Science of the Total Environment 324 (2004) 55–66 0048-9697/04/$ - see front matter  2003 Elsevier B.V. All rights reserved. doi:10.1016/j.scitotenv.2003.10.035 Assessment of river contamination by estrogenic compounds in Paris area (France) Maelle Cargouet*, Daniel Perdiz, Asmaa Mouatassim-Souali, Sara Tamisier-Karolak, ¨ ¨ Yves Levi Laboratoire Sante Publique-Environnement, EA 3542, Universite Paris XI-Faculte de Pharmacie 5, rue Jean-Baptiste Clement, ´ ´ ´ ´ 92 296 Chatenay-Malabry Cedex, France ˆ Received 13 March 2003; received in revised form 27 October 2003; accepted 31 October 2003 Abstract Wastewater treatment plants (WWTPs) receive a large spectrum of endocrine disrupting compounds (EDCs) that are partially eliminated during treatment processes and discharged into rivers. Given the lack of information in France about river contamination by EDCs, we chose to examine estrogenic potential of WWTP influents, effluents and receiving waters in Paris and its suburbs. Water samples were analyzed using gas chromatography coupled with mass spectrometry for quantifying natural and synthetic estrogens combined with an in vitro estrogenicity bioassay associated to a high pressure liquid chromatography fractionation. The four estrogens investigated, Estrone (E1), 17b-Estradiol (E2), Estriol (E3) and 17a-Ethinylestradiol (EE2) were found in all WWTP and river samples at concentrations ranging from 2.7 to 17.6 ngyl and 1.0 to 3.2 ngyl, respectively. The synthetic estrogen EE2 seems more resistant to biodegradation in WWTPs and thus accounted for 35–50% of the estimated estrogenic activity in rivers. However, fractionation of samples and differences between concentrations of E1, E2, E3 and EE2 and the estrogenic activity measured by the in vitro bioassay suggested a complexity of mechanisms underlying the biological response that could not be attributed only to the investigated molecules.  2003 Elsevier B.V. All rights reserved. Keywords: Estrogenic activity; Estrogens; GC-MS; In vitro bioassay; Waste water treatment plants; Surface waters 1. Introduction Endocrine disrupting compounds (EDCs) are a newly defined category of environmental contam- inants that interfere with the function of the endo- crine system (Colborn and Clement, 1992). EDCs *Corresponding author. Tel.: q33-1-46-83-58-55; fax: q 33-1-46-83-57-32. E-mail address: maelle.cargouet@cep.u-psud.fr (M. Cargouet). ¨ have received much more attention from the reg- ulatory agencies since a possible relationship between EDC exposure and humanywildlife repro- duction disorders was suggested (Crisp et al., 1998). Many studies have focused on compounds that are estrogen receptor agonists. These chemi- cals included a wide range of molecules such as organochlorine pesticides, phthalates, alkylphenols, natural hormones and pharmaceuticals (Safe and Gaido, 1998). Among these compounds, natural