Most of us know that fossil fuel-powered vehicles emit tailpipe pollutants that harm human health and contribute to climate change. However, did you know that car tires also generate toxic pollutants?
Every time a vehicle brakes, turns, or accelerates, its tires wear down slightly. This gradual wear makes it necessary to change your vehicle’s tires about every five years, but it also releases pollutants into the atmosphere and bodies of water. This is a major challenge for countries that are trying to decarbonize their transportation sector by shifting to electric vehicles (EVs). EVs do not emit the harmful tailpipe gases that contribute to climate change, but EV tires still pose an environmental hazard.
Luckily, the problem is finally starting to attract attention. One London-based startup called The Tyre Collective has even developed a potential solution.
How Does Tire Dust Hurt the Environment?
According to a study published in Nature Communications, microplastics produced by road traffic, including tire wear particles and brake wear particles, are a major source of global emissions.
Tire wear particles account for 6.1 million metric tons of pollutants in the earth’s atmosphere and waterways each year. Tire dust is one of the most common microplastic pollutants found in oceans, even in extremely remote places like the Arctic.
Tire wear particles are a mixture of tire fragments, such as synthetic rubber, fillers, and softeners. These particles are created by the friction of the tire against the pavement and are dispersed from roadways by wind and rainfall. The runoff often finds its way into storm drains, where the particles eventually make their way into rivers and oceans. The particles are also released from sewage and from the atmosphere, and make their way to the ocean before the process starts again.
The main chemical of concern in tire wear particles is called 6PPD-quinone, which some experts have referred to as a “stealth pollutant.” 6PPD-quinone is a toxic chemical product of the widely used preservative 6PPD, which is added to tires as a protectant to prevent them from wearing down too rapidly. A January 2022 study in Environmental Science & Technology Letters found that 6PPD-quinone is “more toxic than previously calculated” and should be considered a “very highly toxic” pollutant for aquatic life.
The Importance of Reducing Particulate Emissions
EVs may have solved the problem of tailpipe emissions, but these vehicles still produce tire and break wear particles. As the world transitions to EVs, these particulate emissions must be minimized. A study by Emissions Analytics found that particulate emissions from tire wear are now thousands of times more impactful than tailpipe emissions, which have been significantly cut in recent years with the introduction of high-efficiency exhaust filters.
EVs are still important for decarbonizing transportation, but they will still contribute significantly to non-exhaust emissions if technology is not used to address these emissions. Moreover, EVs are often heavier than fossil fuel-powered vehicles, a fact that can cause them to generate more tire dust. This is why some experts have projected tire wear to rise as EVs become the norm.
About The Tyre Collective
The Tyre Collective was founded as a student project in 2020. Each of the four founders was pursuing a master’s degree in innovation design engineering at Imperial College London and the Royal College of Art. One of the founders, Siobhan Anderson, learned of the tire dust problem due to her interest in microplastics and their impact on the environment.
The founders discovered that non-exhaust emissions (including tire, brake, and road surface wear) are responsible for 90% of all particulate emissions from vehicles. Microplastics found in tire dust contribute to PM2.5 air pollution—very tiny particulate matter that can cause respiratory health problems. These particles can be inhaled and even pass through membrane barriers in the body.
The Tyre Collective calculated the amount of tire dust produced by a single London bus each day and found that it was about the size of a grapefruit. Next, they began strategizing how to stop tire dust from flying onto the road and into the atmosphere.
An “a-ha moment” came when the team realized that these particles are electrostatically charged, and they set about engineering a solution that takes advantage of this fact. The Tyre Collective’s device is fitted to a vehicle directly behind the tires. It’s powered by the vehicle’s alternator and creates an electric field using a copper plate. This field attracts the tire dust and traps it as it flies off the tires, preventing the particles from entering the atmosphere. The collected dust can then be processed for reuse in a closed-loop system.
The Tyre Collective prototype had its first road test in 2021, with assistance from the automotive company Geely Auto Group. This and other partnerships are helping the group improve the device for real-world use, starting with fleet vehicle operators.
The Tyre Collective Partnership with Zhero
The Tyre Collective is currently in a three-month trial with another London-based company called Zhero, which offers low-emission and sustainable logistics services. The two companies believe that this trial will help The Tyre Collective gather more data about its device and measure its efficiency.
The current device captures about 60% of airborne particles when tested in the lab. The team is looking for ways to improve this percentage, including fine-tuning the electrostatics, determining the best area to place the device on the vehicle, and manipulating airflow.
The team is also exploring ways to reuse and upcycle the collected tire dust. For example, the particles can be reused as retreads in truck tires and in shoe soles, soundproofing materials, and bitumen.
The Tyre Collective is planning to soft-launch its device in 2024, with a focus on retrofitting large fleet vehicles and delivery vans. These vehicles have a more regular maintenance schedule, which makes it easier to introduce, clean, and monitor the devices.
The Tyre Collective is an excellent example of the kind of ingenuity and solutions-oriented thinking we need to fight climate change, protect natural resources, and promote public health. There are likely many more environmental threats beyond tire dust that we are only beginning to identify and understand. We must be ready to confront them with innovation and creativity.