BIOACCUMULATION FACTORS (BAFS) AND BIOTA TO SEDIMENT ACCUMULATION FACTORS (BSAFS) FOR PCBS IN PIKE AND EELS

''Freely-dissolved'' aqueous concentrations of 9 trichloro-through hep tachlorobiphenyls are reported, alongside those in sediments and fish from the R. Severn. For most congeners, BSAFs and lipid-normalised BAF s for pike exceed those for eels. Whilst R. Severn BSAFs are comparabl e with those for L. Ontario trout and New Bedford Harbour flounder, R. Severn BAFs are 1-2 orders of magnitude lower. This discrepancy may b e due to inter-species variability, as well as inter-laboratory differ ences between operational definitions of ''freely-dissolved'' aqueous PCB, underlining that the same operational definition must be employed if R. Severn BAFs are extrapolated elsewhere. For eels, correlation o f Log K-ow with Log BAF is better (R-2 = 0.66) than with BSAF (R-2 = 0 .13), whilst similar correlation coefficients (R-2 = 0.81 and 0.82) we re observed for pike. When Log K-ow is plotted against BSAF and Log BA F for both species combined, better correlation is observed for Log BA F (R-2 = 0.65), than BSAF (R-2 = 0.36). For both species combined, the observed relationship between Log BAF and Log K-ow for trichloro-thro ugh heptachlorobiphenyls is: Log BAF = 0.96 Log K-ow -0.24.