JULIA DARABANER
Carleton University, MS Biology
EREF Scholar 2025
Microbe-Mediated Contaminant Cycling: Assessing Microbial Effects on Ontario Landfill Leachate Toxicity
In 2020, 2.01 billion tons of solid waste were produced globally. This growing volume of waste presents significant environmental concerns because of the accumulation of persistent environmental contaminants that can negatively affect human and environmental health. Contaminants are frequently detected in landfill leachate, including heavy metals, halogenated flame retardants (HFRs), polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFAS), and more. Although many of these contaminants are routinely monitored, their effects on microbial community structure in landfills remain poorly understood. Microbes are environmental sentinels, and their response to contaminants as such can provide early warning indications of contaminant toxicity in leachate. Microbes can also play a key role in the mobility and toxicity of contaminants, however, their contributions to priority contaminant cycling in landfills remains poorly characterized.
The overall objective of my project is to characterize microbes that respond to and control priority contaminants in landfills. I will do this by leveraging natural contamination gradients found in model landfills, representative of those found in Canada and the USA, to investigate shifts in microbial community structure. Using genetic sequencing to identify which microbes are present, coupled with comprehensive chemical analysis of leachate samples, I aim to identify contaminants classes that control microbial community assemblages in landfills. Additionally, whole-community analysis will be employed to detect genes and microbial populations responsive to changes in contamination as well as metabolic pathways that can contribute to contaminant transformation. Addressing these gaps presents an opportunity to better understand how microbial communities respond to and transform contaminants in complex environments and pave the way for future development of monitoring programs and toxicity assessments.
Biography
Julia earned her BSc in Biology from Carleton University, Canada in 2023. Following her graduation, Julia had the opportunity to work as a research assistant at the National Wildlife Research Centre for Environment Climate Change Canada (ECCC), where she was introduced to the field of ecotoxicology. This experience marked her first opportunity to engage in hands-on experiments studying how persistent organic pollutants affected aquatic wildlife health and sparked her interest in ecotoxicology. Julia is currently pursuing an MSc in Biology with a specialization in Chemical and Environmental Toxicology at Carleton University under the supervision of Daniel Grégoire in collaboration with Dr. Derek Smith at ECCC. Julia is slated to graduate in summer 2026.
