title: Polycyclic aromatic hydrocarbons in soils from urban to rural areas in Nanjing: Concentration, source, spatial distribution, and potential human health risk.
abstract: Polycyclic aromatic hydrocarbons (PAHs) have become a major type of pollutant in urban areas and their degree of pollution and characteristics of spatial distribution differ between various regions. We conducted a comprehensive study about the concentration, source, spatial distribution, and health risk of 16 PAHs from urban to rural soils in Nanjing. The mean total concentrations of 16 PAHs (∑16PAHs) were 3330 ng g(-1) for urban soils, 1680 ng g(-1) for suburban soils, and 1060 ng g(-1) for rural soils. Five sources in urban, suburban, and rural areas of Nanjing were identified by positive matrix factorization. Their relative contributions of sources to the total soil PAH burden in descending order was coal combustion, vehicle emissions, biomass burning, coke tar, and oil in urban areas; in suburban areas the main sources of soil PAHs were gasoline engine and diesel engine, whereas in rural areas the main sources were creosote and biomass burning. The spatial distribution of soil PAH concentrations shows that old urban districts and commercial centers were the most contaminated of all areas in Nanjing. The distribution pattern of heavier PAHs was in accordance with ∑16PAHs, whereas lighter PAHs show some special characteristics. Health risk assessment based on toxic equivalency factors of benzo[a]pyrene indicated a low concentration of PAHs in most areas in Nanjing, but some sensitive sites should draw considerable attention. We conclude that urbanization has accelerated the accumulation of soil PAHs and increased the environmental risk for urban residents.
authors.affiliation: School of Geographic and Oceanographic Science, Nanjing University, Nanjing 210046, China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Wang
authors.affiliation: School of Geographic and Oceanographic Science, Nanjing University, Nanjing 210046, China. Electronic address: wsh@nju.edu.cn.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Wu
authors.affiliation: School of Geographic and Oceanographic Science, Nanjing University, Nanjing 210046, China.
authors.forename: Sheng Lu
authors.initials: SL
authors.lastname: Zhou
authors.affiliation: The First Affiliated Hospital of Soochow University, Suzhou 215006, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Geographic and Oceanographic Science, Nanjing University, Nanjing 210046, China.
authors.forename: Baojie
authors.initials: B
authors.lastname: Li
authors.affiliation: School of Geographic and Oceanographic Science, Nanjing University, Nanjing 210046, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Geographic and Oceanographic Science, Nanjing University, Nanjing 210046, China.
authors.forename: Yanna
authors.initials: Y
authors.lastname: Yu
authors.affiliation: School of Geographic and Oceanographic Science, Nanjing University, Nanjing 210046, China.
authors.forename: Yaxing
authors.initials: Y
authors.lastname: Shi
mesh_terms: D018533:Biomass; D003031:Coal; D003077:Coke; D003407:Creosote; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004787:Environmental Pollution / Q000706:statistics & numerical data; D006801:Humans; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D018570:Risk Assessment; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*; D014507:Urbanization; D001335:Vehicle Emissions
chemical_list: D003031:Coal; D003077:Coke; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D001335:Vehicle Emissions; D003407:Creosote
keywords: Health risk assessment; Kriging; PAHs; Positive matrix factorization; Urban soil