Distribution and levels of eight toxaphene congeners in different tissues of marine mammals, birds and cod livers

Levels and distribution of eight compounds of technical toxaphene (CTTs) we re determined in different marine species (seals, cetaceans, birds, and fis h). The eight CTTs included six commercially available and two chlorobornan es prepared in our lab. These congeners were present in all investigated sa mples. In agreement with earlier studies, the octachlorobornane B8-1413 (P- 26) and the nonachlorobornane B9-1679 (P-50) were the most abundant congene rs in most of the samples. In seal blubber, B8-1413 (P-26) and B9-1679 (P-50) contributed with up to s imilar to 80% (Weddell seal) to the sum of the eight CTTs. In seals from th e northern hemisphere the nonachlorobornane was more abundant while in thos e from the southern hemisphere (Antarctic and Namibia), the octachloroborna ne B8-1413 (P-26) usually appeared at higher concentrations. Depending on the species the contribution of the other congeners varied sig nificantly. B9-1025 (P-62) ranged from 2-20%, B8-1412 was found at 4-25% wi th highest contribution in birds, and B8-2229 (P-44) was found at 5-15%. Th e remaining three congeners B7-1453, B8-1414 (P- 40), and B8-1945 (P-41) we re lower abundant except B8-1414 (P-40) which was found at high contributio n in liver and kidney of birds. The sum of the eight CTTs ranged from 4 mug/kg to 1.4 mg/kg, depending on t he species and region. In most of the seal blubber samples, PCBs and DDT we re more abundant (factor 2-20) but Antarctic Weddell seals showed higher CT T levels than PCBs and DDT. (C) 2001 Elsevier Science Ltd. All rights reser ved.