title: Sedimentary records of polycyclic aromatic hydrocarbons (PAHs) in remote lakes across the Tibetan Plateau.
abstract: Sediment cores from five lakes across the Tibetan Plateau were used as natural archives to study the time trends of polycyclic aromatic hydrocarbons (PAHs). The depositional flux of PAHs generally showed an increasing trend from the deeper layers towards the upper layer sediments. The fluxes of PAHs were low with little variability before the 1950s, and then gradually increased to the late 1980s, with a faster increasing rate after the 1990s. This temporal pattern is clearly different compared with those remote lakes across the European mountains when PAHs started to decrease during the period 1960s-1980s. The difference of the temporal trend was attributed to differences in the economic development stages and energy structure between these regions. PAHs are dominated by the lighter 2&3-ring homologues with the averaged percentage over 87%, while it is notable that the percentage of heavier 4-6 ring PAHs generally increased in recent years, which suggests the contribution of local high-temperature combustion sources becoming more predominant.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Ruiqiang
authors.initials: R
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Xie
authors.affiliation: School of Public Health, University of Illinois at Chicago, Chicago, IL 60612, United States.
authors.forename: An
authors.initials: A
authors.lastname: Li
authors.affiliation: Environmental Change Research Centre, University College London, Pearson Building, Gower Street, London WC1E 6BT, UK.
authors.forename: Handong
authors.initials: H
authors.lastname: Yang
authors.affiliation: Environmental Change Research Centre, University College London, Pearson Building, Gower Street, London WC1E 6BT, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Turner
authors.affiliation: Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Guangjian
authors.initials: G
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China. Electronic address: cyjing@rcees.ac.cn.
authors.forename: Chuanyong
authors.initials: C
authors.lastname: Jing
mesh_terms: D002681:China; D019015:Geologic Sediments / Q000737:chemistry*; D060106:Lakes / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D018609:Tibet; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical
keywords: Historical trend; Long-range atmospheric transport (LRAT); PAHs; Sediment