Award honours ‘best and brightest’ at Concordia
By Sue Tiffin
From a very young age, Cassandra Johannessen was interested in science.
Her parents, Shirley and Derek Johannessen of Brady Lake, remember her being interested in math and science as a young student. As a Haliburton Highlands Secondary School graduate, she received the Governor General’s Academic Medal for achieving the highest academic average.
Now a Concordia PhD student, Johannessen is one of two doctoral students to win the Miriam Aaron Roland Graduate Fellowship, which includes a $100K prize to help support her research.
Johannessen was recommended for the award by her supervisor and department chair at Concordia, based on academic merit and the scope of her research.
“The purpose of the Miriam Aaron Roland Graduate Fellowship is to attract and retain the best and brightest graduate students to the university, who will support key components of the university’s strategic directions; as well as, pursue bold goals in research that will reflect the university’s talents and ambitions to tackle big challenges,” reads the award’s call for applicants.
Johannessen has been pursuing bold goals in research and tackling big challenges throughout her post-secondary education.
She doesn’t remember when she became interested in science.
“It has always just felt like a major aspect of who I was,” she said.
Growing up, Johannessen said she was encouraged to be a doctor, and she herself thought she would be, intending to specialize in neuroscience.
“Throughout university, I slowly realized that being really good at science doesn’t mean you have to become a doctor and that a career in science isn’t limited to medicine, she said. “I became really interested in chemistry, specifically environmental pollution modelling and monitoring, and so I focused the rest of my studies around that.”
Johannessen said she had had a hard time choosing which university to attend, initially pursuing studies at the University of Toronto because they offered her the biggest scholarship, but later transferring to Trent University for chemistry, which she said was the best choice for her.
“Going to a smaller university came with a lot of benefits that impacted my journey as an early career scientist,” she said. “For example, because the class sizes were so small, we got access to state-of-the-art instrumentation to learn on. I also got access to more opportunities, I was able to get a summer job in a laboratory at Trent and published papers from that work during my undergrad. I got to interact with my professors on a very personal level, and they really encouraged my success.”
One of those interactions resulted in an assignment Johannessen had submitted for class being published as a 40-page peer-reviewed article.
“I don’t feel like undergraduate students get to publish that often at other universities, so I feel really lucky for those experiences,” she said.
In Johannessen’s fourth year at Trent, she did a thesis, that project ending up being her focus for a Master’s project, a degree she finished in one year.
“Mass coho salmon mortality has been occurring in the United States, but the causal agent was unknown until last year,” said Johannessen, when asked about her area of study. “For years, the salmon would return to spawn in rivers and streams, and prematurely die. Research had determined that this mass die-off was due to road runoff from nearby highway systems. When it rains, the precipitation washed off chemicals from the roadway into the rivers and streams. These researchers identified some chemicals that were associated with this mass-mortality inducing highway runoff.”
One of these compounds, called hexamethoxymethyl-melamine (HMMM), was previously detected in Lake Ontario by the Metcalfe Lab at Trent University, she said, and while it has been sporadically detected across the globe, not much was known about it.
“Turns out, HMMM is a significant chemical component of car tires,” said Johannessen. “Also, it readily transforms in the environment into a bunch of equally-long named chemicals, of which we know even less about. So, we decided that I would investigate HMMM and its transformation products for my thesis. Using computational chemistry, we estimated the properties (water solubility, vapour pressure, etc.) of these compounds, which dictate their behaviour in the environment. Knowing these, we could predict the environmental fate of these pollutants.”
Johannessen said she also monitored the chemicals in the GTA, sampling, with the help of the Ministry of Environment, Conservation and Parks, two watersheds that were likely to be impacted by road runoff : Don River, which is adjacent to the Don Valley Parkway, and Highland Creek, which goes directly under the 401.
“We confirmed that these pollutants are unfortunately contaminating urban Canadian watersheds during rain events,” said Johannessen.
And then near the end of her Masters studies, the toxic compound inducing the mass coho mortality in the United States was identified.
“This compound is called 6PPD-quinone, and it is a transformation product of a compound called 6PPD, which is added to tires as an anti-ozonate,” she said. “I went back to the samples we had collected from the Don River and found that this compound is present at extremely high concentrations after rain events. 6PPD-quinone is now known as one of the most toxic chemicals to aquatic organisms in the whole world. Recent work shows that, not only is this compound toxic to coho, but also rainbow trout and brook trout. My work shows that this compound is in the Canadian urban aquatic environment at concentrations that well exceed the toxic thresholds for these species.”
A year off between her Masters and PhD saw her working on projects within her expertise with Environment and Climate Change Canada. A colleague at ECCC was appointed to Concordia University at the same time that Johannessen was in the process of looking for a PhD opportunity.
“Everything worked out really well, as our areas of research interest really overlapped,” she said.
“In my PhD work, I am shifting away from focusing just on the aquatic environment and am instead turning my attention to airborne tire pollution,” she told the Times. “Tires are a complex chemical mixture. We have limited knowledge about the fate and effects of many tire chemicals and their transformation products, which makes it a really interesting and important topic of study. My PhD work aims to identify tire-derived compounds of concern, and quantify their emissions to air. This will allow us to assess the exposures and health risks of these compounds to humans.”
Johannessen was in the middle of doing some lab work when an email notified her she was the recipient of the award.
“It was pretty exciting because I honestly forgot that I applied for it, and I forgot about the monetary amount associated with it,” she told the Times. “It felt really nice to know that the selection committee saw me as one of the strongest candidates and found my research proposal compelling.”
Johannessen said she also felt relief in winning the award.
“Being a student isn’t the easiest thing financially,” she said. “The stipends for federally funded graduate students haven’t increased with inflation and have been static since 2004. So, this fellowship meant more financial stability.”
The award will help Johannessen pay for rent, tuition, food (including chocolate croissants, she notes) and other bills, so that she can focus on her work.
Johannessen said the work is especially important given how frequently the average person is around tires.
“Not only are they used for transportation, but they are now frequently recycled into artificial turf or playground fields,” she said. “Although children may be playing on recycled tires everyday at school, we do not yet know the risks associated with these products.”
While Johannessen started her PhD just this past May, she’s spent much of the time since then out of the province sharing her work with academics from all over the world, networking, and “learning about a lot of cool ongoing projects,” in her field.
Despite being abroad, she’s still thinking about her home in the Highlands.
“I had the opportunity to present my research to California’s Department of Toxic Substances Control, who are now looking at regulating 6PPD in tires,” she said. “It would be great for our local community to become aware of the issue of tire pollution and encourage our local MP to demand regulation for this chemical in Canada as well.”