The problem of marine waste pollution has drawn the attention of many environmentalists and ecologists, and plastic is a serious part. Scientists are worried that too much plastic waste and the plastic particles it decomposes will cause environmental and ecological problems. In recent years, environmental scientists have begun to notice another marine pollutant that seems inconspicuous, even invisible to the naked eye, which is “tyre dust” known as the invisible killer.
Tyre dust is black fine particles produced when tires are worn out. Usually, when the car turns, brakes, or accelerates, it is more prone to wear and tear, and tire dust will remain on the road. These particles flow into the ocean as the rain washes away, turning into pollutants that are difficult to clean up and becoming invisible ecological killers. Experts estimate that millions of tons of tire dust are generated in Europe every year. If the amount generated by other countries and regions is added, the overall amount will be quite staggering.
But now we found a small tire dust which has a huge impact on the ocean. Environmental scientists observed these tiny black particles in rainwater flowing through the streets, and after analysis found that they were the same as the material of tires. Unlike plastic waste, tire dust has a relatively high density. It will not float on the sea surface but will sink to the bottom. It will drift around the world with seawater, or enter the body of marine organisms, making it difficult to remove.
The death crisis of Coho salmon, an important fish in streams in the Pacific Northwest of the United States, is related to the toxic substances in tire dust. Scientists observed decades ago that coho salmon returned to Puget Sound on the west coast of Seattle from the Pacific Ocean to spawn often die collectively for unknown reasons after heavy rains, so they are trying to find out the possible reasons. Pesticides, metallic substances, and hydrocarbons were tested, but no evidence of death was found. They also researched in the direction of fish hypoxia or disease but still found nothing.
After 15 years of research, Jenifer McIntyre, assistant professor of aquatic toxicology at Washington State University, and her research team began collecting dust samples from roads near streams and placing them in the living spaces of coho salmon. It turned out that after a few hours, the salmon participating in the experiment died, and these dust samples were tyre fine particles.