Tire Wear Kills Fish

When you buy a new set of tires, have you given any thought to where the old ones go? One problem is that they are not made purely of rubber and the dust they produce as they wear has become a stealth pollutant becoming a huge threat to life in the oceans.

Scientists have spent decades on the trail of a mystery toxin killing salmon in large numbers. A recent breakthrough, reports the Guardian, revealed the culprit.

For decades, Coho salmon returning to spawn from the Pacific Ocean to the creeks and streams entering Puget Sound in Washington state were dying in large numbers. No one knew why; however, scientists working to solve the mystery of the mass deaths noticed they occurred after heavy rains.

Toxicologists suspected pesticides, as the main creek they studied ran through a golf course, but found no evidence of pesticides. The first real breakthrough happened when they tested actual runoff collected from a nearby road and exposed test salmon to it. The fish died within hours.

Tire-wear particles - a mixture of tire fragments, including synthetic rubbers, fillers, and softeners, and road surface particles - are one of the most significant sources of micro plastics in the ocean. The average tire loses about 10 pounds during its lifetime and it's only going to get worse because electric cars are heavier than their gasoline equivalents and produce greater torque from their motors so that the dust from tires and brakes becomes even more significant.

Last month we reported on how marine critters, once inside the rim of a tire, can't climb out. Now, the problem is much larger.