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(18-25) Endocrine disruption in freshwater invertebrates. Weltje, Lennart*,1, van Doornmalen, Jacco1, Oehlmann, Jörg2, Markert, Bernd1, 1 International Graduate School (IHI) Zittau, Zittau, Germany2 J.W. Goethe University, Frankfurt am Main, Germany ABSTRACT- A significant part of the emissions of chemicals with (suspected) endocrine disrupting properties ends up in freshwater ecosystems. Depending on their chemical stability, sorptive and hydrophobic properties, endocrine disrupting compounds (EDCs) may accumulate in organisms and thereby reach effective concentrations. As concentrations of endogenous hormones are usually very low, effective concentrations of EDCs may be reached fast and subsequently interfere with hormone and receptor action or synthesis. Whereas many studies have been conducted with fishes and vertebrates, data on invertebrates are relatively scarce and do no justice to their high abundance in natural habitats. In the search for sensitive bioindicator species for EDCs in freshwater environments we have chosen to experiment with representatives of different taxonomic invertebrate groups, such as Crustacea (Asellus aquaticus), Mollusca (Potamopyrgus antipodarum) and Insecta (Chironomus riparius). Possible disruption of endocrine function was assessed by studying reproductive and developmental endpoints, typically the number of offspring, sex-ratio and development rate, which was compared to performance of a (solvent) control. As test substances we used representatives of agricultural pesticides and phenols. The primary route of exposure was water and nominal concentrations were regularly renewed and checked analytically. In addition, organismic concentrations were measured to be able to relate observed effects to body burdens and calculate bioconcentration factors, which in turn can be used in the risk assessment of EDCs. Key words: freshwater, invertebrates, endocrine disruption, pesticides |
