Hands-on work with advanced aerosol and gas research equipment inside a laboratory facility
In a world where the smallest particles can tell the biggest stories, Rym Mehri finds meaning in measuring the invisible forces that shape our air, our environment and our health.
Airborne nanoparticles, also known as aerosols, can have major effects on people and the planet. They rise from engine exhaust, drift with wildfire smoke and move through the air we exhale. Once airborne, aerosols can change the atmosphere around us and have a significant impact on our environment and health. They can affect the air we breathe, the climate we live in and even the safety of our health care facilities.
But how do we measure the impacts of these invisible particles?
That is the question Rym Mehri, a research officer at the National Research Council of Canada (NRC)'s Metrology Research Centre, has dedicated her career to answering. She conducts research to understand how these particles behave and to build standards that protect Canadians and people around the world.
"I have always been fascinated by fluid flow, particles and their complex nature, whether they come from engines, the environment or people," she says. "All these topics are related to aerosol science."
Rym grew up in Sousse, Tunisia, and earned her PhD in mechanical engineering from the University of Ottawa. Following her post-doctoral research, when she studied pharmaceutical inhalers and nebulizers—like those used by asthma sufferers—she developed an interest in allergens and their health impacts.
"This made me realize the importance of measurement precision," she explains. "My motivation is really the impact that these particles have on our health."
Before joining the NRC, Rym worked at Health Canada during the COVID-19 pandemic where she evaluated the safety of medical devices and personal protective equipment before they entered the Canadian medical device market.
"This project opened the door for me to join the NRC," Rym explains. "My team at Health Canada worked with the NRC's Metrology Research Centre as they were developing N95 testing capabilities in Canada."
Today, Rym is part of the research centre's aerosol and gas metrology team and works at the intersection of environmental science, health and engineering. Her work helps improve how airborne particles are measured and understood.
"I love the flexibility to work across different research areas. They're challenging, interesting and impactful," she says. "Even during my graduate studies, I admired the NRC's work, for its innovation and its real impact on Canadians."
Her research is a collaboration across disciplines. She works closely with NRC colleagues who specialize in chemical and optical measurement to study how well masks filter airborne particles, including particles from wildfire smoke and aircraft engines.
The pursuit of precision extends beyond Canada's borders. Rym helps coordinate international studies comparing how laboratories measure aerosols. The goal is to ensure scientists around the world measure these particles the same way—like musicians tuning their instruments before playing together, so every note aligns.
The same pursuit of precision guides her other projects. Rym works to improve how scientific instruments measure nanoparticles released by aircraft engines and to assess how reliable those readings are.
"The goal is to know both how precise the tool is and how much you can trust its results," she says.
By refining calibration methods, Rym and the team make aerosol and gas measurements more reliable everywhere by helping improve the accuracy in aerosol and gas measurements. Their work also ensures that emissions data collected are precise and internationally trusted and support global efforts to reduce air pollution.
"These projects are highly technical," she says, "but they have a direct impact on safety and on standards development and build confidence in emission certifications."
Together, these projects reflect the broader mission of Rym's team, conducting state-of-the-art research and developing methods and instruments. They also contribute to international organizations such as the International Civil Aviation Organization (ICAO), the International Maritime Organization (IMO), the ISO - International Organization for Standardization and ASTM International.
"It's always about the safety of Canadians," she explains. "Whether we're studying nanoparticles from masks or emissions from engines, our goal is to make sure the measurements are accurate and trustworthy."