A study from Environment Canada has discovered high levels of mercury in a 17,000 square kilometre area encompassing the oilsands.
It says in the most affected area, levels are about ten times higher than normal.
That spot is north of town, and east of Fort McKay.
Though the study concludes the deposits are coming from site, it does say the levels are below federal guidelines.
It also says more research is needed to find how the toxin is integrating with plants and animals.
