Lactational transfer of PCBs and chlorinated pesticides in pups of southern elephant seals (Mirounga leonina) from Antarctica.
Seven pairs of southern elephant seals (Mirounga leonina) pups and their dams were sampled during the late weaning season among a breeding population of seals on Elephant Island in Antarctica. The blubber of the pups and the milk and blubber of their dams were analyzed for lipid-normalized concentrations of PCBs and organochlorines compounds in order to evaluate the lactational transfer of these contaminants. The lipid-normalized concentrations in these tissues were in the ppb range (i.e., ngg(-1) lipid). The levels of contaminants in southern elephant seals were low in comparison with residues that have been reported in pinnipeds from the northern hemisphere. The relative tissue concentrations of the analytes measured followed the pattern: SigmaDDT>mirex>SigmaPCB>Sigmachlordane>HCB>heptachlor epoxide>dieldrin>methoxychlor>SigmaHCH>other organochlorines. The very high DDE/SigmaDDT ratio (0.91) in the blubber of dams and pups was an indicative of long-term, extremely distant pollution. On the other hand, the relatively high levels of some other organochlorine pesticides (e.g. mirex, heptachlor epoxide, dieldrin, methoxychor) may reflect the continued use of these insecticides in developing countries located in the southern hemisphere. For most of the analytes measured, the lipid-normalized concentrations were lower in pup blubber and in the milk than in the maternal blubber. Lactational transfer rates were dependent on the logK(ow) (octanol/water partition coefficient) values of the analytes measured, less lipophilic compounds being more readily transferred to the pups by the lactational route.
Miranda Filho
Kleber C
KC
Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Av. Itália km 8, 96201-900 Rio Grande, RS, Brazil.
Metcalfe
Chris D
CD
Worsfold Water Quality Centre, Trent University, Peterborough, ON, Canada.
Metcalfe
Tracy L
TL
Worsfold Water Quality Centre, Trent University, Peterborough, ON, Canada.
Muelbert
Mônica M C
MMC
Programa de Pós-Graduação em Oceanografia Biológica, Universidade Federal do Rio Grande, Av. Itália km 8, 96201-900 Rio Grande, RS, Brazil.
Robaldo
Ricardo B
RB
Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Av. Itália km 8, 96201-900 Rio Grande, RS, Brazil.
Martinez
Pablo E
PE
Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Av. Itália km 8, 96201-900 Rio Grande, RS, Brazil.
Colares
Elton P
EP
Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Av. Itália km 8, 96201-900 Rio Grande, RS, Brazil.
Bianchini
Adalto
A
Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Av. Itália km 8, 96201-900 Rio Grande, RS, Brazil. Electronic address: adalto@octopus.furg.br.
D000818:Animals; D000831:Animals, Newborn; D000864:Antarctic Regions; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D020387:Food Chain; D006843:Hydrocarbons, Chlorinated / Q000032:analysis* / Q000378:metabolism; D007774:Lactation; D010573:Pesticide Residues / Q000032:analysis* / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000378:metabolism; D046048:Seals, Earless / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
D006843:Hydrocarbons, Chlorinated; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls