Legacy and new halogenated persistent organic pollutants in polar bears from a contamination hotspot in the Arctic, Hudson Bay Canada

R J Letcher; A D Morris; M Dyck; E Sverko; E J Reiner; D A D Blair; S G Chu; L Shen

doi:10.1016/j.scitotenv.2017.08.035

Legacy and new halogenated persistent organic pollutants in polar bears from a contamination hotspot in the Arctic, Hudson Bay Canada

Sci Total Environ. 2018 Jan 1:610-611:121-136. doi: 10.1016/j.scitotenv.2017.08.035. Epub 2017 Aug 10.

Authors

R J Letcher¹, A D Morris², M Dyck³, E Sverko⁴, E J Reiner⁵, D A D Blair⁶, S G Chu⁶, L Shen⁵

Affiliations

¹ Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada; Department of Chemistry, Carleton University, Ottawa, ON, Canada. Electronic address: robert.letcher@canada.ca.
² Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada; Department of Chemistry, Carleton University, Ottawa, ON, Canada.
³ Government of Nunavut, Igoolik, NU, Canada.
⁴ Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
⁵ Ontario Ministry of the Environment and Climate Change, 125 Resources Rd, Toronto, ON, Canada.
⁶ Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada.

PMID: 28803190
DOI: 10.1016/j.scitotenv.2017.08.035

Abstract

A large and complex suite of 295 legacy and new halogenated persistent organic pollutants (POPs) were investigated in fat or liver tissue samples of polar bears collected in 2013-2014 from Southern (SHB) and Western (WHB) subpopulations of the Canadian Arctic contaminants hotspot of Hudson Bay. A total of 210 POPs were detected and/or quantifiable with some frequency in all fat or liver samples. POP profile and concentration differences were investigated both within (e.g. age and sex) and between the two subpopulations. Two time-point comparisons were made relative to POPs reported for Hudson Bay polar bears harvested in 2007-2008. ΣPolychlorinated biphenyl (PCB) concentrations at both time points were the most concentrated of the POP groups, and were spatially uniform with no detectable influence of sex or age, as were concentrations of the dominant congener CB153. ΣChlordanes (ΣCHLs, 74-79% oxychlordane) and the Σperfluoroalkyl substances (ΣPFASs, ≈60% perfluorooctane sulfonate (PFOS)) had the second greatest POP group concentrations in SHB and WHB respectively, with ΣPFASs and ΣCHLs being significantly influenced by age and/or sex. ΣCHLs were spatially uniform but ΣPFASs were greater in the SHB bears, as were e.g. some flame retardants, due to e.g. local contamination and/or changes in bear behavior and diet. Endosulfans and hexabromocyclododecane were detectable in samples from 2007-2008 but not from 2013-2014, which is consistent with their global POP regulations. ΣPolychlorinated naphthalenes (ΣPCNs) were consistently detected at relatively high concentrations compared to other arctic wildlife, however these concentrations were low relative to legacy POPs. ΣShort-chain chlorinated paraffins (ΣSCCPs) were major contributors to the overall POPs burden with concentrations comparable to other legacy POPs, though there was no significant difference between or within subpopulations for PCNs or SCCPs. Except for octachlorostyrene, POPs concentrations were generally lower in female and male bears from SHB in 2013-2014 relative to 2007-2008, however those of WHB males were greater over the same timeframe for almost all POPs.

Keywords: Arctic; Canada; Hudson Bay; Legacy and new contaminants; Persistent organic pollutants; Polar bears.

MeSH terms

Adipose Tissue / chemistry*
Animals
Arctic Regions
Bays
Canada
Chlordan / analysis
Environmental Monitoring
Environmental Pollutants / analysis*
Female
Liver / chemistry*
Male
Polychlorinated Biphenyls / analysis
Ursidae*

Substances

Environmental Pollutants
Chlordan
Polychlorinated Biphenyls