Camila Dominovsky

And we was a lot of people. Biologists, modelers, community scientists, environmental chemists. Some researchers rule out all the obvious culprits. Temperature, oxygen, known toxins. It's none of those. They need a lead.

And we was a lot of people. Biologists, modelers, community scientists, environmental chemists. Some researchers rule out all the obvious culprits. Temperature, oxygen, known toxins. It's none of those. They need a lead.

They look through the data about where fish were dying and started running models.

They look through the data about where fish were dying and started running models.

They look through the data about where fish were dying and started running models.

Traffic. It's something to do with the roads, the urban runoff. So after years of work, the list of suspects is narrowing, but what part of the runoff? Enter another team of scientists from the University of Washington, including Zhen Yu. They're testing chemicals in runoff.

Traffic. It's something to do with the roads, the urban runoff. So after years of work, the list of suspects is narrowing, but what part of the runoff? Enter another team of scientists from the University of Washington, including Zhen Yu. They're testing chemicals in runoff.

Traffic. It's something to do with the roads, the urban runoff. So after years of work, the list of suspects is narrowing, but what part of the runoff? Enter another team of scientists from the University of Washington, including Zhen Yu. They're testing chemicals in runoff.

Smoking gun. It's coming from tire particles. But tires have tons of chemicals in them, and they need to find which one is the culprit. So today on the show, how a team of researchers finally cracked the case of the coho salmon, and how their discovery is having ripple effects. I'm Camilla Dominovsky, and you're listening to Shortwave, the science podcast from NPR.

Smoking gun. It's coming from tire particles. But tires have tons of chemicals in them, and they need to find which one is the culprit. So today on the show, how a team of researchers finally cracked the case of the coho salmon, and how their discovery is having ripple effects. I'm Camilla Dominovsky, and you're listening to Shortwave, the science podcast from NPR.

Smoking gun. It's coming from tire particles. But tires have tons of chemicals in them, and they need to find which one is the culprit. So today on the show, how a team of researchers finally cracked the case of the coho salmon, and how their discovery is having ripple effects. I'm Camilla Dominovsky, and you're listening to Shortwave, the science podcast from NPR.

So knowing that tires have tons of chemicals in them that would need to be narrowed down, Zhenyu and his team step in and start testing batches.

So knowing that tires have tons of chemicals in them that would need to be narrowed down, Zhenyu and his team step in and start testing batches.

So knowing that tires have tons of chemicals in them that would need to be narrowed down, Zhenyu and his team step in and start testing batches.

And one by one, they narrowed down the options until they found the deadly chemical. But that chemical, whatever was killing the salmon, it wasn't a tire additive. It didn't match anything put into tires. They still had no idea what it was. So Zhenyu and his team were stuck. They'd zeroed in on this chemical killing the salmon.

And one by one, they narrowed down the options until they found the deadly chemical. But that chemical, whatever was killing the salmon, it wasn't a tire additive. It didn't match anything put into tires. They still had no idea what it was. So Zhenyu and his team were stuck. They'd zeroed in on this chemical killing the salmon.

And one by one, they narrowed down the options until they found the deadly chemical. But that chemical, whatever was killing the salmon, it wasn't a tire additive. It didn't match anything put into tires. They still had no idea what it was. So Zhenyu and his team were stuck. They'd zeroed in on this chemical killing the salmon.

They knew it came from the tires somehow, but it just didn't match any tire additive. Zhenyu says, yeah, that's the scientific process for you.

They knew it came from the tires somehow, but it just didn't match any tire additive. Zhenyu says, yeah, that's the scientific process for you.

They knew it came from the tires somehow, but it just didn't match any tire additive. Zhenyu says, yeah, that's the scientific process for you.