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Coal-fired electricity generating plants in the US will soon have to monitor
how much mercury they emit into the air. The Environmental Protection Agency
wants to limit mercury pollution, 20 per cent of which comes from coal-fired
power plants. But it needs to know how factors such as the type of coal affect
emissions, and whether changes in plant design can reduce them. 鈥淭his will let
us get a handle on how effective any of these techniques will be,鈥�
says Guy Williams of the National Wildlife Federation鈥檚 Great Lakes Natural
Resources Center in Ann Arbor, Michigan.