While sophisticated high-tech monitoring equipment is often set up around the city to measure Windsor’s air quality, Alice Grgicak-Mannion and Joel Gagnon believe some of the simplest and most inexpensive indicators might be growing right in our backyards.~

Grgicak-Mannion, a geospatial learning specialist in the university’s Great Lakes Institute for Environmental Research and Gagnon, an associate professor in Earth and Environmental Sciences, were funded by Health Canada to study the possibility of using leaves from area Norway maples and littleleaf linden trees as indicators of local air quality by examining the contaminants that have accumulated on them.

“It’s not a novel idea, but it’s the first time it’s been done here in Windsor,” said Grgicak-Mannion, whose areas of expertise include geographic information systems and air pollution modelling.

She said urban trees are effective biomonitors because they are evenly distributed, allowing researchers to choose specific sites representative of a larger region, and because their leaves can capture pollutants similar to the way traditional sampling filters operate.

“That allows us to measure pollutant concentrations and potentially relate them to specific pollution sources, whether they’re coming from traffic, industry or even something like volcanic ash fallout,” said Gagnon. “Basically toxic metals are what we’re looking for.”

The pair is working on the pilot study with professor and former GLIER director Brian Fryer and Lindsay Miller, a PhD candidate in civil and environmental engineering who works under the tutelage of professor Iris Xu. They’ll partner with the City of Windsor and may involve local students to help with leaf collection and then teach them a little about contaminant analysis techniques.

Those methods include solution analysis, where leaves are dissolved and then studied to determine their contents, and inductively coupled plasma mass spectrometry, a method in which substances are vaporized and their atoms are ionized and examined to determine concentrations in the parts-per-trillion range.

“We’ll also use a scanning electron microscope to examine the particles’ shapes and their compositions to potentially identify individual sources,” said Gagnon.

Grgicak-Mannion will eventually model the data in order to create maps that will provide exposure estimates and show the variability of types of contaminants found throughout the city. That information will help to warn susceptible populations in local neighbourhood communities about outdoor exposure levels, she said.

The team received about $26,000 for the pilot project.

Alice Grgicak-Mannion and Joel Gagnon examine a leaf from a linden tree.

News story courtesy of UWin Daily News.