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Concentrations of legacy and new contaminants are related to metabolite profiles in Hudson Bay polar bears.

https://arctichealth.org/en/permalink/ahliterature303135
Source
Environ Res. 2019 01; 168:364-374
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
01-2019
Author
A D Morris
R J Letcher
M Dyck
B Chandramouli
J Cosgrove
Author Affiliation
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: adam.morris@canada.ca.
Source
Environ Res. 2019 01; 168:364-374
Date
01-2019
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Animals
Arctic Regions
Bays
Canada
Environmental monitoring
Environmental Pollutants - metabolism
Hydrocarbons, Chlorinated - metabolism
Male
Polychlorinated Biphenyls - metabolism
Ursidae - metabolism
Abstract
There are very few metabolomics assessments based on field accumulated, uncontrolled contaminant exposures in wildlife, particularly in the Arctic. In the present study, targeted metabolomics and contaminant data were analyzed together to assess potential influences of contaminant exposure on the hepatic metabolome of male polar bears (n?=?29) from the southern and western Hudson Bay (SHB and WHB respectively), Canada. The 29 metabolites identified as important in the differentiation of the two subpopulations after partial least squares discriminant analysis (PLS-DA) included phosphatidylcholines (PCs), acylcarnitines (ACs; involved in ß-oxidation of fatty acids), and the fatty acid (FA) arachidonic acid (ARA). Perfluorinated alkyl substances, polybrominated diphenyl ethers, dichlorodiphenyldichloroethylene (p,p'-DDE) and some highly chlorinated ortho-polychlorinated biphenyl congeners were greater in the SHB bears and were consistently inversely correlated with discriminating ACs and PCs between the subpopulations. The concentrations of discriminatory, legacy organochlorine pesticides along with one tetrachlorobiphenyl were greater in the WHB and were directly correlated with the VIP-identified ACs and PCs. ARA, glycerophospholipid and several amino acid metabolic pathways were identified as different between subpopulations and/or were impacted. ARA is an important, conditionally essential, dietary n-6 FA and is also part of the inflammation response, and elevated concentrations in the SHB could be related to differences in chronic contaminant exposure and/or differences in diet and/or season, among a number of possible explanations. Dietary tracers (stable isotopes of carbon and nitrogen) were correlated with some discriminatory metabolites, supporting the hypothesis that dietary variation was also an important factor in the differentiation of the subpopulations. The results suggest linkages between contaminant exposure in Hudson Bay polar bears and elements of the hepatic metabolome, particularly those related to lipid metabolism.
PubMed ID
30384230 View in PubMed
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Legacy and new halogenated persistent organic pollutants in polar bears from a contamination hotspot in the Arctic, Hudson Bay Canada.

https://arctichealth.org/en/permalink/ahliterature294456
Source
Sci Total Environ. 2018 Jan 01; 610-611:121-136
Publication Type
Journal Article
Date
Jan-01-2018
Author
R J Letcher
A D Morris
M Dyck
E Sverko
E J Reiner
D A D Blair
S G Chu
L Shen
Author Affiliation
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.
Source
Sci Total Environ. 2018 Jan 01; 610-611:121-136
Date
Jan-01-2018
Language
English
Publication Type
Journal Article
Keywords
Adipose Tissue - chemistry
Animals
Arctic Regions
Bays
Canada
Chlordan - analysis
Environmental monitoring
Environmental Pollutants - analysis
Female
Liver - chemistry
Male
Polychlorinated biphenyls - analysis
Ursidae
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. SPolychlorinated 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. SChlordanes (SCHLs, 74-79% oxychlordane) and the Sperfluoroalkyl substances (SPFASs, ˜60% perfluorooctane sulfonate (PFOS)) had the second greatest POP group concentrations in SHB and WHB respectively, with SPFASs and SCHLs being significantly influenced by age and/or sex. SCHLs were spatially uniform but SPFASs 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. SPolychlorinated naphthalenes (SPCNs) were consistently detected at relatively high concentrations compared to other arctic wildlife, however these concentrations were low relative to legacy POPs. SShort-chain chlorinated paraffins (SSCCPs) 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.
PubMed ID
28803190 View in PubMed
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