Why Fuel Isn't the Only Pollution Concern for Cars

It’s estimated that over a quarter (26%) of greenhouse gases in the UK are produced by the transport industry, with petrol and diesel passenger cars accounting for the vast majority of those emissions. With that in mind, it’s only logical that there has been much focus on environmentally-friendly forms of road transportation as a means of alleviating the contamination that plagues many UK cities.

But while electric vehicles (EVs) and hybrid alternatives may go some way to reduce the pollution caused by cars, they won’t eliminate it all together, according to a new report commissioned by the government. Non-exhaust sources of particulate matter (PM) such as dust and microplastic particles contained in tyres are also responsible for a small but significant component of pollution.

Putting the brakes on pollution

Recent amendments to existing legislation governing the exhaust fumes of cars and other forms of transportation have done much to reduce the amount of PM present in our atmosphere. Unfortunately, they’re not the only source; the dust created when the friction inflicted on road surfaces through braking and tyre contact can also produce harmful contaminants. At present it’s estimated that non-exhaust sources such as these account for 8% of all emissions.

However, as the legislation does its job and older, more polluting vehicles are slowly replaced with EVs and hybrids, the amount of contamination produced by exhaust fumes is expected to decrease. Equipped with regenerative braking capabilities, EVs are thought to be less damaging than traditional forms of transport in terms of non-exhaust emissions, but the heavier battery may offset any gains made.

Plastic another problem

Meanwhile, it’s not just the dust created by tyres which pose a threat to the environment. Tiny particles of plastic contained within the rubber are washed out onto the road surface during heavy rain, and can then be further swept into rivers, lakes and waterways. The highly dangerous problem of microplastic in surface water can jeopardise the life and habitats of all manner of marine organisms, interfering with and adversely affecting natural ecosystems.

In fact, two independent studies have recently confirmed that plastic pollution caused by tyres is a leading factor. A Norwegian study, conducted by the national Environment Agency, found that a significant proportion of pollution was caused in this way, while a Friends of the Earth report concluded that it was the single biggest cause of microplastic pollution in British rivers, lakes and seas.

Searching for a solution

The government has called on the industry to self-regulate its approach to tyre manufacturing and explore avenues of reducing the pollution produced in this manner. “Brake, tyre and road wear is a recognised challenge as emissions from these sources are not easy to measure,” said Mike Hawes, CEO of the Society of Motor Manufacturers and Traders, in response to the news.

“A United Nations global group, including industry experts and government, is working to better understand, and agree how to measure, these emissions. Maintenance of the road surface, as well as further investment in new vehicle technologies, is essential to reducing these emissions, without compromising safety and we welcome further research in this area.”