The secret contamination of polar bears

Hundreds of unrecognized halogenated contaminants discovered in polar bear serum

Date:  December 3, 2018

Source:  Wiley

Using a new approach to measure chemical contaminants in polar bears, scientists from Canada and the United States found a large variety of new chlorinated and fluorinated substances, including many new polychlorinated biphenyl metabolites. Worryingly, these previously unrecognized contaminants have not declined in the past decades, and many long-chain fluorinated alkyl sulfonic acids have been increasing over time, says the study published in the journal Angewandte Chemie.

Polar bears reside at the top of the Arctic food chain. Whatever pollutants fish and other marine living species take up, they can end up biomagnifying in the polar bears that eat them. Halogenated contaminants were recognized in polar bear serum for the first time in the 1970s, and since then have been monitored frequently, as these human-made substances or their direct metabolites have been linked to disturbances of the immune system or endocrine function. The current study with leading author Jonathan W. Martin from the University of Alberta, Edmonton, Canada, and now at Stockholm University, Sweden, gives a survey on the different classes of halogenated contaminants now detected in polar bear serum, and also tracks down the trends in contamination during the last two decades.

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