A sweeping coalition of health organizations, environmental groups and 21 states filed separate federal lawsuits this week challenging the Trump administration’s rollback of stricter mercury and air pollution standards for coal- and oil-fired power plants, arguing the move will expose millions to dangerous neurotoxins.

The legal challenges target EPA’s repeal of the 2024 Mercury and Air Toxics Standards (MATS) rule, which was finalized in February . Since EPA’s Mercury and Air Toxics Standards (MATS) took effect in 2015, they’ve driven down dangerous mercury pollution from power plants by more than 90% .

Minnesota Attorney General Keith Ellison and Illinois Attorney General Kwame Raoul co-led the coalition of 21 states and local governments in filing a lawsuit Tuesday challenging the Trump administration’s repeal of the 2024 Mercury and Air Toxics Standards (MATS) Rule . The American Lung Association, the American Academy of Pediatrics, the American Public Health Association, and Physicians for Social Responsibility, represented by the Southern Environmental Law Center, filed a lawsuit in the U.S. Court of Appeals for the District of Columbia .

The 2024 rule had strengthened protections by requiring more sophisticated pollution controls and monitoring systems. The 2024 MATS Rule implements nationwide standards that limit emissions of toxic air pollutants from coal- and oil-fired power plants, including mercury, arsenic, lead and other toxic metals, in addition to acid gases, such as hydrogen chloride and formaldehyde .

Importantly, the 2024 MATS Rule closed a loophole that applied to a small number of lignite coal-burning power plants, mostly concentrated in North Dakota. It required them to meet the same emissions standards that other coal plants nationwide have followed since 2012 .

Mercury poses severe health risks, particularly for pregnant women and children. Mercury is a potent neurotoxin that poses serious dangers to public health, especially for pregnant women and children. For example, a pregnant person’s consumption of mercury exposes their child to mercury and can cause lifelong developmental harms and neurological disorders such as seizures, vision and hearing loss, or delayed development .

Since the Trump administration gave the country’s dirtiest coal plants a free pass, sulfur dioxide emissions have increased 18% nationally and neurotoxic mercury emissions have risen 9%. The sulfur dioxide spike was the second-largest single-year jump by percentage since EPA began publishing this data 30 years ago .

Minnesota faces particular concerns due to cross-border pollution. It’s a huge part of our long history, cultural identity, and economy. According to Minnesota, the state already has roughly 1,700 bodies of water impaired by mercury, much of it carried by air pollution from out of state . Attorney General Ellison said, “Minnesotans depend on—and love—fishing. It’s a huge part of our long history, cultural identity, and economy . But no one should have to worry about whether they’re being poisoned when enjoying their walleye” .

Health groups emphasized the life-saving impact of the standards. APHA CEO Georges C. Benjamin, MD said, “Maintaining the updated 2024 standards is essential to building on the proven successful track record of the MATS, which have slashed emissions of toxic air pollutants, including mercury, particulate matter, arsenic and lead, and have saved thousands of lives each year” .

American Lung Association President and CEO Harold Wimmer said, “The American Lung Association is taking this action because of EPA’s choice to allow more toxic pollution to impact the health and well-being of children throughout the United States. This will expose more communities to mercury and other toxic pollutants, leading to brain development impacts, asthma attacks, cancers and premature deaths” .

The EPA defended its decision on economic grounds. The EPA estimated the repeal of the 2024 expansion of the regulations will save roughly $670 million and lower costs for consumers . Federal officials pointed to earlier standards adopted in 2012, which they say already reduced mercury emissions from power plants by about 90% .

U.S. House Energy and Commerce Chairman Brett Guthrie, R-KY said, “The EPA’s decision to repeal the 2024 MATS revisions is a victory for American energy dominance. The Biden-Harris Administration’s liberal regulatory agenda would have raised costs, created standards that were impossible to meet, and hurt energy reliability” .

The legal challenges argue EPA failed to properly justify the rollback. The states argue that the repeal is unlawful. The case will highlight how EPA has failed to provide a reasoned basis for the rollback, and failed to adequately consider developments in practices, processes and control technologies in its attempt to revert to outdated standards .

Deborah Murray, senior attorney for the Southern Environmental Law Center, said in a statement that the 2024 safeguards have significantly lowered levels of mercury, arsenic, lead and other toxic air pollutants. “Efforts by the Trump administration’s EPA to undermine this progress to