Exposure to pollution generated by cars, vans and lorries has long been linked to an increased risk of lung and heart disease. However, while past attention has mainly concentrated on exhaust emissions, particles are also released into the air from tyre, road and brake pad wear which are largely unregulated by legislation.

Now a study by the University of Southampton has found microscopic particles emitted from certain types of commonly fitted brake pads can be more toxic than those found in diesel vehicle exhaust.

The research shows that a higher concentration of copper in some pads is associated with increased harmful effects on sensitive cells from people’s lungs, as a result of particles being breathed in.

These ‘non-exhaust’ pollution sources are now responsible for the majority of vehicle particulate matter (PM) emissions in the UK and parts of Europe, with brake dust being the main contributor.

Lead author of the study, Dr James Parkin , explained that a move to EVs is bringing the problem into sharper focus: “People generally associate pollution from cars as being from exhaust pipes and think of electric vehicles as having zero emissions. However, EVs still produce particulate matter due to friction and wear of the road, tyres, and brakes.”

The researchers highlight that while electric vehicles emit no exhaust emissions they aren’t emission-free and that health effects from vehicle emissions won’t necessarily be completely removed once the fleet is fully electrified. They suggest that current legislation, which focuses on exhaust emissions, may be inadequate to fully mitigate the health effects of vehicles in the future.

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