title: [Application of local Moran's I and GIS to identify hotspots of Ni, Cr of vegetable soils in high-incidence area of liver cancer from the Pearl River Delta, South China].
abstract: The index of local Moran's I is a useful tool for identifying hotspots of soil Ni and Cr, and for classifying them into spatial clusters and spatial outliers. To identify hotspots of vegetable soils Ni and Cr in high-incidence area of liver cancer, Shunde area of Foshan City, Pearl River Delta Economic Zone, 208 topsoil samples were collected from vegetable fields to measure the contents of nickel (Ni) and chromium (Cr). The results showed that the mean concentrations of two heavy metals Ni, Cr were 33.21 mg/kg, 80.84 mg/kg, respectively, Which were 130%, 60% higher than their soil background values of Guangdong Province, respectively. Generally, Ni is partly accumulated in soil but the accumulation of Cr is not obvious at all. The local Moran's I of Ni and Cr was calculated using 3 000, 6 000, 9 000 m as distance bands, respectively. The hotspots of Ni and Cr elements in soils were identified by local Moran's I which computed based on 6 000 m; "individual hotspots" are in the north which were affected by anthropogenic factors; "regional hotspots" are in the south which were controlled by parent materials. Moreover, the distributions of "regional hotspots" of Ni, Cr are the same as that of the highest mortality rate of liver cancer, this consistence could come up with a research direction that could reveal environmental etiologic factors of liver cancer.
authors.affiliation: Department of Earth Science, Sun Yat-Sen University, Guangzhou 510275, China. liyn8@mail2.sysu.edu.cn
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Yong-Zhang
authors.initials: YZ
authors.lastname: Zhou
authors.forename: Cheng-Bo
authors.initials: CB
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Dou
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Du
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Lin
authors.forename: Rui
authors.initials: R
authors.lastname: Fan
authors.forename: Min
authors.initials: M
authors.lastname: Du
authors.forename: Xiang
authors.initials: X
authors.lastname: He
mesh_terms: D002681:China / Q000453:epidemiology; D002857:Chromium / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D062665:Epidemiological Monitoring; D040362:Geographic Information Systems; D015994:Incidence; D008113:Liver Neoplasms / Q000453:epidemiology*; D009532:Nickel / Q000032:analysis*; D045483:Rivers; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D014675:Vegetables / Q000254:growth & development*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002857:Chromium; D009532:Nickel