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  • By HANK NUWER, 

It’s a story as old as the story of human progress.

A new discovery or innovation heralded for its efficacy is suspected to have harmful effects that require ingenuity on the part of researchers to find an antidote to the unintended causes.

I consider it compelling news as a journalist and angler that the U.S. Environmental Protection Agency announced in a Nov. 2 release that it is addressing a petition from multiple tribes of northwest U.S. Native American tribes petitioning to tackle the troubling effects of an ever-present chemical commonly abbreviated as 6PPD. The chemical has commonly been used for years to fortify automobile tires and to prevent degradation and cracking. 

The basic chemistry lesson here is that the combination of 6PPD and ozone air pollution transforms into a secondary byproduct process known as 6PPD-quinone, a biological pigment found in many plants and some animals. The deep concern is that road use causes tires to shed 6PPD, which then ends up on roadways, washed by rains and melting snow into streams, rivers and larger bodies of water where, studies show, the chemical proves lethal to coho salmon after mere hours of exposure. Less a threat to salmon, 6PPD also permeates synthetic rubber goods like footwear and playground turf.

The EPA’s Office of Chemical Safety and Pollution Prevention confirmed that the threat from 6PPD goes hand-in-glove with other reasons for the troubling decreases in salmon population hurting the state’s economy, and also tribal cultural, economic and food security. Verified tests of stormwater in the Pacific Northwest showed 6PPD concentrations in stormwater to be lethal in merely a matter of hours. While more controlled studies in Alaska linking salmon deaths with 6PPD-quinine are needed, research by Anchorage geochemist Birgit Hagedorn confirmed alarming amounts of the byproduct in two Anchorage-area creeks.

I understand and support the chain of steps that must now be followed to see if the endgame will be regulations prohibiting the manufacture of products with 6PPD in tires and possibly other commercial products. To this end, the EPA announced that it is gathering data and information from available and planned studies to amass information needed before regulatory actions may be enacted. At this point, a host of agencies have been charged with completing complex investigations into the effects of 6PPD-quinine on aquatic life, particularly coho salmon water contamination, but also to see if there might be human health effects. I personally wonder if the salmon died from oxygen depletion, rapid water chemistry change (pH) or a combination of factors.

My particular question that I hope this EPA addressing of 6PPD can answer is whether researchers in Indiana and other states (as well as in all countries that permit tires with 6 PPD on the road) will be able to link it to the too-frequent fish kills we see or read about in the news. I once personally walked a riverbank at Delaware Water Gap National Recreation Area and observed hundreds of dead and gasping fish in the shallows. 

While I know it is crucial to study more verifiable scientific evidence prior to me taking a full editorial stand, I do stand in unity with affected Native tribes who want a return of the abundant coho salmon runs enjoyed by their ancestors. The urgency, where the rubber meets the road, is for EPA to determine just how much a once-heralded innovation plays a part in salmon depletion.