Water quality criteria derivation and ecological risk assessment of fluoxetine for freshwater organisms in China

Fluoxetine, a commonly used antidepressant, has been widely detected in aquatic environments. It can cause adverse effects on aquatic organisms and poses potential environmental risks. However, comprehensive research on water quality criteria (WQC) and ecological risk assessments for fluoxetine is limited. Toxicity data of fluoxetine on aquatic organisms in China were systematically collected and analyzed using related databases such as ECOTOX, Web of Science, and CNKI. Acute toxicity data encompassed 4 phyla, 7 families, and 11 species, with Ankistrodesmus falcatus identified as the most sensitive species. Chronic toxicity data covered 5 phyla, 10 families, and 13 species, with Poecilia reticulate showing the highest sensitivity. Using the Species Sensitivity Distribution (SSD) method, short-term and long-term WQC for fluoxetine were established at 6.0 and 0.9 μg/L, respectively, in China. Additionally, 215 exposure concentration data of fluoxetine in surface water in China over the past 20 years were compiled, with the highest concentration reaching 160 ng/L. Ecological risk assessments were performed using both probabilistic density and risk quotient methods, yielding probability density areas of 1.3×10⁻⁴ to 8.1×10⁻³ and risk quotient values ranging from 9.9×10⁻⁵ to 2.9×10⁻². Therefore, fluoxetine presented a low overall ecological risk in surface waters in China. The results could provide valuable insights for establishing water quality standards and implementing environmental risk management for fluoxetine.