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

The environmental presence of chemicals capable of affecting the endocrine system has become a matter of scientific and public concern after certain endocrine disruptor compounds (EDCs) have been detected in the aquatic environment. In this work, 31 different EDCs and related compounds (suspect EDCs) belonging to different contaminant classes were studied: 10 estrogens, natural and synthetic, 8 alkylphenolic compounds, bisphenol A, triclosan and triclorocaraban, 4 parabens, 2 benzotriazoles, 3 organophosphorous flame retardants and the chemical marker caffeine, in river water and sediment of four Iberian rivers (Ebro, Llobregat, Júcar and Guadalquivir). An extensive sampling has been undertaken in two monitoring campaigns (2010 and 2011). A total of 77 samples of water and 75 sediments were collected. For this propose two different multiresidue analytical methods were applied, using the automated online EQuan/TurboFlow™ liquid chromatography coupled to mass spectrometry detection in tandem. 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.