title: Occurrence of aryl hydrocarbon receptor agonists and genotoxic compounds in the river systems in Southern Taiwan.
abstract: Water and sediment samples from river systems located in Southern Taiwan were investigated for the presence of aryl hydrocarbon receptor (AhR) agonists and genotoxicants by a combination of recombinant cell assays and gas chromatography-mass spectrometry analysis. AhR agonist activity and genotoxic response were frequently detected in samples collected during different seasons. In particular, dry-season water and sediment samples from Erren River showed strong AhR agonist activity (201-1423 ng L(-1) and 1374-5631 ng g(-1) β-naphthoflavone equivalents) and high genotoxic potential. Although no significant correlation was found between AhR agonist activity and genotoxicity, potential genotoxicants in sample extracts were suggested to be causative agents for yeast growth inhibition in the AhR-responsive reporter gene assay. After high performance liquid chromatography fractionation, AhR agonist candidates were detected in several fractions of Erren River water and sediment extracts, while possible genotoxicants were only found in water extracts. In addition, polycyclic aromatic hydrocarbons, the typical contaminants showing high AhR binding affinity, were only minor contributors to the AhR agonist activity detected in Erren River sediment extracts. Our findings displayed the usefulness of bioassays in evaluating the extent of environmental contamination, which may be helpful in reducing the chances of false-negative results obtained from chemical analysis of conventional contaminants. Further research will be undertaken to identify major candidates for xenobiotic AhR agonists and genotoxicants to better protect the aquatic environments in Taiwan.
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan. Electronic address: phchou@mail.ncku.edu.tw.
authors.forename: Pei-Hsin
authors.initials: PH
authors.lastname: Chou
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Tong-Cun
authors.initials: TC
authors.lastname: Liu
authors.affiliation: National Museum of Marine Biology and Aquarium, Pingtung, Taiwan; Institute of Marine Biodiversity and Evolutionary Biology, National Dong Hwa University, Pingtung, Taiwan.
authors.forename: Fung-Chi
authors.initials: FC
authors.lastname: Ko
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Mong-Wei
authors.initials: MW
authors.lastname: Liao
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Hsiao-Mei
authors.initials: HM
authors.lastname: Yeh
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Tse-Han
authors.initials: TH
authors.lastname: Yang
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chun-Ting
authors.initials: CT
authors.lastname: Wu
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chien-Hsun
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Tsung-Ya
authors.initials: TY
authors.lastname: Tsai
mesh_terms: D019015:Geologic Sediments / Q000737:chemistry; D009153:Mutagens / Q000032:analysis*; D018336:Receptors, Aryl Hydrocarbon / Q000819:agonists*; D045483:Rivers / Q000737:chemistry*; D013624:Taiwan; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000494:pharmacology; D060753:Water Quality
chemical_list: D009153:Mutagens; D018336:Receptors, Aryl Hydrocarbon; D014874:Water Pollutants, Chemical
keywords: Aryl hydrocarbon receptor agonists; Bioassays; Genotoxicants; Polycyclic aromatic hydrocarbons; Sediment