Waste from mill worsening mercury contamination in river near Grassy Narrows, study suggests

Industrial discharge from a paper mill in northern Ontario is exacerbating mercury contamination in a river system near a First Nation that has been plagued with mercury poisoning for decades, a new study suggests.While the wastewater from the Dryden, Ont., mill doesn’t contain mercury, the sulphate and organic matter in it contribute to the elevated production of methylmercury in the Wabigoon River, researchers from the University of Western Ontario said Thursday.The levels of methylmercury – the most toxic form of mercury – in the river’s fish may be twice as high as they would be without the mill discharge, they said.