title: Does an analysis of polychlorinated biphenyl (PCB) distribution in mountain soils across China reveal a latitudinal fractionation paradox?
abstract: Organic and mineral soil horizons from forests in 30 mountains across China were analysed for polychlorinated biphenyl (PCB). Soil total organic carbon (TOC) content was a key determinant of PCB distribution explaining over 90% of the differences between organic and mineral soils, and between 30% and 60% of the variance along altitudinal and regional transects. The residual variance (after normalization by TOC) was small. Tri- to tetra-CB levels were higher in the South in relation to high source density and precipitation. Heavier congeners were instead more abundant at mid/high-latitudes where the advection pattern was mainly from long range transport. This resulted in a latitudinal fractionation opposite to theoretical expectations. The study showed that exposure to sources with different characteristics, and possibly accumulation/degradation trends of different congeners in soils being out-of-phase at different latitudes, can lead to an unsteady large scale distribution scenario conflicting with the thermodynamic equilibrium perception.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Graduate University of the Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zheng
authors.affiliation: Masaryk University, Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic; Norwegian Institute for Water Research, Oslo, Norway. Electronic address: Luca.nizzetto@niva.no.
authors.forename: Luca
authors.initials: L
authors.lastname: Nizzetto
authors.affiliation: Masaryk University, Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic.
authors.forename: Marie D
authors.initials: MD
authors.lastname: Mulder
authors.affiliation: Masaryk University, Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Sáňka
authors.affiliation: Masaryk University, Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic; Max Planck Institute for Chemistry, Mainz, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Lammel
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
authors.forename: Haijian
authors.initials: H
authors.lastname: Bing
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Yishan
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Chunlin
authors.initials: C
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: Ghanzhang@gig.ac.cn.
authors.forename: Gan
authors.initials: G
authors.lastname: Zhang
mesh_terms: D005591:Chemical Fractionation; D002681:China; D004784:Environmental Monitoring; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls
keywords: Cold trapping; Forest; Fractionation; Latitude; Mountain; PCB; POP; Soil