title: Antidepressants and their metabolites in municipal wastewater, and downstream exposure in an urban watershed.
abstract: Antidepressants are a widely prescribed group of pharmaceuticals that can be biotransformed in humans to biologically active metabolites. In the present study, the distribution of six antidepressants (venlafaxine, bupropion, fluoxetine, sertraline, citalopram, and paroxetine) and five of their metabolites was determined in a municipal wastewater treatment plant (WWTP) and at sites downstream of two WWTPs in the Grand River watershed in southern Ontario, Canada. Fathead minnows (Pimephales promelas) caged in the Grand River downstream of a WWTP were also evaluated for accumulated antidepressants. Finally, drinking water was analyzed from a treatment plant that takes its water from the Grand River 17 km downstream of a WWTP. In municipal wastewater, the antidepressant compounds present in the highest concentrations (i.e., >0.5 microg/L) were venlafaxine and its two demethylation products, O- and N-desmethyl venlafaxine. Removal rates of the target analytes in a WWTP were approximately 40%. These compounds persisted in river water samples collected at sites up to several kilometers downstream of discharges from WWTPs. Venlafaxine, citalopram, and sertraline, and demethylated metabolites were detected in fathead minnows caged 10 m below the discharge from a WWTP, but concentrations were all < microg/kg wet weight. Venlafaxine and bupropion were detected at very low (<0.005 microg/L) concentrations in untreated drinking water, but these compounds were not detected in treated drinking water. The present study illustrates that data are needed on the distribution in the aquatic environment of both the parent compound and the biologically active metabolites of pharmaceuticals.
authors.affiliation: Worsfold Water Quality Center, Environmental and Resource Studies, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9J7B8, Canada. cmetcalfe@trentu.ca
authors.forename: Chris D
authors.initials: CD
authors.lastname: Metcalfe
authors.forename: Shaogang
authors.initials: S
authors.lastname: Chu
authors.forename: Colin
authors.initials: C
authors.lastname: Judt
authors.forename: Hongxia
authors.initials: H
authors.lastname: Li
authors.forename: Ken D
authors.initials: KD
authors.lastname: Oakes
authors.forename: Mark R
authors.initials: MR
authors.lastname: Servos
authors.forename: David M
authors.initials: DM
authors.lastname: Andrews
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000032:analysis* / Q000378:metabolism; D002853:Chromatography, Liquid; D003530:Cyprinidae / Q000378:metabolism; D008297:Male; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D000928:Antidepressive Agents; D014874:Water Pollutants, Chemical