Extractable organohalogens (EOX) in sediment and biota collected at an estuarine marsh near a former chloralkali facility

Extractable, organically bound chlorine (EOCI), which is determined by neutron activation analysis (NAA), has been used as a measure of pollution by chlorinated organics. In this study, the concentrations and distribution of extractable organohalogens (EOX = EOCI + EOBr + EOI) were measured in sediment, blue crab, fishes, birds, and terrapin collected at an estuarine marsh and a nearby creek contaminated by the disposal of wastes from a former chloralkali facility. The concentrations of the organohalogens were in the order of EOCI >> EOBr > EOI. The sediment EOCI concentration was comparable to those reported for sediments at sites that have been contaminated by the disposal of bleached kraft pulp mill effluents. The concentrations of EOCI measured in the tissues of blue crab, fishes, and birds were higher than any values previously reported. The absolute concentrations of EOCI coupled with its elevated proportions relative to the concentrations of EOBr or EOI in biota suggest that wastes from the chloralkali processes are a potential source of chlorinated organics present in the environment. The relative proportion of known [such as, polychlorinated biphenyls (PCBs), dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs), polychlorinated naphthalenes (PCNs), and organochlorine pesticides] to unknown organochlorines in sediment, blue crab, fishes, birds, and terrapin was, on average, 48, 35, 5-25, 1-14, and 4.2%, respectively, which suggested that a major portion of the EOCI measured in biota remained uncharacterized. By assuming that the identities of unknown organochlorines in sediment and biota were similar, the estimated biota-sediment accumulation factor (BSAF) for the unknown EOCI fraction suggested that the components of this fraction have a tendency to bioaccumulate in the food chain.