title: Seasonal and Annual Variations in Atmospheric Hg and Pb Isotopes in Xi'an, China.
abstract: We present a 3-year time series of lead (Pb) and mercury (Hg) concentrations and isotope signatures in total suspended particulate (TSP) matter and as total gaseous Hg (TGM) in Xi'an, Northwestern China. Mean concentrations of TSP (299 ± 120 μg m-3), PbTSP(0.33 ± 0.15 μg m-3) and HgTSP(0.64 ± 0.54 ng m-3), and TGM (5.7 ± 2.7 ng m-3) were elevated. We find that atmospheric Pb levels in winter in Xi'an have decreased by 4.6% per year since 2003, yet remain elevated relative to air quality guidelines and therefore a major health concern. δ202HgTSPand Δ199HgTSPaveraged -0.80 ± 0.30‰ (1σ) and -0.02 ± 0.10‰ (1σ) and δ202HgTGMand Δ199HgTGMaveraged -0.08 ± 0.41‰ (1σ) and 0.00 ± 0.04‰ (1σ). Relative to raw coal from Shaanxi and surrounding provinces, δ202HgTSPis enriched in the light Hg isotopes, whereas δ202HgTGMis enriched in the heavy isotopes. TSP and TGM Δ199Hg signatures are indistinguishable from raw coal, indicating little photochemical mass independent fractionation of atmospheric Hg in the near-field urban-industrial environment. δ202HgTGMcorrelates significantly with TGM levels (r2= 0.3, p < 0.01) and likely reflects binary mixing of local industrial TGM emissions with global background TGM.
authors.affiliation: Department of Environmental Science and Engineering, Xi'an Jiaotong University , Xi'an, China.|Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences , Xi'an, China.|Laboratoire d'Aérologie, Université de Toulouse, CNRS, UPS , Toulouse, France.
authors.forename: Hongmei
authors.identifier: 0000-0002-4217-5066
authors.initials: H
authors.lastname: Xu
authors.affiliation: Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse , Toulouse, France.
authors.forename: Jeroen E
authors.identifier: 0000-0001-7146-3035
authors.initials: JE
authors.lastname: Sonke
authors.affiliation: Laboratoire d'Aérologie, Université de Toulouse, CNRS, UPS , Toulouse, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Guinot
authors.affiliation: Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse , Toulouse, France.|State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences , Guiyang, 550081, China.
authors.forename: Xuewu
authors.initials: X
authors.lastname: Fu
authors.affiliation: Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse , Toulouse, France.|Institute of Surface-Earth System Science, Tianjin University , Tianjin 300072, China.
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Sun
authors.affiliation: Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse , Toulouse, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Lanzanova
authors.affiliation: Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université de Toulouse , Toulouse, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Candaudap
authors.affiliation: Department of Environmental Science and Engineering, Xi'an Jiaotong University , Xi'an, China.
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences , Xi'an, China.
authors.forename: Junji
authors.initials: J
authors.lastname: Cao
mesh_terms: D000393:Air Pollutants; D002681:China; D003031:Coal; D004784:Environmental Monitoring; D007554:Isotopes; D007854:Lead; D008628:Mercury; D008629:Mercury Isotopes; D012621:Seasons
chemical_list: D000393:Air Pollutants; D003031:Coal; D007554:Isotopes; D008629:Mercury Isotopes; D007854:Lead; D008628:Mercury