Switch to EVs won’t solve ‘road dust’ pollution – in fact, it could make it worse

Learn more about “road dust” pollution with this video.

Electric vehicles are set to end tailpipe emissions, significantly improving air quality in urban areas. But particulate matter emitted from brakes and tyres will continue to pose health risks and could even increase after the EV revolution, studies show.

To date, policymakers in both member states and Brussels have tended to focus their regulatory powers on pollution from exhaust pipes. However, this is only part of driving’s impact on air quality.

In the coming years, non-exhaust particulate matter will overtake the quantity emitted from tailpipes.

These emissions stem from the scraping of brake pads and the friction between roads and tyre rubber, both of which can cause small particles to break off.

These particles add to those generated from the wear-and-tear of road surfaces to create “road dust”. As vehicles traverse a road, this toxic dust is suspended in the air, making it more likely to be inhaled.

Scientists divide particulate matter into coarse dust (PM10) and fine dust (PM2.5). While both are toxic, the minute size of PM2.5 particles, which are around 30 times smaller than a single human hair, enable them to penetrate more deeply into the respiratory system, damaging lung tissue.

Long-term exposure to elevated levels of PM2.5 increases the risk of heart disease, stroke, lung cancer, and respiratory diseases. It can also lead to disorders in the reproductive and central nervous systems. A joint OECD and EU report from 2020 found that up to 346,000 deaths within the EU in 2018 were attributable to PM2.5.

And while electric vehicles are held up as the antidote to an array of environmental woes, they will not solve the issue of particulate matter – in fact, they could make it worse.

Electric vehicles tend to be heavier than fossil fuel powered vehicles due to the weight of the battery. This is exacerbated in the case of larger electric vehicles, such as plug-in SUVs, which contain a considerably sized powertrain.

Large electric vehicles produce up to 8% more PM2.5 than their internal combustion engine equivalent, according to an OECD study. This is despite electric vehicles’ use of regenerative braking, which reduces the need to slam on the brake pedal.

In addition to harming air quality, the shedding of particles is a major contributor to microplastics in Europe. These microplastics can shift from highways to surrounding areas, impacting plant and animal life.

Recent studies suggest that microplastics have infiltrated the food we eat and the water we drink – a 2019 global study produced by the environmental charity WWF shows that people could be eating up to five grams a week of plastic, the equivalent of a credit card.

Separate regulations are being considered by lawmakers that would cover tyre abrasion, which would force manufacturers to adhere to minimum durability standards. However, it is unlikely an agreed test method will be established before 2023.

The tyre industry has pushed back against the pending legislation, arguing that scientific consensus on the link between harmful microplastics and tyres remains unclear.

“Driving behaviour, road and vehicle characteristics can together have a much bigger influence on the rate at which tyre and road wear particles are formed than tyre design alone,” states a tyre industry-backed website advocating a “holistic approach” to address the challenge.

EU seeks 'reliable' method to measure microplastic pollution from tyres

An EU regulation on tyre labelling due to come into force on 1 May will not cover the rate at which tyres shed particles – a major contributor to microplastics in Europe – as an agreed method for the calculation of abrasion is still not in place.

Clearing the air

The chair of the European Parliament’s Transport Committee, French lawmaker Karima Delli, formally wrote to the European Commission in 2021 to ask the EU executive what measures it intends to adopt to remedy the health hazard posed by non-exhaust particulate matter.

“The main source of particulate matter emissions from road traffic does not, as things stand, fall within the scope of Euro standards. However, technology exists which is able to significantly reduce non-exhaust emissions, particularly with regard to brake dust,” wrote MEP Delli.

One such solution, developed by the French company Tallano, essentially sucks the dust from the brake pads into a filter before it can be released into the environment.

According to the makers of the product, up to 90% of brake emissions can be prevented.

The same technology can be applied to trains and trams. France’s national rail company, SNCF, is working with the company to cut its fleets’ particulate matter output.

Upcoming EU standards on car emissions – the so-called Euro 7 law, set to be unveiled in July – are expected to include emissions from brake pads alongside tailpipe pollution.

Under the current Euro 6 regulation, only particulate matter emitted through exhaust pipes are regulated.

While Euro 7 will expand the scope of the law to brake pads, particles shed from tyres will remain exempt, largely due to questions over how best to measure these emissions.

[Edited by Frédéric Simon]

Read more with Euractiv

Oil ban: EU seeks a refined solution to a crude problem

After weeks of speculation, the news from Brussels is that sanctions on Russian oil will be finalised today and put to member states tomorrow.