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thelastgallon 3 hours ago [-]
China has 350 million electric two-wheelers, 20 million EVs. China reduced air pollution from transportation by 80% in a decade.
Delhi: 442. Lahore: 334. Beijing: 16. These are the levels of PM 2.5, one of the principle measures for air pollution, on November 19. How China cleaned up its air pollution – and what that meant for the climate: https://theconversation.com/how-china-cleaned-up-its-air-pol...
thelastgallon 1 hours ago [-]
Outdoor pollution ---> Use these for transportation: walk, bicycle, e-scooters, public transit, electric 2 wheeler, EV
Indoor pollution ---> Use these for cooking (induction, electric resistance) stove, heatpump waterheater and furnace for HVAC
Would also be nice to do: stop using coal, gas power plants. These are usually farther out from cities and probably not the most urgent. (except when Elon Musk or new DCs decide to use gas turbines in cities).
It is important to use metrics and language that people can understand. Cigarette smoking is very well known, because public health initiatives make sure the harm is labeled. Air Pollution and Cigarette Equivalence: https://berkeleyearth.wpengine.com/air-pollution-and-cigaret...
Cars and automobility have killed 60–80 million people since their invention. 1 in 34 deaths are caused by cars and automobility with 1,670,000 deaths per year. Car harm: https://news.ycombinator.com/item?id=39465354
>Delhi’s air pollution equivalent to smoking 50 cigarettes
Per day, which for some reason the headline didn’t include. Two packs a day is a pretty terrible baseline. At least it’s not addictive.
thelastgallon 22 minutes ago [-]
Thanks for catching that, yes, per day is critical to understand the harm. I edited my post.
saidnooneever 18 minutes ago [-]
most pollution on my area is a steel refinery larger than my town :'). the air is less healthy than chainsmoking. we have heatpumps and electric everything. costs for civilization is super high, but these major main polluters just get billions given to them for cleaner systems which will never happen.
depending on where you live, its really hard to motivate to take part in generating less polition due to the involved costs and living costs already being too high
briandear 40 minutes ago [-]
So you support nuclear power?
thelastgallon 24 minutes ago [-]
I support solar. Democratize energy, everyone should have the right to produce and store energy.
1) Plug-in solar and batteries are plug-n-play. This is the first step to teach everyone energy literacy and numeracy.
2) Vertical panels immediately add 3 - 4 hours. Vertical panels have zero real estate cost and no need to build costly and slow transmission infrastructure. Every building in a city can produce energy.
3) EVs to store excess energy during the day and supply power back to the grid later.
1.8 billion vehicles connect 4 billion buildings. Buildings can produce clean energy and EVs can store energy. The lowest hanging fruit is to make sure all new buildings are built to produce, and all new vehicles are EVs. New buildings can be built with vertical panels and rooftop. The easiest thing to do is change building code, thats it. Then, we can deal with the built environment.
matthewdgreen 14 minutes ago [-]
This particular brand of confrontational nuclear “advocacy” does not help nuclear. Please consider stopping it.
bee_rider 7 minutes ago [-]
It isn’t really advocacy (there’s no argument for nuclear here, just a sort of distracting non-sequitur).
thelastgallon 14 minutes ago [-]
Solar can be deployed in months, produce immediately. Solar is dirt cheap and continues to get cheaper. 21 - 25% efficiency is normal now and most likely we'll have tandem (silicon + peroskvite) with 45% efficiency. With each doubling of production, solar costs continue to go down. In a decade or two, maybe we'll be able to print solar like paper or textile, or spray paint on any surface. Or grow solar from microorganisms (fastest and cheapest).
A nuclear deployment takes 3 - 5 decades, costs continue to skyrocket, actually needs nuclear scientists to design and run.
Which one do you think is a better choice? If you were an investor, would you put your money on a nuclear plant and wait 3 - 5 decades for returns?
TechDebtDevin 2 hours ago [-]
[dead]
graemep 4 hours ago [-]
A few things standout to me from the article.
1. London when the ULEZ was brought in was already a lot less polluted than historically.Are there gains from that? London was not that bad by global standards.
2. This was followed by the benefits of COVID lockdowns (not a phrase often used!) as pollution dropped much further.
3. Is this effect even across London? Suburbs vs centre, different types of housing etc.? I grew up a the edge of London and the difference in pollution was visible (i.e. you did not need instruments to see signs of it).
4. There was also a reduction in sales of diesel cars which had been heavily encouraged (because of lower CO₂ emissions) in previous decades.
5. As the articles notes, there have been a lot of other changes at roughly the same time. It only mentions one, but there have been significant lifestyle changes, so a lot of potential confounding variables.
foven 3 hours ago [-]
1. Less than historically still has a quite high baseline compared to after ULEZ - if it was more polluted, presumably the change seen here would be more dramatic.
2. Definitely kickstarted it, but we're looking at taking that impact and continuing it for some 5 years after covid ended now.
3. You can look at the ULEZ map and it really covers everything but the outer tube line suburbs [1].
5. The control group in Luton, presumably, has the same lifestyle changes - it's not that far away (about 30 miles), so it is as close as you can get to a one to one comparison, not accounting for the fact that Luton is likely to be more deprived than London (especially in the council estates, which have horrible reputations).
1. yes, but there was probably a bigger gain before. Confirmation would be good.
2. does the study separate impact during lockdown from after?
3. my question is whether it had the same impact everywhere. I would guess very much not.
5. the impact of those changes might not be the same from a much better baseline, nor are lifestyle changes the same in a big city and a small town.
7952 3 hours ago [-]
Particulate pollutant levels decay exponentially and have a substantial drop off with distance. So levels across a large area (like London) are not the whole story.
dabinat 4 hours ago [-]
Wouldn’t most of those effects also be in the control group too?
graemep 3 hours ago [-]
Much smaller place and starting from a better baseline so they would not have experienced the same changes.
ecshafer 12 hours ago [-]
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.
Aurornis 9 hours ago [-]
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.
mrob 7 hours ago [-]
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.
> 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.
enquirewithin 6 hours ago [-]
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.
throwway120385 57 minutes ago [-]
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.
Aurornis 52 minutes ago [-]
> What I can't buy off the shelf is any other non-HEPA filter machine like you're describing
In locations with central air handlers, the filter in that handler already serves this purpose. That’s how my house is set up: Central handler has a high throughout MERV filter. Several rooms have additional HEPA purifiers.
The parent comment also has a fallacious argument in assuming that the CADR is too low if a HEPA filter is present, but even the cheap HEPA purifiers I bought have sufficient CADR to cycle the room over and over.
If you’re in a location with no central air handler (only mini splits or no air conditioning at all) and you have a giant space to cover and you have a constant exchange of air from the outside to overwhelm your filtration (must leave windows open, for example) then what the commenter above would apply. You would be better with a higher throughput, lower rated filter.
For everyone else, it’s kind of a misplaced “well actually” take that has just enough information to feel truthy but misses the bigger facts.
kingstnap 4 hours ago [-]
You don't need to seperate the clean and dirty air. Mixing them isn't as efficient but it should still be roughly 63% efficient (1-1/e).
hxtk 2 hours ago [-]
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.
Aurornis 1 hours ago [-]
> If you get to recycle the air through the filter several times, MERV-13 offers much better performance tradeoffs
This level of filter goes in the central air system.
The HEPA purifiers are for scrubbing the finer particles.
victorbjorklund 5 hours ago [-]
What you wanna say is it might be more efficient with more CADR per minute with less filtration than less CADR an a higher filtration.
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)
adrianN 6 hours ago [-]
Any air purifier should be able to cycle the air in a normal room often enough that it should be quite clean in a short time.
red-iron-pine 49 minutes ago [-]
aye, like as long as you're not leaving the kids window open all night, or multiple other windows open nearby, it oughta fix itself soon enough
tallanvor 6 hours ago [-]
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.
rcxdude 6 hours ago [-]
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.
OroPla 3 hours ago [-]
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.
mrob 2 hours ago [-]
>If you only use 99% it means there are small particles you can't catch.
Air filters don't work like sieves. The smallest particles are easier to block than the mid-sized particles. See:
Clean Air Delivery Rate is often specified for specific pollutants. One is smoke, which is mostly small particles.
patrickk 7 hours ago [-]
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.
if you're going to IKEA for the filters you might as well buy the whole purifier. it's cheap and it works well
red-iron-pine 48 minutes ago [-]
aye, it's ikea and is cheap. this seems like a "i had a ton of parts around + a 3d printer" sorta thing
OroPla 3 hours ago [-]
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.
patrickk 48 minutes ago [-]
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.
smackeyacky 3 hours ago [-]
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
inigyou 3 hours ago [-]
This was done during COVID and made international news.
swiftcoder 6 hours ago [-]
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
patrickk 40 minutes ago [-]
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.
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.
vincnetas 3 hours ago [-]
what a nice externality example "I recommend anyone in those locations buy an air purifier for their kids' rooms"
I drive the car, you buy the purifier.
Aurornis 59 minutes ago [-]
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.
red-iron-pine 44 minutes ago [-]
the purifier is $30 and low maintenance.
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?
kakacik 50 minutes ago [-]
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
II2II 33 seconds ago [-]
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.
energy123 9 hours ago [-]
It's a good start, but for VOCs and gases you'll need activated carbon. Those 2-in-1 filters do exist but cost more. And many are scams because they don't have enough volume of activated carbon.
Aurornis 8 hours ago [-]
Getting rid of the VOC source, if possible, is much easier than trying to filter it.
> Those 2-in-1 filters do exist but cost more. And many are scams because they don't have enough volume of activated carbon.
Any filter with a little bit of carbon added is going to be useless after a few days, or maybe even hours.
The only VOC filters that work have multiple pounds of carbon, with the good filters having upwards of 10-20 pounds. It also has to be replaced regularly.
energy123 7 hours ago [-]
I was referring to the gases from the cars on the highway more than easily removed indoor sources.
Aurornis 58 minutes ago [-]
The pollution from highways is primarily particulate matter: Rubber from tires wearing down, brake pad dust, particles disturbed by fast vehicles and kicked into the air.
LegitShady 5 hours ago [-]
My common winix air purifier has a replaceable carbon filter.
Aurornis 58 minutes ago [-]
Unless it has multiple pounds of carbon, it’s not doing much. These are for show.
Sha1rholder 9 hours ago [-]
Why would they cut corners? Activated carbon isn’t expensive.
Retric 8 hours ago [-]
Because it’s not obvious to most customers that a corner’s been cut. Same reason most new construction in the US sucks.
You can safely put a washer and dryer on the upper floor of a house if you add a proper floor drain, but you’re unlikely to see anyone add a floor drain in new construction because buyers aren’t looking for it. Now multiply that by everything a buyer isn’t looking for and you’re talking real money.
throwway120385 53 minutes ago [-]
What brand of washer do you use so I can studiously avoid it?
mschuster91 4 hours ago [-]
> You can safely put a washer and dryer on the upper floor of a house if you add a proper floor drain
European here, we've always been placing washer/dryer stacks in our bathrooms without needing floor drains. We have machines with a system called Aquastop [1] that stop the water flow if the machine detects a leak inside the system.
You have companies choosing the component that cost 10 cents instead of 15 cents even if the 10 cents component will break 10 times faster than the more expensive one.
Aurornis 8 hours ago [-]
You simply cannot put enough activated carbon in a little foam thing that goes in front of a filter to do anything useful.
The real activated carbon filters have 10s of pounds of carbon. The little black foam thing that comes with those 2-in-1 carbon filters is useless.
gambiting 8 hours ago [-]
And manufacturers do a sneaky swap too, my Coway 150 which is a great air filter by the way, came with a nice thick grid of hexagonal cells each filled with carbon granules - that insert alone weighs like half a kg. I ordered official filter and carbon filter replacements off their website ....got a thin carbon "foam" that weighs maybe 50g instead.
karlgkk 8 hours ago [-]
But it does cost money and so… corners are cut
gib444 7 hours ago [-]
The clue is in your name
tomcam 7 hours ago [-]
Also he had the kid switch to smoking filtereds
solatic 7 hours ago [-]
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.
Might be better to upgrade your air handler if you're putting HEPA in every room.
Gigachad 6 hours ago [-]
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.
lompad 6 hours ago [-]
>Asthma looks to be mostly caused by gas stoves.
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.
d2323 4 hours ago [-]
This was in the news last month and might be referring to the same source
'Replacing gas stove can help asthmatics as much as some drugs, US experts find'
Germany has a ton of NO2 for other reasons, for example diesel motors
AlecSchueler 3 hours ago [-]
> 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.
enquirewithin 6 hours ago [-]
I’ve often wondered about this.
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?
rcxdude 5 hours ago [-]
Can you smell what's being cooked on the gas stove? If so, the combustion products from the stove are also reaching your nose.
enquirewithin 2 hours ago [-]
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.
Gigachad 6 hours ago [-]
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.
throwway120385 50 minutes ago [-]
There's a filter in it you're supposed to change regularly when they're in that configuration.
flir 3 hours ago [-]
> 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.
inigyou 3 hours ago [-]
Air molecules move randomly at over 300 meters per second (not coincidentally close to the speed of sound).
enquirewithin 2 hours ago [-]
That’s a hyper local measurement, and temperature dependant.
You’d sure notice if the air in your kitchen was swooshing around at 671 miles per hour.
inigyou 2 hours ago [-]
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.
nathancahill 11 hours ago [-]
Doctors used to prescribe a "change of air" in the 18-19th centuries. Maybe they still should.
I guess the modern descendants are the health retreat, the rural airbnb, and the day spa that offers oxygen therapy.
aitchnyu 4 hours ago [-]
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.
Hugsbox 59 minutes ago [-]
Brother what are you even talking about
dzhiurgis 3 hours ago [-]
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. All while it's what actually saves their health lol.
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.
pasc1878 5 hours ago [-]
In London that is difficult – there is not a lot of space.
Plus the idea of having everything within a 15 minute walk including access to public transport.
vincnetas 3 hours ago [-]
highway != public transport
And pollution from bus or tram is much easier to control. Looking at you petrolheads who like to "Rolling coal"
pasc1878 1 hours ago [-]
Yes but in London you are never far from a highway you cannot get away from them.
In London now many if not most buses are electric.
inigyou 2 hours ago [-]
Because the highways are built to the places where people and jobs are?
Once you build anything of significance, a highway gets built to it anyway.
roughly 11 hours ago [-]
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.
JayShower 9 hours ago [-]
What about biking near a highway? E.g. in Chicago the lakeshore bike trail is next to a busy 8 lane highway
theplumber 9 hours ago [-]
I remember I’ve read somewhere that jogging is actually net harmful for health in the city due the air pollution.
Generations of men have been taught that when walking with a woman on a pavement, they should always take the side closer to the road allowing her to keep further away from the traffic.
But Dr Iarla Kilbane-Dawe claimed that Londoners should avoid walking too near the kerb because on busy streets, air pollution can be up to a third higher than on the inside of the pavement.
goobatrooba 7 hours ago [-]
So in effect, if you want to be the chivalrous man (which no one forces you to be) you still should choose the roadside side of the pavement.
marliechiller 6 hours ago [-]
Shame you cant remember the source. Ive long since wondered if its actually more deleterious for my health to cycle to work in London due to air quality. I came to the conclusion that youre damned if you do and damned if you dont in the end, as in London at least, many of the tube lines have particulates higher than is considered safe
ben_w 5 hours ago [-]
Probably depends on the tube line; one of them, can't remember which now as I left the country in 2018, left me with black snot on each use. Cycling wasn't that bad, but neither were the other lines.
dzhiurgis 3 hours ago [-]
Add to the mix - indoor gyms are perfect for spreading respiratory viruses.
smcin 9 hours ago [-]
Doesn't it depend on the mix of diesel/petrol/electric? In particular many cities ban or restrict diesel.
danielheath 9 hours ago [-]
Tyre pollution is significant regardless of fuel source.
nerdsniper 7 hours ago [-]
EV's have 100% reduction of NOx/tailpipe VOCs, 100% reduction in soot/tailpipe particulates, 70% reduction in brake pad dust (due to regenerative braking), in exchange for 25% increase in tire wear.
Vehicles are capped at emissions of 3mg/mile of particulates and 30mg/mile of VOC's. Something like 1-2mg of tire material actually becomes airborne PM10 particles every mile (and only about 10% of that for PM2.5 particles).
So, EV's really do a great job reducing emissions from 35mg/mile to <2mg/mile (PM10) or even <0.1mg/mile for PM2.5. A 95%-99.8% reduction in air pollution near highways would seem absolutely fantastic for me and my children!
> EV's have 100% reduction of NOx/tailpipe VOCs, 100% reduction in soot/tailpipe particulates, 70% reduction in brake pad dust (due to regenerative braking), in exchange for 25% increase in tire wear.
I replaced the tires on my Tesla model 3 at 74,000 km and they still had tread above the indicator bars. I'm now at 140,000 km and the tires look great, the back ones look like they're only about halfway done. I might be an outlier but my previous Subaru needed tires every 50,000 to 60,000 km.
Needless to say, the brake pads have never been touched and when I saw the left front one at around 110,000 to 120,000 to patch that tire, it looked like it was just installed. The regen braking almost completely eliminated the brake pad or rotor as a wear item.
enquirewithin 6 hours ago [-]
Yeah, aren’t the EV tyre’s compounded differently in some way to account for the extra weight?
If the weight on each wheel is greater I’d have assumed the tyre would need to be harder, for the same performance.
I would have assumed that would counter the otherwise additional wear, but I keep hearing EV tyre pollution is higher and yet everyone who owns one has always said they aren’t changing tyres an more than they did on their combustion cars.
nerdsniper 5 hours ago [-]
Given that tires have a range of warranties from 40,000 miles to 80,000 miles ... it's possible that the tires are wearing 25% faster but the consumers aren't noticing because it's still around the normal 40k-80k mile range.
dotancohen 5 hours ago [-]
No matter the warranty - I still notice when I replace them.
And the warranty requires proof of periodic rotation. If the tires are wearing evenly, as is the likely case for a new vehicle, then rotation costs significantly more than the pro-rated rebate.
enquirewithin 6 hours ago [-]
Until one has a battery thermal runaway event.
Or an entire truckload of batteries catches fire.
StasheD is an engineer and firefighter, quite eye opening.
One might similarly note the awe-inspiring destructive power demonstrated by tanker trucks of fuel catching fire and causing interstate bridges to collapse.
Surly you don’t mean to imply that a sufficiently large lithium ion battery fire couldn’t burn down a bridge?
Lio 1 minutes ago [-]
You're speculating about something that hasn't happened, using something that doesn't exist; no body is driving batteries large enough to destroy a bridge about.
They are driving liquid fuel tankers that can do that around regularly.
You're going to have to face facts, battery powered vehicles are safer than petrol powered one.
Also consider that as battery tech improves new chemistries lower the risk of fire even more. E.g. sodium based batteries are very inert. There's now way you can make petrol less flammable.
SideburnsOfDoom 6 hours ago [-]
The odds of an EV catching fire are lower than for a gasoline vehicle.
And safer, less-flammable kinds of battery are in development. Less-flammable kinds of gasoline are not.
enquirewithin 2 hours ago [-]
Is that an aged adjusted statistic?
Or is it comparing with the entire gasoline vehicle fleet?
SideburnsOfDoom 2 hours ago [-]
Why ask things that you can easily look up?
vee-kay 7 hours ago [-]
[dead]
9 hours ago [-]
sasaf5 10 hours ago [-]
What about the vicinity of large or uphill streets inside a city? I am curious how the data compares with highways.
lazide 10 hours ago [-]
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.
Surprise surprise.
energy123 10 hours ago [-]
It's a dumping ground for poor people.
tony69 10 hours ago [-]
It’s not like they do it on purpose rubbing hands
weird-eye-issue 9 hours ago [-]
Housing development happens at random?
alex0015 7 hours ago [-]
Developers build apartments where they can make money from them, in other words where they can rent them for enough that they'll make back their investment. It's very expensive to build housing, so the only way to make the investment back and have low rental prices is to try to make the building costs as low as possible. A big part of those costs is the price of land.
weird-eye-issue 7 hours ago [-]
What's even the point of this comment?
alex0015 6 hours ago [-]
The parent and thread seemed to be arguing that low cost housing was intentionally built in places that disadvantaged the people who lived there.
weird-eye-issue 3 hours ago [-]
People don't build housing to intentionally disadvantage people but they do intentionally build housing for disadvantaged people
lazide 6 hours ago [-]
Or, the only places to build houses with reasonable costs are in areas that weren’t already built out with very expensive houses.
Which will tend to be less desirable areas, by definition.
One approach, of course, would be to also make existing houses less expensive/desirable. Notably, wealthy people tend to have the resources to fight efforts to do that.
ben_w 4 hours ago [-]
The other approach is to expand what land is available to build on. I understand that in the UK, farmers consider it a lottery win if they get planning permission for some of their farmland to become housing.
Despite what many in the UK think about it "being full", this is mostly an illusion from how cramped are the parts in which the houses are allowed to go; the country as a whole is mostly undeveloped.
(There are of course other considerations, with "why did you build on a flood plain?" being one of the failure modes in the UK).
lazide 3 hours ago [-]
Well, letting people build houses right next to freeways and/or on things like earthquake faults or flood plains is what is being done here. Which is, uh, also a problem. Since those people are now at much higher risk, eh?
Building on farmland has national security concerns (as countries are slowly realizing), as the country ends up dependent on foreign food imports after awhile. Can't grow food effectively when there is a subdivision there instead eh?
In most high demand areas (which are the ones everyone is complaining about, generally), all the decent land (or even just 'normal' land) is already developed.
Bonus - next time around, even the flood plain land might be 'too expensive' to develop on, and folks will only be able to afford houses at the dump, or in a swamp, or the like. Yay.
Plus the US literally built highways in the middle of poor neighbourhoods.
afiori 6 hours ago [-]
Woke activists love the word "systemic" for a reason.
If a bunch of good people acting in good faith produce a result an evil mastermind would want does it matter if they are good? On many levels obviously yes, on some practical levels the system and the incentives still need to change.
pasc1878 7 hours ago [-]
My anecdote would be the revesre.
Living in the country gave me bad hay fever/asthma in the city much less asthma.
YeahThisIsMe 4 hours ago [-]
You discovered that you have an allergy.
Not exactly the same thing.
gib444 7 hours ago [-]
Same. I visit my family in London and my sleep improves because of no hay fever. Though then I get black boogers, horrible chalky hair, a renewed sense of misanthropy etc
enquirewithin 6 hours ago [-]
You need a NMAID Non-Misanthropic Anti-Inflammatory Drug.
dyauspitr 10 hours ago [-]
As long as the country doesn’t involve large scale farms because the glyphosate sprayed on them causes serious issues.
xyzzy123 43 minutes ago [-]
I'm not really sure the thing they were trying to measure was measurable with the study design and level of funding they had. To be fair, the paper is fairly clear on the limitations and much better than the press release.
The study is supposed to measure how clearing up pollution in London improved children's lung function. The decrease in London was meaningful — NO2 fell about 22%. But particulates fell faster in Luton and NO2 in London is still roughly double Luton's. The gap is larger than the decrease.
By 2022 both cohorts get the same results on blow tests. But how does this happen if we believe that the study's dose-response model is true?
Put another way, if the change in London NO2 is so crucial, how come it doesn't matter that it's double Luton's?
bilekas 10 hours ago [-]
> 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?
Symbiote 7 hours ago [-]
The right (Conservative) and far right (Reform) parties both say they will abolish low-emission zones and other measures to reduce pointing traffic.
They made it into a culture war topic.
mr_toad 2 minutes ago [-]
Cultivating a voter base that consistently acts against their own interests seems to be a winning strategy.
pjc50 2 hours ago [-]
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.
citrin_ru 2 hours ago [-]
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.
iamflimflam1 6 hours ago [-]
The right latches onto anything where a small minority are upset and amplify it. They are the ultimate rage baiters.
rightnutwingjob 4 hours ago [-]
Somehow I don’t think that is the exclusive domain of the Right.
scns 4 hours ago [-]
It is not, but all they have to offer.
_joel 2 hours ago [-]
Reform are latching on to anything to detract from the 5 million pound "gift" to Farage from a crypto billionaire, Christopher Harbourne..
mboto 2 hours ago [-]
Reform is not a far right party. It is important not to polarise.
Hugsbox 50 minutes ago [-]
Reform is a textbook far-right party, I'm not even sure why you'd try to argue otherwise.
thrance 1 hours ago [-]
What is it, then?
Neil44 3 hours ago [-]
Fact check, the conservatives want to block the expansion into outer London. Reform wants to end them all.
_joel 2 hours ago [-]
Ironic, considering it was Johnson that started it before Khan "took the flak"
citrin_ru 2 hours ago [-]
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.
_joel 2 hours ago [-]
How's Reform UK Ltd. done since then? They've lost 2 by-elections and beaten a bin. Sterling job I guess if you listen to any of their members.
4ndrewl 7 hours ago [-]
Bloody Sadiq Kahn and his militant sharia ulez improving the health of forriners. /s
Using scientists being "stunned" should take the same amount of relevance as someone being "slammed" in article titles.
Nition 11 hours ago [-]
It's a direct quote from one of the scientists:
'"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."'
dabinat 10 hours ago [-]
The BBC should have put it in quotes in the headline; I kept the HN title faithful to the original article.
Nition 9 hours ago [-]
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.
satvikpendem 10 hours ago [-]
I know, generally it is not a direct quote, hence "should."
alansaber 9 hours ago [-]
Scientists are only allowed to be stunned when results exceed 5 sigma of deviation
Koffiepoeder 7 hours ago [-]
Or when their papers are retracted for political reasons.
throwaway2037 5 hours ago [-]
To be fair, BBC is aimed at the normies, not the scientifically literate. (No hate on BBC!) Stunned probably gets more clicks than surprised.
bell-cot 1 hours ago [-]
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.
bryanlarsen 11 hours ago [-]
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.
anon48293 10 hours ago [-]
> “ Smokers don't magically undo the damage they did to their lungs after they stop smoking”
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.”
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".
throw310822 4 hours ago [-]
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?
dave7 9 hours ago [-]
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!
"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.
Nition 10 hours ago [-]
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.'
vfclists 9 hours ago [-]
Sounds like an announcement of the latest AI news from Wes Roth. I'm surprised the Professor wasn't "shocked"
Neil44 6 hours ago [-]
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.
cucumber3732842 3 hours ago [-]
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.
powerpcmac 12 hours ago [-]
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
Nition 10 hours ago [-]
The scientist who used the word "stunned" is one of the study's authors.
stuaxo 12 hours ago [-]
I've needed my inhaler way less since the ULEZ came in.
Visiting London used to mean blowing your nose to black snot for a week afterwards, these days living in London it's pretty good.
tarkasteve 9 hours ago [-]
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.
I've not lived in London for more than a decade. I always thought the black snot was from the Tube. Is it not?
mrec 7 hours ago [-]
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.
walthamstow 6 hours ago [-]
People tend to walk 10-15 mins at either end when taking the tube, and will walk more through the day. 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
ifwinterco 6 hours ago [-]
Almost certainly some asbestos dust still in there from prior decades as well, the tube is absolutely filthy and never cleaned properly
I've lived in London all my life and I only get black bogeys on days that I've been on the tube. Before COVID that was every day.
nullify88 10 hours ago [-]
I lived on Upper Street in Angel, London by some traffic lights and there was always a layer of black dust inside. I assumed it was brake particulate.
walthamstow 7 hours ago [-]
Every house inner London is covered in black soot from the days of coal fires. Have you ever seen one after it's been sandblasted?
sokoloff 5 hours ago [-]
Tire wear was probably a greater source than brake wear.
lazide 10 hours ago [-]
It is, but not just from it.
BrunoBernardino 6 hours ago [-]
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)!
elric 7 hours ago [-]
More anecdata: I've been using my inhaler more since moving to a city with worse air quality than my previous location.
flipbrad 8 hours ago [-]
People don't fire their chimneys or have garden bonfires much any more, either.
smashah 10 hours ago [-]
Pretty sure that's due to the tube.
jabl 9 hours ago [-]
What's so uniquely bad about the tube in London? Poor ventilation and brake dust?
vkazanov 7 hours ago [-]
Its the oldest metro in the world. An achieviement, yes, but in old stations ventillation is crap, materials are poisonous, etc.
badgersnake 7 hours ago [-]
Yeah, seems way better now than it was in the 90s though. They’ve improved the ventilation a lot.
pcrh 5 hours ago [-]
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 obviously welcome.
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
astatine 8 hours ago [-]
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.
trial_version 9 hours ago [-]
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.
weird-eye-issue 9 hours ago [-]
Yes, pollution has both acute and chronic effects. What you describe here is an acute effect.
14 9 hours ago [-]
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.
throwaway2037 5 hours ago [-]
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.
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!
IrishTechie 6 hours ago [-]
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).
shawabawa3 5 hours ago [-]
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
collabs 5 hours ago [-]
A quick note for my fellow US Americans -- A British speaker calling it 'pavement' is referring to what we call the sidewalk.
rcxdude 6 hours ago [-]
Most air pollution is pretty localized. CFCs and greenhouse gases are the biggest outliers for how global their effects are.
raphinou 34 minutes ago [-]
Any advice on in and outdoor detectors os small particles for home use?
tomcam 7 hours ago [-]
> Initial results showed children's lungs in London were smaller in capacity than those in Luton
Sure but they had to live in Luton
wartywhoa23 7 hours ago [-]
Newsflash, living in a healthy environment is healthy!
internet_points 6 hours ago [-]
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.)
TheOtherHobbes 4 hours ago [-]
Of course, but governments and corporations have consistently argued otherwise.
In the UK's far-right media culture, Khan's ULEZ is painted as fringe extremism, not as a common sense public health measure.
noelwelsh 6 hours ago [-]
Pointless anti-intellectualism.
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.
dzhiurgis 34 minutes ago [-]
Found the government consultant!
wartywhoa23 1 hours ago [-]
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 either exactly those who profit off that, or eat crumbs from that table.
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.
matsemann 3 hours ago [-]
I grew up in a small town in the mountains in Norway. There is a children's "hospital" there (Geilomo Barnesykehus), where kids come to live because they can't live in the cities. Kids with severe asthma, eczema and some other conditions. It started as far back as the 1930s, still unfortunately a problem so kids have to come live there away from their families.
8by3 4 hours ago [-]
Seems electric cars produce the same or sometimes more non combustion particulates than ICE cars, eg. bits of road and tire that are flung into the air while driving.
So EVs are better than ICE for air quality, but fewer cars even better.
dan-robertson 3 hours ago [-]
I think it’s mostly break dust. Electric cars are heavier but can also hopefully mostly use regenerative breaking instead of break pads. Road vibrations (and wear?) tend to go as the fourth power of weight over the axle and so it tends to be worse for (naturally heavier) electric cars but even worse for goods vehicles.
dzhiurgis 3 hours ago [-]
But london tube have order of magnitude of dust pollution and buses damage roads (aka pollute) 30,000 (yes 30k) times more due to weight.
herbst 7 hours ago [-]
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 ...
itsyonas 7 hours ago [-]
The street isn't the problem. Cars and trucks are. If those streets were filled with people walking, cycling, etc., the health penalty of living next to one would vanish overnight.
adrianN 6 hours ago [-]
A street full of EVs in a traffic jam is also pretty good. No exhaust pollution and low tire wear due to low speeds and low acceleration.
itsyonas 2 hours ago [-]
Sure, but it still has the 90% of issues caused by ICE cars.
herbst 7 hours ago [-]
Ok that's not what I consider a "busy street" but I get your point, need better wording there.
itsyonas 6 hours ago [-]
Why not? A lot of streets often seem busy simply due to the incredible space inefficiency of cars. What I like to do sometimes, when I wait at a traffic light with my bicycle, is to count the actual number of cars that cross during a phase. The amount feels large, but when you count, it's often not more than the amount of cyclists that cross in the next phase, and they take up just a tiny fraction of what cars need.
herbst 6 hours ago [-]
Sure it absolutely makes sense. But for me and my eyes 200 people passing by are somehow still less "busy" than 25 loud and stinky cars. That's what I mean with I need better wording
rsynnott 6 hours ago [-]
Generally, the busiest streets are pedestrianised; you just can't move that volume of people in cars.
(Actually, the _very_ busiest streets are probably major bus gates (where, again, there are no cars), those can have fairly ridiculous density at peak times.
rob74 6 hours ago [-]
Opinion article on this by Sadiq Khan, the London mayor who introduced ULEZ:
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.
wickedsight 5 hours ago [-]
> 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.
At one point during Covid, I tried (not very hard at all) to float a conspiracy that the vaccine was in fact not the poison, but the antidote. That Covid was deliberately designed by governments to filter the 'independent thinkers' (who won't take the vaccine) from the sheep (those who do take the vaccine). So by not taking the vaccine, you were giving the governments what they wanted.
This was because the conspiracy that governments were killing the loyal sheep with the vaccine, therefore only leaving the 'independent thinkers' behind, made absolutely no sense at all to me.
Animats 7 hours ago [-]
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.
unglaublich 2 hours ago [-]
Europe should hurry up adopting ULEZ in every dense urban area. It's completely worth it in terms of health, neurological development, noise and quality of life, and has practically no downsides but "boohoo" from those who make everything into a culture war. A good start would be to immediately ban all two-stroke mopeds aka "super polluters" (emitting 50x as much PM2.5 as a truck), and then follow up with Diesel trucks and delivery vehicles.
It's ridiculous that we voluntarily emit fossil fuel and oil fumes in our densest urban areas.
thecaio 2 hours ago [-]
the framing of this headline - "scientists stunned" while conveying pollution hurts lung recovery is a gem
briandear 44 minutes ago [-]
How about chopping down all of the London Plane trees next? Absolutely disastrous for public health. They are also all over Barcelona and cause nothing but respiratory misery.
Isn't this common sense? What is being "stunned" !!
bjackman 4 hours ago [-]
If you click the link at the top you'll find it goes to an article. The article will often expand upon the text in the link!!!
In this case:
"While we would expect children's lungs to grow year on year, our results indicate that the London children's lung growth had accelerated during the four years to 'catch up' with the control group in Luton to reach similar levels of lung capacity," researchers say.
"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 speed of catch up in lung capacity in the London group was surprising and impressive."
himata4113 6 hours ago [-]
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.
"TNO tested in-use vehicles directly at the tailpipe. Three diesels with DPFs emitted: 3.9–5.3 million particles/cm³ at warm low idle. The same report measured warm Euro 5 direct-injection gasoline cars without gasoline particulate filters at: 50,000–60,000 particles/cm³ at low idle."
"In 2017, the highest diesel was approximately 12 g black carbon/kg fuel, versus roughly 0.4 g/kg for the highest gasoline car.
In 2023, the highest diesel was roughly 8 g/kg, versus approximately 0.7 g/kg gasoline."
"approximately 5% of measured Euro 5b/Euro 6 diesel vehicles exceeded one million particles/cm³, and this small group produced more than 90% of the particle emissions from the tested diesel group"
unglaublich 2 hours ago [-]
- Fuck two stroke engines even more
"Levels in the raw 2S scooter exhaust were as high as 300,000 μg m−3 or 146 p.p.m.(v) from idling. The EU annual mean limit for the protection of human health is 5 μg m−3 (ref. 13), while the US National Institute for Occupational Safety and Health recommends that workers wear special breathing equipment when exposed to benzene at levels exceeding 1 p.p.m. for 15 min. Waiting in traffic behind a 2S scooter, for example, at junctions and while the scooter is idling, may therefore be highly deleterious to health."
[0]: http://dx.doi.org/10.1038/ncomms4749
But cities are full of shitty mopeds and old Vespas, for no benefit but cultural cosplay reasons.
seanp2k2 8 hours ago [-]
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.
2 hours ago [-]
XorNot 12 hours ago [-]
So punchline, probably a good idea to electrify all the cars yeah?
simonsquiff 9 hours ago [-]
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
Aozora7 1 hours ago [-]
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.
jabl 9 hours ago [-]
Absolutely.
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.
garbawarb 2 hours ago [-]
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.
adonovan 7 hours ago [-]
You can switch it off, or make it play one of several different ridiculous sounds.
dotancohen 6 hours ago [-]
On which vehicles can the humming in reverse gear be switched off? I understand the Tesla (my car) and the BYD (expires car) can not turn that off.
zekrioca 2 hours ago [-]
That, and even better when coupled with good public transportation.
mellosouls 11 hours ago [-]
Probably a much better idea first to have a decent public transport and electric car support network throughout the country first.
We don't all live in the city.
hdgvhicv 5 hours ago [-]
And those of us who don’t can just plug in at home.
cryptopian 3 hours ago [-]
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)
ZeroGravitas 4 hours ago [-]
Yes, and...
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.
jimbob45 12 hours ago [-]
That doesn’t solve brake and tire particles. Although…rail might solve those?
jillesvangurp 10 hours ago [-]
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.
6LLvveMx2koXfwn 9 hours ago [-]
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'.
No shit Sherlock.
throwaway89201 8 hours ago [-]
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.
testing22321 9 hours ago [-]
I look forward to the day coke is marketed as “zero fat!”
Do the numbers in that article make sense? 5.8g/km for tyre wear? Generally my tyres last maybe 25000 miles. So at that rate they would lose 230kg. Seems high.
danparsonson 10 hours ago [-]
"Non-exhaust emissions (NEE) are particles released into the air from brake wear, tyre wear, road surface wear and resuspension of road dust during on-road vehicle usage."
I guess they mean total non-exhaust particulates.
lazide 10 hours ago [-]
They might be counting trucks?
masklinn 9 hours ago [-]
> That doesn’t solve brake and tire particles.
Regen 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.
Symbiote 7 hours ago [-]
The usual brake on a train that can't do regenerative breaking is a big grid of resistors to dump the energy as heat.
It's much less wear and tear than friction brakes.
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 track / tunnel maintenance personnel should probably already be wearing respirators if not full breathing apparatus), and I could see things get pretty dire in case of breakdowns.
rsynnott 6 hours ago [-]
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.
mhandley 12 hours ago [-]
Tyre, no, but regen braking almost eliminates brake particles at the speeds I drive in London. But mostly I take the train. Unfortunately the highest I measured on my particulate sensor is not near the roads, but in the tube.
Gibbon1 8 hours ago [-]
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.
OutOfHere 11 hours ago [-]
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.
Terr_ 11 hours ago [-]
> The window purifiers also keep excess CO2 and VOCs out.
I assume you mean that the increased air-exchange (purified or not) helps CO2 that originates inside the house to leave promptly? (Equalizing it with the outdoors.)
Literally "keeping CO2 out" is a much trickier and more-expensive proposition.
OutOfHere 6 hours ago [-]
You are quite correct on both counts.
bad_username 8 hours ago [-]
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.
OutOfHere 6 hours ago [-]
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.
energy123 10 hours ago [-]
You have activated carbon to filter out the VOCs?
OutOfHere 7 hours ago [-]
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.
scotty79 4 hours ago [-]
Who knew that populating Earth with mechanical horses that shit into the air is not such a great idea.
ggm 10 hours ago [-]
s/stunned/pleased/
4ndrewl 7 hours ago [-]
Rtfa. "Stunned" is the actual word the scientist used.
14 9 hours ago [-]
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.
rimworld 6 hours ago [-]
cease all travel and live to 88
Havoc 4 hours ago [-]
And yet we’ve still got people cutting down the enforcement cameras with angle grinders at night
inigyou 2 hours ago [-]
Shame they're not doing it to Flock cameras.
marsven_422 3 hours ago [-]
[dead]
Aeolun 7 hours ago [-]
Scientists stunned healthy living is healthy?
noelwelsh 6 hours ago [-]
Pointless anti-intellectualism.
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.
userbinator 10 hours ago [-]
Short-term gains are likely to produce long-term negative effects.
Hormesis and natural selection have been driving factor of evolution for a long time.
rsynnott 6 hours ago [-]
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).
inigyou 2 hours ago [-]
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.
alansaber 9 hours ago [-]
What is this, eugenics from first principles?
sublinear 8 hours ago [-]
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 line of thinking, wouldn't sensitive lungs be an advantage? The incentive to find cleaner air is also breaking away from the pack. Since humans are social creatures, that's more likely to look like new leadership for followers who have their own reasons to break away.
Every civilization in history has started out that way. It takes more than mere brute force to beat the competition. Survival is just as much about picking your battles and working smarter.
Delhi: 442. Lahore: 334. Beijing: 16. These are the levels of PM 2.5, one of the principle measures for air pollution, on November 19. How China cleaned up its air pollution – and what that meant for the climate: https://theconversation.com/how-china-cleaned-up-its-air-pol...
Indoor pollution ---> Use these for cooking (induction, electric resistance) stove, heatpump waterheater and furnace for HVAC
Would also be nice to do: stop using coal, gas power plants. These are usually farther out from cities and probably not the most urgent. (except when Elon Musk or new DCs decide to use gas turbines in cities).
Researchers say they have cracked how air pollution leads to cancer, in a discovery that completely transforms our understanding of how tumours arise: https://www.bbc.com/news/health-62797777 (discussion: https://news.ycombinator.com/item?id=32788706)
Surprise! Electric cars are already making California healthier (2023): https://electrek.co/2023/02/10/surprise-electric-cars-are-al...
Air Pollution Kills 10 Million People a Year. Why Do We Accept That as Normal? https://www.nytimes.com/2022/07/08/opinion/environment/air-p...
Tiny air pollutants may cause changes in brain structure that resemble those of Alzheimer’s disease: https://www.nytimes.com/2019/11/25/well/mind/air-pollution-b...
It is important to use metrics and language that people can understand. Cigarette smoking is very well known, because public health initiatives make sure the harm is labeled. Air Pollution and Cigarette Equivalence: https://berkeleyearth.wpengine.com/air-pollution-and-cigaret...
Delhi’s air pollution equivalent to smoking 50 cigarettes per day but experts say it can be fixed: https://epic.uchicago.in/delhis-air-pollution-equivalent-to-...
Almost all countries failing to meet mark for PM2.5, tiny particles expelled by vehicles and industry that can cause health problems: https://www.theguardian.com/environment/2024/mar/19/air-poll...
Bees struggle to find flowers because of air pollution: https://news.ycombinator.com/item?id=37434381
Cars and automobility have killed 60–80 million people since their invention. 1 in 34 deaths are caused by cars and automobility with 1,670,000 deaths per year. Car harm: https://news.ycombinator.com/item?id=39465354
Gas stoves pollute homes with benzene, which is linked to cancer: https://news.ycombinator.com/item?id=36364524
Amazon backs power plant that may become top source of US climate pollution: https://news.ycombinator.com/item?id=49249971
Per day, which for some reason the headline didn’t include. Two packs a day is a pretty terrible baseline. At least it’s not addictive.
depending on where you live, its really hard to motivate to take part in generating less polition due to the involved costs and living costs already being too high
1) Plug-in solar and batteries are plug-n-play. This is the first step to teach everyone energy literacy and numeracy.
2) Vertical panels immediately add 3 - 4 hours. Vertical panels have zero real estate cost and no need to build costly and slow transmission infrastructure. Every building in a city can produce energy.
3) EVs to store excess energy during the day and supply power back to the grid later.
1.8 billion vehicles connect 4 billion buildings. Buildings can produce clean energy and EVs can store energy. The lowest hanging fruit is to make sure all new buildings are built to produce, and all new vehicles are EVs. New buildings can be built with vertical panels and rooftop. The easiest thing to do is change building code, thats it. Then, we can deal with the built environment.
A nuclear deployment takes 3 - 5 decades, costs continue to skyrocket, actually needs nuclear scientists to design and run.
Which one do you think is a better choice? If you were an investor, would you put your money on a nuclear plant and wait 3 - 5 decades for returns?
1. London when the ULEZ was brought in was already a lot less polluted than historically.Are there gains from that? London was not that bad by global standards.
2. This was followed by the benefits of COVID lockdowns (not a phrase often used!) as pollution dropped much further.
3. Is this effect even across London? Suburbs vs centre, different types of housing etc.? I grew up a the edge of London and the difference in pollution was visible (i.e. you did not need instruments to see signs of it).
4. There was also a reduction in sales of diesel cars which had been heavily encouraged (because of lower CO₂ emissions) in previous decades.
5. As the articles notes, there have been a lot of other changes at roughly the same time. It only mentions one, but there have been significant lifestyle changes, so a lot of potential confounding variables.
2. Definitely kickstarted it, but we're looking at taking that impact and continuing it for some 5 years after covid ended now.
3. You can look at the ULEZ map and it really covers everything but the outer tube line suburbs [1].
5. The control group in Luton, presumably, has the same lifestyle changes - it's not that far away (about 30 miles), so it is as close as you can get to a one to one comparison, not accounting for the fact that Luton is likely to be more deprived than London (especially in the council estates, which have horrible reputations).
[1] - https://tfl.gov.uk/ruc-cdn/static/cms/images/ulezdetailedmap...
2. does the study separate impact during lockdown from after?
3. my question is whether it had the same impact everywhere. I would guess very much not.
5. the impact of those changes might not be the same from a much better baseline, nor are lifestyle changes the same in a big city and a small town.
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.
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
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.
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.
In locations with central air handlers, the filter in that handler already serves this purpose. That’s how my house is set up: Central handler has a high throughout MERV filter. Several rooms have additional HEPA purifiers.
The parent comment also has a fallacious argument in assuming that the CADR is too low if a HEPA filter is present, but even the cheap HEPA purifiers I bought have sufficient CADR to cycle the room over and over.
If you’re in a location with no central air handler (only mini splits or no air conditioning at all) and you have a giant space to cover and you have a constant exchange of air from the outside to overwhelm your filtration (must leave windows open, for example) then what the commenter above would apply. You would be better with a higher throughput, lower rated filter.
For everyone else, it’s kind of a misplaced “well actually” take that has just enough information to feel truthy but misses the bigger facts.
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.
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)
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.
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-...
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
However they look somewhat commercial and I'm not sure the funding/incentives so definitely corroborate with other sources.
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.
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?
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.
> Those 2-in-1 filters do exist but cost more. And many are scams because they don't have enough volume of activated carbon.
Any filter with a little bit of carbon added is going to be useless after a few days, or maybe even hours.
The only VOC filters that work have multiple pounds of carbon, with the good filters having upwards of 10-20 pounds. It also has to be replaced regularly.
You can safely put a washer and dryer on the upper floor of a house if you add a proper floor drain, but you’re unlikely to see anyone add a floor drain in new construction because buyers aren’t looking for it. Now multiply that by everything a buyer isn’t looking for and you’re talking real money.
European here, we've always been placing washer/dryer stacks in our bathrooms without needing floor drains. We have machines with a system called Aquastop [1] that stop the water flow if the machine detects a leak inside the system.
[1] https://de.wikipedia.org/wiki/Aquastop
The real activated carbon filters have 10s of pounds of carbon. The little black foam thing that comes with those 2-in-1 carbon filters is useless.
DHH is also a fan (pun not intended?): https://world.hey.com/dhh/air-purifiers-are-a-simple-answer-...
I’ve got a sensor that can detect no2 and it noticeably spikes when using gas. Switched to induction after that.
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.
'Replacing gas stove can help asthmatics as much as some drugs, US experts find'
https://www.theguardian.com/environment/2026/jul/24/replacin...
That makes sense but the unverified claim is that gas stoves are the main contributors to asthma.
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?
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.
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.
You’d sure notice if the air in your kitchen was swooshing around at 671 miles per hour.
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.
Funny part is that locals here are absolutely scared of any sign of draft or direct aircon. All while it's what actually saves their health lol.
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.
Generations of men have been taught that when walking with a woman on a pavement, they should always take the side closer to the road allowing her to keep further away from the traffic.
But Dr Iarla Kilbane-Dawe claimed that Londoners should avoid walking too near the kerb because on busy streets, air pollution can be up to a third higher than on the inside of the pavement.
Vehicles are capped at emissions of 3mg/mile of particulates and 30mg/mile of VOC's. Something like 1-2mg of tire material actually becomes airborne PM10 particles every mile (and only about 10% of that for PM2.5 particles).
So, EV's really do a great job reducing emissions from 35mg/mile to <2mg/mile (PM10) or even <0.1mg/mile for PM2.5. A 95%-99.8% reduction in air pollution near highways would seem absolutely fantastic for me and my children!
https://pmc.ncbi.nlm.nih.gov/articles/PMC11636205/#:~:text=W...
Needless to say, the brake pads have never been touched and when I saw the left front one at around 110,000 to 120,000 to patch that tire, it looked like it was just installed. The regen braking almost completely eliminated the brake pad or rotor as a wear item.
If the weight on each wheel is greater I’d have assumed the tyre would need to be harder, for the same performance.
I would have assumed that would counter the otherwise additional wear, but I keep hearing EV tyre pollution is higher and yet everyone who owns one has always said they aren’t changing tyres an more than they did on their combustion cars.
And the warranty requires proof of periodic rotation. If the tires are wearing evenly, as is the likely case for a new vehicle, then rotation costs significantly more than the pro-rated rebate.
Or an entire truckload of batteries catches fire.
StasheD is an engineer and firefighter, quite eye opening.
https://youtu.be/diaUMNONpvw?si=7lxYS8iJHLvCTUkt
https://archive.ph/VadwU : Tanker Truck Fire Collapses Bay Area Overpass
https://archive.ph/4INYw : I-95 Overpass Collapses in Philadelphia After a Tanker Fire
Lithium ion battery fires less so.
Surly you don’t mean to imply that a sufficiently large lithium ion battery fire couldn’t burn down a bridge?
They are driving liquid fuel tankers that can do that around regularly.
You're going to have to face facts, battery powered vehicles are safer than petrol powered one.
Also consider that as battery tech improves new chemistries lower the risk of fire even more. E.g. sodium based batteries are very inert. There's now way you can make petrol less flammable.
And safer, less-flammable kinds of battery are in development. Less-flammable kinds of gasoline are not.
Or is it comparing with the entire gasoline vehicle fleet?
Surprise surprise.
Which will tend to be less desirable areas, by definition.
One approach, of course, would be to also make existing houses less expensive/desirable. Notably, wealthy people tend to have the resources to fight efforts to do that.
Despite what many in the UK think about it "being full", this is mostly an illusion from how cramped are the parts in which the houses are allowed to go; the country as a whole is mostly undeveloped.
(There are of course other considerations, with "why did you build on a flood plain?" being one of the failure modes in the UK).
Building on farmland has national security concerns (as countries are slowly realizing), as the country ends up dependent on foreign food imports after awhile. Can't grow food effectively when there is a subdivision there instead eh?
In most high demand areas (which are the ones everyone is complaining about, generally), all the decent land (or even just 'normal' land) is already developed.
Bonus - next time around, even the flood plain land might be 'too expensive' to develop on, and folks will only be able to afford houses at the dump, or in a swamp, or the like. Yay.
https://en.wikipedia.org/wiki/Ely%2C_Cambridgeshire
If a bunch of good people acting in good faith produce a result an evil mastermind would want does it matter if they are good? On many levels obviously yes, on some practical levels the system and the incentives still need to change.
Living in the country gave me bad hay fever/asthma in the city much less asthma.
Not exactly the same thing.
The study is supposed to measure how clearing up pollution in London improved children's lung function. The decrease in London was meaningful — NO2 fell about 22%. But particulates fell faster in Luton and NO2 in London is still roughly double Luton's. The gap is larger than the decrease.
By 2022 both cohorts get the same results on blow tests. But how does this happen if we believe that the study's dose-response model is true?
Put another way, if the change in London NO2 is so crucial, how come it doesn't matter that it's double Luton's?
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?
They made it into a culture war topic.
We're going to see the same when EV-only mandates, true zero emissions zones, start appearing across the next decade.
https://www.theguardian.com/politics/2023/aug/01/fake-tweets...
https://clara.southlondonscientific.com/
He also runs this repo:
https://github.com/southlondonscientific/aeolus
'"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.
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...
https://old.reddit.com/r/OldSchoolCool/comments/1v73w9s/hydr...
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.'
Visiting London used to mean blowing your nose to black snot for a week afterwards, these days living in London it's pretty good.
Sources:
https://www.bbc.com/news/articles/c75q9d2pqyeo https://www.theguardian.com/environment/2026/jun/12/emergenc...
https://www.theguardian.com/uk-news/2026/jul/18/london-under...
>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 obviously welcome.
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2...
even New York is so much more better than Bangalore or my small village in the middle of coffee farms
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
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!
Sure but they had to live in Luton
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.
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 either exactly those who profit off that, or eat crumbs from that table.
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.
So EVs are better than ICE for air quality, but fewer cars even better.
However most people live next to a busy street ...
(Actually, the _very_ busiest streets are probably major bus gates (where, again, there are no cars), those can have fairly ridiculous density at peak times.
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.
At one point during Covid, I tried (not very hard at all) to float a conspiracy that the vaccine was in fact not the poison, but the antidote. That Covid was deliberately designed by governments to filter the 'independent thinkers' (who won't take the vaccine) from the sheep (those who do take the vaccine). So by not taking the vaccine, you were giving the governments what they wanted.
This was because the conspiracy that governments were killing the loyal sheep with the vaccine, therefore only leaving the 'independent thinkers' behind, made absolutely no sense at all to me.
It's ridiculous that we voluntarily emit fossil fuel and oil fumes in our densest urban areas.
https://www.telegraph.co.uk/news/2026/05/04/scourge-of-londo...
In this case:
"While we would expect children's lungs to grow year on year, our results indicate that the London children's lung growth had accelerated during the four years to 'catch up' with the control group in Luton to reach similar levels of lung capacity," researchers say.
"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 speed of catch up in lung capacity in the London group was surprising and impressive."
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.
[0]: https://www.zh.ch/content/dam/zhweb/bilder-dokumente/themen/...
"High diesel-family averages were approximately 1–3 g NOx/km. Most gasoline-family averages clustered around approximately 0.02–0.15 g/km."
[1]: https://publications.tno.nl/publication/34635198/KxBBl3/TNO-...
"TNO tested in-use vehicles directly at the tailpipe. Three diesels with DPFs emitted: 3.9–5.3 million particles/cm³ at warm low idle. The same report measured warm Euro 5 direct-injection gasoline cars without gasoline particulate filters at: 50,000–60,000 particles/cm³ at low idle."
[2]: https://d-nb.info/137495313X/34
"In 2017, the highest diesel was approximately 12 g black carbon/kg fuel, versus roughly 0.4 g/kg for the highest gasoline car. In 2023, the highest diesel was roughly 8 g/kg, versus approximately 0.7 g/kg gasoline."
[3]: https://trueinitiative.org/insights/true-brussels-emissions-...
"approximately 5% of measured Euro 5b/Euro 6 diesel vehicles exceeded one million particles/cm³, and this small group produced more than 90% of the particle emissions from the tested diesel group"
"Levels in the raw 2S scooter exhaust were as high as 300,000 μg m−3 or 146 p.p.m.(v) from idling. The EU annual mean limit for the protection of human health is 5 μg m−3 (ref. 13), while the US National Institute for Occupational Safety and Health recommends that workers wear special breathing equipment when exposed to benzene at levels exceeding 1 p.p.m. for 15 min. Waiting in traffic behind a 2S scooter, for example, at junctions and while the scooter is idling, may therefore be highly deleterious to health." [0]: http://dx.doi.org/10.1038/ncomms4749
But cities are full of shitty mopeds and old Vespas, for no benefit but cultural cosplay reasons.
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.
We don't all live in the city.
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.
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.
I guess they mean total non-exhaust particulates.
Regen 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.
It's much less wear and tear than friction brakes.
https://en.wikipedia.org/wiki/Dynamic_braking
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 track / tunnel maintenance personnel should probably already be wearing respirators if not full breathing apparatus), and I could see things get pretty dire in case of breakdowns.
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.
I assume you mean that the increased air-exchange (purified or not) helps CO2 that originates inside the house to leave promptly? (Equalizing it with the outdoors.)
Literally "keeping CO2 out" is a much trickier and more-expensive proposition.
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.
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.
Hormesis and natural selection have been driving factor of evolution for a long time.
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).
Anyway, by your own line of thinking, wouldn't sensitive lungs be an advantage? The incentive to find cleaner air is also breaking away from the pack. Since humans are social creatures, that's more likely to look like new leadership for followers who have their own reasons to break away.
Every civilization in history has started out that way. It takes more than mere brute force to beat the competition. Survival is just as much about picking your battles and working smarter.