Groundbreaking study is expected to yield clues about where mercury comes from and what happens to it in the Far North
BY ANDREW VOWLES
Only 750 kilometres from the North Pole, with the mercury in the thermometer stuck at about -50 C, a U of G master's student is beginning a study this month of how environmental mercury moves between the snow pack and the air in Canada's High Arctic.
Frank Cobbett's groundbreaking study is expected to yield information about the origins and behaviour of mercury, which is becoming a growing health hazard for people living in northern regions.
In early January, the environmental engineering student boarded a military transport plane bound via Greenland to Alert in Nunavut. He'll spend six months collecting data at an Environment Canada research station on a Cold War-era military base on the northern tip of Ellesmere Island, the world's most northerly inhabited settlement.
There he'll monitor mercury concentrations and flux to track the movement of different forms of the element, including gaseous mercury, between the snow pack and the atmosphere.
Although Environment Canada routinely monitors mercury levels around the country, the agency normally measures only concentrations rather than how much mercury escapes from the ground or is deposited from the air.
“Results from six months in such a cold climate haven't been published,” says Prof. Bill Van Heyst, Engineering.
Learning more about what happens to mercury under different conditions might provide clues to where it comes from and what happens to it in the Arctic.
Although earth-bound mercury may be released naturally through, say, volcanic eruptions, much of the mercury deposited in the Arctic is believed to originate farther south from such industrial processes as power generation, smelters and waste incineration.
“Practices in industrialized countries are harming sensitive ecosystems,” says Van Heyst.
He hopes his student's work will help underline the connection between toxic pollutants in remote areas and industrial practices in built-up areas, perhaps leading to new environmental policy or pollution regulations.
“This work will give us a better understanding of the physical and chemical properties of mercury and its behaviour in a remote ecosystem,” he says. “Ideally, we want to stop mercury from getting up there.”
Trace amounts of the element have been detected in breast milk of Inuit women. The substance is believed to bioaccumulate or become more concentrated through the food chain, eventually reaching humans through a diet heavy in seal meat and fish.
Mercury is photosensitive, meaning that its movement may be triggered by varying amounts of light. Cobbett says he expects more mercury will be released from the snow pack with lengthening daylight, an idea he'll test by tracking the flux of different forms of mercury, beginning in the January polar night and ending under the round-the-clock sunshine of June.
He will assemble a weather station and a mercury analysis station, then monitor the equipment daily. During January, he'll be working in 24-hour darkness, in temperatures that can reach -70 C with wind chill. (He'll also complete a co-op work term for Environment Canada, helping to maintain equipment at the base, which is home to about 150 people.)
Cobbett earned an undergraduate degree in environmental engineering from Guelph in 2004. He traces his interest in air pollution issues to an air quality course he took with his supervisor. He plans to defend his thesis later this year.
Van Heyst studies trace toxic compounds. Before coming to Guelph two years ago, he worked for an environmental consulting firm in Mississauga. Among his assignments there, he conducted pesticide modelling for the U.S. Environmental Protection Agency. He will join his student in Alert later this spring.
They plan to compare their Arctic results with last fall's study of mercury flux from biosolids spread on a farmer's field in Maryhill, near Guelph. Working there with Environment Canada, they found that more mercury escapes from soils immediately after rainfall and after tilling. Van Heyst also hopes to study mercury flux in tropical regions.
He purchased the analytical equipment for the study with funding from the Canada Foundation for Innovation and the Ontario Investment Trust. Cobbett also receives funding from the Natural Sciences and Engineering Research Council.
