title: Potential sources of and ecological risks from heavy metals in agricultural soils, Daye City, China.
abstract: Concentrations of eight heavy metals (arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn)) were measured in 92 topsoil samples collected from agricultural areas in Daye City to (1) assess the distribution of these heavy metals, (2) discriminate natural and anthropic contributions, and (3) identify possible sources of pollution. Mean concentrations of As, Cd, Cu, and Zn in the investigated soils were 23.8, 1.41, 105, and 159 mg kg(-1), respectively. These values were higher, in some cases by several orders of magnitude, than their corresponding background values. Estimated ecological risks, based on contamination factors and potential ecological risk indexes, were mostly low, but were considerable for As and Cd. A range of basic and multivariate statistical analyses (Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis) clearly revealed two distinct metal groups, comprising As/Cd/Cu/Zn and Cr/Ni/Hg/Pb, whose concentrations were closely associated with the distribution and pollution characteristics of industries in and around the city. Results demonstrated that As/Cd/Cu/Zn were indicators of anthropic pollution, while Cr/Hg/Ni/Pb were from parent materials. Maps of pollutant distribution compiled for the entire arable area further indicated that non-ferrous metal smelting and mining is the main source of diffuse pollution, and also showed the contribution of point source pollution to metal concentrations in agricultural topsoil. Results of this study will be useful for planning, risk assessment, and decision making by environmental managers in this region.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China, duping@craes.org.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Du
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Xie
authors.forename: Shijie
authors.initials: S
authors.lastname: Wang
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Zhao
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.forename: Fasheng
authors.initials: F
authors.lastname: Li
mesh_terms: D000383:Agriculture; D002681:China; D004463:Ecology; D004784:Environmental Monitoring / Q000379:methods*; D007221:Industry; D019216:Metals, Heavy / Q000032:analysis*; D015999:Multivariate Analysis; D018570:Risk Assessment; D012987:Soil / Q000592:standards*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants