A newly discovered pollutant found in vehicle tire tread wear particles on our roads is creating great concern because it is highly toxic to aquatic life, especially endangered salmon. A chemical compound, called 6PPD, is found in most tires to prevent damage from ozone. When this chemical oxidizes in the air, it changes to 6PPD-quinone . A scientific study published in Science December 2020 concluded that stormwater runoff carries these tire particles into the nearby waterways. When the 6PPD-Q chemical leaches out into the water, it is acutely deadly in even tiny amounts to Coho Salmon. In the study, the scientists found that in most urban watersheds where there is a high amount of impervious surfaces, 40 to 90% of salmon returning from the sea die before spawning. Death to salmon may occur after only a few hours of exposure to 6PPD-quinone.
California CoastKeeper Alliance is planning on addressing this problem of 6PPD-quinone and trying to get pilot projects in place throughout the state. Russian Riverkeeper is most likely going to manage one or two project locations in our watershed. Of great concern are the bridges along the 101 freeway over the Russian River where direct discharge into the river is possible. We will be looking at potential stormwater treatment options in these high-exposure areas, and putting pressure to ban this substance from future tire manufacturing.
The Environmental Protection Agency is putting a lot of resources into actions and possible solutions for this threat to our national waterways, and more information can be found here: