Organochlorine residues (PCBs and DDTs) in two Torpedinid species liver from the Southeastern Mediterranean Sea.

Purpose: Polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and PCB congeners accumulation profile were measured in the liver of two torpedinid species ( Torpedo nobiliana and Torpedo marmorata) from the Mediterranean Sea (Adriatic Sea) in order to investigate the relative toxicological impact of these highly toxic PCBs in the organisms in question. Methods: A Thermo Trace GC connected to a Thermo PolarisQ MS operated in electron impact ionization (EI) mode was used to quantify PCBs and DDTs. The method performance was assessed through participation in interlaboratory studies organized by QUASIMEME. Results: PCBs emerged as the most abundant pollutants, followed by DDTs. Contaminant load was higher in T. nobiliana (PCBs, 1,040 ng g lipid weight; DDTs, 234 ng g lipid weight) than in T. marmorata (PCBs, 434 ng g lipid weight; DDTs, 78 ng g lipid weight). PCB 118, 138, 153, and 180 were the dominant congeners accounting for over 95.0% of the total PCBs. Among DDTs, p,p'-DDE was detected in both species, always with a greater concentration than other pesticides. Conclusions: This study provides, for the first time, data regarding levels of organochlorine contamination in torpedinid species from the Mediterranean Sea. The comparability of TEQ levels with those encountered in predators at top of trophic chains constitutes a warning signal that should not be underestimated. [ABSTRACT FROM AUTHOR]