first statement is incorrect. I’m glad we sorted that out.
So I am a bit wrong, but you are very wrong.
Do you have a source for that? Because as far as I can see, asthma isn't _that_ less common in countries where gas stoves are barely used, such as germany. Still has like 60-70% of the asthma cases the US has. There's also a ton of other pollutants the US hasn't yet forbidden, but the EU has, which could also explain a lot of the difference in rates.
Don't get me wrong, it's certainly a good idea to get rid of gas stoves. I just think it's a bit much to declare them the primary cause of asthma.
That makes sense but the unverified claim is that gas stoves are the main contributors to asthma.
'Replacing gas stove can help asthmatics as much as some drugs, US experts find'
https://www.theguardian.com/environment/2026/jul/24/replacin...
It's better now with more EVs and low pollution vehicles and the street should be pedestrianised from October.
There is evidence of a lot of ugly diseases caused by this, without even mentioning the constant 40+ dB background noise.
Plus the idea of having everything within a 15 minute walk including access to public transport.
And pollution from bus or tram is much easier to control. Looking at you petrolheads who like to "Rolling coal"
In London now many if not most buses are electric.
Once you build anything of significance, a highway gets built to it anyway.
Also, quitting smoking definitely eases a number of symptoms, especially if you're not at the point of chronic emphysema. The reduction of inflammation triggers alone after a bit of time is fairly significant. Less coughing, less mucus buildup, etc.
'"I was absolutely stunned when I first saw the results," Prof Chris Griffiths, a senior author on the study, at Queen Mary University of London, told the BBC.'
Except that they do undo the damage.
“ After 15 years, your chances of getting lung cancer are almost the same as someone who has never smoked.”
https://www.nhs.uk/conditions/lung-cancer/prevention/
https://www.verywellhealth.com/risk-of-lung-cancer-in-former...
This study looks more broadly, notably also at onset of smoking:
https://jamanetwork.com/journals/jamaoncology/fullarticle/27...
And this is the TL;DR:
“ Thus, those who quit smoking at ages 15 to 34, 35 to 44, 45 to 54, and 55 to 64 years avoided an estimated 100%, 89%, 78%, and 56% of the excess cancer mortality risk associated with continued smoking, respectively”
https://old.reddit.com/r/OldSchoolCool/comments/1v73w9s/hydr...
'"I was absolutely stunned when I first saw the results," Prof Chris Griffiths, a senior author on the study, at Queen Mary University of London, told the BBC."'
HN needs a 's/^scientists stunned by/Scientists notice/i' filter for Titles.
Europe has quite a few cities where traffic is increasingly discouraged from going to the inner cities. Cities like Paris and London are much transformed from what they used to be and it shows in the health statistics.
It's not just the particulates but also nitrous oxides (nox) produced by combustion engines. Nox is correlated with lots of health issues. Take it away and you see lower rates of chronic lung issues, cancer, development issues with kids, etc.
But yes, tires are also an issue. But a fairly minor one to anything coming out of a combustion engine.
Mass transit indeed is nice in big cities. Removes the need for taking the car.
No shit Sherlock.
During the 90s "Fat is evil" craze, all yogurt was replaced with "Fat free" yogurt that had 100 extra calories worth of sugar.
The yogurt aisle in the US is still primarily made up of this garbage product category which exists based on utter falsehoods pushed by the sugar industry. 30 years later and we are still constrained by what ignorant fad chasers in the 90s did.
Regens braking means significantly less brake dust, especially at city speeds and with blended braking.
> Although…rail might solve those?
Trains still have brakes. Some can regen brake but because they usually don’t have batteries they need the rail or overhead gantry to support inputs.
But on a passenger-mile basis, I expect an electric train produces essentially no particulates compared to a car, even a light rail on tyres. I do not however have numbers.
https://engineering.nyu.edu/news/subway-air-pollution-dispro...
But I expect it's much better in open-air rail systems.
For all that I did not care for them originally this is probably something full-height platform screen doors help with, assuming the trains themselves are also filtered that would keep the pollutants clear of drivers and users, although it does not exactly resolve the question of managing their presence in the tunnels themselves, and I could see things get pretty dire in case of breakdowns.
It's much less wear and tear than friction brakes.
https://en.wikipedia.org/wiki/Dynamic_braking
We don't all live in the city.
Yeah that seems to be the general problem here. Electric car champions and city dwellers living in a bubble.
Of the three Villages I know well (my sisters, the one I lived in until moving to a larger 8000 person town, and the one with the primary school) I can’t think of any
Likewise the tiny hamlets I drove through on the way to school didn’t have people parking on the road, there’s simply no room. You occasionally get delivery vehicles stop and it causes chaos.
Different to cities in that there isn't remotely the public transport infrastructure to support getting rid of cars, or the private facility to support electric overnight charging for the longer distance car-commuting etc that isn't generally needed if you live in cities.
Things are improving with technological advance but - again - not everybody can afford those advances and the latest models.
It's a completely different lifestyle living in those sorts of places in some respects.
Even including your towns the vast majority of houses have off street parking, at least according the the rac
You have a very niche issue.
1) storing car on public land at home and office
2) driving excessively long mileage each day
3) having a small capacity car
This is a tiny number of people.
That's still leaves millions (?) of households with on street parking.
Most commuters outside cities get on quite ok with normal cars - because they have to - and a third of them is hardly "niche".
You’re combining. My mother doesn’t have off street parking as she lives in a town. She’s one of the 30%
If she had a typical ev she’d have to charge it once a month.
You’re talking the 30% without off street parking and have high mileage (same needing more than one charge a week).
You can probably get away with that in most cases with on-street parking with a mix of commercial chargers and work if you're lucky.
That "probably" is the point. Your average normal car user (especially in financially challenged times) fighting for a car space on their street is not motivated to take on that higher risk at higher cost in a less competitive market to keep the equivalent of HN demographics happy.
I can’t think of a single house in my sisters village without parking. The village hall also has a carpark with two 7kW chargers.
It's annoying though that EV's need that extra Darth Vader on wheels sound to warn pedestrians, I'd prefer them to be as quiet as possible.
But I'll take it if diesels and two-strokes will die in a fire
So yeah.
That said not clear to me about PM2.5 is I've never seen anything legit seeming that tries to characterize the harm based on the type/source. Though it seems agreed diesel is especially bad.
In some areas of London the ULEZ has been so successful that the measured NOx is now coming mostly from gas boilers used for heating, probably mostly old large commerical units.
So shifting from gas boilers to heat pumps and from gas ovens and stoves to electric/indusction is also beneficial.
Note that because this purifier is mounted at the window, it filters incoming air from outside, not the indoor VOCs that are already in the residence. The indoor VOCs will simply have to get exhausted from elsewhere due to the air pressure.
What I am suggesting is that my need for activated carbon is slightly less because I am rapidly pushing the VOCs out in the resulting exhaust.
It's incredible this is even in debate. It's one of those intuitive things well known since the reduction of coal burning and smog during the industrial revolution in London?
https://www.theguardian.com/politics/2023/aug/01/fake-tweets...
https://www.pollcheck.co.uk/gb-polls
We're going to see the same when EV-only mandates, true zero emissions zones, start appearing across the next decade.
Show you how people are out of touch with reality. Even something commonsensical like what you mentioned is often countered with - "Show me the data"
Hormesis and natural selection have been driving factor of evolution for a long time.
Anyway, by your own reasoning, wouldn't sensitive lungs be an advantage? The incentive to find cleaner air is also breaking away from the pack. Every civilization in history has started out that way. It takes more than mere brute force to beat the competition.
Larry Niven played with this in one of his stories; a time traveller from the far (and highly polluted) future has to use mechanical breathing assistance, because the levels of CO2 in the air in the past weren't high enough to prompt the breathing response properly (human breathing is controlled largely by blood CO2 levels).
even New York is so much more better than Bangalore or my small village in the middle of coffee farms
However most people live next to a busy street ...
Sure but they had to live in Luton
https://clara.southlondonscientific.com/
He also runs this repo:
https://github.com/southlondonscientific/aeolus
There is a big difference between believing something is true, and demonstrating it is true and measuring the effect. One is a vibe. The other can drive policy.
There is a big difference between believing something is true, and demonstrating it is true and measuring the effect. One is a vibe. The other can drive policy.
History holds enough examples of intellectuals who out of absolute lack of any human compassion subjected fellow human beings to anti-humane conditions, hoping to find and push the limits of their bodies and psyches in order to maximize profits, ahem, sorry, optimize spending.
And those who you hope to be able to set "policies" on further cramming of people into the machine are exactly those who profit off that.
Yet there are always heart/right hemisphere dead morons who need precise numbers and conclusions written in blood instead of simply relying on common sense.
We had a lot of construction work in the neighborhood, our house covered in fine dust particles each day. My kid got asthma in the same period, keeps asking when she can stop taking the medicines, and I say "I don't know" thinking "probably never". But maybe now the construction work is over, there is hope? (And if construction starts again, we know that it is better to move, because there is hope.)
In the UK's far-right media culture, Khan's ULEZ is painted as fringe extremism, not as a common sense public health measure.
So unlike greenhouse gases, which can last in the atmosphere for years, seems like NO2 and particulates only stay in the air for less than a day or a few days. This is an amazing little fact because we can start small and call for meaningful reform where we live without requiring a global coordination. Maybe there will be a global consensus later but it doesn't matter because we can start making improvements today within our own local context. The bonus is we will likely also lower our own carbon footprint as we reduce our other emissions. I think this is the "selfish" breakthrough we need to convince people.
When I say it doesn't matter, I don't mean like cross border contamination does not happen but rather that we can improve our own lives with our own action regardless of what others do.
The obvious actionable thing that you can do for your own life is to stop using or being around gasoline or petrol powered two stroke engines such as in a leaf blower. But we can do more. We can completely ban these two stroke engines from being sold at all and that will bring meaningful improvements in weeks, not years.
The problem is to make more impact, we will need to actually get people to give up or retrofit their existing equipment. We will need to educate people about the harms that these things cause and why the change is good. However, in today's siloed world, I don't think it will be easy at all. So perhaps the most difficult part ironically in a very connected and yet siloed world is the marketing of this idea and connecting the required change in behavior with the benefits.
As we saw with the leaf blower example, the costs are concentrated, yes but so are the benefits! The benefits are NOT at all diffuse because guess who benefits the most from not inhaling in gasoline fumes? The person operating the leaf blower!
I recommend getting one of these https://www.youtube.com/watch?v=sQGfO4hNb60 and just slapping a MERV 12 to 16 filter on it, you can get a whole roll off aliexpress for cheap and replace them monthly if you wanted to and it would be cheaper than 1 hepa filter replacement. They can also filter vastly more air, while you can keep hepa for 6 to 12 months MERV will filter a lot more air.
https://www.theguardian.com/commentisfree/2026/aug/18/ulez-h...
I bet if some youtube weirdos pushed out videos against "big soap" for making us unnecessarily clean our hands after pooping... we'd have a growing following of angry "freedom from big soap" people.
I will never forget watching this documentary about a Canadian man, Doug Rogers, who went to Japan in 1964 to train martial arts at a dojo. This YouTube video[1], watch it from 1:00 to 1:10. The air pollution is simply stunning. It shows you just how terrible the air pollution was in Tokyo in 1964. Today, it is night and day. The same is true for most large cities in highly industrialised nations.
[1] https://www.youtube.com/watch?v=CBFx1a4L2ig
>At baseline, 184 (14%) of 1280 children with successful FEV1 measurement in London had a clinically low FEV1 (pre-bronchodilator FEV1 <80% of predicted value) compared with 126 (9%) of 1339 children in Luton (appendix p 8). At the end of the study, these values had dropped to 51 (9%) of 585 children in London and 41 (7%) of 606 children in Luton (appendix p 8).
So the proportion of children with low lung function dropped from 14% to 9% in London, and from 9% to 7% at the comparator site in Luton. It's not that much different, though any improvement is welcome.
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2...