Presence of diclofenac, estradiol, and ethinylestradiol in Manzanares River (Spain) and their toxicity to zebrafish embryo development.

Diclofenac (DCF), 17-ß-estradiol (E2), and 17-α-ethinylestradiol (EE2) are emerging pollutants included in the first watch list agreed by European countries and set in the EU Water Directive. The objective of the present study was the analytical monitoring of DCF, E2, and EE2 in surface water and sediment of the Manzanares River in a stretch that crosses the city of Madrid, Spain, and to assess whether such environmental levels could affect the development of aquatic vertebrates through a zebrafish embryo-larval assay. Samples taken during two campaigns in the spring of 2015 were analyzed for DCF, E2, and EE2 by LC-MS or GC-MS. The levels of E2 and EE2 measured in surface water and sediments of the Manzanares were within the ranges reported in other Spanish and European studies; however, DCF levels were higher in the present study. The zebrafish embryos exposed to the Manzanares River water (0-144h) showed lethal effects and sublethal effects (developmental delay, bradycardia, and reduced locomotion). Nevertheless, these effects were not primarily associated with the levels of DCF, E2, and EE2 present in the Manzanares River, because representative mixtures of the field study prepared in the laboratory did not exhibit such toxicity to the zebrafish embryos.

Plasma vitellogenin levels and gonadal morphology of wild carp (Cyprinus carpio L.) in a receiving rivers downstream of sewage treatment plants.

A field study was carried out in order to assess, in a wild cyprinid fish, the biological effects related to the exposure to estrogenic compounds. The gonadosomic index (GSI), plasma vitellogenin (VTG) level and histological observations of gonads were performed to evaluate the reproductive health in common carp (Cyprinus carpio) from three rivers receiving sewage treatment plant (STP) effluents (Guadarrama, Henares and Jarama rivers, Spain) and from a reference site (Lozoya river). No significative differences in male GSI between sites were described. Only in the 18% of fish from Guadarrama river were elevated plasma VTG levels detected. The presence of oocytes in the testis was not found in any of males examined. The results suggest that the released estrogenic compounds by STPs effluents are not enough capable to adversely affect the gonadal development of the fish studied. Additional studies will be required to assess the risk of estrogenic compounds on fish from other sites of this area.

Identification of organic compounds and ecotoxicological assessment of sewage treatment plants (STP) effluents.

An integrated approach combining chemistry and biological methods was conducted to assess the toxicity of seven sewage treatment plant effluents. Solid phase concentration procedures were applied to facilitate the study of organic micro pollutants. A chemical analysis was performed by GC/MS. Organic fraction toxicity was determined by using bioassays such as Daphnia magna and Chlorella vulgaris tests and sub-lethal effects were also evaluated by using Salmonella typhimurium Test (mutagenicity), recombinant yeast screen (estrogenicity), and Oryzias latipes embryo-larval test. More than 49 compounds were detected in the organic fraction due to the various inputs of each effluents. The most frequently detected compounds in the effluents were bisphenol A (BPA), octylphenol (OP), 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (DEHP) and 1,2-benzenedicarboxylic acid, bis(methylpropyl) ester (DBP). Biological assays showed toxicity effects on D. magna tests in all samples, whereas toxicity on C. vulgaris or S. typhimurium tests were not observed. Estrogenicity and teratogenicity were observed in several samples. The cause-effect relationship could not be established given the high chemical complexity of the effluents and the lack of information available on 70% of the detected compounds subsequent to reviewing various data bases. Nevertheless, due to the high chemical variability revealed by STP effluents, bioassay sets may provide a very useful amount of information for detecting potential toxicity risks.