title: Classification and ordination of DDT and HCH in soil samples from the Guanting Reservoir, China.
abstract: Organochlorine pesticides (OCPs) have been a major environmental issue, drawing much scientific and public attention due to their bioaccumulation potential, persistence and toxicity. Soil samples from three villages around the Guanting Reservoir, one of Beijing's five major water systems located to the northwest of the city, were collected in 2003 and analyzed to determine DDT and HCH-concentrations. The samples were also analyzed for soil texture, pH, and concentrations of total carbon, nitrogen and phosphorus to investigate their possible relationship to current OCP-concentrations. Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used to study the distribution and contamination levels of OCPs within the study area. Classification splits were made to divide the 30 samples into three groups. The first group contained samples in soils from village C; the second group contained all of the samples in village B and most of the samples in village A; and the third group contained just three samples from village A, and the three samples had a relatively high concentration of OCPs. Ordination plots of the first two axes from PCA (cumulative percentage 80.91%) were constructed to explore the HCH and DDT-distribution patterns as well as the degradation ratios between the parent substances and their isomers.
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Yonglong
authors.initials: Y
authors.lastname: Lu
authors.forename: R W
authors.initials: RW
authors.lastname: Dawson
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Shi
authors.forename: Tieyu
authors.initials: T
authors.lastname: Wang
mesh_terms: D002681:China; D016000:Cluster Analysis; D003634:DDT / Q000032:analysis*; D003633:Dichlorodiphenyl Dichloroethylene / Q000032:analysis*; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D001556:Hexachlorocyclohexane / Q000032:analysis*; D007306:Insecticides / Q000032:analysis; D015999:Multivariate Analysis; D010573:Pesticide Residues / Q000032:analysis*; D025341:Principal Component Analysis; D012987:Soil; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply
chemical_list: D007306:Insecticides; D010573:Pesticide Residues; D012987:Soil; D014874:Water Pollutants, Chemical; D003633:Dichlorodiphenyl Dichloroethylene; D001556:Hexachlorocyclohexane; D003634:DDT