POLYCHLORINATED-BIPHENYLS IN UK AND NORWEGIAN SOILS - SPATIAL AND TEMPORAL TRENDS

Contemporary soil samples from 46 sites across the UK and 12 sites in Norway have been analysed for a range of PCB congeners. Results show s patial differences, in terms of concentration and congener profile. Th e difference is partly caused by an increased proportion of the mid-mo lecular weight congeners in the samples from Norway. The soils from so uthern Norway and the UK contained similar amounts of PCBs per unit ar ea: those from northern Norway contained lesser amounts. The possible influence of long-term air-soil exchange, latitudinal fractionation pr ocesses and differences in land management practices on the observed p atterns is discussed. Archived soils (1951-1974) from the UK sites hav e also been analysed and the results show increasing concentrations of these compounds up to the late 1960s/early 1970s, after which there h as been a substantial decline. This temporal trend is in accordance wi th that reported in previous studies. However, it is possible that som e of the archived samples were contaminated in the process of air-dryi ng. Due to this contamination artifact, it is not possible to ascertai n whether the scale of the observed temporal differences truly reflect changes in the environment. The data are discussed in terms of possib le spatial/temporal trends and the potential for air-soil exchange of these compounds. Copyright (C) 1997 Elsevier Science B.V.