Brake pad dust is more toxic than diesel exhaust - study
Researchers at the University of Southampton have found that microscopic particles released as a result of brake pad wear may be more harmful to the lungs than diesel car exhaust. The study, published by Biomedcentral in the journal Particle and Fibre Toxicology, links high concentrations of copper in the pads to increased toxic effects.
Here's What We Know
Previously, the focus has been on car exhausts, but there are other sources of air pollution - tyre wear, road surface wear and brake pads. These are the main contributors to particulate matter (PM) air pollution in the UK and Europe today.
"Non-exhaust" sources of pollution are now responsible for the majority of particulate matter (PM) emissions from vehicles in the UK and parts of Europe. Illustration: Particle and Fibre Toxicology
Researchers from the University of Southampton tested four different types of brake pads with different chemical compositions:
- Low-metallic,
- Semi-metallic,
- Non-asbestos organic,
- Hybrid-ceramic.
Non-asbestos organic pads were found to be the most harmful to lung cells - they caused inflammation and other toxicity markers even more than diesel exhaust particles. The second most harmful were ceramic pads. Both types contain high levels of copper.
The researchers later removed the copper from the particles and noticed that the toxicity decreased. This indicates the need to limit its use in braking systems.
The authors of the study point out that even switching to electric cars will not make the roads "cleaner." Although they have no emissions, particulates from braking and driving will continue to be a problem. Legislation that now only regulates exhaust emissions may not be effective enough to protect human health in the future.
Source: Particle and Fibre Toxicology
