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 by former President Donald Trump’s administration to weaken the legal basis for limiting mercury emissions.

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 former 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 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 new rule aims to eliminate up to 70% of mercury emissions and other toxic pollutants such as lead, nickel and arsenic, while also reducing fine dust from coal plant emissions.

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.

Biden has pledged to make the U.S. electricity sector carbon neutral by 2035, and stricter pollution standards have pushed electric plants to replace coal and oil with natural gas, wind and solar power.

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 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.''

The Edison Electric Institute, which represents U.S. investor-owned electric companies, said it was reviewing details of the EPA proposal, but added that its members “have fully and successfully implemented the Mercury and Air Toxics Standards" for 11 years, “resulting in dramatically reduced mercury and related emissions” from U.S. power plants.

“We look forward to continuing to work with" EPA to ensure the final standard “is consistent with our industry’s ongoing clean energy transformation,” said Emily Fisher, the group's executive vice president of clean energy,

Sen. Shelley Moore Capito, R-W.Va., took a more combative approach, saying President Joe Biden's administration “continues to wage war on coal and affordable, reliable energy by issuing unnecessary regulations intended to drive down electricity production from our nation’s baseload power resources.''

Capito, the top Republican on the Senate Environment Committee and a fierce champion of coal produced by her home state, said the Biden administration "has again put politics over sound policy. With one job-killing regulation after another, the EPA continues to threaten the livelihoods of those in West Virginia and other energy-producing communities across the country.''