Toxaphene contamination in Lake Baikal's water and food web

Water and biological samples were obtained from Lake Baikal in June 1991 and analyzed for toxaphene and other organochlorines. Dissolved toxaphene concentration ranged from 34 pg/L to 143 pg/L and were similar in magnitude to ∑DDT (47 pg/L; sum of 2,4′-DDT, 4,4′-DDT, and 4,4′-DDE) and ∑chlordanes (28 pg/L; sum of cis- and trans-chlordane and cis- and trans-nonachlor). Toxaphene in biota was 1.9 mg/kg-lipid in the pelagic sculpin Comephorus dybowskii, 1.1 mg/kg-lipid in the omul (Coregonus autumnalis migratorious) and 2.3 mg/kg-lipid in Baikal seal (Phoca siberica) blubber. Toxaphene chromatographic patterns, determined by gas chromatography electron capture negative ion-mass spectrometry, were transformed in the seal relative to either of the fish, which is likely due to the seal's greater ability to metabolize some toxaphene congeners. The major peak in the Baikal seal toxaphene chromatogram was an 8-chlorinated bornane unlike that found by other investigators for narwhal or beluga whale blubber, but similar to ringed seals from the Canadian Arctic.