[HN Gopher] Vehicle brakes produce charged particles that may ha...
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Vehicle brakes produce charged particles that may harm public
health: study
Author : geox
Score : 64 points
Date : 2024-03-12 18:53 UTC (4 hours ago)
(HTM) web link (news.uci.edu)
(TXT) w3m dump (news.uci.edu)
| u320 wrote:
| Electric vehicles are heavier, which means they must spend more
| brake pads to stop. But they also use regenerative breaking,
| which reduces pad wear. So I'm not sure if they make it worse or
| not.
| gr2m wrote:
| I drive an EV for over a year, I barely use the break any more.
| Single pedal driving is wonderful
| qwertox wrote:
| Curious: How do you roll towards a red traffic light, do you
| somehow push a "neutral" button?
| jordanbeiber wrote:
| Just take the foot off the accelerator gradually.
|
| 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).
| IncreasePosts wrote:
| You just slowly let off the pedal as you approach.
| dzhiurgis wrote:
| Release the pedal. Car figures out where the next car or
| stop line is (I think. Even when you're not using radar
| cruise control).
| cbolton wrote:
| I hope we'll crack down on heavy SUVs vs normal cars before
| electric vs ICE.
| ok_dad wrote:
| Tires are somewhere near the top for distributing
| microplastics and heavier cars cause more tire wear, so yea
| we should get on that. I live next to a main road and we run
| filters in our house and have to wash the surfaces at least
| once a week to get off the oil and rubber dust. You can't
| just dust that stuff either, you have to wash it with soap. I
| almost regret buying this place, but where else would I have
| bought in this economy!?
| sambazi wrote:
| most ppl live next to a road so i gather yours is a pretty
| hefty one or you overlooked other sources of polution
| ok_dad wrote:
| Yea it's the main road for the whole town and my house is
| ten feet from it.
| darrenkopp wrote:
| They likely make it better. I rarely use my brakes unless I
| have to brake suddenly.
| realusername wrote:
| The danger with electric vehicles is actually that the break
| pad is in risk of rusting since you don't use it enough
| mschuster91 wrote:
| Hit the brakes softly once after driving and the rust is
| gone.
| dzhiurgis wrote:
| That's why some EVs are moving back to drum brakes
| _whiteCaps_ wrote:
| I have a Bolt and the brake pads rarely get used. It's almost
| all regenerative braking, I would bet it's much better than ICE
| cars.
|
| Tire wear on the other hand... :(
| zyang wrote:
| I love the little hand flap that does max regen. Bolt could
| be a cult classic too bad GM was in such hurry to kill it.
| nozzlegear wrote:
| They've unkilled it last I heard. I got an email a few
| months ago from Chevrolet saying they decided to keep
| making Bolts due to their popularity, and to keep an eye
| out for the next model in 2024 or 2025 (can't remember
| which year).
| nozzlegear wrote:
| Same here with my Bolt EUV. The only time I use the brakes
| are when I occasionally misjudge how quickly I'm coming up on
| a turn and one-pedal braking isn't slowing me down fast
| enough; or when I first leave home, the car is fully charged,
| and one-pedal braking can't regenerate the battery any
| further so it won't brake for me.
| cjensen wrote:
| Pad wear is the source of the pollution. If there is less wear
| there is less brake dust pollution.
| jordanbeiber wrote:
| But you rarely have to brake an EV though.
|
| 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.
| EForEndeavour wrote:
| I've never driven an EV. How do you approach stop signs and
| red lights other than braking? Is "engine braking"
| (regenerative braking?) strong enough to handle _that_ big a
| fraction of slowing down in city traffic?
| bryanlarsen wrote:
| The engine can slow down the vehicle at roughly the same
| rate it can accelerate it. And if you have an EV that has a
| 3 second 0-60...
| WaxProlix wrote:
| Generally, yes. Usually there are settings for how much
| regen you want, but the term 1 pedal usually inies a
| regenerative brake strong enough to stop at stop signs or
| when exiting freeways.
| baq wrote:
| An electric engine running in reverse is a battery charger,
| so yeah you run it in reverse and you slow down about as
| fast as you accelerate.
|
| It doesn't work completely like that obviously for reasons,
| but it does work like that for gentle accel/decel.
| Vvector wrote:
| I have a Prius hybrid. It has an indicator when the brake
| pads are used. It's easy to slow down and stop without
| using the brakes about 95% of the time
| Spartan-S63 wrote:
| From what I know, there are several settings of
| regenerative braking you can choose. The higher levels will
| bring the vehicle to a stop, while the lower ones won't. So
| it's user-configurable to a degree.
| GrooveSAN wrote:
| Based on my experience (electric motorbike), the
| regenerative breaks are super strong indeed. You can tweak
| their << force >>, but usually, the strongest level is the
| most comfortable - that you eventually keep all day long.
| It will cause you to full stop even on the steepest slopes.
|
| 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.
| jauntywundrkind wrote:
| Recently had to learn how to force a Prius to use the
| brakes, as the rotors were rusting up & starting to pit!
|
| 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.
| tzs wrote:
| I would have expected cars that have both conventional
| and regenerative brakes to keep track of how often the
| conventional brakes are being used and to automatically
| increase the use of the conventional brakes if they
| aren't being used enough to keep them in good shape.
|
| Are there any that work that way?
| dagmx wrote:
| You just let off the accelerator. They have tuneable
| deceleration curves for the regenerative braking.
|
| 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.
| dunham wrote:
| In city traffic, I rarely have to break. It's basically
| running the motor backwards (putting a load on it) and
| dumping the energy back into the batteries. It's limited by
| how fast the batteries can accept a change, so it doesn't
| always work when it's very cold out. I'll have to brake
| when a light catches me by surprise, and I brake when
| backing down my steep driveway. (The car does stop before
| getting into the street, but it's going faster than I'm
| comfortable with when approaching the sidewalk.)
|
| 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.
| thejazzman wrote:
| It's a timing skill you rapidly develop. Switching models
| throws off your timing, so don't be surprised when you
| initially use the brakes more.
| wkearney99 wrote:
| Some EVs also tie in the same detection devices used for
| adaptive cruise control to adjust regenerative braking. It
| can be configured to 'coast' in a manner similar to old-
| school automatic transmissions, but will apply regen
| braking when other vehicles are detected ahead. This lets
| me drive it sort of like a regular automatic when on the
| highway but get the added return of wattage when traffic
| gets heavier.
|
| 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.
| dzhiurgis wrote:
| I'm sometimes convinced Tesla's cameras identifies the stop
| line and stops itself exactly there. All I do is release
| the throttle pedal and it coasts there where it needs to
| be.
| k8sToGo wrote:
| Crusing is much more efficient than one pedal driving. So it
| does not save power at all.
| losvedir wrote:
| Are there any cars that "cruise" (by which I assume you
| mean maintain velocity without applying a pedal)? Non-EVs
| mostly sort of do so, they still slow down gradually. I'd
| be interested in trying a car that cruises indefinitely.
| Sort of an automatic, always on cruise control.
| k8sToGo wrote:
| Well cursing in an EV is the equivalent of putting an ICE
| car in neutral. Modern ICE do that as well. To answer
| your question it still slows down due to wind resistance
| and friction.
| always-open wrote:
| If you put a modern ICE car in neutral while moving,
| you'll use as much gas as you would while sitting in a
| parking lot idling. However if you just coast in gear
| with the engine braking slowing you down, a modern car
| will turn off the fuel to the engine, so zero gas is
| used.
| Kirby64 wrote:
| If you're lifting off the throttle enough to activate regen
| braking, you would be applying the friction brakes in a car
| as well. Maintaining a steady speed is more efficient than
| varying speed, but if you have to vary speed then one pedal
| driving is superior in every way.
|
| If your one pedal driving doesn't save power, then I would
| suggest a driver mod.
| k8sToGo wrote:
| Yes of course. These are very theoretical discussions
| anyways. In reality one pedal driving is quite awesome.
| jameshart wrote:
| You don't have to use one pedal driving to use
| regenerative braking in most EVs. They use regenerative
| braking to effect control inputs on the brake pedal too.
| jameshart wrote:
| The control scheme has nothing to do with the efficiency of
| the car. Whether one pedal or two, it's going to use the
| same power for the same acceleration/cruise/deceleration
| profile.
|
| Unless you're concerned about the energy usage in your
| ankle when maintaining pressure on the gas with your foot?
| dzhiurgis wrote:
| IIRC 10% more effective to be precise. The UX is worth the
| cost.
| kalaksi wrote:
| But gasoline also needs ongoing heavy transportation over long
| distances
| IncreasePosts wrote:
| Tire wear and tear, which can also give off nasty particles, is
| also increased with the generally increased weight of EVs
| dzhiurgis wrote:
| 30% higher tyre wear vs 90% less brake wear && 100% less
| cancer fumes
| techdmn wrote:
| I drive a Tesla Model 3, a few thoughts:
|
| * 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.
| thejazzman wrote:
| It DOES bring them to a stop in newer models. Not sure which
| year it started but it's been at least 2
|
| But I know what you mean from my older models
| Lendal wrote:
| Good to see dozens of replies to this. Means EVs are popular.
|
| 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".
| l1tany11 wrote:
| Regen braking in most EVs is significant enough that the brake
| lights come on when you lift off the throttle pedal (which is
| what engages the regen). Tesla has said their brake pads are
| potentially lifetime. And for good reason. You barely use them;
| so much less than a normal car it's not even close. I have a
| friend with a 3 approaching 100k miles and isn't even through
| half a set of pads. My EV, you couldn't even bother me to
| check. I already know it's pointless.
|
| 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?).
| maigret wrote:
| They make it better. One data point is that VW had to install
| drum brakes at the rear as they get barely any use.
| https://topgear-autoguide.com/category/tech-future/vw-electr...
| byw wrote:
| I wonder for drivers who drove with regen-only for too long, do
| they lose the reflex to hit the brake?
| emsign wrote:
| We need to go back to horseback riding. It's inevitable.
| itishappy wrote:
| I suspect horses come with their own health issues. Can you
| imagine a city parking garage for horses?
| fragmede wrote:
| You mean a stable? They had those in ancient times in
| castles. A multi-story stable is funny to picture, but I
| don't see why not.
| itishappy wrote:
| I do indeed mean a stable! I don't imagine the particulates
| coming out of stables are going to be all that great. Also,
| my car doesn't get sick if I park it next to somebody's
| beater.
| fragmede wrote:
| There are classes of parking garages too. I'm not parking
| my hypothetical dream Ferrari next to some poor person's
| beat up Honda civic from the 90's to get dinged and the
| windows broken. The underground parking garage at Apple
| must be astounding.
| quesera wrote:
| I'd take a stable over a parking garage any day.
|
| But yeah, the excrement does accumulate.
| fsckboy wrote:
| back when we all rode horses, falling off of them was at the
| top of the accidental death risk for the average person.
| kwhitefoot wrote:
| > for the average person.
|
| For the average horse rider perhaps but not the average
| person. Most people were never on a horse.
| fsckboy wrote:
| if enough people on horses fall off and die, the average
| could still win over the population. I don't have the
| original statistic I saw in front of me, but that's how I
| interpreted it.
|
| and in agricultural times in the US, I'd say most people
| were on horses.
| undersuit wrote:
| Or just walk. America was a horse powered nation before the
| automobile, not a horse riding nation.
| drewzero1 wrote:
| And busy streets once again knee-deep in manure? Horses aren't
| exactly zero-emission either.
|
| Though realistically, a lot more people walked. Not everybody
| could afford to feed or care for a horse.
| tzs wrote:
| Fatality rates for riders, passengers, and pedestrians from
| horses in the early 20th century were actually comparable to
| those for cars in the in the late 20th century.
|
| 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...
| legulere wrote:
| The article still leaves off tire wear which is another way cars
| emit particles.
| bastawhiz wrote:
| I mean, if you want to bring up all the particles cars give
| off, look no further than the _tail pipe_ on most cars.
| briandw wrote:
| Break use on my EV is about once per trip. I have to stop after
| backing up and that seems to need the breaks. Honestly not sure
| if that's just a bad habit at this point or of regen doesn't work
| in reverse.
| varelaz wrote:
| Clickbait. "The toxicity and health effects of brake wear
| particles are largely unknown". Is there any real harm found?
| What's the concentration of them close to the dangerous road?
| What's effect of them comparing to pm10 or pm2.5?
| whatshisface wrote:
| The brake pad particles are pm10 and pm2.5.
| varelaz wrote:
| Well I meant other particles treated in the regular study of
| them. Because effect of pm10 and pm2.5 is studied. Do break
| pad particles somehow worse than usual.
| grecy wrote:
| Do you really need an independent peer-reviewed study to know
| if inhaling brake dust is bad for you or not?
|
| 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.
| wkearney99 wrote:
| While the sentiment on that is laudable, it's that kind of
| assuming that leads all kinds of idiots to jump to entirely
| ridiculous conclusions.
| grecy wrote:
| Given that we're on HN, I was assuming that everyone here
| is educated and has some kind of basic reasoning skills.
| Common knowledge and all that.
| varelaz wrote:
| Instincts often cheat you. I'm not saying that it's healthy
| but Does it really have any effect at all? What's the
| concentration of particles? How harful is it comparing to
| cooking or peeling onions? Do we need to care about it at
| all?
| chucksta wrote:
| Familiar with asbestos? Its pretty widely regarded as a bad
| time
|
| https://www.asbestos.com/exposure/automobiles/
| _aavaa_ wrote:
| Another day another set of researchers justifying their research
| which then gets spun as anti-EV FUD.
| wyldfire wrote:
| Why would that happen? EVs use their brakes much less often.
| when I read the article it occurred to me that this could
| eventually used to justify policy that would subsidize EVs more
| than they are.
| thebruce87m wrote:
| The article has this statement:
|
| > 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.
| _aavaa_ wrote:
| The first sentence of the abstract also shows a technically
| correct statement easily used for disingenuous framings:
|
| "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."
| ThinkBeat wrote:
| This will come from all ground transportation sources, right?
| Busses, trains, trams, subways etc.
|
| Probably the heavier the vehicle the more particles are likely to
| be produced?
| rightbyte wrote:
| Heavy vehicles like busses and trucks more often have drum
| brakes which I guess are better from a air pollution view?
| adgjlsfhk1 wrote:
| drum breaks have the breaks enclosed so the particles won't
| be in the air
| rickydroll wrote:
| If you've ever worked on a vehicle with drum brakes, you
| would see the foolishness in your statement. Brake dust
| goes everywhere, whether it be drums or disc brakes. Older
| drum brakes were even more hazardous because the brake
| linings were built with asbestos, at least until the 1990s
| for US-made brake products. Aftermarket and foreign-made
| brake pads apparently still have asbestos in them.
|
| I'm not too worried about this. It's an engineering problem
| and now that is been raised, we can find solutions.
| FredPret wrote:
| > It's an engineering problem and now that is been
| raised, we can find solutions.
|
| This should be the default attitude of society
| akira2501 wrote:
| It should at least be the default attitude on this site.
| londons_explore wrote:
| > It's an engineering problem and now that is been
| raised, we can find solutions.
|
| Engineers won't be permitted to spend any time or dollars
| solving this till there is a law capping particulate
| emissions.
| aceazzameen wrote:
| Being on or near a train platform and you can see brake dust
| caked on everything. Probably dust combined with grease. It's
| worse looking than roads.
| ninininino wrote:
| All wheeled ground transportation sources that use brakes.
| Legged vehicles and ground effect vehicles would not suffer
| from this problem, and we shouldn't necessarily assume the
| wheel will be the forever solution, we should not fail to
| dream.
| beembeem wrote:
| > All you would need to do is to collect them with an
| electrostatic precipitator - a device that exposes the charged
| particles to an electric field and efficiently sweeps them away."
|
| 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.
|
| [1] https://www.mdpi.com/2073-4433/13/7/1121
| petre wrote:
| Too complicated, why not use a magnetic brake instead? The
| electric motor on hybrids essentially operates like a magnetic
| brake during regen. Works in 80% of the scenarios and for the
| rest of 20% we can just use the regular brakes.
| alcyone wrote:
| I didn't see an explanation of the effects that charged particles
| have on my health. This research and finding seems important but
| including some effects other than "pollution" would be great.
| Anyone have specifics?
| frickinLasers wrote:
| I think it's a poorly titled article.
|
| 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.
| daft_pink wrote:
| Just want to point out that most electric and hybrid vehicles use
| regenerative braking most of the time and only use real brakes at
| very slow speeds or in emergencies. So it might be totally
| misleading to say that electric vehicles are the problem, when
| they are probably the solution.
| imbusy111 wrote:
| The article has weird reasoning. 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.
| But we won't deal with the latter before the former is dealt
| with.
| api wrote:
| There's a whole load of anti-EV FUD going out right now.
| gleenn wrote:
| I didn't really see them picking on EVs terribly in the article
| but maybe I missed it? Agree that a lot of EVs have
| regenerative braking so they should in theory produce less
| charged particles from the brake and caliper interaction, which
| they mentioned.
| Reason077 wrote:
| Not only does regenerative braking itself reduce PM emissions,
| the reduced demand on friction brakes is enabling some EVs,
| such as the Volkswagen ID3 and ID4, to switch to drum brakes.
|
| Due to their enclosed nature, drum brakes greatly reduce PM
| emissions compared to disc brakes.
| sokoloff wrote:
| [delayed]
| alliao wrote:
| air filtration isn't expensive nor hard... last generation
| cleaned water, perhaps we should clean the air. start small,
| indoors and transportation, reduce exposure simple stuff and just
| gotta do it.
| TylerE wrote:
| The problem is that all the bad stuff from cars by definition
| is OUTIDE, where it's essentially impossible to filter besides
| wearing a properly fitting respirator.
| autoexec wrote:
| The problem of "brake dust" on human health and air quality has
| been known for a long time (https://phys.org/news/2020-01-air-
| pollution-effects-immune-c...) before that there were also issues
| with asbestos in brakes, but thankfully those haven't been used
| since the 90s as far as I know.
|
| The bottom line is that proximity to cars 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.
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