Chemical in tire dust killing Coho salmon, scientists warn

Scientists across the state are warning that a chemical from tire dust poses a major threat to coho salmon. Right now, environmentalists and state leaders are doing work to track this pollutant and find solutions.

It took two decades for local researchers from Washington State University, University of Washington, NOAA Fisheries and U.S. Fish and Wildlife to figure out that a chemical called "6PPD-quinone" was responsible for killing salmon in urban streams. This contaminant targets coho salmon - a population that is at an all-time low in Puget Sound.  

"They just expire," said Jacques White.

White is the executive director for Long Live the Kings, a non-profit that works to protect northwest salmon. He said this discovery about tire dust - specifically a chemical byproduct from a preservative in car tires - is a game changer.

"I thought ‘this is the most important finding in salmon management and recovery in the last 20 years, hands down,’" said White.

Tire manufacturers said they hadn't known 6PPD-quinone even existed. However, its parent chemical compound 6PPD is touted as a critical safety feature in car tires. Without 6PPD, tires are quickly attacked by ozone.

Here’s how this all works: when it’s raining, the chemical from that tire dust washes away before gushing into drains and running into local creeks and streams.

The U.S. Tire Manufacturers Association told FOX 13 they're working on it. USTMA said it's "concerned about this issue and committed to understanding and minimizing the impact of their products on the environment." To read more, click here.

USTMA also said it's working to find a potential alternative.

"We need tires on our cars and stuff, but we also need to make sure we’re doing it in like environmentally safe ways," said Dennis Huang, who lives in Seattle.

People we interviewed in Seattle said they had no idea that something as common as tire dust was hurting salmon.

"I never heard of that, but that sounds like it’s something that should be solved," said Huang.

"Well, I hope they survive, I mean yeah I mean - what else can you say about that?" said Mark Aytch, who lives in Seattle.

Scientists with the University of Washington-Tacoma and Washington State University-Puyallup first made this discovery about a toxic chemical in tire dust at the end of 2020.

Since then, researchers, policymakers and ​activists have been looking for solutions, including things like "biofiltration" systems -- where plants, rocks and organic matter clean out contaminants before the runoff flows into local streams.  

"So trying to think of ourselves as part of everything that’s going on and then being careful about what we do," said James Rasmussen, who is a member of the Duwamish Tribal Council and the superfund manager at the Duwamish River Community Coalition.

Rasmussen said collaborating on issues like this are key and emphasizes that caring for salmon is about caring for the entire region.

"Just as the salmon are suffering, so do the communities. And so we have to try to take all of those things into consideration," said Rasmussen.

USTMA said it will provide tire samples to scientists to help them research 6PPD. The association is also part of a global task force with organizations from other countries - all with the goal of learning more about this deadly chemical on tire dust.