Campaigning for clean water and a healthy environment for humans and wildlife
Category for 6PPD blog posts
Ecology’s current work to address 6PPD and 6PPD-quinone (6PPDQ) is highlighted below. This update includes current agency actions. Contact us at 6PPD@ecy.wa.gov.
Momentum Builds for Solutions to Tire Wear Pollution: Last month, Ecology hosted a virtual 6PPD State of the Science Forum, connecting researchers, policy practitioners, and partners from across the globe to share knowledge and accelerate progress.
Continue reading “6PPD Update – January 2026”January 27, 2026
Puget Soundkeeper
Link to My Edmonds News article
Since 2015, Puget Soundkeeper has monitored coho salmon health in Seattle’s Longfellow Creek, producing data on the impacts of urban pollution on salmon survival. For years, Longfellow Creek has been the epicenter of research studying the effects of 6PPD-quinone — a toxic tire chemical lethal to coho salmon.
According to a Puget Soundkeeper news release, exposure to 6PPD-quinone causes a condition called Urban Runoff Mortality Syndrome (URMS), a disease characterized by symptoms such as disorientation and gasping for air, often killing coho within 24 hours. Furthermore, this chemical has been strongly linked to Pre-Spawn Mortality (PSM), where adult salmon die before successfully reproducing, the news release said.
Puget Soundkeeper’s annual Pre-Spawn Mortality Survey analyzes the spawning success of coho salmon in Longfellow Creek to better understand the impacts of 6PPD-quinone. From October through December, trained volunteers count and dissect returning coho salmon, particularly assessing the presence of eggs and milt to determine whether spawning was successful.
Results from the 2025 study show that 55.5% of coho salmon died before spawning. This aligns with data collected since 2015, which shows that 49-90% of returning salmon die before reproducing each year.
“This level of pre-spawn mortality is devastating,” said Ewan Henderson, clean water program specialist at Puget Soundkeeper. “The dramatic reduction in successful spawning opportunities is a huge blow to our ecosystems, particularly for our resident orcas who already face major challenges as their food sources dwindle.”
According to the press release, Green Stormwater Infrastructure (GSI) projects, such as rain gardens or bioswales, can effectively remove toxins from runoff and prevent harmful chemicals from entering local waters. In addition to GSI projects, a bill (HB 2421) aimed at removing 6PPD from tires was introduced to the Washington State House and Senate Environment Committees last week.
Puget Soundkeeper will be recruiting the next cohort of salmon surveyors in August. More information will be made available on their website.
To learn more about the 2025 Salmon Survey report results, visit pugetsoundkeeper.org/volunteer/salmon-surveys.
By Greg Ferguson and Jane O’Dell
December 6, 2025
Link to My Edmonds News article
On Oct. 16, a group of Edmonds-Woodway High School students with the Students Saving Salmon Club were performing routine water quality testing in Shellabarger Creek when they saw something disturbing: a young coho smolt swimming weakly on its side. On the shore nearby was another dead coho smolt.
Continue reading “Reader view: Dead coho in Shellabarger Creek — was stormwater runoff to blame?”NOAA Fisheries
September 17, 2025
NOAA scientists develop method to track toxic chemical in finfish, shellfish, and marine mammals.
March 28, 2025 at 6:00 am
By Amanda Zhou
Seattle Times staff reporter
For decades, toxic tire dust has choked coho salmon before they can spawn in their natal streams. Now, King County scientists say they have made a “potential breakthrough” in how to save them.
By Camila Domonoske, Jessica Yung, Rebecca Ramirez
November 20, 2024
For decades, Coho salmon were turning up dead in urban streams the Pacific Northwest. The salmon would stop swimming straight, and then die before they had a chance to spawn. Researchers worried that unless they figured out the cause, the species would eventually go extinct.
Continue reading “Why are so many Coho salmon dying? The answer might be in your tires”by Cathy Hamilton-Wissmer
November 1, 2024
In May 2024, our Safer Products for Washington team identified a new set of toxic chemicals in everyday consumer products. That’s important because it gives us an opportunity to reduce exposure to toxic chemicals and prevent their release into the environment. We want your feedback on the products we’ve identified as significant sources of these toxic chemicals.
Continue reading “From tires to nail polish, we’re studying a new round of consumer products with toxic chemicals”Department of Ecology
6PPD is a chemical that prevents automotive tires from degrading (i.e., breaking down) and helps them last longer. When 6PPD is exposed to air, it reacts with ozone to create 6PPD-quinone (also known as 6PPDQ). 6PPDQ is lethal to coho salmon and can contaminate water systems.
We work with Tribal and local governments, state and federal agencies, academic institutions, and industrial organizations to reduce the pollution and sources of 6PPDQ released from tires in Washington.
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