The One-health approach applied to micropollutants in the water environment: assessing the risk from sources to humans to plan monitoring and mitigation strategies

Micropollutants, including pharmaceuticals, pesticides, PFAS, bisphenols, and polycyclic aromatic hydrocarbons, are increasingly detected in water systems, raising concerns for environmental and human health. Their ubiquitous presence, multiple sources, and complex fate require an integrated risk assessment approach to guide monitoring and mitigation strategies effectively. This study develops a quantitative framework to assess micropollutant risks in urban water systems, integrating environmental and human health risk assessments. Three case studies are analyzed: (i) environmental risk from polycyclic aromatic hydrocarbons (PAHs) discharged via combined sewer overflows (CSOs), wastewater treatment plant (WWTP) bypasses, and effluents; (ii) human health risks from bisphenol A (BPA) and nonylphenol (NP) in drinking and irrigation water; and (iii) simultaneous environmental and human health risks of pharmaceuticals in reclaimed wastewater reuse. Monte Carlo simulations quantify uncertainties, ensuring robust risk characterization. Results highlight CSOs as the highest-risk source to surface water, irrigation water as a key contributor to BPA exposure, and pharmaceuticals posing greater environmental than human health risks in wastewater reuse. By integrating source monitoring, fate modeling, and quantitative risk assessment, this approach supports decision-making for water quality management and policy development, ensuring safer urban water reuse practices.