title: Occurrence, spatial distribution, sources, and risks of polychlorinated biphenyls and heavy metals in surface sediments from a large eutrophic Chinese lake (Lake Chaohu).
abstract: Surface sediment from large and eutrophic Lake Chaohu was investigated to determine the occurrence, spatial distribution, sources, and risks of polychlorinated biphenyls (PCBs) and heavy metals in one of the five biggest freshwater lakes in China. Total concentration of PCBs (Σ34PCBs) in Lake Chaohu was 672 pg g(-1) dry weight (dw), with a range of 7 to 3999 pg g(-1) dw, which was lower than other water bodies worldwide. The majority of heavy metals were detected at all sampling locations, except for Sr, B, and In. Concentrations of Al, Fe, Ca, Mn, Sr, Co, Zn, Cd, Pb, and Hg were similar to that reported for other lakes globally. Concentrations of K, Mg, Na, Li, Ga, and Ag were greater than the average, whereas those of Cr, Ni, and Cu were lower. Cluster analysis (CA) and positive matrix factorization (PMF) yielded accordant results for the source apportionment of PCBs. The technical PCBs and microbial degradation accounted for 34.2 % and 65.8 % of total PCBs using PMF, and PMF revealed that natural and anthropogenic sources of heavy metals accounted for 38.1 % and 61.8 %, respectively. CA indicated that some toxic heavy metals (e.g., Cd, In, Tl, and Hg) were associated with Ca-Na-Mg minerals rather than Fe-Mn minerals. The uncorrelated results between organic matter revealed by pyrolysis technology and heavy metals might be caused by the existence of competitive adsorption between organic matter and minerals. PCBs and heavy metals were coupling discharge without organochlorine pesticides (OCPs), but with polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs). No sediment sample exceeded the toxic threshold for dioxin-like PCBs (dl-PCBs) set at 20 pg toxicity equivalency quantity (TEQ) g(-1), (max dl-PCBs, 10.9 pg TEQ g(-1)). However, concentrations of Ag, Cd, and Hg were at levels of environmental concern. The sediment in the drinking water source area (DWSA) was threatened by heavy metals from other areas, and some fundamental solutions were proposed to protect the DWSA.
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
authors.forename: Ze-Lin
authors.initials: ZL
authors.lastname: Bai
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
authors.forename: Wen-Xiu
authors.initials: WX
authors.lastname: Liu
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
authors.forename: Xiang-Zhen
authors.initials: XZ
authors.lastname: Kong
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yang
authors.affiliation: Section of Toxicology and Environmental Chemistry, Institute A, University of Copenhagen, University Park 2, 2100, Copenhagen, Denmark.
authors.forename: Sven Erik
authors.initials: SE
authors.lastname: Jørgensen
authors.affiliation: MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China. xufl@urban.pku.edu.cn.|Institute of Water Sciences, Peking University, Beijing, 100871, China. xufl@urban.pku.edu.cn.
authors.forename: Fu-Liu
authors.initials: FL
authors.lastname: Xu
mesh_terms: D002681:China; D004147:Dioxins / Q000032:analysis; D060766:Drinking Water / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D005068:Eutrophication; D019015:Geologic Sediments / Q000032:analysis*; D055768:Halogenated Diphenyl Ethers / Q000032:analysis; D000075322:Heavy Metal Poisoning; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D060106:Lakes / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis*; D011041:Poisoning; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004147:Dioxins; D060766:Drinking Water; D055768:Halogenated Diphenyl Ethers; D006843:Hydrocarbons, Chlorinated; D019216:Metals, Heavy; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls
keywords: Heavy metals; Lake Chaohu; Occurrence; Polychlorinated biphenyls; Positive matrix factorization (PMF); Risks; Spatial distribution; Surface sediment