Imperial College London experts are urging more action to limit the potentially harmful impact of toxic tire particles on health and the environment.
The researchers from Imperial College London's Transition to Zero Pollution initiative warn that while electric vehicles eliminate the problem of fuel emissions, particulate matter will continue to be a problem due to tire wear.
Prioritize tackling toxic emissions from tires
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Each year, six million tons of tire wear particles are released globally, and 2.6 million vehicles in London alone emit approximately 9,000 tons of tire wear particles, as per Phys.org.
Despite this, research into the environmental and health effects of tire wear has lagged behind research and innovations aimed at reducing fuel emissions.
According to Imperial researchers, the impact of new technologies on tire generation and impact should be prioritized.
A multidisciplinary group of Imperial experts, including engineers, ecologists, medics, and air quality analysts, have called for the same amount of investment in tire wear research as there is in reducing fuel emissions and understanding their interactions in a new briefing paper.
Tire wear particles pollute the environment, the air we breathe, and the water runoff from roads, and have compounding effects on waterways and agriculture, according to lead author Dr. Zhengchu Tan of Imperial's Department of Mechanical Engineering.
Even if all of vehicles eventually run on electricity rather than fossil fuels, we will still have harmful pollution from vehicle tire wear.
Tan urge policymakers and scientists to conduct ambitious research into tire wear pollution in order to fully understand and reduce its impacts on biodiversity and health, as well as research to reduce particle generation.
Transition to Zero Pollution is an Imperial College London initiative that aims to foster new collaborations between research, industry, and government in order to achieve a zero-pollution future.
Professor Mary Ryan, Vice Provost (Research and Enterprise) at Imperial College London, and a co-author on the briefing paper said, Safeguarding our planet and the health of future generations requires us to look not just at a problem from a single perspective but to take a systems level approach.
That is why we must consider human-made pollution in all of its forms, rather than just carbon.
Electric vehicles are a critical step toward decarbonizing transportation, but we must also consider the big picture.
Some people are concerned that the weight of electric vehicles will increase tire wear.
This is precisely why Imperial College London is promoting a holistic, integrated approach to sustainability challenges.
As tires degrade, they emit a variety of particles, ranging from visible pieces of tire rubber to nanoparticles.
Rain carries large particles from the road into rivers, where they may leach toxic chemicals into the environment, whereas smaller particles become airborne and are inhaled.
They are small enough to penetrate the lungs.
Polyaromatic hydrocarbons, benzothiazoles, isoprene, and heavy metals such as zinc and lead may be present in these particles.
Rubber tires, as Salon pointed out, are necessary for modern transportation, but they shed.
The average tire will lose around 30% of its tread after a lifetime of rolling down the highway, running over gravel, and jarring against potholes, as per the World Economic Forum.
This means that tire materials, such as synthetic rubber, filling agents, oils, and other additives, will join the other synthetic particles already polluting the environment.
According to a 2017 study, 1.5 million metric tons of tire particles enter the US environment each year.
It also calculated that tire particles account for 5% to 10% of ocean plastic pollution.
Tire pollution exacerbates the issue of microplastic and nano plastic pollution.
Microplastics are less than 5 millimeters in size, while nano plastics are less than a micrometer in size.
To that end, the researchers exposed indicator species from estuarine and freshwater ecosystems to tire microparticles and nanoparticles, as well as their leachate, or the chemicals that leach from tires as they degrade.
They used Inland Silverside (Menidia beryllina) and mysid shrimp as estuary organisms (Americamysis bahia).
They discovered that the tire particles changed the swimming behavior of the animals and hampered their growth.
Leachates had an effect on their behavior as well, but not on their growth.
Researchers studied embryonic Zebrafish (Danio rerio) and the crustacean Daphnia magna for freshwater organisms.
They discovered that exposure to tire particles and leachate could be fatal and cause developmental issues.
The leachate was the most toxic to the organisms, but when the organisms were exposed to both the leachate and the nanoparticles at the same time, it became even more toxic.
Health Effects
The impact of tire wear particles on human health is becoming increasingly concerning, and more research into the long-term effects on our health is urgently needed.
There is emerging evidence that tire wear particles and other particulate matter can have a negative impact on a variety of health outcomes, including heart, lung, developmental, reproductive, and cancer outcomes.
We are growing increasingly concerned about the impact of tire wear on human health, according to co-author Professor Terry Tetley of Imperial's National Heart and Lung Institute.
Because some of these particles are so small that they can be carried in the air, simply walking on the pavement may expose us to this type of pollution.
It is critical that we gain a better understanding of the impact of these particles on our health.
