Jason M E Ahad

Jason M E Ahad
Natural Resources Canada | NRCan · Geological Survey of Canada

About

60
Publications
8,350
Reads
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1,919
Citations
Additional affiliations
December 2008 - present
Natural Resources Canada
Position
  • Geological Survey of Canada
September 2007 - December 2008
McMaster University
September 2006 - September 2007
Queen's University Belfast
Education
October 2001 - January 2005
The University of Edinburgh
Field of study
  • Geochemistry
September 1997 - January 2000
University of Toronto
Field of study
  • Geology / Geochemistry
September 1993 - May 1997
University of Ottawa
Field of study
  • Geology

Publications

Publications (60)
Article
Full-text available
Mercury (Hg) is a pollutant of concern across Canada and transboundary anthropogenic Hg sources presently account for over 95% of national anthropogenic Hg deposition. This study applies novel statistical analyses of 82 high-resolution dated lake sediment cores collected from 19 regions across Canada, including nearby point sources and in remote re...
Article
Full-text available
Fugitive dust associated with surface mining activities is one of the principal vectors for transport of airborne contaminants in Canada's Athabasca oil sands region (AOSR). Effective environmental management requires quantitative identification of the sources of this dust. Using natural abundance radiocarbon (Δ14C) and dual (δ13C, δ2H) compound-sp...
Article
Full-text available
A wide variety of sampling techniques and strategies are needed to analyze polycyclic aromatic compounds (PACs) and interpret their distributions in various environmental media (i.e., air, water, snow, soils, sediments, peat, and biological material). In this review, we provide a summary of commonly employed sampling methods and strategies, as well...
Article
Tree cores and bark were sampled from jack pine trees at 18 sites in the Athabasca Oil Sands Region (AOSR) of Alberta, Canada, to investigate spatial and temporal trends of polycyclic aromatic compounds (PACs). Spatial trends were investigated in the bark samples, where ΣPAC concentrations ranged from 75 to 3615 ng/g. Highest concentrations were ob...
Article
Full-text available
Purpose The aim of this work was to identify and analyze the records of flood-drought cycles as preserved in the sediments of the Notwane reservoir, southern Botswana, in order to better understand how extreme events affect water and sediment quality. This work represents the first attempt to study the reservoir sediments in arid to semi-arid envir...
Article
Full-text available
Distinguishing between naphthenic acids (NAs) associated with oil sands process-affected water (OSPW) and those found naturally in groundwaters in contact with the bituminous McMurray Formation poses a considerable analytical challenge to environmental research in Canada’s oil sands region. Previous work addressing this problem combined high-resolu...
Article
Full-text available
The objective of this study was to advance analytical methods for detecting oil sands process-affected water (OSPW) seepage from mining containments and discriminating any such seepage from the natural bitumen background in groundwaters influenced by the Alberta McMurray formation. Improved sampling methods and quantitative analyses of two groups o...
Article
In the last decade, production of shale gas has tremendously increased, and the need for local pre-exploitation baseline data on dissolved natural gas in aquifers has been stressed. This study investigated the origin of hydrocarbons naturally present in shallow aquifers of the Saint-Édouard area (Québec, eastern Canada), where the underlying Utica...
Article
Potential impacts of shale gas development on shallow aquifers has raised concerns, especially regarding groundwater contamination. The intermediate zone separating shallow aquifers from shale gas reservoirs plays a critical role in aquifer vulnerability to fluid upflow, but the assessment of such vulnerability is challenging due to the general pau...
Article
Full-text available
Previous characterization of a low permeability (10−16 ≤ Kh ≤ 10−12 m s−1) and high salinity (> 5 M of Cl−, > 10× seawater salinity) aquiclude, in Upper Ordovician-aged sediments situated on the eastern flank of the Michigan Basin, where a deep geological repository for low and intermediate level nuclear waste is proposed, suggested a microbial ori...
Article
Full-text available
This air synthesis review presents the current state of knowledge on the sources, fate and effects for polycyclic aromatic compounds (PACs) and related chemicals released to air in the oil sands region (OSR) in Alberta, Canada. Through the implementation of the Joint Canada-Alberta Oil Sands Monitoring Program (JOSM) in 2012 a vast amount of new in...
Article
Potential seepage of naphthenic acids (NAs) from tailings ponds into surface water and groundwater is one of the main environmental concerns associated with the Canadian Athabasca oil sands mining operations. Here we report the application of 13C-labelled NA surrogate compounds to evaluate intrinsic biodegradation along groundwater flow-paths origi...
Article
The acid extractable organics (AEOs) containing naphthenic acids (NAs) in groundwater overlying undeveloped shale gas (Saint-Édouard region) and tight oil (Haldimand sector, Gaspé) reservoirs in Québec, Canada, were analysed using high resolution Orbitrap mass spectrometry and thermal conversion/elemental analysis – isotope ratio mass spectrometry....
Article
Oil sands operations in Alberta, Canada generate large volumes (>840 × 10⁶ m³) of oil sands process-affected water (OSPW) that contains contaminants that are toxic to aquatic life. OSPW is stored in open tailings ponds and leakage from the ponds presents a potential long-term environmental risk. However, the presence of naturally occurring saline w...
Conference Paper
Research on constraining the diagenetic history of organic matter (OM) in a deep seated aquiclude is currently being undertaken at the University of Ottawa. The site is located on the eastern flank of the Michigan Basin and was part of a geoscientific study related to a proposed Deep Geological Repository (DGR) for Low and Intermediate Level Radioa...
Article
We report a historical record of atmospheric deposition in dated sediment cores from Hasse Lake, ideally located near both currently and previously operational coal-fired power plants in Central Alberta, Canada. Accumulation rates of spheroidal carbonaceous particles (SCPs), an unambiguous marker of high-temperature fossil-fuel combustion, in the e...
Article
Full-text available
In recent years, concerns have been raised about the potential environmental impacts of oil and gas (O&G) exploitation, especially regarding groundwater resources. However, there have been few studies carried out to assess the actual risk of O&G exploitation based on specific local conditions. This paper reports on a study aiming to assess the pote...
Conference Paper
The Upper Ordovician Utica Shale located in the St. Lawrence Lowlands (Quebec, Canada) represents a promising reservoir of unconventional gas, which is still 'virgin' with respect to fracking due to a de facto moratorium. A project was initiated in order to evaluate the vulnerability of shallow groundwater with respect to potential future activitie...
Article
The continued growth of mining and upgrading activities in Canada’s Athabasca oil sands (AOS) region has led to concerns about emissions of contaminants such as polycyclic aromatic hydrocarbons (PAHs). Whereas a recent increase in PAH emissions has been demonstrated within around 50 km of the main center of surface mining and upgrading operations,...
Article
The downstream accumulation of polycyclic aromatic hydrocarbons (PAHs) in the Peace-Athabasca Delta (PAD), an ecologically important landscape, is a key issue of concern given the rapid development of the oil sands industry in Northern Alberta, Canada. In addition to PAHs derived from industrial activity (i.e., oil sands mining) within the Athabasc...
Conference Paper
Full-text available
In the Haldimand sector of Gaspé, Québec, Canada, a study was carried out to assess the potential risk on a shallow fractured rock aquifer system due to development of a tight sandstone petroleum reservoir. Petroleum exploration wells are being drilled in the forested core of a hilly 50 km2 peninsula by the sea (up to 200 m amsl) and where local re...
Article
The past several decades have witnessed a significant expansion of mining activities in the Athabasca oil sands region, raising concerns about their impact on the surrounding boreal forest ecosystem. To better understand the extent to which distal sites are impacted by oil sands-derived airborne contaminants, we examine sources of polycyclic aromat...
Article
Full-text available
In their paper, Parajulee and Wania (1) use a multimedia fate model to argue that emissions of polycyclic aromatic hydrocarbons (PAHs) in environmental impact assessments conducted to approve developments in the Athabasca oil sands region (AOSR) are likely underestimated. The discrepancy between their model and reported emissions was mainly attribu...
Article
Full-text available
The extraction of bitumen from the Athabasca oil sands is rapidly expanding, and emission of sulphur and nitrogen oxides has substantially increased. To determine whether lakes downwind of this development in northwest Saskatchewan have been detrimentally impacted since development of the oil sands, a paleolimnological assessment of ten lakes was c...
Article
Full-text available
Compound-specific stable (δ13C) and radiocarbon (Δ14C) isotopes of phospholipid fatty acids (PLFAs) were used to evaluate carbon sources utilized by the active microbial populations in surface sediments from Athabasca oil sands tailings ponds. Algal-specific PLFAs were absent at three of the four sites investigated and δ13C-PLFA values were general...
Article
Evaluating the impact that airborne contamination associated with Athabasca oil sands (AOS) mining operations has on the surrounding boreal forest ecosystem requires a rigorous approach to source discrimination. This study presents a century-long historical record of source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dated sediments...
Article
The high levels of acid extractable organics (AEO) containing naphthenic acids (NAs) found in oil sands process-affected waters (OSPW) are a growing concern in monitoring studies of aquatic ecosystems in the Athabasca oil sands region. The complexity of these compounds has substantially hindered their accurate analysis and quantification. Using a r...
Article
Full-text available
Context Recent scientific literature underlines the consensus between oil sands stakeholders regarding the need to separate mining-related and naturally occurring contaminants in the Lower Athabasca region where mining operations and geological units can both release contaminants to groundwater and to the river. This report discusses two new isotop...
Article
Here we report a novel approach to extract, isolate and characterize high molecular weight organic acids found in the Athabasca oil sands region using preparative capillary gas chromatography (PCGC) followed by thermal conversion/elemental analysis - isotope ratio mass spectrometry (TC/EA-IRMS). A number of different "naphthenic acids" surrogate st...
Conference Paper
The growth of bitumen mining activities in northeastern Alberta poses significant environmental challenges. One of the main concerns is a potential increase in emissions of harmful organic contaminants such as polycyclic aromatic hydrocarbons (PAHs). PAHs are widespread in the environment and result from incomplete organic matter combustion (kineti...
Article
The continued development of Canada's Athabasca oil sands poses a significant environmental challenge. Low buffered boreal lakes located downwind of the prevailing eastward wind direction may be threatened by acidification and elevated inputs of airborne contaminants such as polycyclic aromatic hydrocarbons (PAHs). An accurate assessment of the imp...
Article
Diagnostic molecular ratios and compound-specific C-13 and C-14 analyses were used to identify n-alkane sources in surface sediments collected along a transect from an urbanized estuary draining a peat-rich catchment (Tyne, UK). The most abundant homologues were generally C-29 or C-31, and the carbon preference index (CPI; 1.8 to 6.4) and average c...
Article
Carbon sources utilized by the active microbial communities in shallow groundwater systems underlying three petroleum service stations were characterized using natural abundance radiocarbon ((14)C). Total organic carbon (TOC) Delta(14)C values ranged from -314 to -972 per thousand and petroleum-extracted residues (EXT-RES) ranged from -293 to -971...
Article
Full-text available
The Monkstown zero-valent iron permeable reactive barrier (ZVI PRB), Europe's oldest commercially-installed ZVI PRB, had been treating trichloroethene (ICE) contaminated groundwater for about 10 years on the Nortel Network site in Northern Ireland when cores from the reactive zone were collected in December, 2006. Groundwater data from 2001-2006 in...
Article
Identifying the carbon pools that are being actively cycled by microbial communities is an important component of understanding the fluxes and persistence of organic compounds in environmental systems. Microbial activity can play a primary role in determining the rate at which carbon pools are remineralized and rejoin the active carbon cycle versus...
Article
Hydrogen peroxide (H(2)O(2))-mediated oxygenation to enhance subsurface aerobic biodegradation is a frequently employed remediation technique. However, it may be unclear whether observed organic contaminant mass loss is caused by biodegradation or chemical oxidation via hydroxyl radicals generated during catalyzed Fenton-like reactions. Compound-sp...
Article
In order to evaluate the respiration–photosynthesis dynamics in two contrasting North Sea estuaries, pH, temperature, alkalinity, chlorophyll-a (chl-a), and isotopic ratios of dissolved inorganic carbon (δ13CDIC) and dissolved oxygen (δ18ODO) were measured in the Tyne (July 2003) and Tweed (July 2003 and December 2003) estuaries. Using a concentrat...
Article
The mixing behaviour of dissolved organic carbon (DOC) was investigated in two U.K. estuaries with peatland derived river inputs (Tyne and Tweed), under varying discharge regimes and in different seasons. DOC removal (i.e. non-conservative) was common to both estuaries at low salinities, but DOC addition also occurred in the Tyne at higher saliniti...
Article
The ability to distinguish water inputs from both natural and anthropogenic sources was investigated in the complex environment of an urban estuary (Tyne) and a relatively pristine estuary (Tweed). We used a data set from a total of 11 estuarine transects, comprising measurements of bulk dissolved organic matter (dissolved organic carbon and nitrog...
Article
Nitrogen isotope ratios (delta(15)N) were used to help elucidate the sources and fate of ammonium (NH(4)(+)) and nitrate (NO(3)(-)) in two northeastern English estuaries. The dominant feature of NH(4)(+) in the heavily urbanised Tyne estuary was a plume arising from a single point source; a large sewage works. Although NH(4)(+) concentrations (rang...
Article
The isotopic composition (delta13C and Delta14C) of high molecular weight dissolved organic carbon (HMW DOC) was studied in the Tyne and Tweed estuaries, NE England. Despite significant removal of terrigenous HMW DOC in the low salinity regions (S < 15), Delta14C remained modern with little variation around 1150/00. This lack of apparent age discri...
Article
In order to delineate the potential sources and to understand the main controls on the biogeochemical cycling of dissolved and particulate organic matter (DOM, POM) and dissolved inorganic nitrogen (DIN) during estuarine mixing, comprehensive seasonal geochemical and isotopic and surveys across the freshwater-tidal interface were carried out in the...
Conference Paper
Concentrations and stable isotope ratios (delta13C or delta15N) of nitrate, ammonium, high molecular weight dissolved organic carbon (HMW-DOC) and suspended particulate organic carbon (POC) and nitrogen (PON) from the Tyne River Estuary, NE England, were analysed during winter and summer periods. Samples were collected across a salinity gradient ra...
Article
To accurately interpret isotopic data obtained for volatile organic compounds (VOCs) dissolved in groundwater systems, the isotopic effects of subsurface processes must be understood. Previous work has demonstrated that volatilization and dissolution of BTEX and chlorinated ethene compounds are not significantly isotopically fractionating. This stu...
Article
Equilibrium headspace analysis of toluene for δ2H isotopic composition by continuous flow compound specific isotope mass spectrometry was determined to have an accuracy and reproducibility of ±5‰. Using this analytical approach, the hydrogen isotope fractionation produced by anaerobic biodegradation of toluene was evaluated in laboratory experiment...
Article
Carbon isotope fractionation produced by anaerobic biodegradation of toluene was evaluated in laboratory experiments under both methanogenic and sulfate-reducing conditions. A small (2‰) but highly reproducible 13C-enrichment in the residual toluene at advanced stages of microbial transformation was observed in both cultures. The maximum isotopic e...
Article
In experiments involving anaerobic biodegradation of trichloroethylene (TCE), δ13C values for residual TCE changed from −30.4‰ to values more enriched than −16‰. All data exhibit a consistent correlation between δ13C value of the residual TCE and the extent of biodegradation of TCE, described by a fractionation factor (α) of 0.9929. In contrast, du...
Article
Petroleum products and industrial solvents are among the most ubiquitous contaminants of soil and groundwater and the source of several common and hazardous volatile organic chemicals (VOCs). Volatilization is a key determinant of the fate of VOCs in the subsurface environment, impacting contaminant partitioning between the aqueous, gaseous, and no...
Article
Full-text available
Thesis (M.Sc.)--University of Toronto, 2000. Includes bibliographical references.

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Project (1)
Project
To promote discussion on methods for characterizing water cycling processes in the region including isotopic, organic and inorganic fingerprinting of OSPW and natural waters.