title: Quantifying the global fractionation of polychlorinated biphenyls.
abstract: Due to the wide range of their physical-chemical properties, polychlorinated biphenyls (PCBs) have played an important role in the derivation of the global fractionation hypothesis, which predicts changes in the composition of persistent organic pollutant mixtures with latitude. Recent historical emission estimates, the derivation of an internally consistent property data set, in combination with a zonally averaged global fate and transport model, allow a quantitative investigation of the compositional shifts PCBs experience as a function of environmental compartment, latitude and time. Model simulations reproduce the higher relative abundance of lighter PCB congeners with increasing latitude, observed in air and soil, and quantify the relative importance of partitioning, persistence and emissions in establishing PCB patterns. Compositional variations consistent with global fractionation, as well as inverted concentration profiles with higher levels in the Arctic than at lower latitudes, are consistent with only minor fractions of the global PCB inventory being transferred northward.
authors.affiliation: University of Toronto at Scarborough, Department of Physical and Environmental Sciences, Ontario, Canada. frank.wania@utoronto.ca
authors.forename: Frank
authors.initials: F
authors.lastname: Wania
authors.forename: Yushan
authors.initials: Y
authors.lastname: Su
mesh_terms: D001110:Arctic Regions; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D008962:Models, Theoretical; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000737:chemistry; D012016:Reference Values; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D004785:Environmental Pollutants; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls