New research that claims pollution from Alberta oil sands mines remains largely local is unlikely to change any minds among those staunchly opposed to the massive energy development.
The surprising conclusions of two studies published in the last few weeks by respected Canadian scientists suggest that while the area immediately surrounding oil sands mining operations contaminate the area within 50 kilometres, the pollution doesn't appear to be reaching downstream areas 200 kilometres away.
According to the Globe and Mail, the scientists sampled lake-bottom sediment and discovered negligible levels of pollutants such as volatile organic compounds and particulates.
In fact, drilling deeply into the sediments, they found many lakes were cleaner today than in past decades or even centuries, the Globe said.
"It's still, by and large, a natural landscape," Roland Hall, a University of Waterloo professor of biology and one of the lead researchers on one of the studies, told the Globe.
The research conclusions run counter to longstanding claims by communities downstream from the oil sands operations around Fort McMurray, Alta., that pollutants have contaminated water, fish and people.
Hall said his study concluded the toxins originate from natural sources of polycyclic aromatic compounds "via the water continue to be a main process that's delivering them."
But critics were quick to jump on the results. The Globe noted University of Alberta professor David Schindler said the researchers' lake sampling was "well outside the range where atmospheric transport would reach it, so tells nothing about that source. In short, it adds very little to the controversy over the amount that industry is contributing to the river."
The research was also funded by Suncor Energy Inc., a major oil sands developer. But Hall and his associates apparently couldn't find anyone else to pay for the work, the Globe said.
The scientists behind the study aren't crackpots. Hall is associate dean of graduate studies at the University of Waterloo, currently on sabbatical, the Globe reported. Brent Wolfe holds the northern research chair from the Natural Sciences and Engineering Research Council of Canada. And George Dixon, Waterloo vice-president of research, is known internationally for his expertise on water toxicology.
According to the Globe, the researchers found levels of airborne metals peaked in the late 1950s and 1960s, when oil sands extraction was still a concept. Arsenic dropped to pre-industrial levels and lead is now 10 per cent above "background" concentrations.
The scientists suggested the declines could be tied to the move to unleaded fuel and the closure of smelting operations at Yellowknife's Giant Mine, a huge emitter of arsenic.
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Levels of polycyclic aromatic compounds, known to cause cataracts, organ damage and cancer, were lowest between 1975 and 1995, during a period of oil-sands growth, the Globe said. The researchers found the compounds were higher in the mid-18th and mid-19th centuries, when Prairies saw a lot of forest-fire activity.
Hall noted his research doesn't negate the findings of Schindler and others showing contamination within a 50-kilometre radius of oil-sands operations.