Chemicals that have banned for decades are still showing up in Illinois rivers and streams, according to a new study. Researchers at the University of Illinois found traces of the long-banned pesticide dieldrin in the livers of river otters. Otters sit at the top of the aquatic food chain, making them the best detection system to what other wildlife are being exposed to.
Illinois and other states in the Midwest applied millions of pounds of dieldrin to crops before it was banned in 1987.
“There are states outside of the Midwest that have fish consumption advisories in place for dieldrin. There are no fish consumption guidelines with respect to dieldrin in Illinois,” said Samantha Carpenter, a wildlife technical assistant at the Illinois Natural History Survey at the University of Illinois’s Prairie Research Institute.
Carpenter says it’s not surprising that chemicals like dieldrin are still in the environment, as they’re known as persistent pollutants that are resistant to being broken down over time.
There’s disagreement on the effects of dieldrin on humans, but studies have established it can disrupt brain development in fetuses.