title: Water exposure assessment of aryl hydrocarbon receptor agonists in Three Gorges Reservoir, China using SPMD-based virtual organisms.
abstract: SPMD-based virtual organisms (VOs) were deployed at five to eight sites in the Three Gorges Reservoir (TGR), China for five periods in 2008, 2009 and 2011. The water exposure of aryl hydrocarbon receptor (AhR) agonists was assessed by the VOs. The chosen bioassay response for the extracts of the VOs, the induction of 7-ethoxyresorufin-O-deethylase (EROD) was assayed using a rat hepatoma cell line (H4IIE). The results show that the extracts from the VOs could induce AhR activity significantly, whereas the chemically derived 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalent (TEQcal) accounted for <11% of the observed AhR responses (TEQbio). Unidentified AhR-active compounds represented a greater proportion of the TCDD equivalent in VOs from TGR. High TEQbio value in diluted extract and low TEQbio in concentrated extract of the same sample was observed suggesting potential non-additive effects in the mixture. The levels of AhR agonists in VOs from upstream TGR were in general higher than those from downstream reservoir, indicating urbanization effect on AhR agonist pollution. The temporal variation showed that levels of AhR agonists in 2009 and 2011 were higher than those in 2008, and the potential non-additive effects in the area close to the dam were also obviously higher in 2009 and 2011 than in 2008, indicating big changes in the composition of pollutants in the area after water level reached a maximum of 175 m. Although the aqueous concentration of AhR agonists of 0.8-4.8 pg TCDDL(-1) in TGR was not alarming, the tendency of accumulating high concentration of AhR agonists in VO lipid and existence of possible synergism or antagonism in the water may exhibit a potential hazard to local biota being exposed to AhR agonists.
authors: TUM, Wissenschaftszentrum Weihenstephan für Ernährung Landnutzung und Umwelt, Department für Biowissenschaften, Weihenstephaner Steig 23, 85350 Freising, Germany; Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany; The State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China. Electronic address: wangjx@ihb.ac.cn.
authors: Jingxian
authors: J
authors: Wang
authors: Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
authors: Silke
authors: S
authors: Bernhöft
authors: Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
authors: Gerd
authors: G
authors: Pfister
authors: TUM, Wissenschaftszentrum Weihenstephan für Ernährung Landnutzung und Umwelt, Department für Biowissenschaften, Weihenstephaner Steig 23, 85350 Freising, Germany; Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany. Electronic address: schramm@wzw.tum.de.
authors: Karl-Werner
authors: KW
authors: Schramm
mesh_terms: D000818:Animals; D001681:Biological Assay; D002681:China; D003198:Computer Simulation; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*
chemical_list: D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1
keywords: EROD activity; Hydrophobic organic contaminants (HOCs); Non-additive effect; TGR (Three Gorges Reservoir); Virtual organisms (VOs)