You may not know it, but lead is a key element in your car battery and expensive to produce domestically.

So, U.S. automakers often use recycled lead produced overseas, a practice long framed as an environmental success story.

But a new investigation has found that the recycled lead used by U.S. auto and battery manufacturers is not safe and is linked to dangerous lead

poisoning. Our Stephanie Sy has more.

The New York Times in a non-profit newsroom called The Examination followed the supply chain

of U.S. car batteries over the course of a year to villages in Nigeria where factories recycle lead.

The team was able to test 70 people who live in those villages and agreed to a blood test.

The result, these Nigerians are being poisoned at an alarming rate with 7 out of 10 showing

harmful levels of lead in their bodies.

That recycled lead goes into U.S. cars.

I'm joined now by Peter Goodman, global economics correspondent for the New York Times,

who was part of this reporting team.

Peter, thank you so much for sharing your reporting with the News Hour.

You know, you traveled to a town

near Lagos, Nigeria, for this story, just got back. How is lead getting into the community?

And is there any doubt that it can be traced back to these lead recycling factories?

Yeah, there's no doubt. I mean, that's why we did the tests and we had a control group and it's really clear.

So, you know, it's a very strange supply chain that we're invited to not think about.

It's effectively invisible to most consumers here in the U.S.

But basically, there are all these batteries that get picked up by this group of

people known as the pickers. They go around Nigeria, they find spent batteries, they buy them,

they bring them to these yards where the breakers use machetes to break apart the plastic

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