lactation; elephant seals; tranfer of organochlorines
Abstract :
[en] The transfer of PCBs and DDTs from mother to pup was studied in 20 Northern elephant seal Mirounga angustirostris mother-pup pairs. Organochlorine concentrations in milk increased from 127.3 ± 25.0 ng/g to 200.9 ± 39.6 ng/g for PCBs and from 278.2 ± 92.4 ng/g to 494.9 ± 163.4 ng/g for DDTs between day 4 and day 21 of lactation. A similar longitudinal rise was observed in the serum of mothers (5.4 ± 0.8 to 7.7 ± 1.4 ng/ml for PCBs and 7.8 ± 2.4 to 11.9 ± 4.1 ng/ml for DDTs) and, to a lesser extend, in the serum of their pups (5.8 ± 1.4 to 6.1 ± 2.5 ng/ml for PCBs and 8.3 ± 2.5 to 9.9 ± 4.3 ng/ml for DDTs) between early and late lactation. The rise of contaminants in serum and milk might originate from the changes observed in maternal inner blubber in which PCB and DDT levels increased significantly throughout lactation (604.2 ± 142.8 to 1292.5 ± 421.6 ng/g lipids for PCBs and 1223.9 ± 460.0 to 2395.9 ± 737.3 ng/g lipids for DDTs). By contrast, contaminant levels remained constant in outer blubber (933.2 ± 271.8 to 999.7 ± 223.5 ng/g lipids for PCBs and 2010.7 ± 698.3 to 2061.9 ± 603.5 ng/g lipids for DDTs).
