In this bonus episode of Rethinking EHS, Beatrice Bizzaro and Ivy Liu take a deeper dive into the environmental consequences of 6PPD-quinone, focusing on its devastating effects on coho salmon. As a keystone and indicator species, coho salmon play a critical role in ecosystem health and provide an early warning signal for water pollution. The episode explains how 6PPD, a widely used tire additive, reacts with ozone to form a highly toxic byproduct that enters waterways through stormwater runoff. This has led to acute and often rapid mortality events in salmon populations, particularly in urban streams, with significant ecological, cultural, and economic implications. Ultimately, the episode underscores the urgent need for improved stormwater management, stronger regulatory action, and the development of safer chemical alternatives. It calls on organisations and regulators to take proactive steps to reduce pollutant release and better protect aquatic ecosystems. ----- Timestamps: 00:06 – Introduction & episode overview 00:43 – Why coho salmon are key indicator species 03:28 – How 6PPD enters waterways 05:04 – Why research is concentrated in the Pacific Northwest 06:09 – Key takeaways and urgency for action 07:28 – Salmon life cycle and vulnerability 09:25 – “Canary in the coal mine” explained 11:45 – Closing reflections ----- Sponsor: Rethinking EHS is brought to you by the Inogen Alliance. Inogen Alliance is a global network of 70+ companies providing environment, health, safety, and sustainability services, working together to provide one point of contact to guide multinational organizations to meet their global commitments locally. Visit inogenalliance.com to learn more. ----- Links https://www.Inogenalliance.com/resources https://www.Inogenalliance.com/podcast Beatrice on LinkedIn https://www.linkedin.com/in/beatrice-bizzaro/ Ivy on LinkedIn https://www.linkedin.com/in/ivy-liu-p-geo-qpra-4a797520/ Produced by https://www.madcontent.co.nz Transcript 1 00:00:06,100 --> 00:00:12,000 Beatrice: Hello everyone and welcome to Season 3 of Rethinking. 2 00:00:12,000 --> 00:00:20,000 Beatrice: The EHS Global Goals, Local Delivery and Inogen Alliance podcast. 3 00:00:20,000 --> 00:00:28,000 Beatrice: My name is Beatrice Designer, Water Stewardship Technology Lead at HPC Italy, 4 00:00:28,000 --> 00:00:32,200 Beatrice: and your host for today’s bonus episode. 5 00:00:32,230 --> 00:00:43,140 Beatrice: I’m joined by Ivy from Terrapex. Thanks for being here again, Ivy. 6 00:00:43,190 --> 00:00:55,200 Beatrice: Why is coho salmon used as an early warning indicator? 7 00:00:55,220 --> 00:01:07,150 Ivy: Coho salmon are extremely sensitive. 8 00:01:07,150 --> 00:01:14,010 Ivy: It helps to view them in the broader Pacific Northwest salmon context. 9 00:01:14,030 --> 00:01:26,000 Ivy: They’re among the most affected species by 6PPD-quinone contamination. 10 00:01:26,000 --> 00:01:38,000 Ivy: Salmon are vital to ecosystems — as predators, prey, and nutrient recyclers. 11 00:01:38,000 --> 00:01:50,000 Ivy: They also act as indicator species, reflecting overall water quality. 12 00:01:50,220 --> 00:02:05,000 Ivy: Coho salmon are especially useful indicators because their response is acute and repeatable. 13 00:02:05,000 --> 00:02:21,110 Ivy: This makes them key for identifying urban runoff contamination. 14 00:02:21,130 --> 00:02:28,190 Ivy: 6PPD-quinone has been recognised as a global contaminant since 2023. 15 00:03:28,210 --> 00:03:36,000 Beatrice: How does it enter surface water? 16 00:03:36,000 --> 00:03:44,080 Ivy: It comes from 6PPD, a chemical used in car tyres. 17 00:03:44,080 --> 00:03:56,140 Ivy: When tyres wear down, particles react with ozone. 18 00:03:56,140 --> 00:04:05,000 Ivy: This creates the toxic byproduct, 6PPD-quinone. 19 00:05:04,120 --> 00:05:16,000 Beatrice: Why did research start in the Pacific Northwest? 20 00:05:16,000 --> 00:05:30,000 Ivy: Because coho salmon are native there, and mass die-offs were highly visible. 21 00:05:30,000 --> 00:05:51,000 Ivy: That triggered strong local research efforts across universities and institutions. 22 00:05:51,020 --> 00:06:03,000 Beatrice: What’s the key takeaway from your work? 23 00:06:03,000 --> 00:06:20,000 Ivy: The chemical is highly toxic and shouldn’t be taken lightly. 24 00:06:20,000 --> 00:06:34,000 Ivy: We urgently need safer alternatives and better stormwater management. 25 00:07:16,180 --> 00:07:28,140 Beatrice: Why are salmon especially vulnerable? 26 00:07:28,160 --> 00:07:42,000 Ivy: They are anadromous — moving between ocean and freshwater. 27 00:07:42,000 --> 00:08:03,060 Ivy: This exposes them to risks across multiple environments. 28 00:08:03,080 --> 00:08:20,000 Ivy: They hatch in streams, move through estuaries, then mature in the ocean. 29 00:08:20,000 --> 00:08:41,000 Ivy: Finally, they return to freshwater to spawn — often in urban areas. 30 00:09:25,060 --> 00:09:35,060 Beatrice: What does “canary in the coal mine” mean? 31 00:09:35,080 --> 00:09:50,000 Ivy: They signal broader water quality issues caused by urban runoff. 32 00:09:50,000 --> 00:10:07,230 Ivy: Their response is rapid and often lethal. 33 00:10:08,000 --> 00:10:27,160 Ivy: Mortality can reach 60–90%, sometimes within 90 minutes. 34 00:10:27,180 --> 00:10:44,000 Ivy: Even at extremely low concentrations. 35 00:11:02,110 --> 00:11:20,000 Ivy: This makes them powerful indicators of broader environmental contamination. 36 00:11:45,010 --> 00:11:47,230 Beatrice: Thank you, Ivy. 37 00:11:48,000 --> 00:12:05,000 Beatrice: Thanks for listening. Follow the podcast on Spotify, YouTube, LinkedIn and Apple. 38 00:12:05,000 --> 00:12:30,000 Beatrice: Until next time, thank you for being part of this community.
