title: Evaluation of genotoxic effects of surface waters using a battery of bioassays indicating different mode of action.
abstract: With the burgeoning contamination of surface waters threatening human health, the genotoxic effects of surface waters have received much attention. Because mutagenic and carcinogenic compounds in water cause tumors by different mechanisms, a battery of bioassays that each indicate a different mode of action (MOA) is required to evaluate the genotoxic effects of contaminants in water samples. In this study, 15 water samples from two source water reservoirs and surrounding rivers in Shijiazhuang city of China were evaluated for genotoxic effects. Target chemical analyses of 14 genotoxic pollutants were performed according to the Environmental quality standards for surface water of China. Then, the in vitro cytokinesis-block micronucleus (CBMN) assay, based on a high-content screening technique, was used to detect the effect of chromosome damage. The SOS/umu test using strain TA1535/pSK1002 was used to detect effects on SOS repair of gene expression. Additionally, two other strains, NM2009 and NM3009, which are highly sensitive to aromatic amines and nitroarenes, respectively, were used in the SOS/umu test to avoid false negative results. In the water samples, only two of the genotoxic chemicals listed in the water standards were detected in a few samples, with concentrations that were below water quality standards. However, positive results for the CBMN assay were observed in two river samples, and positive results for the induction of umuC gene expression in TA1535/pSK1002 were observed in seven river samples. Moreover, positive results were observed for NM2009 with S9 and NM3009 without S9 in some samples that had negative results using the strain TA1535/pSK1002. Based on the results with NM2009 and NM3009, some unknown or undetected aromatic amines and nitroarenes were likely in the source water reservoirs and the surrounding rivers. Furthermore, these compounds were most likely the causative pollutants for the genotoxic effect of these water samples. Therefore, to identify causative pollutants with harmful biological effects, chemical analyses for the pollutants listed in water quality standards is not sufficient, and single-endpoint bioassays may underestimate adverse effects. Thus, a battery of bioassays based on different MOAs is required for the comprehensive detection of harmful biological effects. In conclusion, for genotoxicity screening of surface waters, the SOS/umu test system by using different strains combined with the CBMN assay was a useful approach.
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. Electronic address: hyn_call@163.com.
authors: Yingnan
authors: Y
authors: Han
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. Electronic address: linazone@163.com.
authors: Na
authors: N
authors: Li
authors: Institute of Life and Environmental Sciences, Osaka Shin-Ai College, 6-2-28 Tsurumi, Tsurumi-Ku, Osaka 538-0053, Japan. Electronic address: oda.1948@hotmail.com.
authors: Yoshimitsu
authors: Y
authors: Oda
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. Electronic address: mamei@rcees.ac.cn.
authors: Mei
authors: M
authors: Ma
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. Electronic address: raokf@rcees.ac.cn.
authors: Kaifeng
authors: K
authors: Rao
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. Electronic address: wangzj@rcees.ac.cn.
authors: Zijian
authors: Z
authors: Wang
authors: Shijiazhuang Environmental Monitoring Center, Shijiazhuang 050000, PR China.
authors: Wei
authors: W
authors: Jin
authors: Shijiazhuang Environmental Monitoring Center, Shijiazhuang 050000, PR China.
authors: Gang
authors: G
authors: Hong
authors: Shijiazhuang Environmental Monitoring Center, Shijiazhuang 050000, PR China.
authors: Zhiguo
authors: Z
authors: Li
authors: Shijiazhuang Environmental Monitoring Center, Shijiazhuang 050000, PR China.
authors: Yi
authors: Y
authors: Luo
mesh_terms: D001681:Biological Assay; D002273:Carcinogens; D002681:China; D004249:DNA Damage; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water / Q000737:chemistry; D006801:Humans; D015162:Micronucleus Tests; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000633:toxicity*; D061005:Ponds / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D012486:Salmonella typhimurium / Q000187:drug effects*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D060753:Water Quality
chemical_list: D002273:Carcinogens; D009153:Mutagens; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Genotoxicity; Micronucleus assay; Mode of action; SOS/umu test; Surface water