Iain Grant-Weaver | University of Alberta (original) (raw)
Papers by Iain Grant-Weaver
EGU General Assembly Conference Abstracts, Apr 1, 2019
Journal of Hydrology: Regional Studies, 2022
<p><em>Sphagnum</em> mosses hav... more <p><em>Sphagnum</em> mosses have been used in some of the earliest works in biomonitoring of atmospheric deposition of trace elements (TEs). Since their adoption into the field the Sphagnaceae have become one of the foremost biomonitors. When taken as contemporary samples, these mosses have allowed us to identify spatial variations as well as trends and major changes in atmospheric deposition due to changing policy, technology, industry, and land use. While long term monitoring programs, such as the European Moss Survey, allow us to track these changes through time, these ongoing studies only reach as far back as their start dates. In the case of the European Moss Survey this was 1990. The use of materials already collected and archived in herbaria provides a low-cost method for retrospective analysis of atmospheric deposition of TEs. The critical advantage of herbarium specimens over other historical monitoring method is their high temporal resolution, as their exact collection date is known. Once collected, stored, and protected from atmospheric dust, the concentrations of non-volatile TEs present remain effectively unchanged. The oldest herbarium records can predate industrialisation, but most have records from the beginning of industrialisation, with the frequency of collection increasing in the modern era. Using only the top 2 cm of herbarium specimens of<em> Sphagnum</em> mosses (<em>S. fuscum, S. angustifolium, S. capillifolium, S. magellanicum</em>) found in Canadian ombrotrophic bogs, we will be creating historical reconstructions of atmospheric deposition in northern Alberta since the 1940s and southern Ontario since 1860’s. The first objective is to determine how best to balance preservation of the limited herbarium material available while also using sufficient material to achieve suitable levels of analytical accuracy. As TE analyses using ICP-MS are destructive and some specimens have immeasurable value from a natural history perspective, as little material as possible should be taken for analysis. Grinding of the sample was avoided, to minimize sample loss and the risk of contamination. We compared the measured concentrations obtained with ICP-MS as a function of the mass of <em>Sphagnum</em> digested, using selected herbarium samples as well as two certified, Standard Reference Materials (NIST 1515 and HB36-M2). These analyses allow us to determine the optimal amount of material necessary to balance the analytical accuracy and preservation of material of 4 species of <em>Sphagnum</em> mosses from Alberta over the last 80 years. The results will be compared with the data already available for TE concentrations in age-dated peat cores from the same region.</p>
Ombrotrophic peatlands: natural, holistic, integrated, long-term monitoring systems for atmospher... more Ombrotrophic peatlands: natural, holistic, integrated, long-term monitoring systems for atmospheric deposition of environmental contaminants to terrestrial and aquatic ecosystems William Shotyk1, Fiorella Barraza1, Rene Belland, Sundas Butt1, Na Chen1, Kevin Devito2, Chad Cuss 1 , Jacqueline Dennett 1 , Lukas Frost 1 , Iain Grant-Weaver 1 , Muhammad Javed 1 , Scott Nielsen 1 , Tommy Noernberg 1 , and Andrii Oleksandrenko 1
Goldschmidt2021 abstracts, 2021
Goldschmidt2021 abstracts, 2021
Environment International, 2022
Fort McMurray and the Athabasca oil sands region (AOSR) experienced major wildfires in 2016, but ... more Fort McMurray and the Athabasca oil sands region (AOSR) experienced major wildfires in 2016, but the impact of these on regional deposition of polycyclic aromatic hydrocarbons (PAHs) and trace elements has not been reported nor compared to industrial sources of these pollutants in the region. Living moss (Sphagnum fuscum) was collected in triplicate from five ombrotrophic bogs in the AOSR after the wildfires, and analyzed for PAHs and trace elements. These post-wildfire data were compared to data from previous years at the same sites, and also to remote reference bogs in Alberta and Ontario. Elevated post-wildfire concentrations and flux of naphthalene and fluorene were observed at all five bogs in the AOSR, but no consistent trend was evident for higher molecular weight PAHs or the sum of priority PAHs (∑13PAH). Trace elements at most AOSR bogs were not elevated post-wildfire, except at one bog in the burned area (MIL), but even here the elements that were increased (1.7-5.6 × ) were likely of bitumen-origin (i.e., V, Ni, Se, Mo and Re). Significant post-wildfire correlations between PAHs and most trace elements suggested a common source, and few significant correlations were observed with retene, suggesting that wildfires were not the dominant source of most contaminants detected. Mass balance receptor models were used to apportion sources, indicating that the major sources of trace elements among five AOSR bogs post-wildfire were oil sands ore (mean 42%), haul road dust (17%), and petcoke (11%), whereas wildfire was always a minor source (3-4%). For PAHs at the most contaminated site (MIL), delayed petcoke (27%) and wildfire (25%) were the major sources, but the contribution of wildfire to PAHs at other sites was less or not discernable. Impacts of the 2016 wildfires on regional atmospheric deposition of major pollutants was less than from ongoing deposition of anthropogenic dust from oil sands activities.
Journal of Hydrology, 2020
Abstract Boreal river systems globally provide specialized habitats and conduits for the transfer... more Abstract Boreal river systems globally provide specialized habitats and conduits for the transfer of nutrients, iron and trace elements (TEs) from wetlands and groundwaters to lakes and oceans. Many large boreal rivers are also the site of controversy due to their dual purpose providing ecosystem services for Indigenous peoples and supporting industrial activity; however, water quality monitoring in these systems is more complex than realized. This work demonstrates the impacts of delayed tributary mixing in a typical large boreal river on the properties and transport of Fe-bearing colloids, and water quality monitoring, in two subsequent autumns. The forms and concentrations of Fe colloids were conserved through the mixing zone for more than 100 km, despite salinity changes. Delayed mixing for ca. 60–80 and more than 100 km led to TE concentration differences of more than five-fold across the river. Using traditional samples from the middle of the river, the coincidence of mixing zones with areas of potential industrial impact obscured the potential contributions of some TEs, and caused the erroneous attribution of other TEs to industry at concentrations that were double upstream values. Adequate water quality monitoring and source attribution in large boreal rivers thus requires high-resolution spatial sampling, both across the river and upstream–downstream of potential natural and industrial sources. Since mixing behavior and water quality in large boreal rivers are highly sensitive to hydrologic changes such as seasonal fluctuations, drought/floods, and climate change, fluctuations in water quality and associated mixing behaviours render traditional monitoring approaches unsuitable.
Science of The Total Environment, 2018
Approximately 1/3 of elements analysed in otolith were below limits of detection. • Cu, Li and Pb... more Approximately 1/3 of elements analysed in otolith were below limits of detection. • Cu, Li and Pb differed among Lower Athabasca Region locations. • Patterns of variation did not support impacts of industrial footprint. • Differences between Alberta and Ontario otoliths likely reflect geology.
Analytical Chemistry, 2017
The smallest colloids exert a disproportionately large influence on colloidal systems owing to 12... more The smallest colloids exert a disproportionately large influence on colloidal systems owing to 12 their greater surface area; however, the challenges of working in the smaller size range have limited most field-flow fractionation-ICPMS analyses to sizes > ca. 1 kDa. We discuss 14 considerations and present solutions for overcoming these challenges, including: high pressures 15 associated with using the 300-Da membrane, calibration in this small size range, accounting for 16 drifting LODs and separation conditions during membrane aging, and optimizing the 17 compromise between resolution and recovery. Necessary flow program ranges for observing 18 pressure limits are discussed, and calibration is conducted using a combination of chemical and 19 polystyrene size standards. The impact of membrane drift on size is demonstrated, and 20 effectively corrected by routine calibration. Separation conditions are optimized by monitoring 21 the recovery and resolution of several trace metals. A precise, high-resolution separation is 22 achieved using fractogram deconvolution to fully resolve overlapping peaks. Method 23 effectiveness and precision are demonstrated through triplicate analyses of three natural water 24 samples: M p = 2.89 ± 0.04, 3.20 ± 0.03, and 3.50 ± 0.12 kDa for DOM-associated Fe in the three 25 samples (± 95% CI). A primarily inorganic Fe fraction with M p = 14.7 ± 0.5 kDa was also 26 resolved from the DOM-associated fraction. Quality control methods and considerations for 27 optimizing flow conditions are detailed in the supplementary information as a guide for 28 researchers seeking to analyze colloids in this smallest size range using AF4-ICPMS with the 29 300-Da membrane.
Fuel, 2017
Abstract There is on-going concern regarding fugitive emissions of trace elements from mining and... more Abstract There is on-going concern regarding fugitive emissions of trace elements from mining and upgrading of the Athabasca Bituminous Sands (ABS) in northern Alberta, Canada, but remarkably few quantitative elemental data about the resource itself exists. By exploring advances in analytical techniques, an inductively coupled plasma sector field mass spectrometry (ICP-SFMS) method was developed for the determination of trace and ultratrace amounts ( 3 -HBF 4 yielded good recoveries (100 ± 20%) for Ag, As, Be, Bi, Cd, Mo, Ni, Pb, Re, Sb, Tl and V in certified reference materials (NIST 1635, NIST 2711). The distribution of elements within the ABS was dichotomous, with V, Ni, Mo and Re predominantly found in the organic fraction (bitumen) and Ag, As, Be, Bi, Cd, Pb, Sb, and Tl predominantly found in the mineral residue. Trace amounts of As and Pb (0.1–2.0 mg/kg), plus ultratrace amounts of Ag, Bi, Cd, Sb and Tl (
Scientific reports, Jan 6, 2017
Lead (Pb) is a metal of special importance because of its long history of commercial and industri... more Lead (Pb) is a metal of special importance because of its long history of commercial and industrial use, global atmospheric contamination accelerated by the use of gasoline additives, and health effects, with children being especially vulnerable. Global atmospheric Pb pollution reached its zenith in the 1970's, but subsequent impacts on freshwater aquatic systems are poorly understood. Employing metal-free sampling and handling protocols, we show that snowmelt from the Athabasca bituminous sands region is an insignificant source of dissolved Pb to the Athabasca River (AR). Total Pb in the AR is low, and almost entirely in particulate form. Lead in the suspended solids in the AR exactly follows thorium (Th), a conservative lithophile element, and a linear regression of Pb against Th (Pb = 1.6 × Th + 0.0; R(2) = 0.99) yields a slope identical to the Pb/Th ratio in the Upper Continental Crust. In the "dissolved" fraction, the Pb/Th ratio is equivalent to that of deep, ope...
Geophysical Research Letters, 2016
Peat cores were collected from six bogs in northern Alberta to reconstruct changes in the atmosph... more Peat cores were collected from six bogs in northern Alberta to reconstruct changes in the atmospheric deposition of Pb, a valuable tracer of human activities. In each profile, the maximum Pb enrichment is found well below the surface. Radiometric age dating using three independent approaches (14 C measurements of plant macrofossils combined with the atmospheric bomb pulse curve, plus 210 Pb confirmed using the fallout radionuclides 137 Cs and 241 Am) showed that Pb contamination has been in decline for decades. Today, the surface layers of these bogs are comparable in composition to the "cleanest" peat samples ever found in the Northern Hemisphere, from a Swiss bog~6000 to 9000 years old. The lack of contemporary Pb contamination in the Alberta bogs is testimony to successful international efforts of the past decades to reduce anthropogenic emissions of this potentially toxic metal to the atmosphere.
Development of the oil sands industry in northern Alberta has raised legitimate concerns about po... more Development of the oil sands industry in northern Alberta has raised legitimate concerns about pollution and disruption of existing ecosystems. Contaminants may be released to the environment during mining, transporting and upgrading of bituminous sands, or through the generation of by‐ products, either solid (coke) or liquid (process water). In respect to potentially toxic heavy metals such as Ag, Cd, Pb, Sb and Tl, much attention has been placed on the study of receptors, but very little attention has been paid to the sources. While natural, geochemical enrichments of V, Ni and Mo in bitumen have been well known for decades, much less is known about the abundance of heavy metals. As a first step to better understand the abundance and occurrence of these elements, samples of bituminous sand were collected from the banks of the McKay River and the Athabasca River (where it receives the Pierre River). Organic and mineral phases were separated using mass spectrometry grade organic sol...
Environmental Science: Atmospheres, 2022
A robust sample handling, processing and analytical method was developed for reliable determinati... more A robust sample handling, processing and analytical method was developed for reliable determination of 40 TEs in dusty snow. The “dissolved” TEs in snow from the ABS region were extremely low, and TEs were almost exclusively found in the particulate fraction.
The Science of the total environment, Jan 16, 2016
Water samples were collected on the Athabasca River (AR), upstream and downstream from bitumen mi... more Water samples were collected on the Athabasca River (AR), upstream and downstream from bitumen mines and upgrading facilities, to identify changes in water quality due to industrial activities in this region of northern Alberta, Canada. Starting upstream of Fort McMurray and proceeding downstream ca. 100km, waters were collected in duplicate at 13 locations on the main stem of the river, as well as 5 tributary streams, using ultraclean sampling protocols developed for polar snow and ice. To estimate potential bioaccessibility, trace elements of concern (Ag, Cd, Pb, Sb, Tl) were determined in the dissolved fraction (<0.45μm) along with metals known for their enrichments in bitumen (V, Ni, Mo, Re) and those found mainly in ionic (Li, Sr) or colloidal forms (Al, Co, Cr, Fe, Ga, Mn, Th, Y). Analyses were performed in the metal-free, ultraclean SWAMP lab using quadrupole and sector-field ICP-MS. Concentrations of Ag, Cd, Pb, Sb and Tl were extremely low, not significantly more abundan...
Science of The Total Environment, 2018
Measured distribution of 18 trace elements (TE) in organic & inorganic colloids using AF4-ICPMS •... more Measured distribution of 18 trace elements (TE) in organic & inorganic colloids using AF4-ICPMS • TE distribution in main river (flow 565 m 3 s −1) different from tributaries (Σ flows = 37.9 m 3 s −1) • Distributions of TE in colloids increasingly resemble tributary inputs from up-downstream.
Cadmium (Cd) is a potentially toxic chalcophile element with profound health consequences when or... more Cadmium (Cd) is a potentially toxic chalcophile element with profound health consequences when organisms are exposed to elevated concentrations. Cadmium is emitted to the atmosphere through various industrial processes (metallurgical smelting, coal combustion), but it is also derived from natural sources (volcanic emissions, wind-borne soil particles). In contemporary air samples collected within urban areas across the globe, Cd enrichment factors (EF) relative to the Upper Continental Crust (UCC) are often up to 100, and are typically interpreted as reflecting inputs exclusively from anthropogenic activities.
2 Contamination by Trace Metals in the Athabasca Bituminous Sands 3 Region 4 William Shotyk,*,† P... more 2 Contamination by Trace Metals in the Athabasca Bituminous Sands 3 Region 4 William Shotyk,*,† Peter G Appleby,‡ Beatriz Bicalho,† Lauren Davies, Duane Froese, 5 Iain Grant-Weaver,† Gabriel Magnan, Gillian Mullan-Boudreau,† Tommy Noernberg,† Rick Pelletier,† 6 Bob Shannon, Simon van Bellen, and Claudio Zaccone 7 †Department of Renewable Resources, University of Alberta, 348B South Academic Building, Edmonton, Alberta T6G 2H1 Canada 8 ‡Department of Mathematical Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom 9 Department of Earth and Atmospheric Sciences, University of Alberta Edmonton, Alberta T6G 2E3 Canada 10 Deṕartement de Geógraphie, Universite ́ du Queb́ec a ̀ Montreál Montreál, Queb́ec H2 V 2B8 Canada 11 Quality Radioanalytical Support, LLC, 123 Cougar Trail, PO Box 774 Grand Marais, Minnesota 55604 United States 12 Department of the Sciences of Agriculture, Food and Environment, University of Foggia Via Napoli, 71122 Foggia Italy
EGU General Assembly Conference Abstracts, Apr 1, 2019
Journal of Hydrology: Regional Studies, 2022
&lt;p&gt;&lt;em&gt;Sphagnum&lt;/em&gt; mosses hav... more &lt;p&gt;&lt;em&gt;Sphagnum&lt;/em&gt; mosses have been used in some of the earliest works in biomonitoring of atmospheric deposition of trace elements (TEs). Since their adoption into the field the Sphagnaceae have become one of the foremost biomonitors. When taken as contemporary samples, these mosses have allowed us to identify spatial variations as well as trends and major changes in atmospheric deposition due to changing policy, technology, industry, and land use. While long term monitoring programs, such as the European Moss Survey, allow us to track these changes through time, these ongoing studies only reach as far back as their start dates. In the case of the European Moss Survey this was 1990. The use of materials already collected and archived in herbaria provides a low-cost method for retrospective analysis of atmospheric deposition of TEs. The critical advantage of herbarium specimens over other historical monitoring method is their high temporal resolution, as their exact collection date is known. Once collected, stored, and protected from atmospheric dust, the concentrations of non-volatile TEs present remain effectively unchanged. The oldest herbarium records can predate industrialisation, but most have records from the beginning of industrialisation, with the frequency of collection increasing in the modern era. Using only the top 2 cm of herbarium specimens of&lt;em&gt; Sphagnum&lt;/em&gt; mosses (&lt;em&gt;S. fuscum, S. angustifolium, S. capillifolium, S. magellanicum&lt;/em&gt;) found in Canadian ombrotrophic bogs, we will be creating historical reconstructions of atmospheric deposition in northern Alberta since the 1940s and southern Ontario since 1860&amp;#8217;s. The first objective is to determine how best to balance preservation of the limited herbarium material available while also using sufficient material to achieve suitable levels of analytical accuracy. As TE analyses using ICP-MS are destructive and some specimens have immeasurable value from a natural history perspective, as little material as possible should be taken for analysis. Grinding of the sample was avoided, to minimize sample loss and the risk of contamination. We compared the measured concentrations obtained with ICP-MS as a function of the mass of &lt;em&gt;Sphagnum&lt;/em&gt; digested, using selected herbarium samples as well as two certified, Standard Reference Materials (NIST 1515 and HB36-M2). These analyses allow us to determine the optimal amount of material necessary to balance the analytical accuracy and preservation of material of 4 species of &lt;em&gt;Sphagnum&lt;/em&gt; mosses from Alberta over the last 80 years. The results will be compared with the data already available for TE concentrations in age-dated peat cores from the same region.&lt;/p&gt;
Ombrotrophic peatlands: natural, holistic, integrated, long-term monitoring systems for atmospher... more Ombrotrophic peatlands: natural, holistic, integrated, long-term monitoring systems for atmospheric deposition of environmental contaminants to terrestrial and aquatic ecosystems William Shotyk1, Fiorella Barraza1, Rene Belland, Sundas Butt1, Na Chen1, Kevin Devito2, Chad Cuss 1 , Jacqueline Dennett 1 , Lukas Frost 1 , Iain Grant-Weaver 1 , Muhammad Javed 1 , Scott Nielsen 1 , Tommy Noernberg 1 , and Andrii Oleksandrenko 1
Goldschmidt2021 abstracts, 2021
Goldschmidt2021 abstracts, 2021
Environment International, 2022
Fort McMurray and the Athabasca oil sands region (AOSR) experienced major wildfires in 2016, but ... more Fort McMurray and the Athabasca oil sands region (AOSR) experienced major wildfires in 2016, but the impact of these on regional deposition of polycyclic aromatic hydrocarbons (PAHs) and trace elements has not been reported nor compared to industrial sources of these pollutants in the region. Living moss (Sphagnum fuscum) was collected in triplicate from five ombrotrophic bogs in the AOSR after the wildfires, and analyzed for PAHs and trace elements. These post-wildfire data were compared to data from previous years at the same sites, and also to remote reference bogs in Alberta and Ontario. Elevated post-wildfire concentrations and flux of naphthalene and fluorene were observed at all five bogs in the AOSR, but no consistent trend was evident for higher molecular weight PAHs or the sum of priority PAHs (∑13PAH). Trace elements at most AOSR bogs were not elevated post-wildfire, except at one bog in the burned area (MIL), but even here the elements that were increased (1.7-5.6 × ) were likely of bitumen-origin (i.e., V, Ni, Se, Mo and Re). Significant post-wildfire correlations between PAHs and most trace elements suggested a common source, and few significant correlations were observed with retene, suggesting that wildfires were not the dominant source of most contaminants detected. Mass balance receptor models were used to apportion sources, indicating that the major sources of trace elements among five AOSR bogs post-wildfire were oil sands ore (mean 42%), haul road dust (17%), and petcoke (11%), whereas wildfire was always a minor source (3-4%). For PAHs at the most contaminated site (MIL), delayed petcoke (27%) and wildfire (25%) were the major sources, but the contribution of wildfire to PAHs at other sites was less or not discernable. Impacts of the 2016 wildfires on regional atmospheric deposition of major pollutants was less than from ongoing deposition of anthropogenic dust from oil sands activities.
Journal of Hydrology, 2020
Abstract Boreal river systems globally provide specialized habitats and conduits for the transfer... more Abstract Boreal river systems globally provide specialized habitats and conduits for the transfer of nutrients, iron and trace elements (TEs) from wetlands and groundwaters to lakes and oceans. Many large boreal rivers are also the site of controversy due to their dual purpose providing ecosystem services for Indigenous peoples and supporting industrial activity; however, water quality monitoring in these systems is more complex than realized. This work demonstrates the impacts of delayed tributary mixing in a typical large boreal river on the properties and transport of Fe-bearing colloids, and water quality monitoring, in two subsequent autumns. The forms and concentrations of Fe colloids were conserved through the mixing zone for more than 100 km, despite salinity changes. Delayed mixing for ca. 60–80 and more than 100 km led to TE concentration differences of more than five-fold across the river. Using traditional samples from the middle of the river, the coincidence of mixing zones with areas of potential industrial impact obscured the potential contributions of some TEs, and caused the erroneous attribution of other TEs to industry at concentrations that were double upstream values. Adequate water quality monitoring and source attribution in large boreal rivers thus requires high-resolution spatial sampling, both across the river and upstream–downstream of potential natural and industrial sources. Since mixing behavior and water quality in large boreal rivers are highly sensitive to hydrologic changes such as seasonal fluctuations, drought/floods, and climate change, fluctuations in water quality and associated mixing behaviours render traditional monitoring approaches unsuitable.
Science of The Total Environment, 2018
Approximately 1/3 of elements analysed in otolith were below limits of detection. • Cu, Li and Pb... more Approximately 1/3 of elements analysed in otolith were below limits of detection. • Cu, Li and Pb differed among Lower Athabasca Region locations. • Patterns of variation did not support impacts of industrial footprint. • Differences between Alberta and Ontario otoliths likely reflect geology.
Analytical Chemistry, 2017
The smallest colloids exert a disproportionately large influence on colloidal systems owing to 12... more The smallest colloids exert a disproportionately large influence on colloidal systems owing to 12 their greater surface area; however, the challenges of working in the smaller size range have limited most field-flow fractionation-ICPMS analyses to sizes > ca. 1 kDa. We discuss 14 considerations and present solutions for overcoming these challenges, including: high pressures 15 associated with using the 300-Da membrane, calibration in this small size range, accounting for 16 drifting LODs and separation conditions during membrane aging, and optimizing the 17 compromise between resolution and recovery. Necessary flow program ranges for observing 18 pressure limits are discussed, and calibration is conducted using a combination of chemical and 19 polystyrene size standards. The impact of membrane drift on size is demonstrated, and 20 effectively corrected by routine calibration. Separation conditions are optimized by monitoring 21 the recovery and resolution of several trace metals. A precise, high-resolution separation is 22 achieved using fractogram deconvolution to fully resolve overlapping peaks. Method 23 effectiveness and precision are demonstrated through triplicate analyses of three natural water 24 samples: M p = 2.89 ± 0.04, 3.20 ± 0.03, and 3.50 ± 0.12 kDa for DOM-associated Fe in the three 25 samples (± 95% CI). A primarily inorganic Fe fraction with M p = 14.7 ± 0.5 kDa was also 26 resolved from the DOM-associated fraction. Quality control methods and considerations for 27 optimizing flow conditions are detailed in the supplementary information as a guide for 28 researchers seeking to analyze colloids in this smallest size range using AF4-ICPMS with the 29 300-Da membrane.
Fuel, 2017
Abstract There is on-going concern regarding fugitive emissions of trace elements from mining and... more Abstract There is on-going concern regarding fugitive emissions of trace elements from mining and upgrading of the Athabasca Bituminous Sands (ABS) in northern Alberta, Canada, but remarkably few quantitative elemental data about the resource itself exists. By exploring advances in analytical techniques, an inductively coupled plasma sector field mass spectrometry (ICP-SFMS) method was developed for the determination of trace and ultratrace amounts ( 3 -HBF 4 yielded good recoveries (100 ± 20%) for Ag, As, Be, Bi, Cd, Mo, Ni, Pb, Re, Sb, Tl and V in certified reference materials (NIST 1635, NIST 2711). The distribution of elements within the ABS was dichotomous, with V, Ni, Mo and Re predominantly found in the organic fraction (bitumen) and Ag, As, Be, Bi, Cd, Pb, Sb, and Tl predominantly found in the mineral residue. Trace amounts of As and Pb (0.1–2.0 mg/kg), plus ultratrace amounts of Ag, Bi, Cd, Sb and Tl (
Scientific reports, Jan 6, 2017
Lead (Pb) is a metal of special importance because of its long history of commercial and industri... more Lead (Pb) is a metal of special importance because of its long history of commercial and industrial use, global atmospheric contamination accelerated by the use of gasoline additives, and health effects, with children being especially vulnerable. Global atmospheric Pb pollution reached its zenith in the 1970's, but subsequent impacts on freshwater aquatic systems are poorly understood. Employing metal-free sampling and handling protocols, we show that snowmelt from the Athabasca bituminous sands region is an insignificant source of dissolved Pb to the Athabasca River (AR). Total Pb in the AR is low, and almost entirely in particulate form. Lead in the suspended solids in the AR exactly follows thorium (Th), a conservative lithophile element, and a linear regression of Pb against Th (Pb = 1.6 × Th + 0.0; R(2) = 0.99) yields a slope identical to the Pb/Th ratio in the Upper Continental Crust. In the "dissolved" fraction, the Pb/Th ratio is equivalent to that of deep, ope...
Geophysical Research Letters, 2016
Peat cores were collected from six bogs in northern Alberta to reconstruct changes in the atmosph... more Peat cores were collected from six bogs in northern Alberta to reconstruct changes in the atmospheric deposition of Pb, a valuable tracer of human activities. In each profile, the maximum Pb enrichment is found well below the surface. Radiometric age dating using three independent approaches (14 C measurements of plant macrofossils combined with the atmospheric bomb pulse curve, plus 210 Pb confirmed using the fallout radionuclides 137 Cs and 241 Am) showed that Pb contamination has been in decline for decades. Today, the surface layers of these bogs are comparable in composition to the "cleanest" peat samples ever found in the Northern Hemisphere, from a Swiss bog~6000 to 9000 years old. The lack of contemporary Pb contamination in the Alberta bogs is testimony to successful international efforts of the past decades to reduce anthropogenic emissions of this potentially toxic metal to the atmosphere.
Development of the oil sands industry in northern Alberta has raised legitimate concerns about po... more Development of the oil sands industry in northern Alberta has raised legitimate concerns about pollution and disruption of existing ecosystems. Contaminants may be released to the environment during mining, transporting and upgrading of bituminous sands, or through the generation of by‐ products, either solid (coke) or liquid (process water). In respect to potentially toxic heavy metals such as Ag, Cd, Pb, Sb and Tl, much attention has been placed on the study of receptors, but very little attention has been paid to the sources. While natural, geochemical enrichments of V, Ni and Mo in bitumen have been well known for decades, much less is known about the abundance of heavy metals. As a first step to better understand the abundance and occurrence of these elements, samples of bituminous sand were collected from the banks of the McKay River and the Athabasca River (where it receives the Pierre River). Organic and mineral phases were separated using mass spectrometry grade organic sol...
Environmental Science: Atmospheres, 2022
A robust sample handling, processing and analytical method was developed for reliable determinati... more A robust sample handling, processing and analytical method was developed for reliable determination of 40 TEs in dusty snow. The “dissolved” TEs in snow from the ABS region were extremely low, and TEs were almost exclusively found in the particulate fraction.
The Science of the total environment, Jan 16, 2016
Water samples were collected on the Athabasca River (AR), upstream and downstream from bitumen mi... more Water samples were collected on the Athabasca River (AR), upstream and downstream from bitumen mines and upgrading facilities, to identify changes in water quality due to industrial activities in this region of northern Alberta, Canada. Starting upstream of Fort McMurray and proceeding downstream ca. 100km, waters were collected in duplicate at 13 locations on the main stem of the river, as well as 5 tributary streams, using ultraclean sampling protocols developed for polar snow and ice. To estimate potential bioaccessibility, trace elements of concern (Ag, Cd, Pb, Sb, Tl) were determined in the dissolved fraction (<0.45μm) along with metals known for their enrichments in bitumen (V, Ni, Mo, Re) and those found mainly in ionic (Li, Sr) or colloidal forms (Al, Co, Cr, Fe, Ga, Mn, Th, Y). Analyses were performed in the metal-free, ultraclean SWAMP lab using quadrupole and sector-field ICP-MS. Concentrations of Ag, Cd, Pb, Sb and Tl were extremely low, not significantly more abundan...
Science of The Total Environment, 2018
Measured distribution of 18 trace elements (TE) in organic & inorganic colloids using AF4-ICPMS •... more Measured distribution of 18 trace elements (TE) in organic & inorganic colloids using AF4-ICPMS • TE distribution in main river (flow 565 m 3 s −1) different from tributaries (Σ flows = 37.9 m 3 s −1) • Distributions of TE in colloids increasingly resemble tributary inputs from up-downstream.
Cadmium (Cd) is a potentially toxic chalcophile element with profound health consequences when or... more Cadmium (Cd) is a potentially toxic chalcophile element with profound health consequences when organisms are exposed to elevated concentrations. Cadmium is emitted to the atmosphere through various industrial processes (metallurgical smelting, coal combustion), but it is also derived from natural sources (volcanic emissions, wind-borne soil particles). In contemporary air samples collected within urban areas across the globe, Cd enrichment factors (EF) relative to the Upper Continental Crust (UCC) are often up to 100, and are typically interpreted as reflecting inputs exclusively from anthropogenic activities.
2 Contamination by Trace Metals in the Athabasca Bituminous Sands 3 Region 4 William Shotyk,*,† P... more 2 Contamination by Trace Metals in the Athabasca Bituminous Sands 3 Region 4 William Shotyk,*,† Peter G Appleby,‡ Beatriz Bicalho,† Lauren Davies, Duane Froese, 5 Iain Grant-Weaver,† Gabriel Magnan, Gillian Mullan-Boudreau,† Tommy Noernberg,† Rick Pelletier,† 6 Bob Shannon, Simon van Bellen, and Claudio Zaccone 7 †Department of Renewable Resources, University of Alberta, 348B South Academic Building, Edmonton, Alberta T6G 2H1 Canada 8 ‡Department of Mathematical Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom 9 Department of Earth and Atmospheric Sciences, University of Alberta Edmonton, Alberta T6G 2E3 Canada 10 Deṕartement de Geógraphie, Universite ́ du Queb́ec a ̀ Montreál Montreál, Queb́ec H2 V 2B8 Canada 11 Quality Radioanalytical Support, LLC, 123 Cougar Trail, PO Box 774 Grand Marais, Minnesota 55604 United States 12 Department of the Sciences of Agriculture, Food and Environment, University of Foggia Via Napoli, 71122 Foggia Italy