The tiny particles that come off tires are likely harming freshwater and coastal estuary ecosystems, according to a pair of recent studies from Oregon State University (OSU).
The first study, published in Chemosphere last month found that exposure to tire particles had harmful effects on organisms in coastal estuaries, while the second, published in the Hazardous Materials Journal, found the same for freshwater organisms. Both studies are driven by the number of tire particles in the environment.
“I think especially with tire particles that everyone measures their quantity, but very few groups measure their impact,” said Susanne Brander, an assistant professor at OSU and ecotoxicologist, who led the coastal study. in a press release. . “That’s really the gap we were trying to fill here.”
Rubber tires are essential for modern transportation, as Salon pointed out, but they are also losing. After spending a lifetime of driving on the highway, rolling over gravel and hitting potholes, the average tire will lose about 30% of its tread. This means that tire materials – which include synthetic rubber, fillers, oils and other additives – join the other synthetic particles currently polluting the environment. A 2017 study estimated that 1.5 million metric tons of tire particles enter the US environment each year. In addition, he calculated that tire particles account for 5-10% of plastic pollution in the oceans.
Tire pollution contributes to the problem of both microplastic and nanoplastic pollution. Microplastics measure less than 5 millimeters, while nanoplastics measure less than a micrometer.
“The focus on microplastics and now nanoplastics is still relatively new,” OSU Professor Stacey Harper, who led the freshwater study, said in the press release. “We are now on the verge of making political decisions for which we do not have the science. That’s why we strive to provide this science.
To this end, researchers exposed indicator species of estuarine and freshwater ecosystems to microparticles and nanoparticles from tires and their leachate, or chemicals that leach out of tires as they decompose.
For estuarine organisms, they used the inner silverside (Menidia beryllina) and mysid shrimp (Americamysis bahia). They found that the tire particles changed the animals’ swimming behavior and restricted their growth. The leachates also had an impact on their behavior but not on their growth.
For freshwater organisms, researchers studied embryonic zebrafish (Danio rerio) and the crustacean Daphnia magna. They discovered that exposure to tire particles and leachate could have a deadly effect and cause developmental problems. Leachate was most toxic to organisms, but was even more toxic when organisms were exposed to both leachate and nanoparticles.
“Even at current environmental levels of tire-related pollution, which are expected to continue to increase, aquatic ecosystems may be negatively impacted,” the estuary study authors concluded.
The study authors also offered suggestions on how to protect freshwater and estuarine ecosystems from tire pollution, according to the press release. These included:
- Install roadside rain gardens to catch tire particles before they enter the environment.
- Install devices on cars that catch particles.
- Designing tires that last longer.
- Build more public transit infrastructure so there are fewer cars on the road to begin with.