The brominated flame retardants have been subject of a particular environmental focus
in the Arctic. The present study investigated the congener patterns and levels of
total hexabromocyclododecane (HBCD), polybrominated biphenyls, polybrominated diphenyl
ethers (PBDEs), as well as methoxylated (MeO) and hydroxylated (OH) PBDEs in plasma
samples of glaucous gulls (Larus hyperboreus) and polar bears (Ursus maritimus) from
the Norwegian Arctic. The analyses revealed the presence of total HBCD (0.07-1.24
ng/g wet wt) and brominated biphenyl 101 (< 0.13-0.72 ng/g wet wt) in glaucous gull
samples whereas these compounds were generally found at nondetectable or transient
concentrations in polar bears. Sum (sigma) concentrations of the 12 PBDEs monitored
in glaucous gulls (range: 8.23-67.5 ng/g wet wt) surpassed largely those of polar
bears (range: 2.65-9.72 ng/g wet wt). Two higher brominated PBDEs, BDE183 and BDE209,
were detected, and thus bioaccumulated to a limited degree, in glaucous gulls with
concentrations ranging from < 0.03 to 0.43 ng/g wet wt and from < 0.05 to 0.33 ng/g
wet wt, respectively. In polar bear plasma, BDE183 was < 0.04 ng/g wet wt for all
animals, and BDE209 was only detected in 7% of the samples at concentrations up to
0.10 ng/g wet wt. Of the 15 MeO-PBDEs analyzed in plasma samples, 3-MeO-BDE47 was
consistently dominant in glaucous gulls (sigmaMeO-PBDE: 0.30-4.30 ng/g wet wt) and
polar bears (sigmaMeO-PBDE up to 0.17 ng/g wet wt), followed by 4'-MeO-BDE49 and 6-MeO-BDE47.
The 3-OH-BDE47, 4'-OH-BDE49, and 6-OH-BDE47 congeners were also detected in glaucous
gulls (sigmaOH-PBDE up to 1.05 ng/g wet wt), although in polar bears 4'-OH-BDE49 was
the only congener quantifiable in 13% of the samples. The presence of MeO- and OH-PBDEs
in plasma of both species suggests possible dietary uptake from naturally occurring
sources (e.g., marine sponges and green algae), but also metabolically derived biotransformation
of PBDEs such as BDE47 could be a contributing factor. Our findings suggest that there
are dissimilar biochemical mechanisms involved in PCB and PBDE metabolism and accumulation/elimination
and/or OH-PBDE accumulation and retention in glaucous gulls and polar bears.