Document Type

Thesis

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Program Name/Specialization

Biological and Chemical Sciences

Faculty/School

Faculty of Science

First Advisor

Dr. Sarah Poynter

Advisor Role

The advisor’s role consisted of supervising the development of research questions, providing guidance, and reviewing the analysis and written drafts.

Second Advisor

Dr. Hind Al-Abadleh

Advisor Role

The advisor provided guidance on research design, methodological approaches, and interpretation of results

Abstract

Rapid industrialization and population growth have contributed to a decline in air quality, with particulate matter (PM) posing particular concern. PM originates from both natural and human sources and often contains toxic chemicals and microorganisms, including potential pathogens. Inhalation of PM is linked to respiratory and cardiovascular diseases, underscoring the need to characterize better its chemical and biological composition in understudied region - Waterloo, Ontario, Canada. The present thesis is a culmination of three main parts. Part 1 will describe the use of the dithiothreitol (DTT) assay to quantify the oxidative potential of PM through DTT consumption of redox-active field PM species. Part II will describe and report details on PM collection from indoor and outdoor sites followed by chemical composition analysis. Part III will examine the biological content of PM using the real-time polymerase chain reaction (qPCR) technique to identify general bacterial load, and will use environmental sequencing to identify bacterial, fungal and DNA-genome viral species in the samples. Results demonstrate that during wildfire events, the Particle Into-Liquid Sampler (PILS) captured higher concentrations of water-soluble organic compounds (WSOC) than the Micro-Orifice Uniform Deposit Impactor (MOUDI), highlighting a predominance of submicron particles. On cleaner days, MOUDI more effectively recovered coarse-mode acid leachable organic compounds (ALOC). DTT assays, ICP-OES, and particle dosimetry modeling revealed size- and iron/copper/ALOC- dependent differences in oxidative potential. Fine particles (0.56-1 μm) showed the greatest reactivity during wildfire smoke event, while particles in the 1-1.8 μm range dominated oxidative potential on cleaner days. Biological analyses showed that PILS samples were more suitable for DNA extraction, qPCR, and sequencing. In contrast, MOUDI was more effective at collecting transition metals and organic compounds. Pathogenic microbes, including bacteria and fungi, were identified in Page | iv Waterloo air, alongside traces of human DNA linked to local activity. These findings point to both exposure risks and opportunities for community engagement on air quality issues. Overall, MOUDI and PILS offered complementary advantages: MOUDI for detailed size-resolved chemical analysis and PILS for operational efficiency and better compatibility with biological assays. Together, they provide a more comprehensive understanding of PM composition, oxidative capacity, and biological relevance. This research delivers the first in depth assessment of PM chemistry and bioaerosols in Waterloo, contributing critical insights for air quality monitoring, health risk assessment, and environmental policy.

Convocation Year

2025

Download

Available for download on Wednesday, August 26, 2026

Share

COinS