Distribution and partitioning of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in the Humber Estuary, UK

The distribution and concentration of polychlorinated dibenzo-para-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs) and polychlorinated biphenyls (PCBs) in Humber Estuary bed sediment and in suspended particulate matter were extensively studied. Dioxin concentrations in sediments ranged from below detection to 3830 pg g−1 and PCB concentrations were from nondetectable to 84 ng g−1. These concentrations were low in comparison to other estuaries. The concentrations of chlorinated organics were found to be correlated with sediment lipid content, which is a significant factor in determining the contaminant distribution in the Humber Estuary. Laboratory experiments were carried out using 14C-radiolabelled compounds to determine partition coefficients (KD). A KD of 2.5 × 105 was determined for 2,3,7,8-TCDD and that of 6.4 × 104 for 2,2′,5,5′-TCB; these did not vary significantly with salinity. There was no evidence in either the concentration data or the homolog profiles that contamination from tributaries to the Humber Estuary had penetrated the estuary in significant quantities.