A group of Australian researchers found that cars pose an even greater threat to human health than previously thought — and the danger isn't coming from the exhaust pipe. Rather, analysis of stormwater runoff found high concentrations of microplastics from tire wear particles, according to New Atlas.
What's happening?
As tires wear down, tire wear particles (TWPs) are released. This leads to an accumulation of TWPs on roadways, where they remain until rainwater scatters them.
To assess the prevalence of TWPs in urban stormwater runoff, the research team collected samples from 25 urban locations across 11 storm events. After analyzing the samples, they concluded that stormwater runoff was a significant contributor to microplastics in the city's waterways.
The study also assessed two possible methods of reducing particle pollution: constructed wetlands and stormwater capture devices, which are essentially a tight mesh cover on storm drains.
Researchers were cautiously hopeful about the results. "Our findings show that both constructed wetlands and the stormwater capture device are strategies that could … decrease the amount of microplastics [and] tire wear particles being transported from stormwater into our waterways," said Shima Ziajahromi, the study's lead author.
Why are TWPs concerning?
Microplastics are dangerous to both human and environmental health. In humans, microplastics have been linked to adverse effects in cardiopulmonary, reproductive, developmental, and cancer outcomes. In the environment, especially in aquatic habitats, microplastics have been linked to abnormalities and even death.
Unfortunately, TWPs are a particularly aggressive source of microplastics, posing a threat up to four times greater than others.
"Pollution of our waterways by microplastics is an emerging environmental concern due to their persistence and accumulation in aquatic organisms and ecosystems," said Ziajahromi.
How can TWPs be managed?
In addition to the constructed wetlands and stormwater capture devices, researchers are innovating other ways to remove microplastics. From boiling water to using a magnetic nano-pillared adsorbent that can pull microplastics out of water using a powdered substance, they've been making progress.
Additionally, many tire brands are planning to transition to natural tires, such as Goodyear's soybean model or Bridgestone's material made from a desert shrub.
For the tires that already exist, there are creative solutions too. One company turns old tires into building materials. Another found a way to source graphite from used tires to build car batteries.
However, researchers urged a reconsideration of the grander question of transportation. After all, while electric vehicles are superior in terms of lowering emissions and cutting fuel costs, they still use tires and generate TWPs.
"Electric vehicles are a crucial step forward to decarbonize transport, but we need to look at the big picture too," said Mary Ryan, co-author of a 2023 paper.
The ultimate health-centric choice? Walking.
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