A significant new paper published in the Proceedings of the National Academy of Sciences finds that emissions of dangerous pollutants from the tar sands operations in Canada may be much higher than previously reported in official estimates collected and reported by the industry.
The pollutants, known as polycyclic aromatic hydrocarbons, or PAH, can increase the risks of cancer in people and are suspected of presenting other hazards, such as tumors and reproductive problems in wildlife.
The new study, by researchers at the University of Toronto, said the exposure risks may prove to be two to three times higher after including pollution from evaporation, such as fumes coming from the tailings ponds where tar sands wastes are stored.
"Our study shows that emissions of polycyclic aromatic hydrocarbons estimated in environmental impact assessments conducted to approve developments in the Athabasca oil sands region are likely too low," the authors wrote in summarizing their work's significance.
"This finding implies that environmental concentrations in exposure-relevant media, such as air, water, and food, estimated using those emissions may also be too low. The potential therefore exists that estimation of future risk to humans and wildlife because of surface mining activity in the Athabasca oil sands region has been underestimated."
While this kind of pollution has been measured in the region, they wrote, official estimates of the amount of PAH in the environment around the Athabasca watershed, where tar sands operations are concentrated, "tend to fall close to or below the minimum measured concentrations."
Accounting properly for evaporation, they said, would produce "more realistic" estimates.
They said that evaporative pathways via tailings ponds may be just as significant as direct emissions into the atmosphere.
They called for a better accounting from industry, especially in light of the steady expansion of tar sands operations.
The science site PhysOrg has more, including comments by one of the authors to the European wire service AFP:
According to corporate interests which are responsible for projecting their environmental impact, the Athabasca oil sands beneath Alberta, Canada—which hold the third largest reserve of crude oil known in the world—are only spewing as much pollution into the air as sparsely populated Greenland, where no big industry exists.
Lead study author Frank Wania, a professor in the department of physical and environmental sciences, described the corporate estimates as "inadequate and incomplete."
"If you use these officially reported emissions for the oil sands area you get an emissions density that is lower than just about anywhere else in the world," he told AFP.
"Only with a complete and accurate account of the emissions is it actually possible to make a meaningful assessment of the environmental impact and of the risk to human health," he added.