Environmental Health - Toxic Substances Hydrology Program

EH Science Feature Email Signup

Neuroactive Pharmaceuticals in Minnesota Rivers

USGS scientists collected water samples in plastic bag to prevent contamination
USGS scientists collected water samples for a study of neuroactive pharmaceuticals in Minnesota Rivers using specialized techniques to insure the samples were not contaminated. Photo credit: Molly Trombley, USGS.

A team of scientists from the U.S. Geological Survey (USGS) and the University of Colorado measured seven neuroactive pharmaceutical compounds in treated wastewater and downstream receiving waters at 24 sites across Minnesota. The analysis of samples collected upstream and downstream of wastewater treatment plants indicated that wastewater treatment plants were the major source of these chemicals.

These neuroactive pharmaceuticals include antidepressants, anti-seizure compounds, and mood stabilizers. The seven compounds (bupropion, carbamazepine, citalopram, fluoxetine, gabapentin, lamotrigine, and venlafaxine) were detected at concentrations ranging from tens of parts per trillion to parts per billion.

Metabolites (byproducts of biochemical transformation) of these compounds also were measured, and metabolites of bupropion, carbamazepine, and venlafaxine were measured commonly, often at comparable concentrations to their parent compounds. Metabolite to parent ratios were used to evaluate transformations among the various sites, and the ratios in wastewater were much lower than those reported for urine from human patients, indicating that the metabolites are relatively more labile than the parent compounds in the wastewater treatment plants and streams.

Results from this study provide a statewide benchmark for the occurrence of antidepressants, which are potential environmental contaminants of concern, and indicate that further understanding of the environmental fate and impacts of these compounds is warranted. The data from this study are available in Lee and others (2011), and Martinović-Weigelt and others (2014) provide additional results from this overall study.

The research was supported by the USGS Toxic Substances Hydrology Program and the Minnesota Pollution Control Agency.


Writer, J.H., Ferrer, I., Barber, L.B., and Thurman, E.M., 2013, Widespread occurrence of neuro-active pharmaceuticals and metabolites in 24 Minnesota rivers and wastewaters: Science of the Total Environment, v. 461-462, p. 519-527, doi:10.1016/j.scitotenv.2013.04.099.

Lee, K.E., Langer, S.K., Barber, L.B., Writer, J.H., Ferrey, M.L., Schoenfuss, H.L., Furlong, E.T., Foreman, W.T., Gray, J.L., ReVello, R.C., Martinovic, D., Woodruff, O.R., H., K.S., Brown, G.K., Taylor, H.E., Ferrer, I., and Thurman, E.M., 2011, Endocrine active chemicals, pharmaceuticals, and other chemicals of concern in surface water, wastewater-treatment plant effluent, and bed sediment, and biological characteristics in selected streams, Minnesota—Design, methods, and data, 2009: U.S. Geological Survey Data Series 575, 49 p.

Martinović-Weigelt, D., Mehinto, A.C., Ankley, G.T., Denslow, N.D., Barber, L.B., Lee, K.E., King, R.J., Schoenfuss, H.L., Schroeder, A.L., and Villeneuve, D.L., 2014, Transcriptomic effects-based monitoring for endocrine active chemicals--Assessing relative contribution of treated wastewater to downstream pollution: Environmental Science and Technology, v. 48, no. 4, p. 2385-2394, doi:10.1021/es404027n.

More Information

Related Science Features


More Science Features


USGS Home Water Land Resources Science Systems Ecosystems Energy and Minerals Environmental Health Hazards

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
Page URL: toxics.usgs.gov/highlights/neuroactive.html
Page Content Contact Information: webmaster@toxics.usgs.gov
Page Last Modified: 27-Jun-2018 @ 07:15:35 PM EDT