Toxic pollutants released by oil sands mining operations are accumulating in freshwater ecosystems, research by Canadian scientists suggests.
A study of sediment in nearby lakes showed the level of pollutants, known as PAHs, had risen since the 1960s when oil sands development began.
However, the researchers added that PAH concentrations were still lower than those found in urban lakes.
The findings appear in the Proceedings of the National Academy of Sciences.
PAH refers to polycyclic aromatic hydrocarbons – a group of chemicals that have been shown to affect aquatic organisms and birds. PAHs have also been described as being responsible for damaging food crops.
The chemicals occur naturally in coal, crude oil, and petroleum; they are also present in products made from fossil fuels, such as creosote and asphalt.
PAHs also can be released into the air during the burning of fossil fuels and organic matter – the less efficient the burning process, the more PAHs are given off. Forest fires and volcanoes produce PAHs naturally.
Digging the dirt
Using sediment cores from five lakes within a 35km (22-mile) radius of major oil sands facilities and one remote lake (90km/56 miles from the facilities), the researchers assessed the ecological impact of oil sands developments on freshwater ecosystems.
Core samples showed a rise in PAH concentrations since the development of oil sands mining
Analysis of the samples showed that PAH levels were now 2.5-23 times greater than levels from about 1960.
Core samples showed a rise in PAH concentrations since the development of oil sands mining
In their paper, the team wrote: “PAH ratios indicate temporal shifts from primarily wood combustion to [decomposed organic material] sources that coincide with greater oil sands development.
“Canadian interim sediment quality guidelines have been exceeded since the mid-1980s at the most impacted sites.”
Oil sands, also known as tar sands, have only recently considered to be a viable component of the world’s oil reserves as a result of rising energy prices and the development of technology that has made its processing profitable.
These factors has resulted in a marked increase in the extraction and processing of oil sands in northern Alberta and Saskatchewan, which account for 97% of the nation’s proven reserves and is the world’s third largest reserve.
The researchers say that in 1980, daily production was 100,000 but has grown to about 1.5 million barrels a day, It is projected to reach 3.7 million barrels by 2025, they added.
The development of the oil sands sector has been controversial, prompting polemic between those in favour of utilising the resource to cushion the Canadian economy from shocks in global energy prices and those who say the environmental costs are too high.
Press secretary for Environment Minister Peter Kent
In 2010, The Star newspaper reported that concerned residents on the shores of Lake Athabasca (downstream from one of the region’s major oil sands facilities) had called for the federal government to commission an independent study to assess the impact on the area’s water bodies.
The call came after local people said a growing number of landed fish where showing signs of deformities.
They voiced concern that there was not an effective system of environmental monitoring was in place.
At the time, the federal environment minister said he was listening to calls for a monitoring programme.
The researchers behind the PNAS study said that there was conflicting findings among the few long-term PAH datasets that existed, with some suggesting increases in limited areas, while other recording no increase between the 1950s and 1998.
“Establishment of background PAH concentrations and historic loadings is essential and would allow the impacts of development, including industrial PAH contributions, to be compared with the natural range… in lake sediment from the region,” they wrote.
“As noted repeatedly in previous assessments of the impacts of the Alberta oil sands operations, insufficient monitoring data and a poor understanding of pre-development conditions have attempts to determine the scope of pollution from oil sands development.”
The team concluded that the findings from their study had to be considered in a wider environmental context.
“As a consequence of climate warming, the physical processes that lakes experience can be altered,” they said.
“Longer ice-free season and enhanced thermal stability, coupled with higher surface-water temperatures and the redistribution of nutrients within the water column, contribute to greater algal production within many lake ecosystems.”
They concluded: “Analyses of sediment cores from five lakes near major oil sands operations and remote Namur Lake demonstrate that modern PAH concentrations and fluxes, including DBTs, are well above ‘natural’ pre-development levels.”
But, they added: “The ultimate ecological consequences of decades-long increases in aquatic primary production, coupled with greater PAH loadings to lakes in the oil sands region, are unknown and require further assessment.”
Adam Sweet, press secretary for Canada’s Environment Minister Peter Kent, said the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring, announced in February 2012, was committed to a “scientifically rigorous, comprehensive, integrated, and transparent environmental monitoring program for the region.
“It is important to note that the results in this paper come from field studies that were conducted prior to the announcement of the Joint Plan,” he told BBC News.
“In fact, the Joint Plan was created, and implemented, to address the very concerns raised by such studies – it was designed to provide an improved understanding of the long-term cumulative effects of oil sands development.
“Canada has strong rules and regulations in place to ensure that the Canadian environment is protected, and our government will continue to ensure that Canada’s oil sands are developed responsibly.”
Chief Theresa Spence is entering what is hopefully her last week of a hunger strike.
The Attawapiskat First Nation Chief has been on a hunger strike since 11 December trying to force Harper into talks with aboriginal leaders.
She vowed not to eat solid food until she gets a meeting with Harper to discuss his controversial Bill C-45, which was approved by the Canadian Parliament in December. For more info see here.
One of the issues Spence and Harper will talk about is tar sands, and how its development is impacting indigenous communities.
Her hand will be strengthened by the latest disturbing scientific research, published in the Proceedings of the National Academy of Sciences, that shows that cancer-causing pollutants are linked to the tar sands.
There has been evidence stacking up for a while that the tar sands are leaving a lethal legacy. And yesterday’s peer-reviewed study adds to the growing evidence of harm.
What makes this interesting is that the scientists include those from Environment Canada. It is going to be hard for the Canadian government to dismiss the evidence from its own scientists.
The scientists analysed sediment dating back about 50 years from six small lakes north of Fort McMurray, the center of the toxic tar sands industry. The scientists were looking for deposits of cancer-causing polycyclic aromatic hydrocarbons, or PAHs.
And what they found disturbed them. They found levels of PAHs have risen roughly at the same pace as the tar sands development. Results from one remote lake showed PAH levels 23 times higher than pre-development levels 50 years ago.
They also concluded that the contamination covered a wider area than had previously been believed.
This is worrying as PAHs are cancer-causing chemicals. The American Agency for Toxic Substances and Disease Registry says it is well “established” that PAHs are carcinogenic, and have been linked to infertility, immune disorders and fish mutation.
“The signature of the PAHs and the timing strongly suggest that development and the refining of the oil sands plays a role in PAHs increasing in these lakes,” argues Joshua Kurek, from Queen’s University in Kingston, Canada, and lead author of the study.
“Now we have the smoking gun,” argues co-author Professor Smol, another Queen’s University professor, who argues that it is the rate of growth that’s most alarming. “You only have to start doing some back-of-the-envelope calculations of, in 15 years, where they might be,” he said. “But it’s going to get worse. It’s not too late but the trend is not looking good.”
The study is another rebuttal to the oil industry line that oil contamination is from natural oil seeps.
“Hopefully, this will kill the all-the-pollutants-are-natural theory once and for all,” David Schindler, a University of Alberta biologist who co-authored a 2010 study that revealed pollution in the Athabasca River near the tar sands told the Globe and Mail. “I think it’s pretty convincing evidence.”
In response Alberta’s Ministry of Environment and Sustainable Resource Development conceded that “Overall, we do know there is an impact from industry”.
The question that Spence needs to ask Harper is how much toxic local pollution is he going to allow, and how much CO2 pumped into the atmosphere, before he realises that the tar sands legacy is just too great.