TY - JOUR

T1 - The influence of environmental and soil-related variables on the spatial distribution of PCBs in Norwegian and UK soils: implications for global cycling.

AU - Meijer, S. N.

AU - Steinnes, E.

AU - Ockenden, W. A.

AU - Jones, Kevin C.

PY - 2002/5/15

Y1 - 2002/5/15

N2 - This paper reports the influence of environmental variables on soil concentrations of polychlorinated biphenyls (PCBs) and their global fractionation. Soils were sampled from remote woodland (coniferous and deciduous) and grassland locations on a latitudinal transect through the United Kingdom and Norway. Different processes control PCB concentrations and burdens in coniferous, deciduous, and grassland soil systems; these are discussed, with emphasis on the influence of canopy scavenging and soil organic matter (OM) content. In general, concentration differences between sites were 1−2 orders of magnitude for lighter PCBs and 2−3 orders of magnitude for heavier PCBs, when expressed on a pg g-1 dry weight basis. These differences decreased by up to an order of magnitude when expressed as pg g-1 OM. The dataset suggests that the more volatile PCBs are moving toward equilibrium with the OM burden of the soil compartment on a European regional scale, while the distribution of the “stickier”, heavier homologues appears to still be primarily influenced by their preferential deposition closer to source areas. The relative concentration of the tri- and tetra-PCBs increases with latitude, while that of the hepta- and octa-PCBs decreases, consistent with the global fractionation theory. However, the regression slopes are quite shallow, with high scatter, implying that many environmental and soil-related factors (such as precipitation, organic carbon content and type, other soil properties, local sources, etc.) are also influencing the observed congener patterns. Temperature-driven fractionation, while clearly operating and detectable, needs to be considered in this broader context.

AB - This paper reports the influence of environmental variables on soil concentrations of polychlorinated biphenyls (PCBs) and their global fractionation. Soils were sampled from remote woodland (coniferous and deciduous) and grassland locations on a latitudinal transect through the United Kingdom and Norway. Different processes control PCB concentrations and burdens in coniferous, deciduous, and grassland soil systems; these are discussed, with emphasis on the influence of canopy scavenging and soil organic matter (OM) content. In general, concentration differences between sites were 1−2 orders of magnitude for lighter PCBs and 2−3 orders of magnitude for heavier PCBs, when expressed on a pg g-1 dry weight basis. These differences decreased by up to an order of magnitude when expressed as pg g-1 OM. The dataset suggests that the more volatile PCBs are moving toward equilibrium with the OM burden of the soil compartment on a European regional scale, while the distribution of the “stickier”, heavier homologues appears to still be primarily influenced by their preferential deposition closer to source areas. The relative concentration of the tri- and tetra-PCBs increases with latitude, while that of the hepta- and octa-PCBs decreases, consistent with the global fractionation theory. However, the regression slopes are quite shallow, with high scatter, implying that many environmental and soil-related factors (such as precipitation, organic carbon content and type, other soil properties, local sources, etc.) are also influencing the observed congener patterns. Temperature-driven fractionation, while clearly operating and detectable, needs to be considered in this broader context.

U2 - 10.1021/es010322i

DO - 10.1021/es010322i

M3 - Journal article

VL - 36

SP - 2146

EP - 2153

JO - Environmental Science and Technology

JF - Environmental Science and Technology

SN - 0013-936X

IS - 10

ER -