Today, the Environmental Protection Agency (EPA) announced that it would ease the restrictions on coal-burning power plants, enabling them to release more heavy metals, such as mercury and lead, into the air.

This move, first put forward in June 2025, aims at the Biden-era amendments to a rule commonly referred to as the Mercury and Air Toxics Standards for power plants (MATS). The amendments tightened the limits on mercury and other hazardous air pollutant emissions from coal-burning power plants and required them to conduct continuous emissions monitoring.

Among all fossil fuels, coal emits the most carbon dioxide per unit of energy, and burning it releases deadly pollutants into the air. Exposure to pollution from coal-powered plants has been associated with asthma, lung cancer, and respiratory infections, among other illnesses.

Coal-fired power plants are also the largest source of airborne mercury emissions in the United States, as the EPA has previously stated. Mercury is a neurotoxin and can have toxic effects on the nervous, digestive, and immune systems, as well as on the lungs, kidneys, skin, and eyes. The MATS regulations have been extremely effective in limiting these health risks. Within six years of coming into effect, the 2012 restrictions led to a drop in mercury emissions from the power sector.

However, MATS has faced a number of challenges since its initial establishment. “It’s been a bit of a back – and – forth,” says Bryan Hubbell, a senior fellow at Resources for the Future, who previously managed the EPA’s Office of Air Quality Planning and Standards Risk and Benefits Group and worked on the original 2012 MATS rule.

After the Obama Administration first set the standard, the Supreme Court overturned it, stating that the EPA did not properly take into account the costs of emissions reductions for the power plants. In response, the EPA published a supplemental finding in 2016 concluding that it remained “appropriate and necessary” to regulate power plants’ emissions.

The first Trump Administration maintained the Obama-era standards but removed the “appropriate and necessary” determination, reducing the EPA’s authority to regulate hazardous air pollutants and narrowing the scope of the Clean Air Act.

In 2024, the Biden Administration strengthened MATS beyond the original 2012 standards, implementing continuous emissions monitoring and stricter pollution limits for particulate matter and mercury. Although the 2024 ruling has been repealed, coal plants will still be subject to the 2012 standards, which set emission limits for mercury, acid gases, and other toxic pollution from power plants. According to the New York, nearly all coal plants in the United States have already met the 2012 requirements.

“Technology has advanced to allow for more stringent regulations of these emissions, and the Biden Administration found that there were very significant health benefits from these reductions,” says Richard Revesz, a professor of law at New York University, who specializes in environmental and regulatory law and policy.

Friday’s announcement is part of a broader effort by the Trump Administration to revitalize the coal industry—even though coal is one of the most costly power sources and has been linked to a number of adverse health effects. The Energy Department previously kept several coal-burning plants that were scheduled for retirement open. Earlier this month, Trump said that he had ordered the Pentagon to purchase more coal-based electricity, and that the Department of Energy would allocate $175 million in funding for six projects to upgrade coal plants in four states.

The EPA has said that today’s rule change is expected to save an estimated $670 million. “The Biden – Harris Administration’s anti – coal regulations aimed to regulate this vital sector of our energy economy out of existence. If implemented, these actions would have destroyed reliable American energy,” EPA Administrator Lee Zeldin said in a statement. “The Trump EPA knows that we can grow the economy, enhance baseload power, and protect human health and the environment simultaneously. It is not a binary choice and never should have been.”

But experts say that this figure does not consider the cost to public health. “There were very large health benefits associated with those standards, and the Trump Administration has eliminated all those health benefits,” says Revesz. “They pretend that the only real consequence of repealing the standard is saving costs for industry regulation, but they are completely ignoring the lost benefits that will now be imposed on the American people. The American people will now be significantly less healthy because of this action.”

The ruling also relaxes the limits on a number of other pollutants released by burning coal, such as arsenic, cadmium, chromium, lead, and nickel.

“Trump’s EPA is attacking public health by repealing the 2024 MATS,” Nicholas Morales, an Earthjustice attorney, said in a statement. “This unlawful repeal will result in higher levels of mercury, soot, and other hazardous pollution in our air and communities. With this move, the Trump administration is eliminating health protections that are crucial for protecting children from toxins like mercury just to save the coal industry some money.”

Hubbell says that, like most of Trump’s recent environmental rollbacks, this move is likely to face legal challenges. “This is just one of many likely deregulatory efforts,” he says. “I think people want to make it clear that we won’t just let them make these changes incrementally.”