WASHINGTON — The Environmental Protection Agency is tightening rules that limit emissions of mercury and other harmful pollutants from coal-fired power plants, updating standards imposed more than a decade ago.

The rules proposed Wednesday would lower emissions of mercury and other toxic pollutants that can harm brain development of young children and contribute to heart attacks and other health problems in adults.

The move follows a legal finding by EPA in February that regulating toxic emissions under the Clean Air Act is "appropriate and necessary" to protect the public health. The Feb. 17 finding reversed a move late in President Donald Trump's administration to roll back emissions standards.

The proposed rule will support and strengthen EPA's Mercury and Air Toxics Standards, which have delivered a 90% reduction in mercury emissions from power plants since they were adopted in 2012 under President Barack Obama, EPA Administrator Michael Regan said.

"By leveraging proven, emissions-reduction measures available at reasonable costs and encouraging new, advanced control technologies, we can reduce hazardous pollution from coal-fired power plants — protecting our planet and improving public health for all," Regan said in a statement.

The rule is expected to become final in 2024

The proposed rule is expected to become final next year, "ensuring historic protections for communities across the nation, especially for our children and our vulnerable populations," Regan said.

The proposal is in line with a larger push by the EPA under President Joe Biden to restore dozens of federal environmental protections that were rolled back by Trump's administration, including reinstating rigorous environmental reviews for large infrastructure projects, protecting thousands of waterways and preserving endangered species.

Coal-fired power plants are the largest single man-made source of mercury pollutants, which enter the food chain through fish and other items that people consume. Mercury can affect the nervous system and kidneys; the World Health Organization says fetuses are especially vulnerable to birth defects via exposure in a mother's womb.

Environmental and public health groups praise the proposal

Environmental and public health groups praised the EPA proposal, saying it protects Americans, especially children, from some of the most dangerous forms of air pollution.

"There is no safe level of mercury exposure, and while we have made significant progress advancing clean energy, coal-fired power plants remain one of the largest sources of mercury pollution,'' said Holly Bender, senior director of energy campaigns for the Sierra Club.

"It's alarming to think that toxic pollutants from coal plants can build up in places like Lake Michigan,'' where many Americans camp and swim during the summer, "and where people fish to feed their families,'' Bender said. "Our kids deserve to live and play in a healthy, safe environment, and our leaders must do everything in their power to make that a reality."