Vehicle brakes produce charged particles that may harm public health: study
news.uci.edu
news.uci.edu
The bottom line is that proximity to traffic is horrible for your health and your air quality. Electric cars can help with some of the problems but don't solve all of them. The people with the least amount of money end up having to move to apartments near highways and so they often suffer the worst impacts, but I've seen very nice and expensive apartments and houses very close to (or directly on) busy streets. Noise is usually the obvious and immediate consideration, and I doubt many people are aware of the risks they expose themselves and their families to just by opening a window in the summer.
"In the United States, it is widely accepted that economically disadvantaged and minority populations share a disproportionate burden of air pollution exposure and risk (26,27). A growing body of evidence demonstrates that minority populations and persons of lower socioeconomic status experience higher residential exposure to traffic and traffic-related air pollution than nonminorities and persons of higher socioeconomic status (5,28–31). Two recent studies have confirmed that these racial/ethnic and socioeconomic disparities also exist on a national scale (32,33)."
Setting aside race, to me it seems like "economically disadvantaged populations share a disproportionate burden of traffic-related air pollution exposure" makes this pretty clear. <shrug>
Even into the 1960s wealthy black people were prevented from buying and living in the 'good' parts of even northern US cities.
[1]: https://www.theguardian.com/us-news/2019/apr/04/new-york-sou...
I suppose that there likely are small numbers of people living far outside of cities and away from traffic, like up in the mountains of Appalachia or living off the grid in tents or in communes deep in forests, who are poorer than people you'd typically find in urban areas, but it's still the poor in the US who are dealing with the worst of the harms traffic causes compared to the better off/wealthy. They're also the least able to mitigate those harms or deal with the fallout caused by them.
Density doesn't equal exposure.
Though to be fair, the tires on my previous ICE vehicle only lasted about 30,000 miles before they needed to be replaced, OEM car tires are often not long lasting. Brake fluid is due to be flushed next year, but not due to use of the brakes, just due to time.
https://www.fox5atlanta.com/news/atlanta-magnet-man-alex-ben...
That 20K set of tires had a slow leak from a nail that was patched incompletely. On the new set I had to replace two using the hazard insurance I purchased after three months and two thousand miles. I expect to use the insurance again.
I now have an EV with sport summer tires. They’re at 5K miles and have a screw embedded in one tire since about 400 miles. That tire was deemed to be safe and best left alone as it’s presumed to be running through a rubber block only. I’m just running it until it goes flat assuming it doesn’t manage to survive its whole expected life span.
Realistically I’ll end up running something else over this spring once construction gets into full swing.
Probably accurate if you exclude the brakes and ignore the fact that removing an ICE engine from consideration also removes nearly all the tricky bits that wear out on an ICE car.
What EV’s produce more of is tire particulates due to weight.
PS: And now the post says tires.
I thought the post had changed, but I wasn't 100%
Having said this, if you can go 70k+ miles with the same brake pads, you could likely go much further than that if the car had regenerative braking.
If people really cared about this, they'd demand train-based public transport instead (no tires! fully electric! self-driving too!), or at very least limits on car weight regardless of the engine.
A mix of solutions will be needed to fix the variety of different and unique problems that exist.
Have you used bus systems in the US? Even in cities that have made a large investment in bus service, it can be a challenge.
An amazing claim.
My EV cost $13k and was fairly new at purchase.
This is especially a problem in enclosed spaces with limited ventilation: on parts of the London Underground, air pollution in the tunnels can be many times worse than on the streets above.
EVs aren’t going to be the savior of climate change. They do some things better than ICE cars, but do some things worse. Denying those worse things is just putting your fingers in your ears.
Some people of course drive their EVs aggressively and wear out the tires faster. But that's true if you have a muscle car too. Doing donuts in the parking lot just wears out your tires. And if you are in Germany and like seeing how fast your car can go regularly that also wears out your tires. The driving style is a much bigger factor than the weight of the car.
But otherwise the numbers are about the same for ice cars and evs in terms of frequency of needing tire replacements. For most people the novelty of abusing their tires wears of quickly.
And because most EVs use regenerative braking, the main issue with the brakes in EVs is that they are used so infrequently that they need to be replaced because of corrosion issues. You actually need to use the brakes once in a while to keep them clean and functioning apparently.
In the case of brake dust specifically, presumably electric cars are worse because they're quite a bit heavier than ICE cars.
This counts even for hybrids though. A friend of mine had to replace his brakes after over 10 years and 180,000km on his Prius for the first time. Not because the brake pads were used up, but because the brake rotors started to rust too much from not being used.
Of course if you're one of those people that floor it and hard brake at every stop light, this doesn't work, but for most cars it works really well.
I tried it a few times, thought it was a gimmick and now I just use gas or brake.
Electric car use regenerative braking. Yes they're heavier but their brakes barely get used...
They only get used at very low speed to bring the vehicle to a stop (low energy), or in case of emergency braking.
I might never replace the pads.
I’d be careful with assuming that. A lot of consumables are imported directly from China, and the cost of car maintenance can be eye-watering, so it’s exactly the type of part I’d expect to be procured as cheaply as possible.
People care about the brand of tyres on their car, I don’t even know of any brake pad brands.
OTOH I don't think most people care about tires either.
On the other hand, EVs unfortunately pollute more with tire particles (thanks to both higher torque - especially from 0 - and higher average mass).
I wonder how much the higher torque of EVs is a real issue? Although they have the potential to do more aggressive acceleration and produce more tyre pollution, the Teslas I see leaving traffic stops seem to be accelerating the same as ICEs.
As the parent comment said - but I was questioning about whether increased torque has an actual impact on tyre wear.
(Certainly when I was young and dumb my clutch wore more when I went dashing about).
We have anecdotes of Tesla owners saying they go through tires more often. But I’ve also heard car fleet owners with both EVs and ICE saying they see no difference between them.
So I’m inclined to think this is entirely dependent on the specific EV. You can get an EV without significantly more weight than an equivalent ICE, and you can drive them in ECO mode where the torque curve is extremely gentle. I don’t see any reason why you’d have more tire particles in that scenario.
I think there are pathways to have less tire wear on EVs than with today’s ICE vehicles. Batteries with higher energy density would obviously help, but I think there are things you could do with the accurate control you have over the torque on the wheels, or making true all wheel drive with torque vectoring more common.
In Dubai prime real estate is along the major highway Sheik Zayed Road. It’s funny how these things can be cultural.
Some of the reason why poor areas in the US are around highways and busy streets have to do with the history of redlining (https://phys.org/news/2024-02-highways-historically-redlined...). Even today when a city wants to build a loud/smelly/polluting highway or a factory or a landfill or a sewer treatment plant it's the poorest areas that are the least able to fight back, and putting them in the areas where poor people are will mean the least amount of inconvenience for the wealthy who often live far away from those neighborhoods. After a source of pollution is in place, very few people want to move in right next to it, so any houses there tend to be inexpensive and may be the only housing poor people can afford which further concentrates them into those areas.
Driving up SZ road, all you see are tons of shitty retailers and car dealerships. Trust me, wealthy people especially are not living next to it.
It’s only Al Quoz that is car dealerships. But on both sides of Al Quoz you find high-end, high rise
Some of the most expensive houses in my neighbourhood are the closest to the highway. I just tried to check, but none of them are for sale right now. Traffic only decreases four hours at night but it never really stops. Only the noise is a big no-no.
https://de.wikipedia.org/wiki/Kontrollierte_Wohnrauml%C3%BCf...
A HEPA filter must remove at least 99.97% of aerosols 0.3μm in diameter. A filter which removed 99% and blows air 1% faster will remove just as much, or one which removes 50% and blows air twice as fast.
For recirculating air, all of those accomplish the same thing. Some of those have much higher noise, running costs, and general upkeep than others.
HEPA makes 100% sense for something where 100% of air passes through it. If you want an exhaust on a facility which handles biohazards, a vacuum cleaner kicking up dust, etc., sealed HEPA 100% is the way to go.
That's not what happens in a residential building, though. For that application, it's just bad engineering.
HEPA doesn't matter unless you have a sealed system. An open door or a cloth curtain means the 99.97% means nothing relative to 99%.
If you have two patients, they should both be isolated from each other. Which one gets the higher pressure, and which the lower?
im gonna need a source on your claim. heres a source that claims the opposite
https://www.washingtonpost.com/climate-environment/2023/07/0...
> our brakes and tires isn’t benign, either. Tests by Emissions Analytics, an engineering consulting company based in England, found tires produce about 2,000 times more particle pollution by mass than tailpipes.
(emphasis mine)
The fact that the majority of tailpipe pollution is not particulate means that tailpipe pollution can be the biggest problem we need to fix, even if it isn't the biggest particle pollution problem.
> If we remove tailpipe emissions, which are by far the largest, then brake/tire wear emissions become visible and are next in the list to deal with.
(clearly claiming that tailpipe emissions are by far larger than both brake and tire emissions)
Impact on health is not linearly proportional to the mass.
It's almost the opposite - the smallest particles can linger in the air and get absorbed. You could eat a chunk of a tire without a significant health effect, but breathing the same mass of almost any gas would kill you.
CO2 is bad for other environmental reasons, but it doesn't get stuck in our lungs.
Due to their enclosed nature, drum brakes greatly reduce PM emissions compared to disc brakes.
The other benefit of EVs is that the feedback on regeneration and efficiency tends to make you less aggressive and a better driver. Which also leads to less brake use.
An all-wheel drive or front-wheel drive EV can regen more effectively than one which can regen on the rear wheels only.
Are you suggesting some metal brake components have unusual rust because of disuse, where they aren't being used regularly enough for friction to "clean" their surfaces?
Otherwise I don't see how regenerative breaking could cause rust, since the braking force is supplied by electrical fields.
Yes, the brake disks, especially if you drive some place where they salt the roads during the winter. I had to change the rear disks on my hybrid after two years because they started to fall apart from rust, now I have learned to do some heavy braking at the end of trips to clean and dry the disks
Below 5mph the brakes are used, but it doesn't seem to be enough. Compared to my ICE car they always look a lot worse, and after parked for a day when it's damp have surface rust.
As another comment says, it seems like a software change could fix it by using the physical brakes more. I believe the issue is they get wet, and then don't get hot enough to dry out before parking.
Furthermore, it is entirely possible and probably desirable that some electric cars actually remove the brakes altogether (with the exception of an emergency brake that is only used in case of total system failure). Theoretically, electric motors should completely capable of doing all necessary braking. Of course there would have to be more emphasis on the reliability of the power electronics but it is doable.
Most EVs blend regen into the brakes so that when you press on the brake pedal it uses regen for normal braking down to about 10mph at which point the friction brakes take over. At low speeds regen is ineffective. That low speed use of friction brakes produces very little wear and very little particulate output.
Those EVs doing blending will also switch entirely to friction braking if you really stomp on the brake pedal in an emergency stop as you can stop more quickly than any regen system. In those cases the priority is stopping quickly regardless of energy efficiency or particulates.
I don’t see a likely hood that EVs will completely get rid of friction brakes using current/near term technology.
They didn't have air conditioning, which isn't particularly strange in the PNW, but we did learn opening the windows for breeze was a very bad idea. The amount of tire and brake dust/soot that would pile up in a single afternoon was disturbing.
We were only in there temporarily for a few months, but boy did it underscore to me how much of an unappreciated health and pollution hazard freeways are.
It takes Alpine air as a point of reference to feel it, which says a lot about the ambient level of pollution in cities.
How do they propose to do this? A little device mounted near each brake pad? A skim of the paper doesn't appear to show an opinion from them beyond citing this prior study [1]. The conclusion of the cited paper appears to show a progression towards a target:
> This study is our first step to install dust collectors in actual vehicles, in order to reduce the brake wear PM emissions. In this study, we evaluated the collection efficiencies of an inertial separator, an ESP, and a hybrid precipitator, independently. In the next stage, we will design a suction system that considers the structure and space of the brake system; then, the full dust collector system setup will be installed on a vehicle. At the final stage, the actual collection efficiency of the dust collector will be measured under various on-road driving conditions.
I drive a hybrid and, when parking, switch between drive and reverse even while still rolling the opposite direction as it's easy for the motor to deal with such loads.
A Corolla sedan is +30% weight over a model 3.
https://www.carsized.com/en/cars/compare/toyota-corolla-2018...
Those numbers you present are a little inflated when it comes to like for like currently. Furthermore, there are combustion engine vehicles which are far far heavier than EV 4wd's.
Acceleration is not performed under braking either so I don't see your latest point.
Many EV's whilst engine braking is applied, also apply the brake lights.
Quote from Tesla's website for Low and Standard regenerative braking "Standard: Provides the maximum amount of regenerative braking. When you release the accelerator, Model Y slows down, reducing the need to use the brakes."
The effect of regenerative braking in an EV is much greater than that of an ICE under engine braking.
Probably the heavier the vehicle the more particles are likely to be produced?
I'm not too worried about this. It's an engineering problem and now that is been raised, we can find solutions.
This should be the default attitude of society
Engineers won't be permitted to spend any time or dollars solving this till there is a law capping particulate emissions.
I had some boxes stored in a storage cage in my apartment car park and after 6 months sitting there, they were all coated in a thick black dust. Since there was no wind or rain to move it around, it just settles and builds up.
It is quite important to discuss exactly where the top sources of pollution are through so we can cut back on the worst sources of them to have the most impact.
The salient points for me were:
- Braking produces [probably] unhealthy dust.
- Much of that dust is electrically charged, meaning sweeping it out of the air (perhaps before it leaves the wheelwell) is easy.
It would be interesting to know whether inhaling charged particles is more or less harmful than neutral particles, though.
EVs produce way less brake dust because manufacturers and drivers are obsessed with regenerative braking.
In car brakes you can have slightly different designs/materials for pads which cause the balance of noise<->dust<->temperature performance to differ. For instance if you want to reduce dust emission, generally you get brakes that are much louder in my experience until they warm up but they are much "cleaner".
We can't filter our way out of this problem. If we can build cars better to reduce their harms and there are ways to place particle collectors near streets and houses to reduce the environment impacts of traffic I'm all for it.
The kia I drive still roll at a couple of km/h when accelerator is fully released and will not hit 0 unless you use a paddle by the steering wheel (or use the breaks).
e.g.: https://cimg0.ibsrv.net/gimg/www.corvetteforum.com-vbulletin...
Tire wear on the other hand... :(
I’ve had two EV’s over the last 6 years, and I have to remember to occasionally hit the brakes to keep them from rusting.
One pedal driving is just money - saves power and is just much smoother over all than old school breaking. IMO.
When you press the brakes on an EVs or hybrid, they typically use regenerative braking up to the limits of the motor and charging system, and only apply the brake pads after those technical limits are met. There are many "two pedal" vehicles that can come to a complete stop, or close to it, with regen.
It doesn’t work completely like that obviously for reasons, but it does work like that for gentle accel/decel.
Once you’re used to it, you dose your deceleration by focusing on how much you release the throttle.
And the only situations where you have to hit the breaks are the unexpected events - e.g., a car coming at the last moment and which you should give priority to.
I could not get my partner to brake hard enough to really engage the brakes. They just would not do it, would not brake hard enough to actually use the real brakes, no matter the prompting & even knowing how critical it was that we start to de-rust these rotors.
What I found out is: if you put the car in neutral, there won't be regenerative braking, & the car will use the actual brakes. That's the only way I could get my partner to use the actual brakes.
Are there any that work that way?
Think of it like playing a console game. When you hold the right trigger, your car goes faster. When you let off of it, it naturally slows down. Unless you opt in to harder difficulties, most racing games don’t make you brake much.
Driving an EV is just like that. You only really brake for an immediate stop.
The regenerative breaking is applied as you let off the "gas" pedal. It's kind of like driving a stick, but slows you down faster.
There's also one-pedal operation, akin to driving a golf cart. Where you feather the accelerator pedal to slow, and it will engage much more aggressive regen braking if you let off the accelerator pedal. Some folks like this. I do not. I still drive other ICE vehicles and find the transition between them too jarring for my liking.
On conversed, usual practice to limit torque of motor to be less than on ICE original, because of regulations (which exactly state, electric motor should not exceed ICE torque), and this mean, they are just not powerful enough for 100% regenerative braking.
From technical view, modern electric engine could easy exceed brakes.
I'm member of Ukrainian EV activists group, and we there mostly talk about conversions. Unfortunately, conversions are not so cool as new EVs, but to be honest I don't know details of other countries regulations, they could be less restrictive.
In the 90s I drove a Dodge Spirit from Florida to NY using cruise most of the way - the cruise adjustment was incredibly responsive.
If your one pedal driving doesn’t save power, then I would suggest a driver mod.
Unless you’re concerned about the energy usage in your ankle when maintaining pressure on the gas with your foot?
Coasting with no acceleration or deceleration except that provided by rolling resistance and the road gradient is so unlikely to be the exact acceleration you actually want - there’s no particular value in privileging ‘zero motor power’ as needing to be an easy state to achieve.
* I'm hard on brakes in general, but have over 70k miles on the original pads. Regen braking reduces brake use a LOT.
* Regen does NOT bring the car to a complete stop, the brakes are blended in below something like 5 MPH. The rotors are not going to rust away, they see action every time you drive. (Some surface rust is fine and normal, EV or no.)
* EVs can be heavier than ICE cars, and most are. There are many things I dislike about Tesla, but the Model 3 is a feather weight in the category. A comparison I like to make is to the AWS Dodge Charger, which is heavier by a couple hundred pounds. I won't even talk about trucks and SUVs.
But I know what you mean from my older models
If I use the ePedal or the brake paddle, the stop is super gradual and you never feel the “grab” that you feel when using the brake. Also, I can sometimes feel/see it slightly rolling (so it’s not even truly a complete stop).
I’ve seen some people swear that the EV6 always uses friction braking at stops, but again, I’m pretty sure this just isn’t true.
A Gen2 Leaf (2018+) with "e-Pedal" mode absolutely does stop the car fully with regen.
Anyway, they're right. Brakes on EVs are normally just for emergency use. Regenerative braking (lifting up on the accelerator pedal) is all you need about 98% of the time. Traffic lights, stop signs, parking, and other such planned stops are all handled by releasing the accelerator which brings the car to a gentle stop while feeding the kinetic energy back into the battery. That's what they mean by "regenerative braking".
There is a lot of variance EV to EV. Some have strong regen, some not so much. Some use 1 pedal driving, some don’t.
For instance the Porsche taycan brake pedal is setup such that the first part of the travel uses exclusively regen braking, and as you push harder it blends in more and more friction braking too. Don’t expect this to become common though, as this primarily just benefits real performance driving. Trail braking is very hard/frustrating without this kind of feature, but driving that way on the street is certainly dumb, and probably illegal (could fall under exhibition of speed?).
Then someone told me the Porsches remain garaged at home until the weekend.
But yeah, the excrement does accumulate.
For the average horse rider perhaps but not the average person. Most people were never on a horse.
and in agricultural times in the US, I'd say most people were on horses.
But most people weren't riding them. A horse and cart is much more efficient.
Though realistically, a lot more people walked. Not everybody could afford to feed or care for a horse.
I doubt the rates would be as high now if we went back to horses, because a lot of injuries that would have been fatal around 1900 would be survivable today, but I bet a lot of people would be surprised by how high the rates would be.
Some articles:
https://www.bmj.com/rapid-response/2011/10/31/cars-and-horse...
https://legallysociable.com/2012/09/07/figures-more-deaths-p...
https://www.pbs.org/video/new-york-horse-manure-crisis-ploay...
> New York City was a crowded mess: no one could figure out what to do with all the horse manure, urine, and rotting horse carcasses on the streets spreading disease. New York had over 100,000 horses producing over 2.5 million pounds of manure every day. Fossil fuel powered trains, electric streetcars and internal combustion vehicles were seen as the clean-energy alternative.
> The new study reveals a problem that may grow as electric cars become more and more common over the next several decades. Electric cars, Smith explained, are not truly zero-emission vehicles, so municipalities need to think about strategies to reduce emissions from brake use as well as tailpipes.
Which completely ignores regenerative braking.
“The coming decades promise a transition from internal combustion engines to electric, and with it a greater relative contribution of nonexhaust sources to urban air pollution.”
I assume the objective is that these people want to see things go from ICE cars to public transportation instead of EVs.
Just to balance the conversation, you know.
At some point, it's important to trust your instincts. I don't think you need a medical degree to understand that inhaling tiny particles made of nasty stuff leads to bad health outcomes.