The recent discovery of the toxic compounds leeching from worn tyre particles into rivers, lakes and oceans is causing alarm.
Modern motor vehicle tyres are more than just rubber, with increasing amounts of plasticisers and other chemicals added for increased friction and durability.
However, with greater acceleration and braking forces, especially as weight is climbing due to heavy batteries in electric vehicles, more tyre particles are ending up in the environment.
Bicycle tyres, on the other hand, shed comparatively little of these fragments as the weights, propulsion and braking forces are so much lower.
Imperial College London researchers have published a new summary titled, "Tyre wear particles are toxic for us and the environment,” which describes the problem and suggests avenues to tackle it.
Six million tonnes of tyre wear waste are produced each year, the report says, ranging from visible pieces of rubber to nanoscale particles.
"Along with microplastics, tyre wear particles contribute significantly to the amount of synthetic (or polymeric) particulate pollution being released into our environment.
"Large particles are transported by road runoff due to rainwater, resulting in the leaching of toxic chemicals and damaging the environment, while smaller particles, of the micro and nanoscale, may be small enough to become airborne and breathed in,” the report says.
"Policy makers and scientists should set out an ambitious research agenda to investigate the problem, from the basics of how and why tyres wear and how this affects people and nature, to potential solutions, including particle capture technologies, new advanced materials and innovative business models, thus enabling a limit to the harmful impact of tyre wear particles on our health, water and air.”
Studies are continuing to investigate the problem and potential solutions, including:
The mechanics of rubber wear and how tyre particles are generated
- Monitoring and modelling of generation, transport and leaching of chemicals from tyre particles into water and the environment
- Advanced real-time monitoring of airborne particulate matter
- Measuring tyre material in environmental samples
- Human cells and human body response to tyre wear particles
- On-board capture and collection of particulates
- Vehicle control and modulation to reduce tyre particle emissions
- Tyre business and ownership models to promote continued innovation
- City-wide access control and route optimisation to mitigate local peak-emissions