Canadian researchers published an article in the Proceedings of the National Academy of Sciences of the United States of America on the legacy of oil sands development in the Athabasca region of Alberta province.
Canadian oil sands developments have provided an economic life-line for the government of Prime Minister Stephen Harper. Last year, he visited Asia to expand oil export opportunities for a country that depends almost exclusively on the United States for oil revenue.
The study, "Legacy of a half century of Athabasca oil sands development recorded by lake ecosystems," says toxic pollutants known as polycyclic aromatic hydrocarbons increased near oil sands developments.
"We show that polycyclic aromatic hydrocarbons (PAHs) within lake sediments ... increased significantly after development of the bitumen resource began, followed by significant increases in dibenzothiophenes," the abstract reads.
The document says PAH influxes into six lake sediments included in the study were at levels as much as 23 times greater than levels recorded in the 1960s. PAHs have been blamed for agricultural crop and marine species problems. They occur naturally in oil, petroleum products and coal.
Production of oil sands, known also as bitumen, has sparked concerns from environmental groups. It's viewed as a more corrosive form of crude oil for pipeline transportation and can linger in the environmental longer than conventional crude oil.