DISTRIBUTION OF CHLORINATED PESTICIDES AND INDIVIDUAL POLYCHLORINATED-BIPHENYLS IN BIOTIC AND ABIOTIC COMPARTMENTS OF THE RIO-DE-LA-PLATA, ARGENTINA

A study of the distribution of chlorinated pesticides (CP) and individual polychlorinated biphenyls (PCBs) in water, sediments, and biota elucidated the sources and the environmental fate of these pollutants. Dissolved CP and PCB concentrations showed a decreasing trend from the industrialized Rio Santiago to offshore stations. Most polluted sediments showed a large contribution of early eluting PCBs. In offshore sediments, congeners with four to six chlorines predominated. Organisms presented maximum levels of p, p′-TDE, -DDT, and -DDE, trans-chlordane, and of tri-to heptachlorobiphenyls, mainly with the 4, 4′ recalcitrant bisubstitution. Their organochlorine patterns reflected the integration of the signals observed in water and sediments. Lipid-rich organisms showed a lesser degradation of CPs than low-fat fishes and sediments. Excepting less chlorinated PCBs, which have shorter half-lives, water bioaccumulation factors (BAF) showed a positive correlation with octanol-water partition coefficients (Kow). Sediment BAF-Kow relationships were very complex but could be explained by compound sources, elimination and degradation rates, stereochemistry, and Kows. © 1990, American Chemical Society. All rights reserved.