title: [Concentrations and pollution assessment of soil heavy metals at different water-level altitudes in the draw-down areas of the Three Gorges Reservoir].
abstract: To investigate the effect of 175 m trial impounding (2008 and 2009) of the Three Gorges Reservoir on soil heavy metals, three draw-down areas with similar geological environment and history of land-use in Zhongxian County were chosen. Altogether 36 surface soil samples (including 0-10 cm and 10-20 cm soil layer) from water-level altitude of 160 m and 170 m were obtained, and their heavy metals concentrations (As, Cd, Cr, Cu, Ni, Pb and Zn) were measured by the X-ray fluorescence spectrometric method. Geoaccumulation index (I(geo)) and Håkanson potential ecological risk index were applied to assess the heavy metals pollution status and potential ecological risk, respectively. Results indicated that although the inundation period of 160 m was 224 d longer than that of 170 m, significant difference in concentrations of heavy metals were not found between the two water-level altitudes. Except for Cd, most of the heavy metals highly related with each other positively. According to the geoaccumulation index, the pollution extent of the heavy metals followed the order: As > Cd > Cu > Ni > Zn = Pb > Cr. The I(geo) value of As, Cd and Cu were 0.45, 0.39 and 0.06, respectively, indicating that the soil was only lightly polluted by these heavy metals. Håkanson single potential ecological risk index followed the order: Cd > As > Cu > Pb > Ni > Cr > Zn. Cd with E(i) values of 59.10, had a medium potential for ecological risk,while As, Cr, Cu, Pb, Ni and Zn only had a light potential. Consequently, although As, Cd and Cu were the major heavy metals with potential ecological risk for surface soil pollution in the draw-down areas in Zhongxian County, the Three Gorges Reservoir.
authors.affiliation: Chongqing Academy of Environmental Science, Chongqing 401147, China. wangyechun@yahoo.com
authors.forename: Ye-Chun
authors.initials: YC
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Lei
authors.forename: San-Ming
authors.initials: SM
authors.lastname: Yang
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhang
mesh_terms: D002681:China; D004463:Ecology; D004784:Environmental Monitoring; D019216:Metals, Heavy / Q000032:analysis*; D018570:Risk Assessment; D045483:Rivers; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013052:Spectrometry, X-Ray Emission; D014881:Water Supply
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants