Minnesota scientists say it appears endocrine-disrupting chemicals and pharmaceuticals are found in even the most pristine lakes in the state.
Researchers say they’re not sure why the chemical compounds are so widespread, but they say more research is needed to better understand the potential impact on wildlife and humans.
The Minnesota Pollution Control Agency sampled a dozen lakes and four rivers across the state. Some of the samples came from water close to cities and others were from lakes in remote northern forests.
Environmental Research Scientist Mark Ferrey said they looked for 110 compounds including residue from plastic bottles, household detergents and pharmaceutical drugs.
Bisphenol A, a compound found in polycarbonate plastics, was found in 82 percent of lakes, the common painkiller acetaminophen was found in 50 percent of samples, 4-octylphenol diethoxylate, a detergent ingredient was found in 36 percent of lakes and 71 percent of rivers.
“These compounds appear to be commonplace in the lakes we’ve studied across Minnesota,” Ferrey said. “Not at high concentrations, but they’re present and in lakes where we might be surprised to find out they’re present.”
One of the puzzles for researchers is Northern Light Lake north of Grand Marais. Endocrine-disrupting compounds are thought to come mostly from sewage treatment plants, or septic systems. Northern Light Lake has neither; it’s an undeveloped lake with just a public boat ramp.