Global relevant concentration of emerging contaminants: species sensitivity distributions and ecological risks to aquatic organisms – a comprehensive data synthesis

Emerging contaminants (ECs) are inadequately monitored or unregulated chemicals that pose growing threats to aquatic ecosystems due to their biological effects on organisms. This study provides a global overview of EC concentrations, species sensitivity distributions (SSDs), and associated ecological risks. We analysed global EC concentrations using comprehensive secondary datasets and applied multivariate statistical techniques such as One-way PERMANOVA and Non-metric Multidimensional Scaling (nMDS) to assess contaminant patterns worldwide. SSDs and Risk Quotients (RQs) were used to evaluate species-level sensitivities and ecological risk. Findings reveal considerable global variation in EC concentrations. Morocco reported the highest levels of estrogens (E1, E2), Australia reported the highest levels of Estriol (E3), and Bangladesh reported the highest levels of pesticides (DDT, Diazinon, Heptachlor). Canada showed peak Bisphenol A (BPA) levels, while China and Japan led in PFOS and PFOA, respectively. The Netherlands and Argentina showed elevated levels of surfactants and pharmaceuticals. PERMANOVA results (F = 1.677, p = 0.10) indicate no significant overall group differences; however, pairwise tests revealed notable distinctions, especially among estrogens, microplastics, and pesticides. nMDS analysis showed clearer clustering by region than chemical class. SSDs highlighted varying sensitivities of aquatic species based on chemical-specific NOECs (µg/L). Elevated RQs were observed in Morocco, China, Bangladesh, and Turkey, with Spain, Japan, and Singapore showing high RQs for surfactants and microplastics. These findings underscore the urgency of incorporating SSD and RQ data into regulatory frameworks to set protective concentration thresholds. Ongoing research is vital to address chronic and sub-lethal effects, supporting evidence-based policymaking and enhanced treatment and risk management strategies.