How much plastic escapes into the environment for a typical car tyre in its lifespan?
> Tires have one engineering principle that’s unlikely to change: they shed. The friction of rubber on abrasive surfaces is what allows a heavy vehicle to grip roads and stop when needed, sloughing off bits and pieces of the tire. A 2017 scientific literature search of 13 industrialized and industrializing countries found that an average car loses between a quarter kilogram and two kilograms of tire fragments annually. In the car-happy United States, the amount jumps to nearly five kilograms—or about the weight of a cat.
Plastic is organic. As it breaks down, it does so in an endless variety of organic molecules. These being similar to biological molecules, they readily interact with all sorts of biological systems. Those systems have all seen a few billion years of optimisation, making it unlikely for any random interference to be beneficial.
1. https://www.hakaimagazine.com/features/when-rubber-hits-the-...
[0] https://dx.doi.org/10.3390%2Fijerph14101265 [1] https://doi.org/10.1016/j.scitotenv.2020.137823
What's interesting is that the thickness of the layer deposited as it rolls (from this simplified model) 1.5E-3/(50E60.250.8)=3nm which is about 0.15nm or a monolayer.
Let's say there are on the order of 100,000,000 cars in regular use in America. That's 300,000,000 liters of of plastic waste generated each year?
That's hundreds of thousands of tons of waste thrown into the environment every year! I had no idea that car tires shed that much.
That's like finding 20 empty two liter bottles just lying there. (Based on a bottle using 50 grams of plastic.)
So yeah, seems like a lot to throw out every year from every car.
Put another way, if every driver threw an empty two liter bottle on the side of the road every two weeks, you'd have an equivalent amount of plastic being shed into the environment.