While electric vehicles (EVs) have emerged as the harbinger of environment-friendly transportation options, a study by Emission Analytics, a firm that analyses emissions data, has challenged the idea. The study has brought attention to the problem of particle pollution originating from brakes and tyres in both electric and fossil fuel-powered cars.
The key finding is that EVs, due to their heavier weight, may release significantly more particulate matter from brakes and tyres compared to modern gasoline-powered vehicles with efficient exhaust filters. The study suggests this could be 1,850 times greater.
As per the Emission Analytics, EVs’ heavier weight causes tyres to deteriorate faster, releasing harmful chemicals into the air. This is because most tyres are made from synthetic rubber derived from crude oil. Also EVs, due to the presence of heavier batteries, put more strain on the brakes and tyres, accelerating wear and tear.
The study further claimed that tyre wear emissions from an EV with a half-tonne (1,100 pounds) battery could be over 400 times higher than exhaust emissions from a modern petrol car.
Similarly, the Guardian has investigated claims regarding electric vehicles in the ‘EV Mythbusters Series,’ examining topics such as carbon emissions, battery fires, and the notion that hydrogen will eventually replace EVs.
The claim
The brakes and tyres of electric cars still depend on friction to function, even though their engines emit no pollution. Friction breaks down materials, some of which may find their way into the environment. There are those who argue that switching to electric vehicles, which are typically heavier and thus wear down more easily, might lead to an increase in air pollution in general.
George Eustice, the United Kingdom’s then-environment minister, expressed his “scepticism” about improvements in air quality to the Parliament in 2022.
A Daily Mail report stated that tyre pollution is the “dirty secret of electric cars,” and EV drivers have been alerted to the fact that their super-heavy electric cars actually produce more pollution than gasoline and diesel engines.
Since EVs only produce electricity from zero-carbon sources, they do not directly burn fossil fuels and do not emit any emissions. This includes not releasing carbon dioxide in populated areas, nitrous oxides, carbon monoxide, or a mixture of metals, carbon, and unburned hydrocarbons.
Although fossil fuel power plants are still a challenge when it comes to charging EVs, they are typically located outside of major cities in wealthy countries.
However, the friction on tyres, brakes, and road surfaces causes all cars to produce particulate matter (PM), which pollutes the air and the ground with a dusty trail. Hazardous chemicals are present in this pollution.
According to Euan McTurk, a battery chemist who has researched the particulate matter issue for the RAC, electric cars typically produce less particulate matter when stopping because they use regenerative brakes.
He said that EV brakes deteriorate far more slowly. However, since more weight equals more tyre wear, electric cars do have a point to make when it comes to tyres and roads.
Meanwhile, a campaign group called ‘Transport and Environment,’ claimed that the average weight of an electric vehicle is approximately 400 kg more due to its large batteries. A large number of assertions regarding electric vehicles contributing to air pollution cite data from the private firm Emissions Analytics.
Founder Nick Molden’s measurements claim that particulate emissions from the vehicle can be 1,850 times higher than those from contemporary car exhausts, which are now cleaner due to regulations. However, it is important to provide some context for the headline finding, as the tests have not undergone peer review by scientists, and the industry contests the results.
Crucially, not only electric cars but all cars emit those pollutants. It is very difficult to measure small particulates, and there aren’t many comparative studies out there at the moment. This indicates that it is still unclear whether the additional weight of EV batteries will cause air pollution to worsen.
The German tyre manufacturer Continental emphasised that driving technique and road curvature impact tyre wear more significantly than vehicle and tyre design.
“In theory, EVs do not produce more particulates than an otherwise similar internal combustion engine vehicle simply because of the battery-induced increased weight,” a Continental spokesperson said.
Any computation has a lot of moving (and rubbing) parts, but some attempts have been made to add them all up.
“The adoption of electric vehicles will lead to very marginal decreases in total PM emissions from road traffic in future years,” according to a 2020 study by the Organisation for Economic Cooperation and Development.
The OECD study further claimed that heavier electric vehicles result in slightly increased tyre and road wear for both the smaller PM 2.5 and larger PM 10 particles. However, the difference in engine pollution between gasoline and diesel cars was not that great.
Any caveats?
Most people concur that tyre pollution is still dangerous. Due to its ability to enter the bloodstream and travel to the brain or placenta, many scientists feel that smaller PM 2.5 matter is more harmful.
Manufacturers of tyres are considering modifying their compositions. An electrostatic device that collects tyre particles and may be recycled into new tyres is the clever potential solution offered by UK start-up” The Tyre Collective.”
“Tyre wear has always been a problem. It has just been overshadowed. You can’t really claim the title of zero-emission vehicle if there are all these non-exhaust emissions,” Hanson Cheng, The Tyre Collective Co-Founder said.
If the SUV juggernaut keeps going, tyre pollution will worsen whether cars run on gasoline or electricity. Automobiles are becoming heavier, wider, and taller, which will reduce energy efficiency and carbon emissions.
Although there isn’t enough data to draw a firm conclusion about whether electric cars will result in higher particulate emissions, Anna Krajinska, manager of Transport and Environment’s vehicle emissions and air quality division, noted that we should work to slow down the adoption of SUVs.
Do EVs emit more particle pollution?
Meanwhile, a study conducted by Emission Analytics, an organisation specialising in emissions data analysis stated that even EVs are not better for the environment.
Published in a Wall Street Journal opinion piece, this study highlights the issue of particle pollution caused by brakes and tyres, affecting both electric and traditional fossil fuel-powered vehicles.
The issue is tyre wear. Emission Analytics reports that the increased weight of electric vehicles accelerates tyre deterioration and releases harmful compounds into the atmosphere. This is because most tyres are made from synthetic rubber derived from crude oil.
The study also emphasises how battery weight matters. Compared to conventional gasoline engines, EVs usually have heavier batteries. This excess weight accelerates wear and tear on the tyres and brakes by placing additional strain on them.
According to the study, tyre wear emissions from an electric vehicle with a half-ton (1,100-pound) battery may be more than 400 times higher than the exhaust emissions from a contemporary gasoline-powered vehicle.
Although tailpipe emissions have historically received most of the attention, this study suggests that when assessing the environmental impact of EVs, particle pollution from brakes and tyres should also be taken into account.
Shift to EVs inevitable?
Undoubtedly, the automotive industry remains unaccountable when it comes to pollution. Tyre wear is one of the few sources of particulate pollution that occurs while a car is in motion, so as internal combustion engines become rarer; expect to see increased attention paid to this issue. For both people and wildlife, that may have significant health benefits.
It is undeniable that increasingly heavier vehicles almost certainly emit more tyre dust. Right now, electric vehicles weigh even more than their counterparts. But even so, tyre pollution seems to be about the same for electric, diesel, and gasoline vehicles. Moving to an electric vehicle also has many other advantages, not the least of which is reduced carbon pollution.
Despite being a significant factor, combating air pollution does not seem to be a good excuse to postpone the switch to electric vehicles.