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(W/EH099) Levels of some POPs in top predators from Italian Seas collected in 1993 and 1999. Corsolini, Simonetta 1, Ademollo, Nicoletta1, Artusi, Maria1, Focardi, Silvano1, 1 ABSTRACT- In the last 40 years, many studies have documented the widespread occurrence of polychlorobiphenyls (PCBs) and organochlorines and their amplification in the food webs. Levels of PCBs and pp'-DDE were measured in two top fish predators of the Mediterranean, tuna (Thunnus thynnus thynnus) and swordfish (Xiphias gladius), collected in 1999 and compared with those obtained in a previous study carried out in 1993. PCB and pp'-DDE levels detected in muscle and liver samples of seven tuna specimens and liver samples of 16 swordfish specimens sampled in summer/autumn 1999 off the coasts of Calabria and Sicily (Ionian and Tyrrhenian Seas) were compared with those obtained in liver and muscle samples of eight tuna specimens and liver samples of nine swordfish specimens captured in 1993 in the South Tyrrhenian. total PCBs (expressed in ng/g fresh weight) were: 69.51 ng/g in 1993 and 79.63 ng/g in 1999 in tuna muscle; 28.91 ng/g in 1993 and 232.78 ng/g in 1999 in tuna liver; 136.04 ng/g in 1993 and 69.03 ng/g in 1999 in swordfish liver. Levels of pp'-DDE were 4.19 ng/g in 1993 and 31.35 ng/g in 1999 in tuna muscle; 3.75 ng/g in 1993 and 74.31 ng/g in 1999 in tuna liver; 28.46 ng/g in both 1993 and in 1999 in swordfish liver. The congener gradient was hexa-CB > hepta-CB > penta-CB, while the most abundant congeners included 22'44'55'(IUPAC 153), 22'344'5' (PCB-138) and 22'344'55' (PCB-180). Toxicity was measured as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs), using Toxic Equivalency Factors (TEFs). Total TEQ concentrations were higher in 1999 than those detected in the 1993 samples; these low values are comparable to those reported for remote areas worldwide. Key words: POPs, top predators, Italian Seas, TEQs |
