U.S. regulators say they will review the use of a chemical found in almost every tire after a petition from West Coast Native American tribes that want it banned because it kills salmon as they return from the ocean to their natal streams to spawn.The Yurok tribe in California and the Port Gamble S’Klallam and Puyallup tribes in Washington asked the Environmental Protection Agency to prohibit the rubber preservative 6PPD earlier this year, saying it kills fish — especially coho salmon — when rains wash it from roadways into rivers. Washington, Oregon, Vermont, Rhode Island and Connecticut also wrote the EPA, citing the chemical’s “unreasonable threat” to their waters and fisheries.The agency’s decision to grant the petition last week is the start of a long regulatory process that could see the chemical banned. Tire manufacturers are already looking for an alternative that still meets federal safety requirements.“We could not sit idle while 6PPD kills the fish that sustain us,” Joseph L. James, chair of the Yurok Tribe, told The Associated Press. “This lethal toxin has no business in any salmon-bearing watershed.”6PPD has been used as a rubber preservative in tires for 60 years. It is also found in footwear, synthetic turf and playground equipment.As tires wear, tiny particles of rubber are left behind on roads and parking lots. The chemical breaks down into a byproduct, 6PPD-quinone, that is deadly to salmon, steelhead trout and other aquatic wildlife. Coho appear to be especially sensitive; it can kill them within hours, the tribes argued.
The structure of the molecule is so simple - it's pretty interesting to understand that the oxidation product is deadly to salmon.
In humans, oxidation products do damage by DNA modification and protein modification, or by consuming glutathione and allowing other oxidation products to run rampant. My expectation would be similar issues here, but I’m no fish biologist. Could be that it’s the stable product that’s a poison, too, but my gut says it’s the reactive issue.
ReplyDeleteThe past decade or so there have been a lot of products developed from recycled tire rubber for use in walkway tiles, sports footing and footing in dirt arenas. The rubber was supposed to be stable from rotting (unlike mulch), able to manage mud in rain. I wonder how much this leaches into the dirt...
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