Researchers find that pollutants in Canada’s Athabasca River are not from natural sources.
Oil-mining operations in Canada’s main tar sands region are releasing a range of heavy and toxic metals — including mercury, arsenic and lead — into a nearby river and its watershed, according to a new study.
Research published online yesterday in the Proceedings of the National Academy of Sciences shows that 13 elements classified as priority pollutants (PPEs) by the US Environmental Protection Agency were found in the Athabasca River in the province of Alberta1. Seven of these were present at high enough concentrations to put aquatic life at risk. The findings are also of concern to human health.
Almost all of Alberta’s known oil reserves — 172 billion barrels — are found within tar sands. The provincial government expects that oil production will increase from about 1.3 million barrels per day to 3 million barrels per day by 2018.
Tar sands mining and upgrading — the process of extracting fuel from the mix of petroleum and sand or clay — produces sand, water, fine clays and minerals that are contained within tailing ponds.
A team led by ecologist David Schindler of the University of Alberta in Edmonton set out to test the government and oil industry’s claims that the concentrations of elements in the Athabasca River and its tributaries were from natural sources and not tar sands development.
The team took samples of surface water from the waterways upstream of the tar sands region and compared them with samples taken within the region — both upstream and downstream of mining projects. The researchers also looked at snow samples from many of the same areas towards the end of winter to look for airborne sources of PPEs, which would be discharged to surface waters when the snow melted.
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Image courtesy of NormanEinstein and Wikimedia Commons.
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