According to new research published in the journal Ecotoxicology and Environmental Safety, river otters  in Central Illinois are being exposed to high concentrations of chemicals such as polychlorinated biphenyls (PCBs) and pesticides, despite the fact that these chemicals were banned decades ago. 

Dieldrin — a byproduct of the pesticide aldrin, which was commonly used across the Midwest before it was banned in 1987 — was present in higher concentrations in the recently deceased river otters than it was in eight specimens examined the years directly following the chemical’s ban.

Dieldrin was used extensively to kill crop pests, termites and mosquitoes before it was banned in 1987 in the U.S. Before these compounds were banned, U.S. farmers applied more than 15 million pounds of dieldrin and aldrin (its parent compound) to their crops every year — much of it in the Midwest. Levels of PCBs, which were banned after being shown to cause cancer in humans and serious health threats in other animals, were similar, as were concentrations of DDE, which was used as a pesticide.

Samantha Carpenter, a wildlife technical assistant involved in the study said that some studies of dieldrin linked it to the development of cancer, Parkinson’s disease, or Alzheimers. Not exactly what we want in our water supply.

“For many of the contaminants we did detect a large range,” Carpenter said.“This is a red flag. We need to understand more about what humans and wildlife are being exposed to in different watersheds.”

What we can understand at this point is that chemicals in the water is never good. Can the chemicals ever be fully removed after years of mistreatment? We can only hope that future research will reveal how much damage has been done and if we can reverse it once and for all.

Image Source: Neil McIntosh/Flickr