Tracking the surge of psychiatric pharmaceuticals in urban rivers of Curitiba amidst and beyond the SARS-CoV-2 pandemic.

The heightened contamination of urban rivers with psychiatric drugs poses significant environmental and public health risks due to their persistence and bioaccumulative nature. In this study, we assessed the concentrations of 10 psychiatric medicines in water and sediment samples from three rivers in Curitiba, Brazil, spanning the SARS-CoV-2 pandemic from September 2020 to November 2023. Our analysis revealed substantial variations in drug concentrations across rivers and sampling periods, with fluoxetine and sertraline being the most prevalent in waters (up to 1118 ng L) and sediments (up to 70 ng g DW). Sediments emerged as primary repositories for psychiatric drugs. The COVID-19 pandemic notably impacted drug concentrations, with fluoxetine and alprazolam concentrations surging by up to 741 % and 524 %, respectively, compared to pre-pandemic levels. The current concentrations of drugs in rivers pose risks to aquatic life. Despite variations, overall drug concentrations increased by 20 % for fluoxetine and 15 % for alprazolam after the pandemic. These findings underscore the persistent environmental risks associated with heightened drug consumption, emphasizing the urgent need for continued monitoring and intervention strategies to mitigate ecological and public health impacts.