Polychlorinated biphenyls in sediments of the Venice Lagoon

Twenty-four surficial sediment samples, representing different environments within the Venice Lagoon, were analyzed for polychlorinated biphenyls (PCB s) in order to assess degrees of pollution, sources, areal distribution, an d potential risk for the environment. Concentrations in surficial sediments range from 2 to more than 2049 mug kg(-1) dw. The maximum is probably due to the discharge of industrial wastes into the Brentella Canal, within the first Industrial Area. Lagoon samples are 11-205 times less contaminated, b eing influenced by pollutants stored in the canals only occasionally. Conge ner profiles distinguish PCBs in two main categories. The baseline pollutio n is probably due to a variety of sources within the lagoon system, whereas less chlorinated PCBs were discharged into the Brentella Canal. Our estima tes suggest that, due to high concentrations, toxic equivalents (TEQs) of P CBs are comparable to those relative to PCDD/Fs for the least contaminated samples, whereas they are lower in case of heavy PCDD/F contamination. (C) 2001 Elsevier Science Ltd. All rights reserved.