HARRISBURG, Pa. — Pennsylvania's coal-fired power plants would have to cut mercury emissions by 90 percent within a decade under a plan that would make the state the first major coal producer with stricter mercury regulations than the federal government.

The proposal, which the administration of Gov. Ed Rendell planned to unveil in detail this week, would require approval from state and federal regulators.

Four other states regulate mercury emissions, but none of them produces more coal than Pennsylvania, the nation's fourth-largest coal producer after Wyoming, West Virginia and Kentucky.

"The hope is that we very substantially take a bite out of a pollutant that is a very serious problem, especially in terms of infants and unborn children and pregnant women," state Environmental Protection Secretary Kathleen McGinty said Tuesday.

The state Department of Environmental Protection said last year that it would try to write a mercury rule that would be tougher than the new federal rule, which projects a 70 percent reduction in mercury emissions by 2018, at the earliest.

Pennsylvania sued over the federal rule, contending it has loopholes that could allow the state's coal plants to avoid cleaning up, and fails to properly account for the type of coal found in Pennsylvania.

Mercury becomes airborne in the coal-burning process and works its way up the food chain, accumulating in plants, fish and humans. Children and fetuses are particularly vulnerable to effects of the toxic metal, which can damage the development of the nervous system.

Pennsylvania, also one of the nation's top power-producing states, generated 5.7 tons of airborne mercury in 2003, second-most in the country, according to federal data. About three-fourths of that airborne mercury came from the state's three dozen coal-fired power plants, according to the figures.

The state's rule also would bar a credit-trading program that federal mercury regulations allow. The program lets some plants put off expensive pollution-control upgrades by purchasing "credits" that cleaner plants earn by exceeding the requirements.

Doug Biden, president of the Electric Power Generation Association, a power industry group in Pennsylvania, said the state rule is the result of "overzealous environmental regulation."

Biden said the state's rule could leave Pennsylvania's coal plants at a competitive disadvantage with less-regulated plants in other states.

Source: Associated Press