Having lived next to a semi-main street through a smallish California coastal city without much rain it is pretty eye opening how much black dirt and junk just coat everything next to the road.
Walk down the street and touch a bush or any plant leaf and get a nice black hand in the process. The plants are covered, parked cars get covered and the inside of my apartment was covered.
It wasn’t until I moved out that I saw the extent of the problem. I only lived there a few years but every surface of my apartment had a coating of the same black dust. I’m now very worried my short time there considerably affected my health.
The Yale article and the paper both highlight the fact that EVs use regenerative braking and produce less dust.
I was worried that this was a rehash of the astroturf campaign from a few years ago focusing on EV weight and how that was so bad for the environment because of tire and road wear. Unfortunately you need to read through the whole thing (instead of the headline and a few paragraphs) to see that information.
> researchers grew human lung cells in a lab and exposed them to dust from car brakes and from diesel tailpipes, finding that brake dust caused greater injury to the cells.
I couldn’t tell if the study found that car brakes are more harmful than exhausts, or that car brake chemicals are more harmful than exhaust fumes - but that may not be significant because they are produced in less quantities.
I wonder about the larger context here, though. No matter what academic studies discover or examine, the rise of anti-intellectual culture suggests that we as a species are going to need to pivot to documentary efforts, in a hope that what we learn in isolation now survives to be acted on in a future, more exploratory, generation.
>Traffic-related resuspended dust is particulate matter, previously deposited on the surface of roadways that becomes resuspended into the air by the movement of traffic.
>Results show that the inclusion of resuspended dust in the emission and dispersion modeling chain increases prediction of near-road PM2.5 concentrations by up to 74%.
The weight, speed, and volume of traffic, are therefore considerable factors even beyond the pollutants the vehicles leave behind.
I'm conflicted about declaring something as "more harmful" in such a narrow context.
The article says that human cells react worse to dust from modern brakes than to exhaust or even dust from asbestos brakes. But this ignores the impact of exhaust on city pollution, or the hazards of asbestos production process, etc.
I guess this only tells us that dust from modern brakes can be dangerous and we should keep an eye on it. Which is valuable information, even if not as sensational.
I think the article linked the wrong article? Because the article describes the linked study as "researchers grew human lung cells in a lab and exposed them to dust from car brakes and from diesel tailpipes", but the linked study is a cohort study of correlation, that doesn't involve any experimental manipulation and is nothing like that description (at least as presented in the abstract I have access to.)
I think this is missing out on the big issue - tyre pollution which contains really nasty chemicals that inevitably get washed into rivers and waterways.
Also, car-shaped EVs often use regenerative braking which will reduce the amount of brake dust pollution, but with their increased weight and powerful torque, they produce a lot more tyre pollution than ICE vehicles.
> For the study, published in Particle and Fibre Toxicology, researchers grew human lung cells in a lab and exposed them to dust from car brakes and from diesel tailpipes, finding that brake dust caused greater injury to the cells.
That seems like an overly narrow way of defining harm.
E.g. what if brake dust is bad for your lungs but your lungs can repair the damage, but diesel fumes are harmful to your brain and the damage is permanent?
I'm not saying that's the case (I have no idea), just that studying lung cells in a lab doesn't tell you anything about the full-body harmful effects.
This is the regular current taboo. Micro-dust from tires and brakes contributes to half of an ICE vehicle’s pollution, with the other half coming from exhaust emissions. The amount of this micro-dust scales with a power of the vehicle’s weight, typically between the square and cube for cars, and up to the fourth power for heavy trucks. EVs are 30–60% heavier than their ICE counterparts. Assuming all other factors remain constant, EVs thus generate more particulate pollution than ICE vehicles. This does NOT even include the environmental impact of battery production and electricity generation.
One solution could be to require ceramic brakes which produce far less dust and may be more environmentally friendly, and even has greater performance which EVs will need for their extra torque.
This sounds similar to claims that cancer rates are increasing.
Which is to say that it may be true but it’s a symptom of improvements. Cancer rates are increasing because people are living longer and dying less of other things. Similarly, a huge amount of work has been done to reduce the harms from car exhaust, and modern vehicles burn really cleanly. It’s no surprise that other factors start to become relatively more important.
I wonder whether washing streets, especially in summer when it doesn't rain as often, would solve two problems at the same time: urban heat islands (through evaporation) and dust spreading around the streets (washed away).
When I hear someone's brake's squealing, I try and avoid them at all cost. I've been behind an old car that when it braked, I was coughing for hours afterwards.
This article is flat out wrong. The study they cite does not state the things the article says it states. And the study they cite certainly does not compare the harm from brakes to the harm from exhaust.
The study simply says that brake dust can cause asthma and hay fever in children. There is no comparison made to the harm from exhaust.
Exhaust is certainly more harmful than brakedust in the quantities one may encounter in the real world. Exhaust contains many chemicals that are actual poisons. Iron is not poisonous and copper can only be poisonous in large amounts. It is true that they can cause sensitivity and autoimmune diseases in the lungs especially in children, but this is much more remote harm than the actual poison in exhaust.
Nobody kills themselves by sniffing brakes but many people have done it by closing themselves in a garage with a running car engine. (They say that is harder now with catalytic converters but it still happens).
Environmentalism really is just a slippery slope ideology. We have electric cars that don’t pollute and are an amazing experience… but oopsy woopsy they have tires so I guess we need to ban them too. Might as well just keep people burning diesel because the electric cars aren’t ideologically pure enough.
How about we just solve the actual problem first? The planet is burning. People used to burn coal indoors for heating, that’s way more fucking harmful than 1 micron of brake dust.
Cars on roads are like 10% of all vehicle emissions. Most comes from vehicles not on roads, like industrial, farming and mining vehicles.
Of those emissions, the emissions from tires and brakes have the most impact.
But it is imperative that you should buy an EV and charge it with electricity from the power grid, and then take a destination trip that involves burning a giant amount of jet fuel.
How many kilograms of brake dust does the average IC car produce in a year, versus gasoline burned?
March of Dimes Syndrome here.
We're entering the end of the gasoline car era. Anti-car activists need something else in order to continue kvetching, so it's down to tire and brake dusts, battery recycling and whatnot.
When that is solved, it will be about the harms of exterior paint, and inhaling the "new car smell".
Transportation that is not powered by one's own muscles can never be virtuous.
Dust from car brakes more harmful than exhaust, study finds
(e360.yale.edu)450 points by Brajeshwar 15 February 2025 | 454 comments
Comments
Walk down the street and touch a bush or any plant leaf and get a nice black hand in the process. The plants are covered, parked cars get covered and the inside of my apartment was covered.
It wasn’t until I moved out that I saw the extent of the problem. I only lived there a few years but every surface of my apartment had a coating of the same black dust. I’m now very worried my short time there considerably affected my health.
I was worried that this was a rehash of the astroturf campaign from a few years ago focusing on EV weight and how that was so bad for the environment because of tire and road wear. Unfortunately you need to read through the whole thing (instead of the headline and a few paragraphs) to see that information.
I couldn’t tell if the study found that car brakes are more harmful than exhausts, or that car brake chemicals are more harmful than exhaust fumes - but that may not be significant because they are produced in less quantities.
This has been shown not to be true in a number of studies.
Tire-related chemical responsible for salmon deaths in urban streams (2020) - https://news.ycombinator.com/item?id=41450563 - Sept 2024 (37 comments)
EPA bans asbestos, a deadly carcinogen still in use decades after partial ban - https://news.ycombinator.com/item?id=39746806 - March 2024 (393 comments)
Vehicle brakes produce charged particles that may harm public health: study - https://news.ycombinator.com/item?id=39683351 - March 2024 (302 comments)
Car’s tires are swirling donuts of pollution - https://news.ycombinator.com/item?id=36660138 - July 2023 (28 comments)
Pollution from tire wear is worse than exhaust emissions? - https://news.ycombinator.com/item?id=22517621 - March 2020 (319 comments)
There are just so many arguments for public transport over cars where possible.
https://www.mdpi.com/1660-4601/17/8/2851
>Traffic-related resuspended dust is particulate matter, previously deposited on the surface of roadways that becomes resuspended into the air by the movement of traffic.
>Results show that the inclusion of resuspended dust in the emission and dispersion modeling chain increases prediction of near-road PM2.5 concentrations by up to 74%.
The weight, speed, and volume of traffic, are therefore considerable factors even beyond the pollutants the vehicles leave behind.
The article says that human cells react worse to dust from modern brakes than to exhaust or even dust from asbestos brakes. But this ignores the impact of exhaust on city pollution, or the hazards of asbestos production process, etc.
I guess this only tells us that dust from modern brakes can be dangerous and we should keep an eye on it. Which is valuable information, even if not as sensational.
Also, car-shaped EVs often use regenerative braking which will reduce the amount of brake dust pollution, but with their increased weight and powerful torque, they produce a lot more tyre pollution than ICE vehicles.
https://earth.org/tyre-pollution/
That seems like an overly narrow way of defining harm.
E.g. what if brake dust is bad for your lungs but your lungs can repair the damage, but diesel fumes are harmful to your brain and the damage is permanent?
I'm not saying that's the case (I have no idea), just that studying lung cells in a lab doesn't tell you anything about the full-body harmful effects.
Which is to say that it may be true but it’s a symptom of improvements. Cancer rates are increasing because people are living longer and dying less of other things. Similarly, a huge amount of work has been done to reduce the harms from car exhaust, and modern vehicles burn really cleanly. It’s no surprise that other factors start to become relatively more important.
The study simply says that brake dust can cause asthma and hay fever in children. There is no comparison made to the harm from exhaust.
Exhaust is certainly more harmful than brakedust in the quantities one may encounter in the real world. Exhaust contains many chemicals that are actual poisons. Iron is not poisonous and copper can only be poisonous in large amounts. It is true that they can cause sensitivity and autoimmune diseases in the lungs especially in children, but this is much more remote harm than the actual poison in exhaust.
Nobody kills themselves by sniffing brakes but many people have done it by closing themselves in a garage with a running car engine. (They say that is harder now with catalytic converters but it still happens).
How about we just solve the actual problem first? The planet is burning. People used to burn coal indoors for heating, that’s way more fucking harmful than 1 micron of brake dust.
Of those emissions, the emissions from tires and brakes have the most impact.
But it is imperative that you should buy an EV and charge it with electricity from the power grid, and then take a destination trip that involves burning a giant amount of jet fuel.
There is no logic.
With AI we can use predictive acceleration to stop the car just in time.
Thank you, I'll show myself out.
Since 60 years. But they just found out today. /s
Money well spent.
Sure this limits the wear, but not the need!
Can we get rid of EGR and DPF now, and go back to diesels that worked better?
March of Dimes Syndrome here.
We're entering the end of the gasoline car era. Anti-car activists need something else in order to continue kvetching, so it's down to tire and brake dusts, battery recycling and whatnot.
When that is solved, it will be about the harms of exterior paint, and inhaling the "new car smell".
Transportation that is not powered by one's own muscles can never be virtuous.