Car tire wear is the greatest source of microplastic pollution in most areas of the world. Wind and water spread it all over the globe. This is a serious issue, because the pollutants come back to us humans, whether through food, water, or breathing.
Tire abrasion: How microplastic is created
Tire wear is the number one source of microplastics. The rubber of the tires is roughened by the friction with the road. On average, a single tire lasts four years and loses one to one and a half kilograms of its material through abrasion. Individual, small rubber particles detach themselves during the journey. The largest proportion of tire wear occurs at high speed, in curves, with many stop-and-go, when driving uphill and on gravel roads. These particles accumulate on and next to roads and are distributed over long distances in the environment by wind and water.
As a simplified thought experiment to clarify the dimensions, let’s assume that there are on average the same number of cars per million inhabitants. Now we multiply the approximately 1.25 kg of abrasion per tire by four, since every car has four tires, and now multiply by the one million. Over four years this results in tire wear of 5000 tons which ends up in the environment.
Tire wear is not just a microplastic problem
In addition to microplastics, tire abrasion also leads to the introduction of zinc, lead, cadmium, and plasticizers, for example. These substances also accumulate in the environment and can often hardly be broken down.
Where does microplastic end up?
Microplastics get into the environment primarily through rainwater. The rain not only flushes tire wear into the sewer system but almost everywhere. Sewage treatment plants hold back up to 95 percent of the microplastics, but hardly any rainwater gets there at all. However, it could still end up in the environment through the use of sewage sludge in agriculture.
The wind blows around 140,000 tons of such particles, which are smaller than 0.01 millimeters, into the oceans every year. Approximately 48,000 tons land on snow and ice every year. Sensitive ecosystems such as those in the Arctic are disrupted as a result. The melting of ice surfaces is also a problem, as these have accumulated microplastics and other pollutants over decades and are now releasing them.
What is the future trend?
The problem is even likely to grow: Because of the SUV boom, cars are tending to become heavier, and most electric vehicles weigh more than comparable combustion engines because of their batteries. And the heavier a car, the greater its tire wear. An additional contribution to the SUV problem if there is more detailed interest: Sport Utility Vehicle (SUV). Climate killer, whether electric or with combustion engine. – Greater Ideas
Solutions to the problem
First of all, of course, do without cars where possible. Walking and taking a bicycle instead of a car is not only better for the carbon footprint, but also scores with low bicycle tire or shoe wear, as, unlike in a car, there is no need to move a large mass. The train is also a very good alternative.
Rain and tire abrasion can be collected through filter inserts in street drainage shafts and then cleaned or disposed of.
Do not use sewage sludge in agriculture. In addition to microplastics, this also contains drug residues, antibiotics, and so on, which should not be distributed in fields.
In areas of land next to highways and roads with heavy traffic where tire abrasion accumulates, the upper layer of soil in the vicinity of the road should be removed and disposed of regularly.
We can assume that microplastics are already in all areas of the environment. This topic has to be dealt with more consciously because regardless of food or breathing, these pollutants somehow find their way back to us.