Electric and hybrid cars pollute the air with just as many toxic particulates as diesel-powered vehicles according to new research, but not for the reason you’d think.
A study published by scientists from Edinburgh University in the journal Atmospheric Environment claims that battery-powered vehicles produce more particulates from tyre and brake wear.
The research says that the weight of the battery packs in electric and hybrid vehicles make them heavier, meaning that the brakes and tyres must work harder and will therefore wear out faster.
Toxic particulates from brakes and tyres
According to the report, the extra emissions from the brakes and tyres are almost equal to the number of toxic particulates emitted from the exhausts of diesel cars.
Peter Achten, who led the study, said: “We found that non-exhaust emissions, from brakes, tyres and the road, are far larger than exhaust emissions in all modern cars.
“These are more toxic than emissions from modern engines so they are likely to be key factors in the extra heart attacks, strokes and asthma attacks seen when air pollution levels surge.”
The researchers combined technical data obtained from the motoring industry and from government research agencies, along with direct tests of tyre and brake wear rates.
Electric and hybrid vehicles weigh around 24 per cent more on average than conventional vehicles, the study states, lending credence to anecdotal complaints from owners who say their tyres wear out faster.
A similar study into the impact of non-exhaust emissions was undertaken by Ranjeet Sokhi of the University of Hertfordshire, who measured air pollution in the Hatfield tunnel on the A1(M).
Majority of emissions not from engines
He found that of the 49,000 vehicles that travel through the tunnel every day, each produced 34 to 39 micrograms of particles per kilometre, but only a third of that came from the engine.
Brake dust, tyre rubber and even pieces of bitumen kicked up from the road made up the majority of the particulate matter, which Professor Sokhi says highlights the significance of non-exhaust emissions.
