Research Day 2024

Most environments exhibit predictable yearly changes, permitting animals to anticipate them. The hypothalamic-pituitary-adrenal (HPA) axis is a key physiological pathway that enables animals to cope with such changes. Monitoring glucocorticoid (the end products of the HPA axis) levels in wild animals throughout the year can improve our understanding of how this pathway responds to different conditions. For this study, we collected 18 months of data on two species of North American flying squirrels (Glaucomys sabrinus and G. volans) living in a southern Ontario forest where temperature and food availability fluctuate dramatically throughout the year. These squirrels are active year-round, nest communally, and rely on scatter hoarded foods in the winter months. Flying squirrels have extremely high levels of free plasma cortisol relative to other mammals, but it is unknown how these levels are affected by environmental and reproductive factors. For both species, our goals were to (1) validate an enzyme immunoassay (EIA) to measure their fecal glucocorticoid metabolite (FGM) concentrations and (2) assess yearly differences, seasonal changes, and the influence of sex, reproduction, and ambient temperature on FGM concentrations in each species. In the lab, we successfully validated the use of antibody 5α-pregnane-3β, 11β, 21-triol-20-one EIA for FGM analysis in both species. In the field, neither sex nor reproductive status (breeding condition or not) were linked to FGM concentrations in either species. FGM concentrations were higher in autumn compared to the spring and summer. There were no other seasonal differences. We discuss possible explanations for the autumn peak in FGM concentrations (increased energy expenditure and social nesting changes), as well as outline possible avenues for future research. Understanding how individuals and populations respond to environmental change is a critical goal in evolutionary ecology, particularly in the context of a rapidly changing Anthropocene.

Active school travel (AST), including walking and wheeling to school, plays a critical role in promoting physical activity among children and reducing the prevalence of obesity and related chronic illnesses throughout their lives. However, AST in the Greater Toronto Area has been declining.

The quality of AST environments, influenced by the built environment, is a crucial determinant of AST outcomes. However, limited research has examined the combined influence of macro (e.g., land use patterns and street connectivity) and micro (e.g., lighting and speed bumps) level-built environment factors on AST outcomes, specifically for determining the quality of AST environments (i.e., walkability). Additionally, there is a lack of attention to the equitable distribution of walkable environments by socioeconomic status, leading to disparities in AST participation and related health and safety outcomes.

Addressing these gaps is essential to ensure equitable access to safe and supportive AST environments. This study aims to fill this research gap by developing a walkability index for schools in Toronto. The index will be created by identifying and quantifying the macro and micro-level-built environment factors that contribute to the quality of AST environments using field audits, GIS analysis, and machine learning techniques. Furthermore, the study will investigate the distribution of the quality of AST environments by socioeconomic status.

This study has significant implications for understanding the relationship between the quality of AST environments and socioeconomic status, enabling the identification and rectification of disparities.

The capital-intensive industrialized food system is a major contributor to the intensifying ecological crisis and deepening social inequity. Cities play a key role in this globalized food system given their dependence on mass imports to feed their large populations. Toronto, as Canada’s largest city, positions themselves as a self-proclaimed ‘leader’ in food systems and equity action, citing their various initiatives such as TransformTO and the Toronto Food Strategy. Yet, these strategies contain little to no action with regards to meaningfully transforming Toronto’s dominant food system to one that is more ecologically sustainable and socially just. This relative inaction is starkly contrasted by the actions of youth food and climate justice activists in the city demanding radical change to the food system. This study aims to understand how relationships between states and social movements within food systems governance are shifting in the midst of the socio-ecological crisis with Toronto, Canada as a case study.

Benzene, a carcinogen, is naturally present in petroleum. Oil spills and leaky gas containers create underground oil plumes that contain benzene. As benzene has been found to be persistent under anaerobic conditions, it puts a serious threat to the communities that rely on well water. Some bacterial mixed communities have been shown to be able to degrade benzene anaerobically, but the underlying mechanisms remain unresolved. My study focuses to understand how these bacteria activate benzene anaerobically, so that we understand how bioremediation could work, and then will be able to remediate contaminated sites more efficiently in a timely manner.

Methane gas in the atmosphere is the second greatest contributor, after carbon dioxide, to anthropogenic global warming. It also has a significantly shorter lifetime in the atmosphere, meaning that emissions reductions today will have an immediate and noticeable effect on the global temperature budget. However, there are still significant discrepancies in between bottom-up emissions inventories, and estimates of emissions as measured in the atmosphere. My work focuses on making facility-scale estimates of methane emissions from the atmospheric composition measurements our research group has made since 2017, using a variety of in situ and remote sensing measurements.

My dissertation research examines sound to better understand sense of place along the Wolastoq (St. John River), located in New Brunswick, Canada. I study how the river structures sound in particular ways that help create an attachment for those who live along its banks. I draw from the fields of anthropology, ethnomusicology, geography, and environmental studies to examine the sonic links between river, people, and place.

Looking at the Aymara notion of Suma Qamaña (living-well together) as an entry point, this dissertation explores the changes in the meaning of land that have taken place throughout the twentieth and twenty-first centuries in the northernmost and one of the newest regions of Chile, the Arica and Parinacota region. Through a multilayered methodology that includes a literature review, a policy and a historical document analysis, and an ethnography collected over the period of two years, the dissertation describes and analyzes the relationship between the process of meaning-making of Land and the formation of people’s political identities, with a focus on Aymara political identity. Following a chronological order that starts at the changes experienced by Indigenous communities with Toledo’s policy of General Resettlement and ends in the current policy of multiculturalism and ratification of the 169 ILO Convention, the dissertation examines the various sociopolitical and economic conjunctures that have played a role in how land is understood, inhabited, and signified, highlighting the intimate relationship between land and people, showing how, in the North of Chile, class, race, citizenship, and indigeneity intersect over the materiality of land. By following the longue durée of the history of land in North of Chile, the dissertation presents four conjuctures: Chilenizacion of the annexed territories after the Pacific war; the period of development attached to ideas of progress that transited between political liberal and socialist ideals of the state; the 17 years of Augusto Pinochet’s dictatorship, and the neoliberal post-dictatorship governments from the 1990s onward. In the dissertation, land is presented as a space where different forces align, collide, reorganize themselves, disappear, or are transformed, influencing social relations, the dynamics of authority, notions of belonging and identity, and the ways that land itself is signified. Finally, the chapter explores the potential consequences of territory, the ultimate significance given to land in the North of Chile under the current policy of multiculturalism and the ratification of the 169 ILO Convention, for the future of land as a place that affords us life.

This presentation shares preliminary findings from a youth participatory action research study embedded in an afterschool land education program focused on the climate crisis. The program, funded by the City of Toronto, was designed for Black and Indigenous youth ages 14 to 18 in the Greater Toronto Area and engaged them in activities to conceptualize climate change, theorize change toward climate justice, and grow more reciprocal relations with urban Land and waters. In addition, youth participants offered recommendations for future land education programs and for the City of Toronto to more effectively engage Black and Indigenous youth in climate-related initiatives.

Cities in the Global North are increasingly turning to climate action strategies to guide their efforts to mitigate and adapt to the impacts of climate change. Attempting to address multiple challenges simultaneously while also recognizing and addressing historic and ongoing inequities, some cities claim to embed equity and justice concerns into their climate action strategies. For those in the early stages of this process, a small cohort of cities are frequently cited by elected officials, policymakers, academics, and international sustainability networks alike as examples of how equitable climate action can be designed, implemented, and, at least theoretically, accomplished. This presentation shares the results of an investigation into the ways in which four of these cities; Amsterdam, Glasgow, New Orleans, and Toronto, address equity and justice in their official climate action strategies. Combining content analysis with interviews with those involved in the development and early implementation of these four city’s strategies, this presentation discusses the theoretical and instrumental conditions that enable and constrain municipal efforts to define and operationalize equity and justice. Given their global reputations as leaders in climate action whose efforts should be emulated, if not directly copied, by other municipalities, understanding the ways in which these cities are engaging with equity and justice has potential broad implications to urban sustainability work globally.

Increasing diversity, equity, inclusion, and accessibility (DEIA) in earth and climate sciences is critical to producing good science that can make the changes we seek. When we include more diverse thinkers in our science, that science will become better and this is especially true for earth and climate sciences. In an effort to prioritize DEIA, I have created a practical guide that will help meeting and conference organizers make their meetings more inclusive and accessible. Scientific meetings and conferences are a good place to do DEIA work, because they are where many early career scientists find opportunities to advance their careers. Here I will present the motivation for my guide, the work that has previously been done in this area, and what my guide brings to the table.

Di-(2-ethylhexyl) phthalate (DEHP), which is ubiquitous in indoor environments, was the predominant phthalate measured in house dust in the Canadian CHILD Cohort and was found to be associated with a large increased risk of childhood asthma. The purpose of this study is to inform interventions by identifying sources of DEHP in dust and assessing behaviors related to DEHP concentrations in house dust. DEHP levels were measured in 726 dust samples collected at ~3 months of age in CHILD. DEHP metabolites were measured in urine for a subset of the ~3-month-old infants. Housing characteristics were assessed at the time of dust and urine collection. Numerous factors from these surveys were investigated as potential sources of DEHP using univariate analyses and multivariable regressions. Overall, DEHP dust concentrations were higher for lower-income families. Homes with vinyl flooring in the kitchen and bathroom showed higher levels of DEHP than those without vinyl flooring. The quantity of vinyl furniture and the presence of mold were associated with higher DEHP concentrations, while the use of mattress covers reduced concentration. No other significant associations were found. These findings may inform the public on their choice of building materials and products, as well as future policies, aimed at reducing the health risk associated with exposures in the indoor environment especially for children.