The Environmental Protection Agency has released the first national standards to cut emissions of mercury and toxic air pollutants from power plants. The agency says the new standards will prevent as many as 11,000 premature deaths and 4,700 heart attacks each year, as well as preventing 130,000 cases of childhood asthma symptoms. Power plants are the leading source of arsenic and cyanide pollution and are responsible for half of mercury emissions in the United States. In a statement, the group Earthjustice, which filed a lawsuit against the Bush administration that led to the new standards, said, “We’re celebrating today after a long fight for cleaner air.”