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Opportunities for Population Health Equity in Legislated Impact Assessments (OPHELIA): Three Iterative Research Studies Informed by Realist Methods
No full textExtractive industries can have profound impacts on the population health equity of Indigenous people and affected communities residing on their ancestral lands and traditional territories, in proximity to developments. Regulatory governance of these developments is a legally complex and politically contested public policy arena in Canada. Impact assessment is one regulatory process that can support efforts to identify and mitigate these potential impacts—but it has been mired in interjurisdictional conflicts. Although the Government of Canada’s Impact Assessment Act, 2019 incorporated population health equity into regulatory governance to a greater extent than in other Canadian jurisdictions, this legislation was successfully challenged before the Supreme Court of Canada as overstepping into provincial jurisdiction. Given these circumstances, the Opportunities for Population Health Equity in Legislated Impact Assessments (OPHELIA) research project examined the theoretical, evidentiary, and epidemiological bases for interventions that prioritize population health equity in impact assessments at multiple jurisdictional scales.
The OPHELIA project employed three complementary study methods informed by realist review methodology—realist interviews, realist synthesis, and legal mapping. Context-mechanism-outcome (or CMO) configurations were used as a rubric from realist methodology to guide and organize the research project and individual studies at various scales. Realist interviews were conducted with thirty-five Canadian and international experts in impact assessment and population health equity to establish a researcher-developed intervention theory framework—as context for the research project. Realist synthesis extracted evidence from 185 peer-reviewed and grey literature sources published in the ten-year period (2009 to 2019) leading up to the passage of the Impact Assessment Act, 2019—mapping this evidence to the 180-day planning phase in the legislation to identify best practices and principles as mechanisms for prioritizing population health equity. Finally, legal mapping was conducted across Canada’s fourteen federal, provincial, and territorial jurisdictions, providing a baseline to quantify relative exposure to population health equity provisions for further legal epidemiology research on outcomes.
Findings from the realist interviews were theorized under three themes and six subthemes employing polycentric regulatory analysis as a mid-range theory according to realist methodology: (a) legitimacy—(i) affirming the socio-ecological determinants of health, and (ii) integrating sustainability and population health equity; (b) accountability—(i) mandated and adaptive responsibilities, and (ii) surveillance and engagement techniques; and (c) communication—(i) free, prior and informed consent, and (ii) social learning and field building. Realist synthesis evaluated evidence of best practices and principles for prioritizing population health equity in (a) preparations prior to planning; (b) involvement by public health authorities; (c) participatory processes; (d) identification of issues and concerns; and (e) development of plans and guidance. Legal mapping examined impact legislation across 38 legal texts, with seven coding questions on requirements to (a) improve population health and wellbeing, (b) consider climate change impacts, (c) ensure accessible information, (d) facilitate public participation, (e) support Indigenous knowledge and engagement, (f) assess mandatory factors, and (g) align with regional assessments. As a baseline for further legal epidemiology, population health equity provisions were strongest federally, and in British Columbia, the Yukon, the Northwest Territories, Nunavut, and Québec—with weaker provisions in the eight remaining jurisdictions.
Overall, the OPHELIA project spanned a key period in the evolution of public policy development for impact assessment of extractive industries in Canada—including the establishment of controversial new federal legislation, and legal requirements for its subsequent amendment. With support and recognition from the Canadian Institutes of Health Research, the Social Sciences and Humanities Research Council, Alberta Innovates, the Impact Assessment Agency of Canada, the National Collaborating Centre for Environmental Health, the International Association for Impact Assessment, the Center for Public Health Law Research, and the International Public Policy Association, integrated knowledge translation and exchange for the OPHELIA project aimed to inform practice, research, and policy diffusion in this emerging arena for health promotion and socio-behavioural sciences research. Findings provide realist-informed insights to orient regulators, proponents, public health stakeholders, other government stakeholders, civil society groups, communities, and Indigenous rights-holders to prioritize population health equity in impact assessment. Further research implications include policy surveillance on the evolution of impact assessment; legal epidemiology of comparative health determinants, status, and outcomes across federal, provincial, and territorial frameworks; and attention to identified jurisdictional gaps as areas of focus for legislative policy development
Assessment of Intended Electric Vehicle Usage and Travel Behaviour during Wildfire Evacuations
No full textThe rise in the adoption of electric vehicles (EVs) presents a unique challenge for disaster planning. Their reliance upon the grid for fuel requires capable and resilient electricity infrastructure to withstand the surge in demand during evacuation scenarios. This grid resilience is crucial for safe and resilient evacuations by those living in areas highly vulnerable to wildfires. On the other hand, EVs present a novel opportunity to act as power sources that fulfill the electricity needs of communities that would otherwise lose power. Underpinning both challenges and opportunities is how EV drivers will behave, especially related to charging. However, research on this behaviour in the context of disasters remains sparse.
To address the behavioural gap, this study developed a series of discrete choice models to understand the factors that impact EV charging behaviour in a future wildfire. Through a non-probability panel from the Canadian provinces of Alberta and British Columbia of people living in high/medium fire risk, we distributed a survey (n=1371) to collect intended choices for a nearby wildfire, assuming a 400 km range EV. Results indicate diverse EV charging patterns, both spatially and temporarily, which could limit some peaks in electricity demand and congestion. Across all models, we found that EV ownership, a preference to reduce risk to property and family, intended evacuation choices, and past hazard experience influenced charging behaviour. Results indicate that targeted improvements in grid capacity and charging stations may be sufficient to meet future demand from EV drivers in evacuations
Magnetic Field Devices and Yeast Magnetobiology
No full textMagnetic fields are known to influence sensory perception, migration and navigational behavior in living organisms, however, the underlying mechanisms of these effects, particularly in microorganisms, remains ambiguous. For this thesis, a magnetic field (MF) platform with two distinct magnetic field exposure configurations was designed and developed, to conduct experiments on S. cerevisiae cultures.
The first publication presented in this thesis describes a MF platform designed and optimized in AutoCAD and COMSOL, with the finalized design being validated through Gaussmeter measurements. Exposure experiments involved the exposure of two genetically engineered S. cerevisiae strains, TBR1 and TBR5, to MFs, cultured in Yeast Peptone Dextrose (YPD) agar in Petri Dishes and YPD liquid medium in culture tubes. Results indicated that MF exposure slowed the expansion of TBR1 mats that expanded in two dimensions, but had no effect on the TBR5 mats that were expanding in three dimensions nor on the growth of liquid TBR1 and TBR5 cultures. It was hypothesized that the presence of an external MF induced a radical pair mechanism mediated microtubule reorganization within the S. cerevisiae cells at the expanding boundary, which consequently led to the spatially hindered expansion of TBR1 mats along the agar surface. A series of future exposure experiments involving extremely strong MFs (i.e. 14 T) and moderately strong MFs (≤ 100 mT) will be necessary to evaluate the validity of this hypothesis.
The second publication presented in this thesis involved a series of TBR1 and TBR5 mats expansion experiments without MF exposure, in which smooth-surface segments resembling the phenotype of TBR5 mats emerged within the rough-surface phenotype TBR1 mat. While some of these smooth-surface phenotypic segments established triangular sections which extended to the boundary of the mats, others were enveloped by the advancing rough-surface TBR1 cells, effectively freezing their growth. A trade-off between expansion and local carrying capacity was proposed to explain these observations based on a modified stepping stone model. The stepping stone model established that the trade-off provides the faster expanding, rough-surface TBR1 phenotype a competitive advantage over smooth-surface TBR5 phenotype, but limits TBR1’s ability to invade resident smooth-surface segments. Model simulations further demonstrated that this trade-off improved the ability of the smooth-surface phenotype to invade in rough-surface phenotype in rough-surface mats, replicating the emergence of smooth segments observed in experiments. The experimental results presented in this thesis in relation to this study enhance the understanding of intricate evolutionary dynamics governing fungal mat expansion.
In conclusion, it is imperative to further explore the mechanisms underlying the effects of magnetic fields on living organisms, and the magnetic field platform designs presented in this thesis offer a versatile tool for conducting exposure experiments on microbes, enabling a better comprehension of these mechanisms and effects of the magnetic fields on microorganisms
The Association Between Income Inequality and Body Mass Index Among Canadian Adolescents During the COVID-19 Pandemic: A Longitudinal Analysis
No full textBackground: Overweight and obesity have become increasingly prevalent among Canadian adolescents, particularly since the onset of the COVID-19 pandemic. The influence of contextual factors, such as income inequality, on adolescent health during times of crises remains poorly understood. As such, the COVID-19 pandemic presents a unique opportunity to investigate how income inequality may have contributed to increased adolescent weight status during a period of societal disruption.
Objectives: This thesis aimed to 1) assess whether BMI increased in a sample of Canadian adolescents following the onset of the COVID-19 pandemic, 2) quantify changes in the association between income inequality and adolescent BMI during this period and 3) examine whether these associations were heterogeneous between genders.
Methods: Longitudinal data from 8,451 students within 37 census-divisions (CDs) were obtained from four waves (2018-19 to 2021-22) of the Cohort on Obesity, Marijuana use, Physical activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) study. Student weight status was measured using age- and sex-standardized BMI z-scores (zBMI). CD-level income inequality was measured using Gini coefficients from the 2016 Canadian census. Gender-stratified multilevel models were used to analyze zBMI changes across survey waves and to quantify the association between income inequality and zBMI over the study period.
Results: No significant changes in zBMI were observed from baseline across post-COVID survey waves. Among males, CD-level income inequality was significantly associated with higher zBMI pre-pandemic (2018-19: regression coefficient (β) = 0.176; 95% CI: 0.054, 0.298; 2019-20: β = 0.129; 95% CI: 0.004, 0.254), but this association attenuated and was no longer significant in the post-COVID-19 waves (2020-21: β = 0.110; 95% CI: -0.012, 0.232; 2021-22: β = 0.107; 95% CI: -0.020, 0.234). CD-level income inequality was not associated with zBMI among females at any time point.
Conclusion: The association between income inequality and BMI among Canadian adolescents varied by gender and seems to have been disrupted during the pandemic. Addressing income inequality and related health disparities will require policies and interventions that target both immediate and broader systemic drivers of inequity
Hydrogen Storage in Underground Salt Caverns - A Lotsberg Case Study
No full textHydrogen (H2) has emerged as a crucial component of the global energy transition, mainly as an energy carrier for energy storage. Salt caverns are the most appealing and suitable choice for large-scale H2 storage due to their inert properties and general impermeability. Salt caverns have been used to store natural gas and other hydrocarbon materials for several decades. However, few research has investigated the possibility of underground hydrogen storage in Canada. This study investigates the feasibility of underground H2 storage in Lotsberg Salt Formation (LSF) in Alberta, exploring H2 diffusion and potential geochemical reactions.
This research hypothesizes that 1) H2 may diffuse into salt rocks and the preferential flow paths for H2 diffusion are grain boundaries and microcracks; 2) diffused H2 may react with salt rock and brine, changing transport properties of the salt rocks; 3) some minerals dissolved in brine such as calcite and anhydrite may react with H2 and cause H2 consumption. To test the hypotheses, this research was conducted in four phases: 1) characterizing salt-rock heterogeneity of Lotsberg salt rocks in terms of mineralogy, crystal size, and pore morphology; 2) measuring helium and H2 diffusion through salt rocks and analyzing salt-rock permeability to H2; 3) evaluating hydrogen geochemical reactions experimentally; and 4) modelling H2-related geochemical reactions.
Different salt-rock samples were selected to represent various depths, rock types, and mineralogical compositions along the walls of an existing cavern. Compositional analysis and CT scans were used to assess the mineralogy, crystal structure, and pore characteristics of these samples, investigating the core-scale heterogeneity. Then helium and hydrogen diffusion tests were conducted using a custom-designed cell and a modified pressure pulse decay (PPD) system respectively, evaluating the transport properties of salt rocks. Additionally, experimental H2-related geochemical reactions were conducted, coupled with geochemical modeling using PHREEQC, to predict potential H2-brine-salt interactions, assess the extent of by-product generation, and investigate the corresponding H2 loss and impurities.
Lotsberg Salt mainly consists of halite with trace amounts of carbonate impurities, while Lotsberg Marlstone comprises halite with a carbonate matrix containing carbonates, clays, quartz, and muscovite. Helium diffusion through pure and intact halite samples is negligible, and the micro-scale halite crystal boundaries are non-open for helium diffusion. Halite samples with macro-scale grain boundaries and carbonate impurities show higher helium diffusion rates due to the more interconnected pore networks. The formation of secondary halite veins between grain boundaries can lead to tightly sealed boundaries that have poor connectivity, limiting helium diffusion within the sample. We also assessed the permeability of different salt-rock samples. All samples demonstrated ultra-low permeability levels, which validates the effectiveness of the engineered cement barriers used in our trials. However, for salt-rock samples with very small pore sizes (<5-10 nm), the use of advanced slip/Knudsen flow models is required to accurately model hydrogen transport through these samples. The geochemical experiments suggest that non-reductive dissolution is the predominant reaction in the H₂-brine-salt rock systems and that the presence of H₂ does not induce observable redox reactions under the experimental conditions if there is no presence of microbial activity. The geochemical modelling demonstrates that silicate and clay minerals exposed in H2-saturated brine maintain geochemical stability, having negligible effects on H2 consumption. However, the presence of carbonates and anhydrite can induce the dissociation process of H2 in brine and result in the potential production of methane and H2S if considering microbial activity. Though hydrogen loss and by-product generation are expected in salt caverns, kinetic modeling reveals that the time elapsed before such reactions pose any concerns is significantly long. Therefore, caverns developed in salt formations with limited impurities are considered preferable options for underground hydrogen storage
Growing Through Fragilities: Exploring the Complex Challenges and Tensions of Urban Agriculture
No full textThis research aims to explore the challenges and opportunities experienced by practitioners of urban agriculture in Edmonton and Sheffield. Reflecting the complexity and uncertainty of contemporary society, these challenges are examined through a conceptual framework of fragilities. This includes an account of the everyday challenges of building and sustaining urban agriculture, as well as the uncertainties around the contribution of urban agriculture to satisfying the broad issues of sustainability and justice to which it is often attached. Drawing upon a community-based framework, this research project drew upon a small-m methodological approach to the qualitative analysis of the data. Data collection methods included semi-structured interviews and public workshops wherein participants were invited to view, check, and have a hand in preliminary analysis. Participants ranged from allotment garden organizers to urban farm managers and directors of social-service organizations working on food security and food justice issues. Where urban agriculture is often positively evaluated as a key aspect of current urban sustainability and food security approaches, this research charts uncertain efforts to build and sustain development, and to achieve the promises ascribed to it. A first contribution of this research is to bring forward the stories and experiences of communities with their hands in the dirt. A second contribution is that through these collaborations I identify needs and strategies for fostering innovation and resilience. Finally, future research interests and areas for organizational/institutional support were identified and explored by participants. Key findings of this research suggest that commonly identified challenges of urban agriculture, such as land access, are representative of systemic and institutional definitions of value as compared to value described by participants. As urban agriculture increasingly becomes a point of interest for municipalities as a sustainable solution to climate change and global food insecurity, these fragilities of urban agriculture will become more prescient as a framework of understanding local urban agriculture
Particle Impact Erosion of the Magnetite Passivation Layer on A106C Steel
No full textBitumen extraction from the oil sand reserves in Alberta primarily employs one of two main methods: surface mining followed by extraction or in situ recovery using steam assisted gravity drainage (SAGD). Steam production is essential in the SAGD process, where once-through steam generators (OTSG) produce steam at high temperatures and pressures using relatively low quality boiler feed water (BFW). Fluid velocities within the boiler tubes can reach up to 30 m/s, and particles contained in the feedwater and/or ones produced through the spalling of tube fouling layers possess sufficient kinetic energy to result in erosion damage in the boiler tubes.
A protective magnetite passivation layer forms under normal OTSG operating conditions (318°C, 11 MPa), but its resistance to erosion has not previously been studied. The objective of this work is to investigate the resistance of the magnetite passivation layer to particle impact erosion (PIE) using a submerged impinging jet tester (SIJT). Understanding the resistance to erosion provided by the magnetite formed at different process operations (pH and temperature) and for different pipeline materials could lead to better practices that will improve OTSG reliability.
This project involves two main experimental phases: first, treating A106C carbon steel coupons in an autoclave at 310°C and 10 MPa for 72 hours to form magnetite; and then exposing these magnetite layers to an erosive particle-laden flow at ambient conditions using the SIJT. The nozzle exit velocity was 10 m/s, with a 90° impact angle. Sand (LM125, ρs = 2650 kg/m^3, d_50 = 100 μm) was used to prepare a slurry with a particle concentration of 0.1% by mass.
Autoclave results from this study show the formation of a duplex magnetite layer, consisting of a dense inner layer and a porous outer layer. Based on the estimated erosion time of magnetite from solid particle erosion (SPE) models, SIJT experiments were conducted for 6 minutes. After each minute of SIJT exposure, cross-section micrographs and morphology assessments were conducted to assess changes in the magnetite layer over time. The results from this study indicate that the magnetite passivation layer formed on OTSG boiler tubes has comparable hardness and resistance to PIE as the base metal.
The main contribution of this work is a novel approach to studying the resistance to erosion of a magnetite passivation layer. It is recommended that, in future studies, combined erosion-corrosion tests are conducted using both A106C carbon and steels with a higher chromium content (e.g. P22). It is also recommended that a new experimental rig be developed to study erosion-corrosion at OTSG temperatures and pressures
Drivers of Electric Vehicle Demand in the United States: A Random Coefficient Logit Model Approach
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Research suggests that greenhouse gas (GHG) emissions contribute to global health and environmental degradation, mainly because of heavy reliance on fossil fuel-based transportation. Electric vehicles (EVs) have gained attention for their potential to reduce transportation-related GHG emissions. However, to fully understand the demand function of EVs, it is essential to examine the characteristics that make EVs attractive to customers. While much focus on increasing EV adoption has been placed on government incentives, understanding the specific characteristics of EVs that drive consumer adoption is equally important. Although the EV market has seen growth and some stability in recent years, what drives consumers to adopt EVs still needs to be explored. As EV adoption increases, it becomes critically important to understand the EV characteristics that influence consumer purchasing decisions. This study aims to employ a random coefficient logit model (BLP) to examine how EV characteristics, such as driving range, charging time, and price, influence consumer purchasing decisions and how consumer demographics, such as education attainment, place of residency, and income, affect EV consumer purchasing decisions. To achieve this research objective, we analyze county-level aggregate EV sales and demographic data in California from 2012 to 2022.
Results suggest that income does not significantly impact price sensitivity. However, education level and urban residence influence consumer sensitivity to price changes. Specifically, the study found that highly educated consumers are more sensitive to price changes, while urban residents are less sensitive to price increases. Additionally, our findings reveal that income and education do not significantly influence preferences for increased EV driving range, whereas urban residents prefer increased driving range less than rural residents. Furthermore, results suggest that income and education do not influence preferences around charging times for EVs. Interestingly, urban residents are less sensitive to charging time than rural residents. Finally, our analysis suggests that preferences for EVs significantly depend on the EV characteristics, price, and consumer socio-demographic factors. Overall, this research highlights the importance of EV characteristics and price for EV adoption and provides valuable insights for policymakers and automakers in the EV industry