title: Utility of soil linear alkylbenzenes to assess regional anthropogenic influences with special reference to atmospheric transport.
abstract: Tracing regional anthropogenic influences is important for assessing the magnitude of human interferences with the environment. In the present study, the utility of soil linear alkylbenzenes (LABs) as indicators of anthropogenic influences was examined, with the emphasis on the role of atmospheric transport in dissipating LABs from input sources to remote areas. The Pearl River Delta, South China, which has experienced rapid economic growth and urbanization, was selected as the study region. The concentrations of LABs (mean: 8.6 ng/g and median: 5.7 ng/g, with an outlier of 2,020 ng/g excluded) suggested that sewage contamination throughout the entire study region was generally light. The spatial variation of sewage pollution was significantly positively correlated with population density and per capita gross domestic product, with hot spots concentrated in the central PRD. Atmospheric deposition was hypothesized as an important input route for soil LABs in forestry and drinking water source areas with little impact of irrigation or direct wastewater discharge. This proposition could explain the opposite spatial patterns of LAB concentrations and values of a biodegradation index (5-C12+5-C13)/(5-C11+5-C10), where i-Cn defines a specific LAB congener with i and n indicating the position of the phenyl group and the number of carbon atoms on the alkyl chain, respectively. These findings somewhat validated LABs as tracers of regional anthropogenically derived contamination, with atmospheric transport of LABs as a viable dissipating mechanism.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Gao-Ling
authors.initials: GL
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Lian-Jun
authors.initials: LJ
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ling-Chuan
authors.initials: LC
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Zai-Cheng
authors.initials: ZC
authors.lastname: He
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Feng-Chang
authors.initials: FC
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: eddyzeng@gig.ac.cn.
authors.forename: Eddy Y
authors.initials: EY
authors.lastname: Zeng
mesh_terms: D000383:Agriculture; D001272:Atmosphere / Q000737:chemistry; D001554:Benzene / Q000032:analysis*; D001673:Biodegradation, Environmental; D002681:China; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000706:statistics & numerical data; D016468:Forestry; D019015:Geologic Sediments / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014507:Urbanization
chemical_list: D012987:Soil; D012989:Soil Pollutants; D001554:Benzene
keywords: Atmospheric transport; Pearl River Delta; Sewage pollution; Soil linear alkylbenzenes; Spatial pattern