PCB AND PAH FLUXES TO A DATED UK FEAT CORE

Concentrations of PCBs and PAHs have been determined om the individual sections of peat cores obtained from an ombrotrophic bog in rural north-west England. Chronological intervals throughout the core were determined om both radiometric (Pb-210, Cs-137, Am-241) and independent, non-chemical characteristics (pollen, magnetics) information. Net fluxes of 25 individual PCB congeners and 14 PAH compounds to the bog were then derived. PCB inputs were apparent from the late-1930s/early-1940s, with maximum sub-surface fluxes (similar to 1300 pg cm(-2) year(-1)) observed at a depth corresponding to 1964. Loadings decreased by similar to 65% over the following 15 year period, before showing a surface enrichment. Initial increases in PAH loadings appeal to coincide with the beginning of the Industrial Revolution, with fluxes peaking in the early-1930s (305 ng cm(-2) year(-1)). Introduction of emission controls and the decline of heavy industry has led to an 80 % reduction in the net flux of PAHs to the bog over the last three to foul decades. Potential effects of post-depositional diagenesis are considered, with particular reference to alteration of contaminant chronologies.