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.

Prozac in the water: Chronic fluoxetine exposure and predation risk interact to shape behaviors in an estuarine crab

“…2009)) have known negative effects on aquatic and marine organisms (e.g., Fong & Molnar, 2008; Metcalfe et al., 2010; Meredith‐Williams et al, 2012; Gaw et al., 2014). Our study and others have assessed the effects of single pharmaceuticals on animal behavior and their potential to alter species interactions (Bossus et al., 2014; Gaworecki & Klaine, 2008; Hazelton et al., 2013; Piggott, Baldwin, Dissanayake, & Sloman, 2007).…”

“…Pharmaceutical compounds and their derivatives regularly enter estuaries and near‐shore coastal ecosystems via transport of contaminated surface and groundwater runoff, suspended river sediments, and untreated sewage effluent (Bringolf et al., 2010; Khairy, Weinstein, & Lohmann, 2014; Metcalfe et al., 2010). These compounds are designed to illicit biological responses as medical drugs and could have considerable effects on organism health, despite detections at low concentrations (Ankley, Brooks, Huggett, & Sumpter, 2007; Seiler, 2002).…”

Solar photo-Fenton and UV/H 2 O 2 processes against the antidepressant Venlafaxine in urban wastewaters and human urine. Intermediates formation and biodegradability assessment

“…Out of the administered amount, 92% is recovered in urine, as the renal excretion pathway is prevailing. However, VFA in urine appears in only 5% (1-10% [10]), unconjugated O-desmethyl Venlafaxine (29%), conjugated O-desmethyl Venlafaxine (26%), 1% N-desmethyl Venlafaxine, and the rest as the other intermediates. Hence, a normal person excretes $2 L urine per day, it is normal to expect lg/L concentrations in patients.…”

“…Chemically, it belongs to the class of benzene and substituted derivatives and is a tertiary amino compound that is N,N-dimethylethanamine substituted at position 1 by a 1-hydroxycyclohexyl and 4-methoxyphenyl group (Table 1). Its excretion from the body follows the renal route, ends up in WWTPs, and therefore it is found in natural waters as VFA, plus its metabolites are escaping in almost 50% rate the wastewater treatment process [9][10][11][12]. Measured concentrations range from 18 to 122 ng L À1 for VFA [13], or 102 and 690 ng L À1 [11,14] which could affect the natural biota.…”

The chemical fate of paroxetine metabolites. Dehydration of radicals derived from 4-(4-fluorophenyl)-3-(hydroxymethyl)piperidine

“…Recent studies have shown that paroxetine and its metabolites [1][2][3] have the potential to accumulate in waste waters, 4 but also in the tissue of fish 5 as a result of discharges of this antidepressant into surface waters from municipal wastewater treatment plants. 6,7 Environmental risk assessment of paroxetine has been performed earlier, but only the parent (3S,4R)-(4-(4′-fluorophenyl)-3-(3,4-methylenedioxyphenoxymethyl)piperidine (I) and its major human metabolite trans-4-[4-(4′-fluorophenyl)-3-piperidinylmethoxy]-2-methoxyphenol (II) have been considered (Scheme 1) in more detail. 8 According to ecotoxicity results, paroxetine itself should not exert any significant effects on aquatic organisms.…”