| In East Greenland polar bears, protein association of organohalogens is an important factor besides lipid accumulation in tissue-specific retention since the highest levels of organohalogen contaminants were found in the liver and blood relative to the fat and brain. The type of halogens also plays a role in tissue-specific accumulation. In the bears, the majority of the chlorinated POP burden was in the fat, while the majority of brominated POP burden was in the liver. With the exception of chlorinated phenolic metabolites, ringed seal blubber is a source for all organohalogens found in the polar bear tissues, the contaminants were found to biomagnify in the bear's fat, blood and liver. In the bear's brain, protected by the blood-brain barrier, levels of contaminants were found lower relative to seal blubber. Organohalogen exposure has been reported to disrupt the endocrine system; this could impact the growth and development of the polar bears. |
