Spatial occurrence of emerging contaminants in rivers and wastewater. Analysis of environmental and human risks.

This study investigates the presence and distribution of 23 emerging contaminants (ECs) related to agricultural and livestock activities in the Salado River basin, Santa Fe province, Argentina, detecting eight compounds including ciprofloxacin, enrofloxacin, chlorpyrifos-methyl, albendazole, fenbendazole, levamisole, diazepam, and thiamethoxam in river and wastewater samples. The organophosphorus pesticide chlorpyrifos-methyl was the most frequently detected contaminant in river samples, often exceeding European regulatory limits, and was linked to ecological risks such as fish mortality. Ecological risk assessments identified ciprofloxacin as posing the highest risk to bacteria, cyanobacteria, and algae, while diazepam and chlorpyrifos-methyl also showed significant hazards to aquatic organisms. Human health risk evaluation indicated that infants and children face higher exposure risks through drinking water compared to adults, raising concerns about long-term effects. The findings emphasize the urgent need for monitoring, regulation, and improved wastewater treatment to mitigate the environmental and health impacts of ECs in this region.