Every year, billions of vehicles worldwide shed an estimated 6 million tons of tire fragments. These tiny flakes of plastic, generated by the wear and tear of normal driving, eventually accumulate in the soil, in rivers and lakes, and even in our food. Researchers in South China recently found tire-derived chemicals in most human urine samples.
Its not only rubber for car tires. There’s a lot of extras to add longevity, and change performance in certain conditions.
Plastic is mostly made from hydrocarbon chains. So are rubber polymers it seems.
Not sure if it matters if the plastic is from a tree or pumped from a really old tree.