A study released this week suggests production of Alberta’s oil sands is polluting air and lakes in the Canadian province at far greater rates than previously thought.
Development over the last several decades has led to “striking” increases in the amount of cancer-causing chemicals known as polycyclic aromatic hydrocarbons (PAHs) in at least six lakes up to 90 kilometres from oil sands projects, the Calgary Herald reported.
“Industry’s role as a decades-long contributor of PAHs to oil sands lake ecosystems is now clearly evident,” researchers said in a the study published in the US Proceedings of the National Academy of Sciences.
A team of scientists at Queen's University in Kingston, Ontario, and Environment Canada examined core samples from five lakes near the mining and upgrading operations in Fort McMurray, Alberta, as well as Namur Lake, 90 kilometres to the north-west.
The team found levels of PAHs in each lake had increased from between 2.5 times to 23 times baseline levels from the 1960s, before industry started developing the oil sands.
PAHs are released when something is burned and can occur naturally from forest fires or volcanic activity. Burning petroleum in the production of the oil sands leaves a particular fingerprint, though, so the scientists were able to identify those mining operations as the cause of the pollution, according to the Canadian Press.
The PAHs fall into the water from air pollution and are deposited in the mud over time, the news wire said.
Biologist John Smol, one of the authors, said these remote lakes are now as polluted as urban bodies of water.
“We’re not saying these are poisonous ponds,” the New York Times reported Smol as saying. “But it’s going to get worse. It’s not too late but the trend is not looking good.”
Operators have made strides to limit their emissions, Canada’s environment minister Peter Kent said, but more efforts are needed.
“Certainly oil sands operators in the last 22 years, since 1990, have reduced their (greenhouse gases) for example and their other contaminants by close to 40%,” he told the Canadian Press. “But this report reminds us of the need of continuing cumulative monitoring to be sure we don't get into situations where cumulative levels do get past acceptable levels.”
Smol said it was a surprise to see the effects of oil-sands production as far as 90 kilometres away.