“For decades, scientists say something alarming has been happening in the streams and rivers where coho salmon return from the Pacific Ocean to spawn along the West Coast. After heavy rain events each fall, the fish have been turning up dead in huge numbers before they spawn, a mysterious phenomenon that has been the subject of intense research for years. Now, scientists think they have found a key piece to this morbid puzzle — and according to a new study, it’s strewn all over North America’s roadways. It starts with a chemical antioxidant known as 6PPD, used in tires around the world to make them last longer.
Roughly 3.1 billion tires for the planet’s more than 1.4 billion vehicles are produced annually, the study said, and this chemical appears to be used in nearly all of them. Previous studies have found that tire abrasion is one of the most significant sources globally of microplastics in aquatic ecosystems, and it’s responsible for an estimated 30% of all the microplastic particles in our oceans. Better treatment and management of runoff before it enters coastal streams is part of the solution, the study authors said, but source control and the development of “green” chemical substitutes for 6PPD in tires is also needed.”
More on “Salmon have been dying mysteriously on the West Coast for years. Scientists think a chemical in tires may be responsible” via CNN.