Mercury has been showing up as a ring in tar sands discovered by scientists in northern Canada. The recent study from Friday, Dec. 27 found high levels of mercury near a massive industrial operation.
Environment Canada researcher Jane Kirk said the ring tar in the sands were 16 times higher than “background” levels for the region. Kirk reported the findings at an international toxicology conference. Mercury can bioaccumulate in living creatures, and chronic exposure can cause brain damage.
Mercury tar is such a concern that Environment Minister Leona Aglukkaq signed an international treaty in October pledging Canada to further reduce releases to the environment.
The federal scientists stress the mercury loadings around the tar sands are low compared to the contamination seen in many parts of North America, including southern Ontario and southern Quebec.
However, they say the mercury ring is “the number-one concern” when it comes to the metal toxins generated by oilsands operations. It is also a major worry for aboriginal and environmental groups concerned about the oilsands’ impact on fishing, hunting and important wildlife staging areas downstream of the oilsands.
Environment Canada scientists are sampling everything from snow to lichens to bird eggs as part of the federal-provincial joint ring tar sands monitoring program.
Kirk, who will publish the findings in a scientific study in 2014, told the Society of Environmental Toxicology and Chemistry conference in Nashville in November that about 19,000 square kilometres are “currently impacted by airborne Hg (mercury) emissions originating from oilsands developments.”
Scientists say that the mercury is like a bulls eye with the strongest concentration nearest the extraction zones and the outside rings less toxic. There is, however, mounting evidence that the toxin is building up in the native wildlife.
The highest loadings of mercury were 1,000 nanograms per square metre, much higher than the background level for the region. Even so, she says the “pulse” of mercury in meltwater entering the ecosystem in the spring is below the limits in water quality guidelines for the protection of aquatic life established by the Canadian Council of Ministers of the Environment.
The scientists also found up to 19 nanograms of methyl mercury per square metre near the tar sands. It is the first report of this more “toxic” form of mercury in snow. Microbes typically convert the potent neurotoxin into methyl when the metal enters aquatic ecosystems and begins to work its way up through the food web.