Polychlorobiphenyls (PCBs) and coplanar congeners in the tissues of the Mediterranean loggerhead turtle caretta

The Loggerhead turtle Caretta caretta is a species sensitive to environmental changes caused by human activity. Stranded specimens found along the Adriatic, Baltic and Northern coasts seem to indicate that their diet, reproduction habits and aerials are the most affected ecological aspects of these organisms. We sampled liver, muscle and fat in C. caretta to detect the presence of polychlorobiphenyls (PCBs) including congeners with meta and par a chlorine substitutions (dioxin;like planar configuration). The specimens analysed in this study come from the Adriatic Sea and were provided by the Fondazione Cetacea, member of the 'Progetto Tartarughe'. Results have revealed average Sigma PCB concentrations of 119 ng/g w.w. in liver, 15 ng/g w.w. in muscle and 334 ng/g w.w. in fat. Differences were found among concentrations of single congeners and of each class of isomers, which were detected as well. Coplanar PCB distribution was consistent with Sigma PCBs, as contamination levels mere higher in fat with respect to Liver and muscle. Such finding suggests not only that metabolic activity takes place in the liver, but that these contaminants bioaccumulate differently in the different tissues.