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Articles discussing 6PPD in tire dust
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.
Ecotoxicology and Public Health
January 5, 2026
By Marlee L. Brown, Nathan Ivy, Melissa Gonzalez, Justin B. Greer, John D. Hansen, Edward Kolodziej, Jenifer K. McIntyre
Extensive mortalities of adult coho salmon (Oncorhynchus kisutch), often called “Urban Runoff Mortality Syndrome” (URMS), have been documented during the fall in creeks where water quality has been degraded by roadway runoff. The primary cause of mortality is 6PPD-quinone (6PPDQ; N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine quinone)–an ozone transformation product that forms on all vehicle tires. Laboratory studies have shown that juvenile coho salmon are highly sensitive to 6PPDQ exposure. Unlike adults, juveniles reside in impacted watersheds year-round, including during the spring when 6PPDQ concentrations can frequently exceed lethal thresholds during storms. To assess the potential incidence of URMS in springtime rearing habitats for juvenile coho salmon, we conducted a paired water quality and toxicology study at Miller Creek, a runoff-impacted watershed in Normandy Park, WA, USA. Using a small field facility, three naïve groups of juvenile coho salmon (N = 720) were exposed to either creek water or groundwater (N = 120 per treatment per storm), across three spring storms while comparing water quality and mortality end points. In creek water during exposures, peak 6PPDQ concentrations reached 73–110 ng/L, exceeding reported median lethal concentrations (LC50) for coho salmon. Over each 24–73 h storm exposure period, ∼80% of Miller Creek-exposed juvenile salmon died. No mortality occurred among control fish exposed to groundwater. These results indicate previously unidentified mortality risks for juvenile life stages of coho salmon during spring storms, suggesting substantial and year-round water quality impediments to coho salmon health and recovery across roadway runoff-impacted spawning, rearing, and migratory habitats.
By Jeff Rice
Puget Sound Institute
Published January 9, 2026
Link to Puget Sound Institute, UW Tacoma article
Untold numbers of hatchery fish may be dying from exposure to tire-contaminated runoff, according to a new study.
Continue reading “Study finds juvenile coho salmon at risk from deadly tire chemical”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.
August 31, 2025
My Edmonds News
Link to My Edmonds News Article
The Edmonds Waterfront Center welcomes Edward P. Kolodziej, internationally recognized environmental chemist and the Allan and Inger Osberg Professor at the University of Washington (Tacoma/Seattle) as the featured speaker in Annie Crawley’s Environmental Speaker Series. The event takes place at 6 p.m. on Thursday, Sept. 11, the latest installment in a community-based science and conservation initiative focused on Puget Sound.
Continue reading “Edmonds Waterfront Center Environmental Series Sept. 11: ‘Caring About Our Roads, Car Tires and Coho Salmon’”Department of Ecology
One of the main pollution sources from urban and suburban communities is stormwater. Stormwater is rain and snow melt that flows over rooftops, streets, landscaping, and parking lots that can pick up and carry pollution into nearby waterways. Stormwater is not always treated even when it flows into street drains and can be a leading threat to water quality. Due to the significant rain and snow across the state, Washington has become a leader in stormwater management.
Continue reading “Stormwater & residential pollution”Environmental protection Agency
November 26, 2024
Vehicle tires contain the chemical known as 6PPD to prevent tires from breaking down due to reactions with ozone and other reactive oxygen species in the air. When 6PPD reacts with ozone in the air, it forms 6PPD-quinone. Tires wear down through contact with roads, releasing particles into the environment. When it rains, stormwater from hard surfaces like parking lots and streets washes these particles into streams and other water bodies. As a result, 6PPD-quinone may be present and aquatic organisms can be exposed to it.
Continue reading “What is 6PPD-quinone?”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”Ecology
October 29, 2024
In both the 2022 Supplemental Operating and 2023 Operating budgets, the Washington State Legislature provided funds to Ecology to work on issues related to 6PPD. As part of this work, the Legislature requested that Ecology provide a progress report on the Action Plan and Alternatives Assessment by December 31, 2024.
Continue reading “6PPD Action Plan and Alternatives Assessment – Progress Report and Recommendations”This new Interstate Technology and Regulatory Council (ITRC) document provides information about 6PPD and 6PPDQ that can help inform future policies and regulations. The guide provides:
Read the report:
https://6ppd.itrcweb.org/?utm_medium=email&utm_source=govdelivery
Interstate Technology and Regulatory Council
September, 2024
PowerPoint slide presentation from September 19th, 2024
WRIA-8 Salmon Recovery Council meeting
July 10, 2024