Chemical complexity of tire particles
Tire particles are a complex mixture of synthetic and natural rubber with hundreds of chemical additives. These combinations can have wide-ranging and sometimes unpredictable consequences.
For example, zinc oxide (zinc oxide ZnO), which constitutes about 0.7% of tire weight, is necessary to increase tire durability. But even in small amounts, this substance is very toxic to fish and aquatic organisms and can disrupt ecosystems.
Another harmful chemical is 6PPD, which is used to prevent tires from cracking. In contact with the weather, this substance turns into a compound called 6PPD-quinone, which has been linked to widespread fish kills in the United States.
Tire particles are a complex mixture of rubber and hundreds of chemical additives
Heavier cars cause faster tire wear and, as a result, produce more microplastic particles. This issue also includes electric cars, which weigh more due to heavy batteries. Nick Molden and Felix Leachauto industry experts suggest that car manufacturers pay a weight-based tax under the “polluter pays” principle. This policy can create an incentive to design lighter cars and encourage consumers to choose environmentally friendly options.
But there are still many unanswered questions. For example, we don’t know how far the tire particles will disperse or where they will accumulate. We need more information to understand their environmental impacts; including the identification of more toxic additives, the reaction of materials to the environment and animal species that are more damaged. For example, some species of salmon are more sensitive to 6PPDquinone. As a result, it will be necessary to standardize tire particle measurement methods and create effective regulations in the future.
