Persistent Pollutants in Arctic and Antarctic Krill and in Commercial Krill Oil

Krill are considered key-species of marine ecosystems of the Polar Regions, being main food source for fish, marine mammals and birds in the Southern Ocean and in Arctic seawaters. Through ingestion, persistent organic pollutants accumulated in their body could be transferred to their predators due to biomagnification process and may cause effects in the entire trophic web. We studied krill from the Arctic and Antarctic seawaters in order to assess the toxic risk for their predators. Recently, the krill oil has been used in commercial preparation of pills for supplying unsaturated fatty acids, hence including humans in the list of krill predators. In order to assess the contaminant level and toxic risk for predators, the presence of some persistent organic pollutants was determined by gaschromatography-mass spectrometry in Antarctic and Arctic krill samples and commercial pills. The sum of 4 congeners of mono- and 8 congeners of non-ortho polychlorinated biphenyls was < 0.001-0.471 and < 0.001-0.499 ng/g wet wt in the Antarctic and Arctic krill, respectively. HCHs and DDTs were more abundant in the Arctic krill (0.856±0.315 ng/g wet wt) while the sum of 23 congeners of polybrominated diphenyl ether predominated in the Antarctic krill (0.121±0.074 ng/g wet wt), with BDE47 making up most of the residue. The same contaminants were detected in the krill oil pills; the assessed TDI was below the limit suggested by the World Health Organization.