New research finds brake dust has a “worrying” effect on health, with potentially “important policy implications” given it makes up a larger proportion of traffic pollution than exhaust fumes. When cars brake, they release metallic dust into the air. According to scientists behind the study, these particles stop vital immune cells from doing their job of protecting our lungs and lead to a greater risk of bacterial infections such as coughs, colds, pneumonia and bronchitis.
The UK-based research group was surprised to find that the brake dust had similar effects as diesel fumes, which typically receive more attention.
The study points out that exhaust pollution only makes up 7% of small particulate matter pollution (PM2.5). The rest comes from non-exhaust sources – namely from tires, clutches and brake pads. The latter is responsible for 20% of particulates.
Ian Mudway, who led the research at the MRC Centre for Environment and Health at King’s College, London, said that while it is “completely justified” that all eyes are on exhaust emissions, “we should not forget the importance of other components”.
A European transition to electric cars, which have less need to brake, “could be a slight benefit”, said Florent Grelier, an engineer at Brussels-based green group Transport & Environment. “Though of course, any car with a brake is going to be contributing.”
Mudway agreed, saying: “There is no such thing as a zero-emission vehicle, and as regulations to reduce exhaust emissions kick in, the contribution from these sources are likely to become more significant.”
According to Grelier, it is possible non-exhaust pollutants will be included in the post Euro-6 car emissions regulation, due in mid-2020. “That being said, the negotiations are still in very early stages,” he added.
He forecast that continued pressure from the EU’s Joint Research Centre and mounting scientific scrutiny will extend the conversation from exhausts to non-exhaust sources of air pollution.
Frans Timmermans, European Commission executive vice-president in charge of the European Green Deal, has said new measures are required to address tire pollution.
[Source: Car Lines, Feb 2020]