Деякі гальмівні колодки створюють токсичніший пил, ніж вихлопи дизельних ДВЗ / Depositphotos
The microscopic particles produced by brake pad wear can be more toxic than those found in diesel exhaust. This is evidenced by research results Dr. James Parkin from the University of Southampton. The study also shows that even a complete switch to electric vehicles will not completely eliminate pollution from transportation.
Researchers have found that increased copper concentrations in some common types of brake pads are associated with increased harmful effects on sensitive human lung cells. This is due to inhalation of fine particles released during braking.
Previously, exposure to polluted air caused by emissions from cars, vans, and trucks was associated with an increased risk of cardiovascular and pulmonary diseases. So far, researchers have focused mostly on exhaust gases, but pollution particles also enter the air as a result of wear and tear on tires, road surfaces, and brake pads.
These emissions are virtually unregulated by current legislation, but the study showed that «non-exhaust» sources of pollution are currently the main sources of particulate matter emissions from transport in the UK and some regions of Europe. The main pollutant among them is brake dust.
«Most people believe that the main pollution from cars comes from exhaust gases, and therefore electric vehicles are perceived as zero-emission vehicles. However, electric vehicles also produce fine particulate matter due to friction and wear and tear on the road surface, tires, and brakes,» said Dr. James Parkin, lead author of the study.
The scientists wanted to understand how different chemical compositions of brake pads affect the toxicity of the particles released and what consequences this could have for human health.
Four types of brake pads with different compositions were selected for the study:
The results showed that organic asbestos-free (NAO) pads were the most toxic – they caused the most severe inflammation of lung cells and showed higher toxicity than diesel exhaust particles. Ceramic brake pads took second place in terms of toxicity.
Dr. Ian Mudway, Senior Lecturer at the School of Public Health, Imperial College London, said that while the study is credible, it is too early to conclude that brake dust is worse than diesel emissions:
«Too many variables are left unaccounted for: brake disc types (which is a very heterogeneous category), diesel exhaust particle composition, selected measurement parameters, etc. In addition, not only brake dust should be taken into account, but also pollution from tire wear and re-raising of road dust. This has major policy implications, as it shows that policies that focus solely on exhaust emissions will not be able to fully address the pollution risks from transport.»
The project leader, Professor Matthew Locksam, agreed that such comments were valid, but explained that the brake dust particles were tested on a special test rig in accordance with a standard braking cycle. He noted that since this methodology is used to test brakes, it can be expected that the particles produced are fairly close to those generated in real-world vehicle use.
In his opinion, while some differences in particle composition may occur due to different braking modes or engine parameters, the overall differences between the pollution sources themselves are much greater.
This study demonstrates that even if cars are fully electric, they will continue to pollute the air through the wear and tear of tires, road surfaces, and brake pads.
Since brake dust particles are not regulated as strictly as exhaust gases, there is a risk that they will become a major source of particulate matter in the air. This poses a new challenge for environmental policy that requires further study and regulatory measures.
Source: theguardian