Dear colleagues, Please, find below the abstract of a new contribution regarding the first assessment of PBDE flame retardants and PCBs in overwintering Steller sea lion in BC, Canada. If you would like a pdf copy of the article in press, please feel free to request the paper to jalavasa@sfu.ca  (Juan José Alava). Cheers Juan Jose Alava Chemosphere Available online 2 May 2012 In Press, Corrected Proof PBDE flame retardants and PCBs in migrating Steller sea lions (Eumetopias jubatus) in the Strait of Georgia, British Columbia, Canada * J. J. Alava, D. Lambourn, P. Olesiuk, M. Lance, S. J. Jeffries, F. A.P.C. Gobas, P. S. Ross * http://dx.doi.org/10.1016/j.chemosphere.2012.03.094 ________________________________ Abstract Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in blubber biopsy samples from 22 live-captured Steller sea lions (Eumetopias jubatus) that had just entered the Strait of Georgia, British Columbia, Canada, for their overwintering feeding season. ∑PBDE ranged from 50 μg kg−1 (lipid weight) in adult females to 3780 μg kg−1 in subadult individuals. ∑PCBs ranged from 272 μg kg−1 in adult females to 14 280 μg kg−1 in subadult individuals. While most PBDE and PCB congeners were transferred through milk to pups, PCBs with log KOW > 7.0 (PCBs 206, 207, 208 and 209) appeared constrained, resulting in a lighter mixture in pups compared to adult females. The ratio of individual PCB congeners by metabolic group (Groups I, II, III, IV and V) to PCB-153 regressed against length of males suggested poor biotransformation of these compounds (slopes did not differ from zero, p > 0.05). PBDE congeners 49, 99, 153 and 183 appeared bioaccumulative (slopes of ratio BDE/PCB 153 versus length were higher than zero, p < 0.05), but the dominance of the single congener, BDE-47 (64% of total PBDEs), likely due in part to debromination pathways, reduced our ability to explore congener-specific dynamics of PBDEs in these pinnipeds. With 80% of our Steller sea lions exceeding a recent toxicity reference value for PCBs, the fasting-associated mobilization of these contaminants raises concerns about a heightened vulnerability to adverse effects during annual migrations. ________________________________ Highlights ► PCBs and PBDEs were found at moderately high levels in Steller sea lions. ► Biotransformation was only evident for a limited number of PCB and PBDE congeners. ► 80% of the sea lions had PCB levels that exceeded toxicity threshold in pinnipeds. Keywords * Steller sea lions; * PBDEs; * PCBs; * Maternal transfer; * Metabolism; * Bioaccumulation   Juan Jose Alava, PhD  Research Associate School of Resource & Environmental Management (Environmental Toxicology Research Group) Faculty of Environment, Simon Fraser University TASC-1; Office 8420; 8888 University Drive Burnaby, British Columbia V5A 1S6, CANADA Office Phone: (778) 782-7375 Fax: (778)782-4968 E-mail: jalavasa@sfu.ca http://www.intechopen.com/profile/53467/juan_jose_alava Collaborating Scientist Charles Darwin Foundation Puerto Ayora, Santa Cruz, Galapagos Islands, Ecuador www.darwinfoundation.org