Leading federal and academic scientists have uncovered “compelling” evidence that Alberta’s oilsands operations have been sending toxins into the atmosphere for decades.
The team has found “striking” increases in contaminants known as polycyclic aromatic hydrocarbons (PAHs) at the bottom of six lakes up to 90 kilometres from the massive oilsands operations in northeastern Alberta.
“Industry’s role as a decades-long contributor of PAHs to oilsands lake ecosystems is now clearly evident,” the team reports in a study published Monday in the U.S. Proceedings of the National Academy of Sciences.
PAHs, which have been linked to cancer, “increased significantly” in the lake sediments after oilsands development began, says the study by a team from Environment Canada and Queen’s University. PAHs are a group of over 100 different chemicals formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances and are one of the top 10 hazardous substances on the U.S. Agency for Toxic Substances and Disease Registry.
Co-author Derek Muir, who heads a priority contaminants team at Environment Canada, gave a preview of the findings at a conference in November. Monday’s study lays out the details.
It says PAHs began to climb in the lake sediments in the 1970s and are now up to 23 times higher than 1960 levels. It says the increased PAHs coincided with oilsands development and the compounds have a distinct “petrogenic” fingerprint different from PAHs generated by natural phenomenon like fire.
Levels of the toxins have almost tripled since the 1960s in Namur Lake, the most remote lake tested. It is about 90 kilometres northwest of oilsands operations in a provincial park known for its fishing. The PAHs are up to 23 times higher in the other lakes, which are within 35 kilometres of the oilsands operations.
“Given the planned expansion of the oil sands, the trend will likely accelerate in future,” says co-author John Smol, a Canada research chair in Environmental Change at Queen’s University.
Smol was named Canada’s top scientist in 2004 and was a member of the federal Oilsands Advisory Panel which in 2010 found serious shortcomings in the monitoring of Alberta’s massive oilsands operations.
Critics have long raised concern about pollution from the massive oilsands operations, but industry and its supporters countered that the PAHs and contaminants in surrounding ecosystems were “natural.”
Smol, an expert on using lake sediments as “archives” to study the past, and his graduate Joshua Kurek teamed up with Environment Canada toxicologists for some scientific sleuthing.
“The absence of well-executed environmental monitoring in the Athabasca oilsands has necessitated the use of indirect approaches to determine background conditions of freshwater ecosystems before development of one of the Earth’s largest energy deposits,” the scientists say.
They took cores of sediments from the six lakes back to the lab and charted how chemicals in the sediments changed over the years revealing “persistent, decades-long PAH loadings.”
The concentrations of PAHs are now “well above ‘natural’ predevelopment levels” and “provide compelling science-based evidence that local industrial activities are important contributors of PAHs to aquatic ecosystems in the Athabasca oilsands region.”
The study says lakes east of the Athabasca River record “particularly striking contaminant increases” that are consistent with the prevailing winds blowing past upgrading facilities and across huge surface-mines.
The study says PAH levels in the sediments in the remote Alberta lakes are similar to those seen in urban lakes, and the most heavily contaminated lake, just a few kilometers from an oilsands plant, has been exceeding Canada’s interim sediment quality guidelines for PAHs since the mid-1980s.
David Schindler, an aquatic scientist at the University of Alberta, and his colleague Erin Kelly, reported in 2010 that heavy metals and other pollutants from oilsands operations were contaminating the landscape up to 50 kilometres away. The new study indicates PAHs are travelling much farther.
Schindler said by email that the new study “underscores the weakness and incompetence of past monitoring in the oilsands area” and the “urgency of getting the long-awaited independent monitoring program under way, overseen by competent scientists who do not report to political masters.”
Schindler says he is “a little puzzled” by the detection of PAHs almost 100 kilometres away from the oilsands operations, since toxins have only been detected in snow up to 50 kilometres away. He suggests some PAHs may travel farther in the warm summer atmosphere or it may be that the toxins that fall over an entire lake surface are concentrated into the deep part of the lake basin.
Given the criticism aimed his way after his 2010 study on oilsand pollution, Schindler says, “I have to admit a fair amount of personal satisfaction from seeing this work, after enduring the vicious diatribes launched by pro-oilsands media after our papers. The likes of (commentators) Vivian Krause and Ezra Levant should be eating generous helpings of crow!”
The Environment Canada-Queen’s team say increased contamination is just one aspect of the change underway in the northern Alberta ecosystems. They say that rising temperatures in recent decades, linked to global warming associated with the burning of fossil fuels, has had a dramatic impact on the lakes, increasing algal growth and abundance of zooplankton.
“Because of the striking increase in PAHs, elevated primary production, and zooplankton changes, these oilsands lake ecosystems have entered new ecological states completely distinct from those of previous centuries,” the study says.
More work is underway to sample sediments in other remote lakes in the region to get a better read on the toxins wafting out of the oilsands.
mmunro@postmedia.com
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