Michigan's bald eagles are the most contaminated birds in the world

Bald eagle.

Monday, March 16, 2015, 4:57 PM - A study published last month in the suggests the livers of Michigan's bald eagles are severely contaminated with phased-out flame retardant chemicals, more so than any other bird on the planet.

While the area's bald eagle population is stable, the chemicals have been known to impair reproduction and disrupt hormones.

Manufacturers began using polybrominated diphenyl ethers, or PBDEs, in furniture, electronics and clothing in an effort to make household products safer. The chemicals were phased-out in the early 2000s, but traces can still be found in the air, dirt and in people.

Nil Basu, associate professor at McGill University and lead author of the study, told Environmental Health News that PDBEs "are everywhere".

"They build up in the food chains so that top predators - such as bald eagles - accumulate high levels."

Scientists tested the liver tissue of 33 dead bald eagles collected between 2009 and 2011 by Michigan's Department of Natural Resources.

They were tested for the four most common types of PDBEs. All but two had had all four in their liver.

So far, the chemicals don't appear to be having a negative effect on the eagles, who appear to be reproducing at a healthy rate.

Researchers are more concerned with the long term, as they suspect PDBEs will be present in the environment for some time.

There's also a concern about exposure to other toxic chemicals, such as those found in fertilizers and pesticides.

At present, a lot remains unknown about how chemicals can impact long-term health.

"The market of flame retardants is a bit like a whack-a-mole game," Marta Venier, an assistant scientist with Indiana University, told Environmental Health Network .

"One gets phased out and another one is introduced keeping properties similar to the one it replaced. It goes on and on."