PARENT SESSION

3D - Exposure and effects of environmental contaminants in marine organisms
Hall 7
8:30 AM - 12:30 PM, Tuesday, 29 April 2003
Chair: Scholz, N.¹, ¹
Co-chair: Karbe, L.², ²

(TU7/9) Methyl Sulfone Metabolites of Polychlorinated Biphenyls (PCBs) and DDE in Harbour Porpoises (Phocoena phocoena) from the North Sea.

Covaci, Adrian¹, Chu, Shaogang¹, Voorspoels, Stefan¹, Maervoet, Johan ¹, Van de Vijver, Kristin², Das, Krishna³, Bouqegneau, Jean-Marie³, De Coen, Wim², Blust, Ronny², Schepens, Paul¹, ¹ Toxicological Center, University of Antwerp (UIA), Wilrijk, Belgium, Belgium² Department of Biology, University of Antwerp (RUCA), Antwerp, Belgium, Belgium³ Department of Oceanography, University of Liège, Liège, Belgium, Belgium

ABSTRACT- Concentrations of 26 methyl sulfone metabolites of PCBs (MeSO₂-CBs) and 3-MeSO₂-DDE were measured in 19 livers collected from harbour porpoises (Phocoena phocoena) stranded on the Belgian coast of the North Sea. The total MeSO₂-CBs concentrations ranged from 39 to 4221 ng/g lipid weight. Higher levels were found in adults (age >2 yrs, range 953 to 4221 ng/g lipid) than in juveniles (age < 2 yrs, range 39 to 1005 ng/g lipid). The concentrations of 3-MeSO₂-DDE were also higher in adults (range 21 to 94 ng/g lipid) than in juveniles (range 0.4 to 60 ng/g lipid). The ratios of total PCBs/MeSO₂-CBs and p,p-DDE/MeSO₂-DDE in porpoise livers presented high variations between individual samples and ranged from 15 to 419 and from 17 to 1088, respectively. Congeners 3- and 4-MeSO₂-CB101 were the dominating metabolites in all samples. The 3-MeSO₂- substituted compounds were the dominant metabolites of CBs 31, 49, 52, 87 and 101, while the 4-MeSO₂- substituted compounds were the main metabolites of CBs 64, 91, 110 and 132. In contrast, in human liver samples (n=11, range 1.7 to 27 ng/g lipid), 3-MeSO₂-CB132 was by far the most abundant congener (approximately 60% of the sum of MeSO₂-CBs). Enantiomeric separations of chiral MeSO₂-CBs revealed a high enantioselective dominance for all measured chiral congeners (3- and 4-MeSO₂-PCB 132, 149 and 174). Persistent MeSO₂-CBs and -DDE are capable of interacting with enzymes (induction of hepatic CYP family) and may influence endocrine-related processes, such as reduction of thyroid hormone levels in blood.

Key words: PCB, methyl sulphone, porpoises, North Sea