The Land of 10,000 Lakes has a water pollution problem. According to a new study by the Minnesota Pollution Control Agency, potentially harmful chemicals — along with a medicine cabinet’s array of pharmaceuticals — are tainting the state’s streams.
Scientists who tested water samples from around Minnesota for 78 chemicals found very low concentrations of the compounds, measured in parts per billion or parts per trillion. But scientist Mark Ferrey told Minnesota Public Radio that they still could have harmful effects.
“More and more results are coming out that show that these compounds can have pretty profound hormonal effects or estrogenic effects even at those concentrations,” he said.
Common ingredients of the chemical brew in Minnesota’s streams, Ferrey said, including sulfamethoxazole, an antibiotic, and carbamazepine, a drug used to treat attention deficit hyperactivity disorder. In addition, researchers found anti-depressants and contraceptive hormones, along with components of detergent and bisphenol A, or BPA, which is found in plastics.
Prescription drugs and over-the-counter medicines filter into waterways because sewage treatment plants can’t break them down.
The study is the most comprehensive on chemicals in Minnesota, with water samples collected from 25 sewage treatment plants across Minnesota as well as upstream and downstream from the plants. Ferrey said researchers were somewhat surprised to find the upstream pollution, which may come from septic systems or agricultural runoff.
According to another water pollution study released last week, about 35 percent of the fish collected on a 2008 research expedition off the West Coast had plastic in their stomachs. The Los Angeles Times reports that the study “raises the concern that garbage, as it works its way through the food chain, could be ingested by humans.”
