Could a chemical in our tires be killing salmon? That's what Humboldt Waterkeeper and the Wiyot Tribe have set out to study. The chemical, 6PPD-quinone, is a breakdown product of 6PPD, which is added to tires to prevent cracking and wear. When tires grind away, little bits of the rubber become susceptible to react with ozone. These are then swept away by rain to local waterways, where even slight concentrations are known to kill coho salmon. 

The Wiyot Tribe and Humboldt Waterkeeper sampled 19 urban streams and parking lots that discharge stormwater runoff. Their findings were alarming: Sixty-three percent of samples (12 out of 19) exceeded the U.S. EPA aquatic screening levels. Jen Kalt and Sylvia van Royen of Humboldt Waterkeeper and Tiffany Douglas of the Wiyot Tribe join the show to discuss their study. 

To learn more, check out their report!

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