Tracking the occurrence of psychotropic pharmaceuticals in Brazilian wastewater treatment plants and surface water, with assessment of environmental risks

According to the World Health Organization, >360 million people worldwide suffer from mental diseases such as depression, anxiety, or bipolar disorder, for which psychotropic drugs are frequently prescribed. Despite being highly metabolized in the human organism, non-metabolized portions of these drugs are excreted, subsequently reaching wastewater treatment plants (WWTPs), where they may be incompletely removed during treatment, leading to the contamination of surface waters. In this work, ten psychotropic drugs widely consumed in Brazil (alprazolam, amitriptyline, bupropion, carbamazepine, clonazepam, escitalopram, fluoxetine, nortriptyline, sertraline, and trazadone) were monitored at five WWTPs located in the metropolitan region of Campinas (São Paulo State, Brazil). The drugs were determined in the influents, at different stages of the treatments, and in the effluents. Surface waters from the Atibaia River and the Anhumas Creek were also monitored. Quantitation of the pharmaceuticals was carried out by online solid-phase extraction coupled with ultra-high performance liquid chromatography and tandem mass spectrometry. The method was validated and presented a limit of quantitation of 50 ng L−1 for all the drugs assessed. Six of the substances monitored were quantified in the samples collected from the different treatment processes employed at the WWTPs. These technologies were unable to act as barriers for these psychotropics drugs. The concentrations ranged from 50 to 3000 ng L−1 in the WWTP effluents, while the main contaminants were found in surface waters at concentrations from 25 to 3530 ng L−1. The levels of the psychotropic detected in this work did not appear to present risks to the aquatic biota. [Display omitted] •10 Psychotropics drugs were prioritized for monitoring in water and WWTPs.•The validated SPE-UHPLC-MSMS method presented a LOQ of 50 ng L−1.•Psychotropics drugs were detectable at ppt levels in superficial water.•WWTPs did not work as a barrier to remove psychotropics from effluents.•The occurrence levels of psychotropics do not pose risk for the biota.