Lactational Transfer of Polychlorinated-Biphenyls (PCBs) and Other Organochlorines in St. Lawrence Beluga Whales (Delphinapterus leucas).
This study uses an individual-based contaminant bioaccumulation model for marine mammals to explore factors controlling the transfer of PCBs from mother to calf via nursing in beluga from the St. Lawrence Estuary. Beluga blubber samples (n = 46), along with four matched milk samples from stranded animals over the 1986-1994 period were used for comparison with modelled results. Based on 68 POPs, including 48 PCBs and 20 other organochlorine compounds, milk:blubber ratios were 0.65 between log K OW 3-6.5, then decreased to 0.1 at log K OW 8. Model simulations based on this relationship indicated females were transferring PCBs that were relatively very hydrophobic and highly chlorinated less readily than their lower chlorinated counterparts, resulting in an enriched concentration of very hydrophobic congeners in nursing females relative to adult males. There was very good agreement between observed and modelled male:female PCB concentration ratios. Four females within our dataset (15 %) had male-like ΣPCB concentrations as well as male-like congener profiles, suggesting that these individuals may have had a reduced or limited nursing history.
Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8, Canada.
Marc A
MA
Cadieux
Aquatic Ecosystem Protection Research Division, Environment Canada, Burlington, ON, L7R 4A6, Canada.
Derek C G
DC
Muir
St. Lawrence National Institute of Ecotoxicology, Montréal, QC, H2J 3C3, Canada.
Pierre
P
Béland
Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8, Canada. bhickie@trentu.ca.
Brendan E
BE
Hickie
D000818:Animals; D050643:Beluga Whale / Q000378:metabolism*; D002170:Canada; D005260:Female; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism*; D007774:Lactation; D008892:Milk / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D006843:Hydrocarbons, Chlorinated; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls