Non-Exhaust Emissions Now Major Source of Vehicle Pollution in the UK

New research from the University of Southampton shows that microscopic particles released from certain brake pads can be more harmful to human lung cells than diesel exhaust. The study highlights a growing concern: as the focus shifts toward electric vehicles (EVs), non-exhaust emissions—such as those from brakes, tires, and road wear—are becoming a significant source of air pollution.

Researchers analyzed the effects of particulate matter (PM) from four different types of brake pads. They found that those containing high levels of copper—particularly non-asbestos organic and ceramic pads—were the most toxic. These fine particles, known as PM2.5, are small enough to penetrate the lungs, leading to oxidative stress, inflammation, and potential long-term respiratory damage. The study found that removing copper from the brake pad material reduced the toxicity of the emitted particles.

Air pollution from vehicles has long been linked to severe health conditions, including asthma, chronic obstructive pulmonary disease (COPD), cardiovascular diseases, and even dementia. While governments have implemented regulations to control exhaust emissions, non-exhaust sources remain largely unregulated.

With the rise of EVs, often heavier than traditional cars, researchers warn that non-exhaust emissions could become an even bigger issue. The study’s authors call for updated policies to address these overlooked pollutants and encourage manufacturers to develop safer brake pad materials to reduce health risks.

Source

University of Southampton. (2025, February 14). New study finds brake pad emissions can be more toxic than diesel exhaust. https://www.southampton.ac.uk/news/2025/02/brake-pad-emissions.page