Meet those leading the way in the field of air pollution science

The Exposure Assessment Section of Health Canada is a multi-disciplinary research team in the field of air pollution science. Their work supports government decision-making, academic advancement, and scientific resolution of questions related to air pollution exposure in Canada. The team includes dedicated scientists with expertise in epidemiology, geography, (bio)statistics, environmental health and modeling, engineering, and toxicology.

Given the unique scientific profile of the women of the Exposure Assessment Section, Canadian Women in STEM would like to highlight their journeys to this exciting scientific field of work.

The Exposure Assessment team: Vanessa Beaulac, Markey Johnson, Morgan MacNeil and Liu Sun. Absent from the photo: Joyce Zhang

The Exposure Assessment team: Vanessa Beaulac, Markey Johnson, Morgan MacNeil and Liu Sun. Absent from the photo: Joyce Zhang

Vanessa Beaulac - Section Head for Exposure Assessment

Vanessa is the Section Head for Exposure Assessment within the Air Health Science Division of Health Canada. Vanessa holds a B.Sc. in Biomedical Toxicology with a M.Sc. in Respiratory Toxicology.

When it came to choosing my career, I knew from the start that I wanted to work in science! I’m at home with pocket protectors and safety goggles, and biology, chemistry and math have always been interests of mine!

The variety and scope offered under the biomedical toxicology program was the best fit for me. It was a great decision! I took the co-operative education path, and had many excellent work terms in biomedical toxicology-adjacent fields learning about soil composition and plant toxicity, rapid field bioassessment (I got to “co-pilot” a beaver plane in Algonquin Park and paddle canoes all summer), and the aquatic toxicity of mining effluents in an ecotoxicology lab.

After working with the Canadian Food Inspection Agency (CFIA), I enrolled in Toxicology Graduate Program at the University of Saskatchewan. I was fortunate to join the lab of Dr. Baljit Singh, and there I studied the effect of barn air quality on worker lungs using a mouse model.

In 2008, I accepted a position as Senior Scientific Evaluator in Health Canada’s Air Quality Assessment Section, performing risk assessments. The work was very interesting and involved a lot of collaboration with Environment and Climate Change Canada (ECCC). Since 2017, I lead the Exposure Assessment team of the Indoor Air Contaminant Assessment Section. Here I manage an ambitious research program and support scientists on the work they do. I find it fulfilling to enable my team to do what they love, which is world-class science!

If I had to offer advice to anyone looking to get into science, I would keep it simple: do your best to do what you love, and see where that takes you.

Morgan MacNeill – Epidemiologist

Morgan MacNeill was recently an Epidemiologist/Researcher with the Indoor Air Contaminants Assessment Section (IACAS). Morgan graduated with a BSc in Biology prior to pursing an MSc in Epidemiology and Community Medicine. She worked in the Exposure Assessment Section for over 10 years as an analyst, study coordinator and principal investigator before joining the IACAS. She just recently joined the Environmental Health Science and Research Bureau at Health Canada, where she continues to work in science.

I never imagined that I would end up working in science. In high school, I thought scientists were reserved, quiet people, who wore pocket protectors.

While I always did well in science, and really enjoyed the subject, I just did not see it as a real career option for myself. Over time, I realized that I really enjoyed the university-level science courses, and learned that the people who were studying science were not the stereotypical scientists that I had had in my mind.

By chance, I ended up taking an environmental health course as an elective through the Epidemiology and Community Medicine Department at Dalhousie University, and I was hooked! It was then I decided to pursue an MSc in Epidemiology and Community Medicine at the University of Ottawa. I applied to the Federal Student Work Employment Program (FWSEP) and two weeks later, I was hired as an analyst in the Exposure Assessment Section, launching my career at Health Canada.

Since joining the Exposure Assessment Section thirteen years ago, I have used analytical tools to determine sources and health effects of air pollutants, led studies aimed at reducing kids' exposure to traffic related air pollution, and most recently, I have lead work looking at building material emissions and indoor air quality in new homes.

One of the things that I like the most about my job is that every day is different. I write code, conduct fieldwork, draft reports/publications/presentations, contribute to risk assessments and risk management activities. However, the thing that I love the most about my job is the people I get to work with every day. While I first thought that scientists "weren't my people", I am learning that they are exactly my people - full of curiosity and passion, and a lifelong love of learning.

Liu Sun – Scientific Evaluator

Liu Sun is Scientific Evaluator with the Air Health Science Division. Liu graduated with a BSc in mathematics prior to pursing MScs in both Geography and Environmental Studies and Geographic Information Systems (GIS) before joining the Air Health Science Division of Health Canada. She has worked in the division for nearly 10 years, collecting and analyzing data related to air pollutant emissions and pollutant exposures in both indoor and outdoor environments.

Early in my career, I managed the data related to air pollutant emissions and pollutant exposures in both indoor and outdoor environments. Through my work, I developed a strong interest in the area of exposure assessment.

Since 2015, my work has focused on extensive research. The first study I led was on reducing the impact of residential cooking activities on exposure to toxic air contaminants. The study showed the importance of kitchen ventilation and the impact a range hood fan can make on improving indoor air quality. My current research explores ways of reducing exposures from cooking, including a nationwide survey on kitchen ventilation.

I love my work, because I get the opportunity to learn something new and exciting every day. I am very grateful and feel blessed to be part of this amazing team. I look forward to continuing to contribute to the overall success of the team while taking strides to create a healthier Canada.

Markey Johnson – Research Scientist

Markey Johnson is a Research Scientist with the Air Health Science Division. Markey has a PhD in environmental health, and her expertise is in air pollution exposure and epidemiology. Before joining the Health Science Division of Health Canada in 2009, Markey worked with the United States Environmental Protection Agency.

When I was a kid, my grandfather had rheumatoid arthritis, and I wanted to find a cure for him. I also had several relatives who loved to tell me about the infectious diseases that were common when they were growing up. I blame those relatives for my interest in public health and diseases. My parents were passionate nature-lovers, who recycled before the days when it was easy. I credit them with instilling in me a profound sense of respect for the natural environment.

By the time I graduated university, I knew I didn’t want to work in a lab, but I didn’t have an alternate plan for the future. I took a year off to think about my priorities and what I was passionate about, before deciding to attend graduate school to pursue a PhD in environmental health.

Ten years ago, I joined the Air Health Science Division of Health Canada as a member of the Exposure Assessment Section. Here, I lead a number of studies, primarily modeling exposure to air pollution and linking air pollution exposure to health.

The thing I like most about my job is that it is never boring. Understanding exposure to pollutants that we cannot see, touch or smell is a challenge that requires the creativity and diverse perspectives that we have in the Air Health Science Division. It is also very satisfying to know that our work contributes to making Canada a healthier place to live. The breadth, focus, and expertise of our group is unique in the world.

Jue Yi (Joyce) Zhang - Researcher

Joyce Zhang is a Researcher with the Air Health Science Division. Joyce has a Masters in Environmental Science, and expertise in air pollution exposure and statistical modelling. After moving to Ottawa to pursue a degree in environmental engineering, Joyce joined the Air Health Science Division in 2017.

As a 13-year-old, I spent my summer watching The Weather Network for 6 hours a day, everyday. The atmosphere was utterly fascinating to me; from the Atlantic hurricane season to heat waves to smog advisories for the City of Toronto—where I grew up.

In high school, like many other teenagers, I explored a wide variety of career options such as graphic designer, doctor, and of course—scientist. But as a teenager, becoming a professional-anything seemed like a larger than life task.

I completed an undergraduate degree in environmental geoscience at the University of Toronto Scarborough followed by a Master of Environmental Science.

After completing my Masters degree, I worked as a research assistant on a small project where I built statistical models to scale down climate change predictions. After completing that project, I made the decision to move to Ottawa and return to school to pursue a degree in environmental engineering at Carleton University. During my time at Carleton, I worked under Dr. Markey Johnson as a student at Health Canada’s Air Health Science Division. Upon completing my environmental engineering degree in 2017, I officially joined Health Canada as a member of the Air Health Science Division (AHSD).

At AHSD, I worked on the development of land-use regression models for ambient air pollutants. This work tied together my interest and knowledge in atmospheric science as well as skills in programming, statistical modelling and geographic information system. The work is very exciting—and I’m very fortunate to be part of the frontier of new science.

Looking back, I’ve come a long way from that Weather-Network-watching teenager. This is just the beginning of my career and I’m excited to see where it will take me. Keep an open mind and never stop learning and challenging yourself.


Let’s draw attention to the incredible work of women in science! This article is part of a month-long series celebrating women in science, from International Day of Women and Girls in Science (February 11) to International Women’s Day (March 8). For even more articles about amazing women working in science, head over to the Canadian Women in STEM blog.


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