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Hundreds of Unrecognized Halogenated Contaminants Discovered in Polar Bear Blood

submitted on 13.11.2018, 06:18 and posted on 23.11.2018, 16:30 by Yanna Liu, Evan S. Richardson, Andrew E. Derocher, Nicholas J. Lunn, Hans-Joachim Lehmler, Xueshu Li, Yifeng Zhang, Julia Yue Cui, Lihua Cheng, Jonathan W. Martin

Exposure of polar bears (Ursus maritimus) to persistent organic pollutants was discovered in the 1970s, but recent evidence suggests the presence of unknown toxic chemicals in their blood. Protein and phospholipid depleted serum was stirred with polyethersulfone capillaries to extract a broad range of analytes, and nontarget mass spectrometry with “fragmentation flagging” was used for detection. Hundreds of analytes were discovered belonging to 13 classes, including novel polychlorinated biphenyl (PCB) metabolites and many fluorinated or chlorinated substances not previously detected. All analytes were detected in the oldest (mid-1980s) archived polar bear serum from Hudson Bay and Beaufort Sea, and all fluorinated classes showed increasing trends. A mouse experiment confirmed the novel PCB metabolites, suggesting that these could be widespread in mammals. Historical exposure and toxic risk has been underestimated, and emerging contaminants pose uncertain risks to this threatened species


Natural Sciences and Engineering Research Council of Canada (NSERC)

Natural Sciences and Engineering Research Council

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United States Department of Health and Human Services

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Environmental Health Sciences Research Center

National Institute of Environmental Health Sciences

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Center for Ecogenetics and Environmental Health

Chinese Scholarship Council

Killam Trusts


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University of Alberta



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Declaration of Conflict of Interest

The authors declare no conflict of interest.

Version Notes

this is the first version submitted to a journal