DAYTON, Ohio (WDTN) — Sixteen years after America’s national bird was removed from the endangered species list, bald eagles are once again at risk.

The bird has been affected by increased exposure to a toxic material: Lead.

Experts say the birds have been exposed to the toxic material through lead ammunition and lead fishing. Now, lead poisoning is slowing down the eagle population growth.

“The biggest thing we can do is for hunters to lead the way to be able to switch to copper,” James Manley of the Skegemog Raptor Center said. “Copper alloy, and different types of ammunition that don’t have lead.”

In 2019, California became the first state to outright ban lead bullets.