On Aug. 15, environmental litigation group, Earthjustice, notified more than a dozen American tire manufacturers of their intent to sue them over violations of the Endangered Species Act if they do nothing to stop their alleged chemical pollution.

In the letter to the tire manufacturers, Earthjustice acknowledges that the suit is being made on behalf of the Institute for Fisheries Resources and Pacific Coast Federation of Fishermen’s Associations, because chemicals used in the production of tires has had adverse impacts on coho, steelhead and Chinook salmon species.

The letter, addressed to tire manufacturers that include Goodyear, Bridgestone, Michelin, and Cooper tires, alleges that the chemicals known as 6PPD and 6PPD-q get from roads into waterways from the tires these companies produce and sell to consumers.

“Exposure to 6PPD-q can kill a coho salmon within hours, and the chemical is responsible for ‘urban runoff mortality syndrome,’ which kills up to 100% of coho returning to spawn in urban streams,” read the letter from Earthjustice’s lawyers.

The environmental advocacy group alleges that these chemicals have already had an impact on Pacific salmon populations, citing research that suggests “[w]ild coho populations cannot withstand the high rates of mortality that are now regularly occurring in urban spawning habitats, and that “it will be difficult, if not impossible to reverse historical coho declines without addressing the toxic pollution dimension of freshwater habitats.”

According to Earthjustice, 6PPD-q is present not only in stormwater runoff and urban watersheds at levels that can harm and kill coho salmon, steelhead trout, Chinook salmon, and other aquatic organisms, but is also now widely present in sediments and soils, household dust, and the urine of pregnant women, with emerging science pointing to toxicity in mammals and therefore potential risk to human health as well.

In the letter to the tire manufacturers, that are mostly based in California, Earthjustice gave the companies 60 days to cease the “unauthorized take of these species” before they engage in litigation against the manufacturers