Occurrence and spatial distribution of EDCs and related compounds in waters and sediments of Iberian rivers

In terms of concentrations the compounds found at the highest average concentrations were: nonylphenol monocarboxylate (NP1EC), tolyltriazole (TT), tris(chloroisopropyl)phosphate (TCPP) found at average concentrations above 100 ng/L, followed by 1H-benzotriazole and tris(butoxyethyl)phosphate (TBEP) found at average concentration higher than 50 ng/L. Natural and synthetic hormones were found at low levels not exceeding 16 ng/L and 7 ng/g for water and sediment, respectively, however they contributed to more than 80% of the total estrogenicity of the samples (expressed as the equivalents of estradiol EEQ, ng/L). Regarding the spatial distribution of these contaminants, the Llobregat river was found to be the most contaminated river basin, having sites near the mouth of the river the ones with the highest contaminant load. In the Ebro river basin several hot spots were identified and Júcar showed to be the least contaminated. Overall, the study confirmed the presence of complex mixtures of unregulated contaminants, thus raising concern about their potential interactive effects.