Research Interests

Wildfires have been increasing in number and severity across North America, spreading smoke across larger areas of the continent, and impacting more people with poor air quality and health impacts. Smoke contains thousands of chemical compounds, both in the gas phase and in aerosol particles, that are chemically and physically transformed as they move through the atmosphere (known as aging). We aim to understand the chemical transformations that organic compounds undergo in smoke as it gets "aged" in the atmosphere, with a particular focus on aqueous phase reactive processes. 

An important component of smoke is known as brown carbon (BrC), which refers to the subset of organic carbon in aerosol particles that absorbs light at ultraviolet and visible wavelengths, giving it a characteristic brown colour. BrC contributes to approximately 20% of total aerosol absorption and can cause a warming effect on the atmosphere. 

Research interests include:

• the reactivity and fate of wildfire smoke-relevant organic molecules in the aqueous phase (e.g. phenolic compounds, substituted furans)

• exploring aqueous reaction pathways through direct photoreaction, OH radical reaction, and photo-nitration processes

• the impact of temperature and pH on reactivity of wildfire smoke-relevant organic molecules

• identifying the formation and loss of brown carbon through aqueous phase reactions

The average person spends 90% of their time indoors, breathing indoor air and being exposed to pollutants unique to indoor activities. Indoor combustion activities, such as cooking, candle burning, and  smoking, are important sources of particles and gases in the indoor environment. Food cooking, in particular, is an important and recurring source of organic gases and particulate matter to indoor air. We aim to investigate the chemistry of food cooking emissions and their reactivity in the indoor environments. 

A key component in food cooking oil and in cooking emissions are triglyceride compounds. The triglycerides most commonly found in cooking oils are made up of unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid. Through the cooking process, triglycerides can also thermally break down to produce free fatty acids. 

Research interests include: 

• the impact of food cooking and other combustion activities on indoor air quality

• the abundance and chemistry of triglycerides in indoor environments

• the reactivity and fate of unsaturated fatty acids with indoor pollutants (e.g. nitrogen dioxide, ozone)

 Water is  ubiquitous in the atmosphere, in clouds, fog, and aerosol particles, and is well known to be an important medium for reactions of organic molecules to take place. Arguably the most important reactive species in the atmosphere the hydroxyl (OH) radical reacts rapidly with a vast majority of molecules resulting in their oxidation. OH radicals can be taken up into atmospheric aqueous phases or produced via a variety of reactive processes. We aim to identify factors that impact OH radical formation and loss in the aqueous phase to ultimately gain a better understanding of the fate of water-soluble molecules in the atmosphere. 

Aqueous aerosol and cloud water containing traces of dissolved iron and hydrogen peroxide can undergo Fenton and (in the presence of sunlight) photo-Fenton reactions to produce OH radicals in situ. These reactions are expected to produce significant amounts of OH radicals, especially in the absence of sunlight. 

Research interests include: 

• the production of OH radicals through Fenton reactions in simulated cloud water and the impact of pH, temperature, and the presence of complexing agents

• the temporal profile of OH radical production through Fenton reactions in simulated cloud water