Microplastics and fine dust are released into the environment in large quantities through the abrasion of tyres and thus enter soils and water bodies. The effects of microplastics on local ecosystems are still poorly understood. Experts are calling for better collection technology and stricter traffic concepts to reduce environmental pollution.
The harmful emissions from vehicles and their effect on air quality are largely known and already regulated by EU directives. But tyre abrasion, which is also a major problem with electric cars, produces not only fine dust but also large amounts of microplastics. In Germany, about 48.5 million car tyres were sold last year, partly because many of the tyres are no longer usable due to wear.
Only about 5 to 10 % of tyre wear ends up in the air as fine dust. Most of the tyres end up in the soil and water as microplastics. Some of it is then transported into the sea.
The Federal Institute of Hydrology (BfG) and the Federal Highway Research Institute (BASt) have now researched where and in what quantities tyre wear is deposited in the environment. According to their calculations, 60,000 to 70,000 tonnes of tyre wear are released into the soil and 8,700 to 20,000 tonnes into surface waters every year. While in cities up to 95 % of the harmful microplastic can be captured by sewage treatment plants, in rural areas the small particles seep into the soil and reach water bodies, where they are deposited in the sediment. About 2 % of the debris eventually ends up in the sea.
Although it is not yet clear exactly how microplastics affect ecosystems, it is certain that sooner or later microplastics can become embedded, for example, in food that is also consumed by humans. Microplastics have already been detected in lettuce and wheat plants as well as fish and are now found in almost all parts of the world.
The experts are therefore calling for better filter systems to catch the microplastic from the road before it can enter the environment. Traffic concepts could also help to reduce tyre abrasion. The company Bridgestone has now developed a tyre that has about 30 per cent less wear. The tyre has a lower rolling resistance than other tyres and is therefore more durable.
It is also crucial that the EU directives are extended to include the emissions of e-cars. Unlike internal combustion engines, these are currently not yet subject to any emission limits. The non-exhaust emissions that enter the air, including microplastics, would then have to be reduced by the industry to such an extent that the environment and people can be sufficiently protected.
Only in this way can e-cars actually contribute to a clean environment and human health.