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Unfortunately, brake dust and tire rubber also represents a surprisingly large amount of particulate matter as well. I wish I had the source, but it was far mor

• clouddrover 6y ago
  A couple of articles on tyre pollution: https://www.emissionsanalytics.com/news/pollution-tyre-wear-worse-exhaust-emissions https://www.emissionsanalytics.com/news/pollution-tyre-wear-... https://edition.cnn.com/2020/07/14/world/microplastic-pollution-arctic-air-transport-climate-change-scn/index.html https://edition.cnn.com/2020/07/14/world/microplastic-pollut...
  • jjcm 6y ago
    I have some very heavy doubts about the validity of their data. Look at their primary findings: "Using a popular family hatchback running on brand new, correctly inflated tyres, we found that the car emitted 5.8 grams per kilometer of particles." Most tires seem to be around 7kg, which means according to their data a car would have all 4 tires reduced to nothing after 4828km. With most tires going bald after ~50,000km (not fully vaporized mind you), there's clearly something wrong here. My guess is they tested brand new tires which may shed particulate quickly at the start, similar to how a new carpet sheds exponentially more at the start.
    • cptskippy 6y ago
      I think you're right, new tires have a lot of flash and channel runners that are artifacts of the rubber molding process and are she'd very early in the tire's life.
    • clouddrover 6y ago
      It's also the material on the road being heated and ground up, not just the material from the tyres themselves.
    • TD-Linux 6y ago
      There's more information here: https://www.ukimediaevents.com/publication/955cc42f/30 https://www.ukimediaevents.com/publication/955cc42f/30 They said that all four tires combined lost 1.8kg, which implies they only drove 340km? Also, this is literally based on measuring the weight of the tires apparently, so how much of that became PM2.5 class particles is a mystery. The article also mentions "track testing", which if used for the test, would easily explain the enormous material lost after a short time. Track racing is very different than highway driving...
    • cameldrv 6y ago
      Is the rubber oxidizing? Some of the mass might be coming from the air.
• throwaheyy 6y ago
  EV regen braking partially helps with the brake dust, at least. May be counteracted by the tire rubber because EVs can be driven in a more “spirited” way.
  • rconti 6y ago
    Great point. I also find it humorous that the busybodies who insist that stop signs be installed every block of their neighborhood arterial have to suffer from the resulting air and noise pollution. I drive 'spiritedly', but I suppose the tire wear due to hard cornering is not nearly offset by the saved brake pad and exhaust emissions!
    • ethanwillis 6y ago
      So you're getting mad at people who are reacting irrationally to you speeding through neighborhoods? I think there's more than one problem here.
      • kube-system 6y ago
        Stop signs are a pretty bad solution for traffic calming, though. The key to effective traffic calming is to shape drivers’ natural behaviors, not authoritatively demand it. A stop sign that serves no purpose than to slow people down will piss off drivers more than anything, and lead to people speeding between signs or running them. It will make your street noisier as impatient people aggressively obey the signs. A typical neighborhood would be much better off if traffic was calmed by adding kerb extensions or narrowing the lanes. I think the above commenter might share my frustration that local politics is often full of people unknowingly demanding the wrong solution to their problem.
        • throwaheyy 6y ago
          The US is gradually coming around (heh) to roundabouts.
          • 6y ago
• pcl 6y ago
  Don’t forget that EVs use regenerative braking heavily, which generates power instead of brake dust.
  • globular-toast 6y ago
    They still rely on friction brakes. Especially at low speeds and/or heavy braking, which is what most braking in cities is. Also because of the extra torque a more jerky driving style is possible. I'm really sceptical that current EVs make any real difference to brake and tyre particulates. Drivers of manual petrol cars can already reduce their brake dust by using engine braking. If one drives very carefully it is possible to not use brakes at all. Indeed it should never be necessary. Any time you hit the brakes means you were going too fast. But how many people drive like this? Barely any. Instead people speed right until the last minute then slam on the brakes. Then as soon as the opportunity arises it's heavy acceleration until the next slam of brakes. Driving EVs like this will produce just as much brake dust.
    • varjag 6y ago
      No, most of EV braking in the cities is regenerative.
    • tobyhinloopen 6y ago
      When I had an EV, I had rusty brakes even after my commute. That’s how little I used my brakes. I used regeneration braking exclusively except for rare circumstances where something unexpected happened. Eventually I had to brake on purpose a few times to keep my brake discs shiny, because the rusty discs looked awful
    • Sharlin 6y ago
      My understanding is that at least where I live most remotely reasonable people use engine braking in city driving almost exclusively. Indeed needless use of the brake pedal is regarded as a sign of a poor driver. But other countries may have different driving cultures…
      • 6y ago
• lostlogin 6y ago
  > Unfortunately, brake dust and tire rubber also represents a surprisingly large amount of particulate matter as well. That crap ruins clothes too. I cycle and the stuff that comes off the road is crazy sticky, oily, black and horrible. It doesn’t wash out and is even hard to get off clear coated bike.
• mrpopo 6y ago
  Why 3 cars though? You did your research, you must be aware of the grey energy associated with manufacturing ~5 tons of extremely inefficient transportation vehicles.
  • ideals 6y ago
    They bought those vehicles used perhaps? Does that change things? Sounds like because that poster has options they don't have to drive the ice vehicles very often
    • rconti 6y ago
      I'm sure those who want to complain will always find a reason. I'm sure that my purchases and 'hoarding' drove up demand which increases prices and pushes people into newer cars or makes used cars less affordable to the poor, meaning they stick with older less safe, less efficient vehicles, or something. FWIW, my wife and I carpooled in the EV to and from work, every work day, until covid hit; now I work from home and she drives solo to the hospital. But again, it probably doesn't matter. The EV is too heavy and the rare earth materials were mined in unfriendly ways, and the weight of the car means it sheds lots of tire material, and not all of our electricity comes from the solar panels on the roof, and we should live closer to work and walk everywhere anyway, and the alcohol I consume has a negative impact on the water supply in a drought state, and.... (don't let anyone find out that sometimes I drive to the racetrack just to go around in circles and end up back where I started!)
      • mrpopo 6y ago
        You seem to clearly understand what's at stake and yet you still passive-aggressively attack me. Everything that you said is true, and it should be evident by now that baby steps like a couple of people carpooling in an EV when it's convenient to do so will not cut it. For every couple like you there are 10 couples who don't have the means to purchase an EV and their situation won't change by 2050, when cheap energy (read petrol) will be on the way out. While it's an honourable thing that you are using your excess hard-earned money to buy EVs and solar panels instead of SUVs and fracking stocks, please understand that you're living above the living standards of most people and not everyone can afford this, and for them, reducing footprint = self-restraint.
• trickstra 6y ago
  Conservation of mass. Fuel turns into CO2, H2O, nitrous oxides and a couple of worse things. Out of that, only H2O isn't a pollutant. Every liter (or every gram) of fuel must fly out of the exhaust as one of these things, otherwise it would accumulate inside the car. Now compare how many liters (grams) of fuel you use per year, versus how many grams of break pads and tires. That figure simply cannot be true, it sounds like a convenient myth circulated by oil industry.
  • mindslight 6y ago
    Referencing conservation of mass doesn't make sense. While CO2 is technically a "pollutant", it's not in the same league as the others. Particulates affect air quality in a way that CO2 does not.
  • generj 6y ago
    The claim isn’t that brakes and tires contribute the most pollutants, but the most particulate pollutants. Specifically, PM10, hard particles below 10 micrometers. CO2, Nox, etc from a car are hot gasses which expand relatively quickly, so dumping kilograms and kilograms of them is required to raise ambient air measurements above unsafe zones (measured in ppbs usually, see [0] for the EPA standards for NOx, PM, lead, etc). Particulate matter, being solid, doesn’t spread as quickly as gasses. Small enough particulate emissions can be ingested into the lungs, and from there into the bloodstream. Once there, they can scrape blood vessels, eventually leading to plague and various heart conditions. Very trace amounts of PM10, and specifically smaller PM2.5 that can slip through the lungs easier, can have terrible health outcomes. In the EPA standards I linked, ug/m^3 is roughly equal to ppb, so the standard for PM2.5 is about 1/5 the level of NO2. ICE engines generally only develop PM10 particles from insufficiently high temp combustion. For modern cars it isn’t absurd to suspect that brakes and tires produce more PM10. Here’s a summary of research done on the matter [1]. If you live in Europe, the US, or Canada, indoor and outdoor PM2.5 emissions will shave a few months off lifespans. China’s lifespans may be cut by as much as 5 years from particulate matter. [2] (not a scholarly source but links to them) [0] https://www.epa.gov/criteria-air-pollutants/naaqs-table https://www.epa.gov/criteria-air-pollutants/naaqs-table [1] https://publications.jrc.ec.europa.eu/repository/bitstream/JRC89231/jrc89231-online%20final%20version%202.pdf https://publications.jrc.ec.europa.eu/repository/bitstream/J... [2) https://qz.com/1071421/this-is-how-much-of-your-life-air-pollution-is-stealing-from-you-based-on-where-you-live/ https://qz.com/1071421/this-is-how-much-of-your-life-air-pol...