They measured the amount of mercury in birds eggs downstream from the tar sands and compared them to eggs some distance away from the polluting region.
What they found was that the eggs of certain species of predatory birds living downstream from the tar sands were found to have “statistically significant increases” of the dangerous heavy metal, mercury.
The study, “Mercury Trends in Colonial Waterbird Eggs Downstream of the Oil Sands Region of Alberta, Canada”, was published in the Environmental Science and Technology Journal.
The levels in the birds are above what would be seen as dangerous, and could in theory cause significant damage to the birds.
In humans, for example, the World Health Organisation argues that “Mercury is highly toxic to human health, posing a particular threat to the development of the child in utero and early in life.” The heavy metal impacts the nervous, digestive and immune systems, lungs and kidneys.
If levels are rising in birds this could be an indicator that mercury levels are rising in fish in local rivers too.
The research is the third peer-reviewed study since 2010 to show rising mercury levels in the ecosystem surrounding the tar sands.
Despite this, and the overwhelming evidence pointing to a tar sands link, the scientists do though point out that more research is needed to conclusively prove that the pollution is being caused by the dirty tar sands operations.
In the scientific paper, they argue that “Oil sands development is only one of the possible factors that could affect mercury levels in Alberta wildlife. Long-range atmospheric transport of mercury could be important as well.”
Environment Canada research scientist and the study’s lead author, Dr Craig Herbert said: “We can’t link the mercury levels we’re seeing in these bird eggs specifically to oil sands. Certainly that’s one possibility, but there are other possibilities as well. Those include coal power plants in Asia”.
Meanwhile the Albertan government, in a typically contemptuous way, was quick to dismiss the research. A spokeswoman for the government Jessica Potter said. “It’s one study. It doesn’t necessarily indicate a trend.”