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26 records – page 1 of 3.

Assessing the contribution of combustion-derived contaminants to a remote subarctic environment from traffic on the Tibbitt to Contwoyto winter road (Northwest Territories, Canada).

https://arctichealth.org/en/permalink/ahliterature270324
Source
Sci Total Environ. 2016 May 15;553:96-106
Publication Type
Article
Date
May-15-2016
Author
Jennifer B Korosi
David C Eickmeyer
Joshua R Thienpont
Michael J Palmer
Linda E Kimpe
Jules M Blais
Source
Sci Total Environ. 2016 May 15;553:96-106
Date
May-15-2016
Language
English
Publication Type
Article
Abstract
Remote mining operations in Canada's Northwest Territories and Nunavut are supported by a 600km winter road, which spans the transition from subarctic boreal forest in Yellowknife to low Arctic tundra. Each year, thousands of truckloads of fuel, large equipment, and other heavy loads are hauled up the winter road. We investigated whether diesel emissions from commercial truck traffic is a major source of metals and polycyclic aromatic compounds (PACs) to aquatic ecosystems along the winter road. In March 2014, at the end of the hauling season, we collected integrated snow samples, water, and sediment from nine lakes located along the winter road, as well as from six lakes located within the city of Yellowknife. Examination of PAC composition and diagnostic ratios in snow samples showed that wildfires are an important source of PACs to lakes along the winter road, while anthropogenic sources are more prevalent in snow from Yellowknife lakes. Concentrations of PACs, including those associated with diesel emissions, were variable in snow, water, and sediment across all sites. The highest concentrations of PACs in snow were reported in winter road lakes located in the subarctic boreal forest, where forest fires are common. No compositional differences were observed for PACs in sediment and water samples between Yellowknife and winter road lakes. We did not observe any evidence of metal contamination in snow collected along the winter road, and metal concentrations in snow from winter road sites were consistently lower than Yellowknife sites. Our results show that a high contribution of PACs from natural sources can obscure potential contributions from diesel traffic emissions along the winter road.
PubMed ID
26906697 View in PubMed
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Broad-scale lake expansion and flooding inundates essential wood bison habitat.

https://arctichealth.org/en/permalink/ahliterature295933
Source
Nat Commun. 2017 02 23; 8:14510
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
02-23-2017
Author
Jennifer B Korosi
Joshua R Thienpont
Michael F J Pisaric
Peter deMontigny
Joelle T Perreault
Jamylynn McDonald
Myrna J Simpson
Terry Armstrong
Steven V Kokelj
John P Smol
Jules M Blais
Author Affiliation
Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N6N5.
Source
Nat Commun. 2017 02 23; 8:14510
Date
02-23-2017
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Animals
Bison - physiology
Climate
Conservation of Natural Resources
Ecosystem
Floods
Geography
Geologic sediments
Lakes
Lignin - chemistry
Northwest Territories
Phenols - chemistry
Abstract
Understanding the interaction between the response of a complex ecosystem to climate change and the protection of vulnerable wildlife species is essential for conservation efforts. In the Northwest Territories (Canada), the recent movement of the Mackenzie wood bison herd (Bison bison athabascae) out of their designated territory has been postulated as a response to the loss of essential habitat following regional lake expansion. We show that the proportion of this landscape occupied by water doubled since 1986 and the timing of lake expansion corresponds to bison movements out of the Mackenzie Bison Sanctuary. Historical reconstructions using proxy data in dated sediment cores show that the scale of recent lake expansion is unmatched over at least the last several hundred years. We conclude that recent lake expansion represents a fundamental alteration of the structure and function of this ecosystem and its use by Mackenzie wood bison, in response to climate change.
Notes
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PubMed ID
28230049 View in PubMed
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Broad-scale lake expansion and flooding inundates essential wood bison habitat.

https://arctichealth.org/en/permalink/ahliterature280321
Source
Nat Commun. 2017 Feb 23;8:14510
Publication Type
Article
Date
Feb-23-2017
Author
Jennifer B Korosi
Joshua R Thienpont
Michael F J Pisaric
Peter deMontigny
Joelle T Perreault
Jamylynn McDonald
Myrna J Simpson
Terry Armstrong
Steven V Kokelj
John P Smol
Jules M Blais
Source
Nat Commun. 2017 Feb 23;8:14510
Date
Feb-23-2017
Language
English
Publication Type
Article
Abstract
Understanding the interaction between the response of a complex ecosystem to climate change and the protection of vulnerable wildlife species is essential for conservation efforts. In the Northwest Territories (Canada), the recent movement of the Mackenzie wood bison herd (Bison bison athabascae) out of their designated territory has been postulated as a response to the loss of essential habitat following regional lake expansion. We show that the proportion of this landscape occupied by water doubled since 1986 and the timing of lake expansion corresponds to bison movements out of the Mackenzie Bison Sanctuary. Historical reconstructions using proxy data in dated sediment cores show that the scale of recent lake expansion is unmatched over at least the last several hundred years. We conclude that recent lake expansion represents a fundamental alteration of the structure and function of this ecosystem and its use by Mackenzie wood bison, in response to climate change.
PubMed ID
28230049 View in PubMed
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Cancer risk to First Nations' people from exposure to polycyclic aromatic hydrocarbons near in-situ bitumen extraction in Cold Lake, Alberta.

https://arctichealth.org/en/permalink/ahliterature257197
Source
Environ Health. 2014;13(1):7
Publication Type
Article
Date
2014
Author
Graham M Irvine
Jules M Blais
James R Doyle
Linda E Kimpe
Paul A White
Author Affiliation
Department of Biology, University of Ottawa, 30 Marie Curie, Pvt, Ottawa, Ontario K1N 6 N5, Canada. paul.white@hc-sc.gc.ca.
Source
Environ Health. 2014;13(1):7
Date
2014
Language
English
Publication Type
Article
Keywords
Adult
Air Pollutants - analysis
Alberta - epidemiology
Carcinogens - analysis
Environmental monitoring
Humans
Hydrocarbons
Neoplasms - epidemiology
Oil and Gas Fields
Polycyclic Hydrocarbons, Aromatic - analysis
Population Groups - statistics & numerical data
Risk assessment
Soil Pollutants - analysis
Abstract
The Alberta oil sands are an important economic resource in Canada, but there is growing concern over the environmental and health effects as a result of contaminant releases and exposures. Recent studies have shown a temporal and spatial trend of increased polycyclic aromatic hydrocarbon (PAH) concentrations in sediments and snowpack near the Athabasca oil sands operations (i.e., open pit mines), but thus far similar studies have not been done for the Cold Lake region where steam assisted gravity drainage (in situ) extraction is performed.
Many PAHs are known mutagenic carcinogens, and this study measured soil and atmospheric concentrations of PAHs in the Cold Lake region to assess the excess lifetime cancer risk posed to the First Nations' inhabitants of the region. Using both deterministic and probabilistic risk assessment methods, excess lifetime cancer risks were calculated for exposures from inhalation or inadvertent soil ingestion.
The mean excess cancer risk for First Nations' people through ingestion who engage in traditional wilderness activities in the Cold Lake region was 0.02 new cases per 100,000 with an upper 95% risk level of 0.07 cases per 100,000. Exposure to PAHs via inhalation revealed a maximum excess lifetime cancer risk of less than 0.1 cases per 100,000.
Excess lifetime risk values below 1 case per 100,000 is generally considered negligible, thus our analyses did not demonstrate any significant increases in cancer risks associated with PAH exposures for First Nations people inhabiting the Cold Lake region.
Notes
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PubMed ID
24520827 View in PubMed
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Comparative histories of polycyclic aromatic compound accumulation in lake sediments near petroleum operations in western Canada.

https://arctichealth.org/en/permalink/ahliterature289241
Source
Environ Pollut. 2017 Dec; 231(Pt 1):13-21
Publication Type
Comparative Study
Journal Article
Date
Dec-2017
Author
Joshua R Thienpont
Cyndy M Desjardins
Linda E Kimpe
Jennifer B Korosi
Steven V Kokelj
Michael J Palmer
Derek C G Muir
Jane L Kirk
John P Smol
Jules M Blais
Author Affiliation
Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada.
Source
Environ Pollut. 2017 Dec; 231(Pt 1):13-21
Date
Dec-2017
Language
English
Publication Type
Comparative Study
Journal Article
Keywords
Alberta
Ecosystem
Environmental monitoring
Geologic Sediments - analysis
Lakes - analysis
Mining
Oil and Gas Fields
Petroleum - analysis
Polycyclic Aromatic Hydrocarbons - analysis
Water Pollutants, Chemical - analysis
Abstract
We examined the historical deposition of polycyclic aromatic compounds (PACs) recorded in radiometrically-dated lake sediment cores from a small, conventional oil and gas operation in the southern Northwest Territories (Cameron Hills), and placed these results in the context of previously published work from three other important regions of western Canada: (1) the Athabasca oil sands region in Alberta; (2) Cold Lake, Alberta; and (3) the Mackenzie Delta, NT. Sediment PAC records from the Cameron Hills showed no clear changes in either source or concentrations coincident with the timing of development in these regions. Changes were small in comparison to the clear increases in both parent and alkyl-substituted PACs in response to industrial development from the Athabasca region surface mining of oil sands, where parent PAC diagnostic ratios indicated a shift from pyrogenic sources (primarily wood and coal burning) in pre-development sediments to more petrogenically-sourced PACs in modern sediments. Cores near in-situ oil sand extraction operations showed only modest increases in PAC deposition. This work directly compares the history and trajectory of contamination in lake ecosystems in areas of western Canada impacted by the most common types of hydrocarbon extraction activities, and provides a context for assessing the environmental impacts of oil and gas development in the future.
PubMed ID
28780061 View in PubMed
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Comparative histories of polycyclic aromatic compound accumulation in lake sediments near petroleum operations in western Canada.

https://arctichealth.org/en/permalink/ahliterature284847
Source
Environ Pollut. 2017 Aug 03;231(Pt 1):13-21
Publication Type
Article
Date
Aug-03-2017
Author
Joshua R Thienpont
Cyndy M Desjardins
Linda E Kimpe
Jennifer B Korosi
Steven V Kokelj
Michael J Palmer
Derek C G Muir
Jane L Kirk
John P Smol
Jules M Blais
Source
Environ Pollut. 2017 Aug 03;231(Pt 1):13-21
Date
Aug-03-2017
Language
English
Publication Type
Article
Abstract
We examined the historical deposition of polycyclic aromatic compounds (PACs) recorded in radiometrically-dated lake sediment cores from a small, conventional oil and gas operation in the southern Northwest Territories (Cameron Hills), and placed these results in the context of previously published work from three other important regions of western Canada: (1) the Athabasca oil sands region in Alberta; (2) Cold Lake, Alberta; and (3) the Mackenzie Delta, NT. Sediment PAC records from the Cameron Hills showed no clear changes in either source or concentrations coincident with the timing of development in these regions. Changes were small in comparison to the clear increases in both parent and alkyl-substituted PACs in response to industrial development from the Athabasca region surface mining of oil sands, where parent PAC diagnostic ratios indicated a shift from pyrogenic sources (primarily wood and coal burning) in pre-development sediments to more petrogenically-sourced PACs in modern sediments. Cores near in-situ oil sand extraction operations showed only modest increases in PAC deposition. This work directly compares the history and trajectory of contamination in lake ecosystems in areas of western Canada impacted by the most common types of hydrocarbon extraction activities, and provides a context for assessing the environmental impacts of oil and gas development in the future.
PubMed ID
28780061 View in PubMed
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A continental scale spatial investigation of lake sediment organic compositions using sedimentomics.

https://arctichealth.org/en/permalink/ahliterature306567
Source
Sci Total Environ. 2020 Jun 01; 719:137746
Publication Type
Journal Article
Date
Jun-01-2020
Author
Madison A Bell
David P Overy
Jules M Blais
Author Affiliation
Laboratory for the Analysis of Natural and Synthetic Environmental Toxicants, Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada. Electronic address: mbell145@uottawa.ca.
Source
Sci Total Environ. 2020 Jun 01; 719:137746
Date
Jun-01-2020
Language
English
Publication Type
Journal Article
Abstract
Sedimentomics is a new method used to investigate carbon cycling in sediment organic matter. This untargeted method, based on metabolomics workflows, was used to investigate the molecular composition of sediment organic matter across northern Canada (Nunavut and Northwest Territories). Unique "lake districts" were defined using unsupervised clustering based on changes in sediment organic carbon compositions across space. Supervised machine learning analyses were used to compare the "lake districts" to commonly used regional classification systems like the treeline, ecozones, and/or georegions. Treeline was the best model to explain the compositional variance of sediment organic carbon from lakes across Canada, closely followed by the georegions model. A novel sediment metaphenomics analysis was also applied to determine how well environmental constraints explain the variation of sediment organic matter composition across a continent. We determined that sedimentomics is more informative than traditional measurements (such as total organic carbon) and can be integrated with other "omics" techniques.
PubMed ID
32173009 View in PubMed
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Controls governing the spatial distribution of sediment arsenic concentrations and solid-phase speciation in a lake impacted by legacy mining pollution.

https://arctichealth.org/en/permalink/ahliterature296056
Source
Sci Total Environ. 2018 Nov 06; 654:563-575
Publication Type
Journal Article
Date
Nov-06-2018
Author
Christopher E Schuh
Heather E Jamieson
Michael J Palmer
Alan J Martin
Jules M Blais
Author Affiliation
Department of Geological Sciences and Geological Engineering, Queen's University, Miller Hall, Kingston, ON K7L 3N6, Canada. Electronic address: c.schuh@queensu.ca.
Source
Sci Total Environ. 2018 Nov 06; 654:563-575
Date
Nov-06-2018
Language
English
Publication Type
Journal Article
Abstract
Forty-seven sediment cores were collected as part of a spatial survey of Long Lake, Yellowknife, NWT, Canada to elucidate the physical and geochemical controls on the distribution of arsenic (As) in sediments impacted by the aerial deposition of arsenic trioxide (As2O3) from ore roasting at legacy gold mines. High-resolution profiles of dissolved As in bottom water and porewater were also collected to determine As remobilization and diffusion rates across the sediment-water interface. Arsenic concentrations in Long Lake sediments ranged from 2.2 to 3420?mg?kg-1 (dry weight). Two distinct types of sediment As concentration profiles were identified and are interpreted to represent erosional and depositional areas. Water depth is the best predictor of As concentration in the top 5?cm of sediments due to the inferred focusing of fine-grained As2O3 into deeper water. At greater sediment depths, iron (Fe) concentration, as a likely indicator of As, Fe, and sulphur (S) co-diagenesis, was the best predictor of As concentration. The sediments are a source of dissolved As to surface waters through diffusion-controlled release to bottom water. Arsenic concentrations, solid-phase speciation, and diffusive efflux varied laterally across the lake bottom and with sediment depth due to the interplay between sediment-focusing processes and redox reactions, which has implications for human health and ecological risk assessments.
PubMed ID
30447595 View in PubMed
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Determining the effects of past gold mining using a sediment palaeotoxicity model.

https://arctichealth.org/en/permalink/ahliterature306832
Source
Sci Total Environ. 2020 May 20; 718:137308
Publication Type
Journal Article
Date
May-20-2020
Author
Cynthia L Cheney
Kristin M Eccles
Linda E Kimpe
Joshua R Thienpont
Jennifer B Korosi
Jules M Blais
Author Affiliation
University of Ottawa, Department of Biology, Gendron Hall, 30 Marie Curie, Ottawa, ON K1N 6N5, Canada. Electronic address: cchen257@uottawa.ca.
Source
Sci Total Environ. 2020 May 20; 718:137308
Date
May-20-2020
Language
English
Publication Type
Journal Article
Keywords
Ecosystem
Environmental monitoring
Geologic sediments
Gold
Lakes
Mining
Water Pollutants, Chemical
Abstract
Ore processing techniques used in Yellowknife's largest mining operation, Giant Mine, is responsible for the atmospheric release of approximately 20,000 t of particulate arsenic trioxide and other heavy metal(loids). This rapid deposition of heavy metal(loids) may have caused ecological disturbances to aquatic food webs. Here we use 210Pb and 137Cs dated lake sediment cores from 20 lakes within a 40 km radius of Yellowknife to examine the spatial-temporal distribution of arsenic, antimony and lead. Further, we model the toxicity of the sediment to aquatic biota pre-, during, and post-mining using palaeotoxicity modelling, enrichment factor assessment, and comparisons to national sediment quality guidelines. We found that metal(loid) profiles in sediment peaked during the height of mining operations. These peak metal(loid) concentrations were highest in lakes near the mine's roaster stack, and decreased with distance from the historic mine. Palaeotoxicity modelling of lake sediment archives indicate that there is no significant difference in the mean predicted toxicity of pre- and post-mining samples (p = 0.14), however mining activities in the region significantly increased the predicted toxicity of sediments to aquatic organisms during mining operations (p 
PubMed ID
32088480 View in PubMed
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Dissolved organic carbon thresholds affect mercury bioaccumulation in Arctic lakes.

https://arctichealth.org/en/permalink/ahliterature258572
Source
Environ Sci Technol. 2014 Mar 18;48(6):3162-8
Publication Type
Article
Date
Mar-18-2014
Author
Todd D French
Adam J Houben
Jean-Pierre W Desforges
Linda E Kimpe
Steven V Kokelj
Alexandre J Poulain
John P Smol
Xiaowa Wang
Jules M Blais
Source
Environ Sci Technol. 2014 Mar 18;48(6):3162-8
Date
Mar-18-2014
Language
English
Publication Type
Article
Keywords
Animals
Canada
Carbon - analysis - chemistry
Humic Substances
Invertebrates - chemistry - metabolism
Lakes - chemistry
Mercury - analysis - chemistry - metabolism
Methylmercury Compounds - analysis - chemistry - metabolism
Water Pollutants, Chemical - analysis - chemistry - metabolism
Abstract
Dissolved organic carbon (DOC) is known to affect the Hg cycle in aquatic environments due to its overriding influence on complexation, photochemical, and microbial processes, but its role as a mediating factor in the bioaccumulation of Hg in aquatic biota has remained enigmatic. Here, we examined 26 tundra lakes in Canada's western Arctic that span a large gradient of DOC concentrations to show that total Hg (HgT) and methyl mercury (MeHg) accumulation by aquatic invertebrates is defined by a threshold response to Hg-DOC binding. Our results showed that DOC promotes HgT and MeHg bioaccumulation in tundra lakes having low DOC (DOC TC), consistent with bioaccumulation results in a companion paper (this issue) using a microbial bioreporter. Chemical equilibrium modeling showed that Hg bioaccumulation factors were elevated when Hg was associated mainly to fulvic acids, but became dramatically reduced when DOC was >8.5 mg C L(-1), at which point Hg was associated primarily with strong binding sites on larger, less bioaccessible humic acids. This study demonstrates that the biological uptake of Hg in lakes is determined by binding thresholds on DOC, a water quality variable predicted to change markedly with future environmental change.
PubMed ID
24524759 View in PubMed
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26 records – page 1 of 3.