Across the world, environmental groups have been encouraging the adoption of
electric vehicles(EVs) for their reduced carbon footprint and lack of
tailpipe emissions. While there are still some greenhouse gases produced in the production of EVs and the electricity that powers them, electric cars are still considered to be more environmentally friendly than gas-powered cars in almost every way.
Regulations imposed to limit air pollution typically are geared towards cars with internal combustion engines that produce tailpipe emissions, but that is not the case anymore in the European Union. Emissions standards are tightening up for all automakers to include a new kind of pollutant—nanoparticles produced from brake pad abrasion known as “brake dust.”
Why electric cars produce more brake dust
EVs don’t use friction braking as much as non-electric cars due to regenerative braking, but they may produce just as much brake and tire-related particulate emissions due to the added weight from heavy battery packs.
Regenerative braking, sometimes referred to as one-pedal driving, is a feature that allows drivers of electric cars to stop and go using just the accelerator. Essentially, regenerative braking works such that when you lift your foot off the gas pedal, the EV’s motor is used as a generator that converts the kinetic energy typically lost when decelerating into extra charge for your battery.
Why is brake dust harmful?
Euractiv, the European Environment Agency estimated that chronic exposure to particulate matter resulted in some 307,000 premature deaths in the EU in 2019. The risk of exposure to toxic particulate matter is especially high in urban areas.
The particles shed from friction braking are fine enough that they can penetrate deep into the lungs, as well as seep into the soil and water. Ingesting these particles, which are mostly comprised of heavy metals, can lead to cancer and increase the risk of Alzheimer’s disease.
The reduction of brake dust is part of the EU’s zero pollution action plan, which aims to improve the air, soil, and water quality throughout the EU.
An initial cost-benefit analysis of the legislation prepared by the European Commission reported that these increased regulations will “greatly benefit public health by cutting the mortality and morbidity caused by air pollution that affects urban populations in particular”
How automakers can reduce particulate pollution
While electric vehicles should in theory emit less brake dust can conventional cars, this sadly may not be the case. Findings from an
OECD studyconcluded that some heavier weights EVs may even shed 3-8% more particulate matter than ICE vehicles.
Some solutions to brake dust shedding already exist, such as one developed by French company Tallano. At the point where brake pad particles would typically be released into the environment, Tallano has created a mechanism that sucks the particles up into a filter.
Whether automakers will be able to implement these solutions right away is another story. The EU is funding millions of euros into research about this kind of technology, but studies are still being done into the real-world conditions of non-exhaust emissions and their impact on the environment.