Analysis and occurrence of endocrine-disrupting compounds and estrogenic activity in the surface waters of Central Spain.

Endocrine-disrupting compounds (EDCs) are chemical compounds with the ability to alter the hormonal systems of organisms. Such compounds are used in several industrial and domestic activities and reach the aquatic environment via wastewater discharge. The aim of this study is to assess the occurrence of 30 EDCs and related compounds in the surface waters of central Spain and to determine the overall estrogenic activity of environmental samples. This study analyzed a large number of EDCs and other emergent or suspected compounds with endocrine-disrupting activity. The results have shown the presence of 19 EDCs at concentrations ranging from 2 to 5928 ng L(-1). Organophosphorus-based flame retardants, alkylphenolic compounds and anticorrosives were found at the highest concentrations. Furthermore, although insufficient data are available to calculate an average over time, these preliminary results show the need to monitor the waters in both rivers studied. Alkylphenolic compounds, particularly nonylphenol, were the main contributors to overall estrogenicity. A higher concentration of the compounds studied was detected in the river Jarama, although the estrogenicity expressed as estradiol equivalents (EEQs) was higher in the river Manzanares due to a higher concentration of nonylphenol. However, the total estrogenicity did not exceed 1 ng L(-1) (EEQ), which is the level that may cause estrogenic effects in aquatic organisms, in any of the samples. In conclusion, the potential estrogenic risk in both rivers is low, although organophosphorus-based flame retardants may increase this risk as they were found at high levels in all samples. Unfortunately, these compounds could not be taken into account when calculating the estrogenic activity due to the lack of activity data for them. For future investigations, it will be important to assess the estrogenicity provided by these flame retardants. Due to the significant concentrations of EDCs detected in both rivers, further studies in this region are required.