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In May 2000, deadly E.coli bacteria from manure spread at a nearby farm seeped into the town well in Walkerton, Ont. Seven people eventually died and another 2,500 became ill.
Avoiding another tragedy is what drives Nathalie Tufenkji, Associate Director of McGill's Brace Centre for Water Resources Management and Dept. of Chemical Engineering professor. Tufenkji and her research team work to develop novel approaches to detecting pathogens in water and to address the myriad issues concerning the transport and fate of groundwater contaminants. As nearly 9 million Canadians rely on groundwater for their domestic water supply, the work is critical.
One area of focus for Tufenkji's team is the behaviour of microbial pathogens (bacteria, viruses and protozoa) that leach into groundwater from sources like manure in agricultural applications, wildlife excrement, leaching landfills and leaking septic tanks.
"We're one of the few groups working with the Walkerton strain, E. coli 0157:H7, and studying its behaviour in soils," Tufenkji said. "If an agricultural producer is going to lay out manure, they have to understand the limitations of the land application. So we're designing experiments to study the behaviour of the micro organisms in different soils to identify those limitations and better gauge the potential for contamination of the drinking water supply."
The group exploring the behaviour and toxicity of engineered nanomaterials as their use becomes more widespread without a clear understanding of how they, too, may act as hazardous contaminants. "We're seeing nanomaterials in everything from rubber tires to cosmetics. And so there's a growing interest in trying to understand the environmental and health implications," Tufenkji said. "We already know that there are health impacts with certain nanomaterials. But there are so many new ones coming out, with so many new properties that we don't fully understand. There could be huge problems down the road."
Pathogen detection, through the development of carefully calibrated biosensors that detect micro-organisms in specific concentrations, is another project the team has been working on. "The biosensor works nicely with the Walkerton bug, and we're now aiming to increase the biosensor's sensitivity and want to start looking at detecting other pathogens like protozoa, viruses as well as beneficial bacteria that we actually want in some systems." What's more, the utility of these biosensors has the potential to go beyond groundwater testing. Once refined, the biosensors could be useful in detecting contaminants for the food and beverage industry and bigger water treatment facilities.
What's next for Tufenkji? She's started thinking about how to remediate Quebec's latest water woe, the blue-green algae that's affecting dozens of lakes. "Were not looking at preventing the problem since it already exists. Rather, we're looking at how can we treat it," Tufenkji said. "Stay tuned, I'm working on it."