In 2012, as part of the National Lakes Assessment (NLA), the Minnesota Department of Agriculture (MDA) cooperated with the Minnesota Pollution Control Agency (MPCA) in a statewide assessment of pesticides in Minnesota lakes. Fifty-two lakes were analyzed using the MDA laboratory's gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) advanced methods for one-hundred and thirty-two different pesticide compounds. Nineteen different pesticide compounds were detected, with atrazine being discovered most frequently in 67 percent of samples. All pesticide compound detections were herbicides. Pesticides and/or degradates were detected in 85 percent of the samples collected. An atrazine enzyme-linked immunosorbent assay (ELISA) method was utilized to analyze samples collected from an additional 122 lakes. All pesticide detections were well below established state water quality standards or United States Environmental Protection Agency (USEPA) reference values. Pesticide detections were widespread and included lakes in non-agricultural areas of the state, however, lakes in agricultural areas of the state tended to have more compounds detected at higher concentrations. Atmospheric deposition of pesticides was suspected as the primary transport mechanism in non-agricultural areas.
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Minnesota Department of Agriculture (St. Paul, Minnesota)
Minnesota Department of Agriculture