Simultaneous Occurrence of Psychotropic Pharmaceuticals in Surface Water of the Megacity Shanghai and Implication for Their Ecotoxicological Risks

Psychotropic pharmaceuticals account for a large proportion of the most prescribed drugs globally. They cannot be completely removed in wastewater treatment plants (WWTPs), which raise a concern about their occurrence and ecotoxicology in the aquatic system. In the present study, we developed a sensitive and reliable method and analyzed 34 psychotropic pharmaceuticals in river water of the megacity Shanghai. The impacts of WWTPs on the contamination of psychoactive drugs were also evaluated by comparing the river water samples collected from upstream and downstream of WWTPs. Among the target substances, 29 drugs were detected in the water samples with the concentrations ranging from 0.03 to 260 ng/L, and the occurrence of five of them in river water was reported for the first time. Many psychotropic pharmaceuticals occurred in river water simultaneously with the total concentration up to 480 ng/L. The spatial distribution of psychotropic pharmaceuticals and the ratio between venlafaxine and its metabolite indicated the contamination of psychotropic pharmaceuticals was higher in populated areas but municipal WWTPs had little impact on their contaminations in the urban river of Shanghai, suggesting other important emission sources other than domestic wastewater exist. Exposure of zebrafish embryos further demonstrated multiple developmental effects caused by several of the most detected substances and, especially, by their mixtures and highlighted their interference with the neural development of zebrafish. Thus, our results provide novel insights into the understanding of the occurrence of psychotropic pharmaceuticals in surface waters and their ecotoxicological risks to aquatic organisms.