Coho salmon continue to die in Puget Sound creeks after rainstorms. The deaths were linked to bits of car tires shed from road friction into stormwater runoff in 2018.
Washington State University’s (WSU) Puyallup Research and Extension Center identified a tire preservative, known as 6PPD, as the main culprit in 2020. Now, after years of digging, WSU Ph.D. student Stephanie Blair figured out how that chemical kills fish.
6PPD becomes a toxic chemical when it interacts with ozone, according to Blair. That chemical, called 6PPD-quinone, breaks through the cellular walls that protect the brain and vascular system, leading to oxygen deprivation…