The Environmental Protection Agency said its reversal of a 2024 policy on mercury and air toxics standards (MATS) would protect public health without compromising prosperity.

But environmental groups said the change -- part of a broader rollback of environmental policy championed by the White House -- raises risks to the public of heart and lung disease, cancer, and premature death.

At issue were measures enacted by Biden's EPA in April 2024 aimed at protecting public health and mitigating climate change.

The EPA at that time said the standards required coal-fired plants to control 90 percent of their carbon pollution.

The rules also demanded more than two-third reductions in emissions of toxic metals and mercury, a policy that could only be met with significant upgrades to older coal-fired powerplants.

On Friday, Trump's EPA said the Biden rule "imposed massive costs and red tape" on the coal industry, according to a press release.

"The Biden-Harris Administration's anti-coal regulations sought to regulate out of existence this vital sector of our energy economy," said EPA Administrator Lee Zeldin.

"The Trump EPA knows that we can grow the economy, enhance baseload power, and protect human health and the environment all at the same time."

But the Natural Resources Defense council called the move "part of a larger Trump administration push to weaken or eliminate bedrock environmental and public health protections," the environmental group said in a press release.

"The coal industry is in decline, and dismantling clean air protections won't bring it back," said NRDC senior attorney John Walke.

"It will only lead to more asthma attacks, more heart problems, and more premature deaths, especially in communities living in the shadow of coal plants."

The action marks Trump's latest effort to fortify coal, which has long been considered the dirtiest fossil fuel and a scourge in terms of climate change.

On February 11, Trump signed an executive order directing US Defense Secretary Pete Hegseth to enter into long-term supply contracts "with America's beautiful clean coal power generation fleet."

In a photo op at the White House signing of that order, the president was feted as the "undisputed champion" of coal, surrounded by miners in hard hats.

The next day, Trump repealed a 2009 EPA "endangerment finding" underpinning US climate regulations. A coalition of environmental and health groups have challenged the action in court.

Trump's energy secretary, Chris Wright, earlier this week threatened to exit the International Energy Agency if the body continued to prioritize mitigating climate change through net zero emissions.