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Arsenic mobility and characterization in lakes impacted by gold ore roasting, Yellowknife, NWT, Canada.

https://arctichealth.org/en/permalink/ahliterature287601
Source
Environ Pollut. 2017 Dec 07;234:630-641
Publication Type
Article
Date
Dec-07-2017
Author
Martin D Van Den Berghe
Heather E Jamieson
Michael J Palmer
Source
Environ Pollut. 2017 Dec 07;234:630-641
Date
Dec-07-2017
Language
English
Publication Type
Article
Abstract
The controls on the mobility and fate of arsenic in lakes impacted by historical gold ore roasting in northern Canada have been examined. A detailed characterization of arsenic solid and aqueous phases in lake waters, lake sediments and sediment porewaters as well as surrounding soils was conducted in three small lakes (80 wt%) of arsenic is contained in the form of secondary sulphide precipitates, with iron oxy-hydroxides hosting a minimal amount of arsenic (
PubMed ID
29223820 View in PubMed
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Arsenic mobility and characterization in lakes impacted by gold ore roasting, Yellowknife, NWT, Canada.

https://arctichealth.org/en/permalink/ahliterature292468
Source
Environ Pollut. 2018 Mar; 234:630-641
Publication Type
Journal Article
Date
Mar-2018
Author
Martin D Van Den Berghe
Heather E Jamieson
Michael J Palmer
Author Affiliation
Department of Geological Sciences and Geological Engineering, Queen's University, 36 Union St., Kingston, ON K7L 3N6, Canada; Department of Earth Sciences, University of Southern California, 3651 Trousdale Pkwy, Los Angeles, CA 90089, USA. Electronic address: mdvanden@usc.edu.
Source
Environ Pollut. 2018 Mar; 234:630-641
Date
Mar-2018
Language
English
Publication Type
Journal Article
Keywords
Arsenic - analysis
Arsenicals - analysis
Canada
Environmental monitoring
Geologic Sediments - analysis
Gold
Lakes - analysis
Mining
Oxides - analysis
Water Pollutants, Chemical - analysis
Abstract
The controls on the mobility and fate of arsenic in lakes impacted by historical gold ore roasting in northern Canada have been examined. A detailed characterization of arsenic solid and aqueous phases in lake waters, lake sediments and sediment porewaters as well as surrounding soils was conducted in three small lakes (80 wt%) of arsenic is contained in the form of secondary sulphide precipitates, with iron oxy-hydroxides hosting a minimal amount of arsenic (
PubMed ID
29223820 View in PubMed
Less detail

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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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
Less detail

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
Less detail

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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Effect of letrozole versus placebo on bone mineral density in women with primary breast cancer completing 5 or more years of adjuvant tamoxifen: a companion study to NCIC CTG MA.17.

https://arctichealth.org/en/permalink/ahliterature168439
Source
J Clin Oncol. 2006 Aug 1;24(22):3629-35
Publication Type
Article
Date
Aug-1-2006
Author
Edith A Perez
Robert G Josse
Kathleen I Pritchard
James N Ingle
Silvana Martino
Brian P Findlay
Tamara N Shenkier
Richard G Tozer
Michael J Palmer
Lois E Shepherd
Shifang Liu
Dongsheng Tu
Paul E Goss
Author Affiliation
St Michael's Hospital, Toronto, Canada. perez.edith@mayo.edu
Source
J Clin Oncol. 2006 Aug 1;24(22):3629-35
Date
Aug-1-2006
Language
English
Publication Type
Article
Keywords
Adult
Aged
Aged, 80 and over
Alkaline Phosphatase - blood
Antineoplastic Agents - therapeutic use
Antineoplastic Agents, Hormonal - administration & dosage
Aromatase Inhibitors - therapeutic use
Biological Markers - blood - urine
Bone Density - drug effects
Breast Neoplasms - blood - drug therapy - metabolism
Canada
Chemotherapy, Adjuvant
Collagen Type I - blood - urine
Estrogen Receptor Modulators - administration & dosage
Female
Humans
Middle Aged
Nitriles - therapeutic use
Peptides - blood - urine
Tamoxifen - administration & dosage
Treatment Outcome
Triazoles - therapeutic use
Abstract
Aromatase inhibition depletes estrogen levels and may be associated with accelerated bone resorption. The National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) study MA.17B evaluated bone turnover markers and bone mineral density (BMD) in postmenopausal women randomly assigned to MA.17, a placebo-controlled trial of letrozole after standard adjuvant tamoxifen.
Eligible women had a baseline BMD T score of at least 2.0 in either the hip or L2-4 spine; all received calcium 500 mg and vitamin D 400 U daily. Percentage change in BMD (L2-L4 spine and hip) at 12 and 24 months, rate of osteoporosis, and change in markers of bone formation (serum bone alkaline phosphatase) and resorption (serum C-telopeptide and urine N-telopeptide) at 6, 12, and 24 months were compared.
Two hundred twenty-six patients (122 letrozole, 104 placebo) were enrolled. Baseline characteristics were similar in the two groups, including BMD, median age of 60.7 years (81%
Notes
Comment In: J Clin Oncol. 2007 Apr 10;25(11):1455-617416873
PubMed ID
16822845 View in PubMed
Less detail

Efficacy of letrozole extended adjuvant therapy according to estrogen receptor and progesterone receptor status of the primary tumor: National Cancer Institute of Canada Clinical Trials Group MA.17.

https://arctichealth.org/en/permalink/ahliterature163983
Source
J Clin Oncol. 2007 May 20;25(15):2006-11
Publication Type
Article
Date
May-20-2007
Author
Paul E Goss
James N Ingle
Silvana Martino
Nicholas J Robert
Hyman B Muss
Martine J Piccart
Monica Castiglione
Dongsheng Tu
Lois E Shepherd
Kathleen I Pritchard
Robert B Livingston
Nancy E Davidson
Larry Norton
Edith A Perez
Jeffrey S Abrams
David A Cameron
Michael J Palmer
Joseph L Pater
Author Affiliation
Division of Hematology and Oncology, Massachusetts General Hospital, Boston, MA, USA. pgoss@partners.org
Source
J Clin Oncol. 2007 May 20;25(15):2006-11
Date
May-20-2007
Language
English
Publication Type
Article
Keywords
Antineoplastic Combined Chemotherapy Protocols - therapeutic use
Breast Neoplasms - drug therapy - metabolism - pathology
Canada - epidemiology
Chemotherapy, Adjuvant
Disease-Free Survival
Double-Blind Method
Female
Humans
Middle Aged
Nitriles - administration & dosage
Placebos
Postmenopause
Receptors, Estrogen - metabolism
Receptors, Progesterone - metabolism
Retrospective Studies
Survival Rate
Tamoxifen - administration & dosage
Treatment Outcome
Triazoles - administration & dosage
Abstract
Controversy exists regarding estrogen (ER) and progesterone (PgR) receptor expression on efficacy of adjuvant endocrine therapy. In the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial, the benefit of anastrozole over tamoxifen was substantially greater in ER+/PgR-than ER+/PgR+ tumors. In BIG 1-98 (Breast International Group), the benefits of letrozole over tamoxifen were the same in ER+ tumors irrespective of PgR. MA.17 randomized postmenopausal women after 5 years of tamoxifen, to letrozole or placebo. We present outcomes according to tumor receptor status.
Disease-free survival (DFS) and other outcomes were assessed in subgroups by ER and PgR status using Cox's proportional hazards model, adjusting for nodal status and prior adjuvant chemotherapy.
The DFS hazard ratio (HR) for letrozole versus placebo in ER+/PgR+ tumors (N = 3,809) was 0.49 (95% CI, 0.36 to 0.67) versus 1.21 (95% CI, 0.63 to 2.34) in ER+/PgR-tumors (n = 636). ER+/PgR+ letrozole patients experienced significant benefit in distant DFS (DDFS; HR = 0.53; 95% CI, 0.35 to 0.80) and overall survival (OS; HR = 0.58; 95% CI, 0.37 to 0.90). A statistically significant difference in treatment effect between ER+/PgR+ and ER+/PgR-subgroups for DFS was observed (P = .02), but not for DDFS (P = .06) or OS (P = .09).
These results suggest greater benefit for letrozole in DFS, DDFS, and OS in patients with ER+/PgR+ tumors, implying greater activity of letrozole in tumors with a functional ER. However, because this is a subset analysis and receptors were not measured centrally, we caution against using these results for clinical decision making.
Notes
Comment In: J Clin Oncol. 2007 May 20;25(15):1957-917452674
PubMed ID
17452676 View in PubMed
Less detail

Lacustrine Arcellinina (Testate Amoebae) as Bioindicators of Arsenic Contamination.

https://arctichealth.org/en/permalink/ahliterature271254
Source
Microb Ecol. 2016 Mar 30;
Publication Type
Article
Date
Mar-30-2016
Author
Nawaf A Nasser
R Timothy Patterson
Helen M Roe
Jennifer M Galloway
Hendrik Falck
Michael J Palmer
Christopher Spence
Hamed Sanei
Andrew L Macumber
Lisa A Neville
Source
Microb Ecol. 2016 Mar 30;
Date
Mar-30-2016
Language
English
Publication Type
Article
Abstract
Arcellininids (testate amoebae) were examined from 61 surface sediment samples collected from 59 lakes in the vicinity of former gold mines, notably Giant Mine, near Yellowknife, Northwest Territories, Canada to determine their utility as bioindicators of arsenic (As), which occurs both as a byproduct of gold extraction at mines in the area and ore-bearing outcrops. Cluster analysis (Q-R-mode) and detrended correspondence analysis (DCA) reveal five arcellininid assemblages, three of which are related to varying As concentrations in the sediment samples. Redundancy analysis (RDA) showed that 14 statistically significant environmental parameters explained 57 % of the variation in faunal distribution, while partial RDA indicated that As had the greatest influence on assemblage variance (10.7 %; p??10000 ppm, min?=?16.1 ppm, n?=?32), while difflugiid dominated assemblages were prevalent in substrates with relatively low As concentrations (median?=?30.2 ppm, max?=?905.2 ppm, min?=?6.3 ppm, n?=?20). Most of the lakes with very high As levels are located downwind (N and W) of the former Giant Mine roaster stack where refractory ore was roasted and substantial quantities of As were released (as As2O3) to the atmosphere in the first decade of mining. This spatial pattern suggests that a significant proportion of the observed As, in at least these lakes, are industrially derived. The results of this study highlight the sensitivity of Arcellinina to As and confirm that the group has considerable potential for assessing the impact of As contamination on lakes.
PubMed ID
27026100 View in PubMed
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Mineralogical, geospatial, and statistical methods combined to estimate geochemical background of arsenic in soils for an area impacted by legacy mining pollution.

https://arctichealth.org/en/permalink/ahliterature303593
Source
Sci Total Environ. 2021 Feb 18; 776:145926
Publication Type
Journal Article
Date
Feb-18-2021
Author
Michael J Palmer
Heather E Jamieson
Anežka Borcinová Radková
Kirsten Maitland
Jon Oliver
Hendrik Falck
Murray Richardson
Author Affiliation
North Slave Research Centre, Aurora Research Institute, Aurora College, Yellowknife X1A 2R3, Canada; Department of Geography and Environmental Studies, Carleton University, Ottawa K1S 5B6, Canada. Electronic address: mpalmer@auroracollege.nt.ca.
Source
Sci Total Environ. 2021 Feb 18; 776:145926
Date
Feb-18-2021
Language
English
Publication Type
Journal Article
Abstract
The estimation of geochemical background is complex in areas impacted by point sources of atmospheric emissions due to unknowns about pollutant dispersion, persistence of pollutants on the landscape, and natural concentrations of elements associated with parent material. This study combined mineralogical analysis with conventional statistical and geospatial methods to separate anthropogenically impacted soils from unimpacted soils in the Yellowknife area, Northwest Territories, Canada, a region that was exposed to 60 years of arsenic (As)-rich atmospheric mining emissions (1938-1999) and that hosts natural enrichments of As. High concentrations of As (up to 4700 mg kg-1) were measured in publicly accessible soils near decommissioned roaster stacks in the region and strong relationships between As and distance from the main emission sources persisted in surface soils and soils at depth in the soil profile more than 60 years after the bulk of mining emissions were released. Mineralogical analysis provided unambiguous evidence regarding the source of As minerals and highlighted that most As in surface soils within 15 km of Yellowknife is hosted as anthropogenic arsenic trioxide (As2O3), produced by roaster stack emissions. Statistical protocols for the estimation of geochemical background were applied to an existing database of till geochemistry (N = 1490) after removing samples from mining impacted areas. Results suggested geochemical background for the region is 0.25-15 mg kg-1 As, comparable to global averages, with upper thresholds elevated in volcanic units (30 mg kg-1 As) that often host sulfide mineralization in greenstone belts in the region.
PubMed ID
33652309 View in PubMed
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13 records – page 1 of 2.