The problem areas of Canada are primarily in the eastern provinces that lie on the Canadian Shield and, therefore, lack natural buffers. Ontario, Quebec, New Brunswick and Nova Scotia are the most significantly damaged by acid rain. Most of the emissions that impact eastern Canada are produced at the large metal smelters in central Ontario and Quebec. Emissions from the US also affect Canada’s eastern region. In the US, the greatest amount of emissions comes from a high density of coal fired power plants in the eastern states. Weather systems carry these pollutants from the upper mid western US states across southern Ontario, southern Quebec and into the northeastern US. Pollutants also travel up the northeast corridor of the US into the Atlantic Provinces.
Major emissions sources that impact western Canada are located in Alberta (from upstream oil and gas production and oil sands), southern Saskatchewan (from electric power generation) and northern Manitoba (from mining and smelting). However, there is currently not enough information to tell us how acid rain is affecting these ecosystems. Historically, western Canada has experienced less industrialization than eastern Canada. This factor, combined with east wardly moving weather patterns and acid resistant soils, has so far protected much of western Canada from the damage of acid rain. Not all areas in western Canada are naturally protected. Some lakes and soils rest on granitic bedrock, such as is found in areas of the Canadian Shield, in northeastern Alberta, northern Saskatchewan and Manitoba, parts of western British Columbia, and the Northwest Territories . Ecosystems in these areas are as vulnerable to acid rain as those found in northern Ontario. Acid rain may also become a regional problem downwind of the Alberta oil sands projects, where rapid expansion of bitumen extraction industries is expected to cause large increases in emissions of SO2 and NOX in the next 20 years. A big concern to scientists is that if SO2 and NOX emissions continue to increase in western Canada, the same sort of acid rain damage that has happened in eastern Canada could occur in the west.