A coalition of 21 states and local governments filed a lawsuit Tuesday challenging the Trump administration’s repeal of the 2024 Mercury and Air Toxics Standards Rule, marking the latest legal battle over environmental regulations that have protected Americans from dangerous pollutants for more than a decade.
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 separate lawsuit the same day in the U.S. Court of Appeals for the District of Columbia challenging the U.S. Environmental Protection Agency’s final action repealing updated limits on mercury and air toxics from power plants finalized in 2024.
The lawsuits challenge the Trump administration’s recent repeal of the Biden-era amendments to the Mercury and Air Toxics Standards for power plants, which effectively allows coal-fired power plants to emit more brain-damaging mercury and other harmful heavy metals such as nickel, arsenic, and lead.
The dual legal challenges represent a unified front of health advocates and state officials against the EPA’s February 2025 final rule repealing the 2024 amendments that had strengthened pollution controls at coal-fired power plants.
“Mercury is a brain-destroying poison that can cause lasting harm to any Marylander who consumes it, especially pregnant people and young children,” Maryland Attorney General Anthony Brown said in a statement announcing the lawsuit. “We are filing this lawsuit to reverse the EPA’s reckless rollback and restore the protections that keep our residents and their families safe.”
American Lung Association President and CEO Harold Wimmer said his organization 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 Mercury and Air Toxics Standards have delivered significant public health benefits since their implementation. According to EPA data, the standards have delivered a 90% reduction in mercury emissions from power plants since 2015, the deadline for their implementation, along with other health benefits including lowered risk of cancer, heart and lung disease, and premature death.
EPA figures cited in the coalition’s press release announcing Tuesday’s lawsuit show that 93% of U.S. coal capacity had already met or were on track to meet the 2024 standards.
The standards, first issued in 2012 by the Obama administration, were strengthened and updated by the Biden administration in April 2024 to reflect the latest advancements in pollution control technologies. However, the Trump administration’s rollback returns regulations to the less stringent 2012 standards.
The state coalition is co-led by Minnesota Attorney General Keith Ellison and includes the attorneys general of Arizona, Connecticut, Delaware, the District of Columbia, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Jersey, New Mexico, New York, Oregon, Rhode Island, Washington, and Wisconsin, along with the city of Chicago, the city of New York and Harris County, Texas.
The coalition argues that the repeal is unlawful because the EPA has failed to provide a reasoned basis for it and failed to adequately consider developments in practices, processes, and control technologies in its attempt to revert to outdated standards. The attorneys general are asking the court to determine that the rule is unlawful and must be reversed.
The EPA defended its decision on economic grounds, with the agency estimating that the repeal of the 2024 expansion of the regulations will save roughly $670 million and lower costs for consumers, according to the agency’s regulatory impact analysis. EPA Administrator Lee Zeldin said the repeal would help ensure “affordable, dependable energy” while maintaining existing health protections.
However, critics argue these economic benefits come at too high a cost to public health. American Public Health Association CEO Georges C. Benjamin noted that the original standards “have slashed emissions of toxic air pollutants, including mercury, particulate matter, arsenic and lead, and have saved thousands of lives each year.”
The health impacts are particularly concerning for vulnerable populations. American Academy of Pediatrics President Andrew D. Racine emphasized that “children are disproportionately impacted by toxic air pollution due to their vulnerable physiology, normal childhood behavior that increases their exposures, and the fact that their lungs are still developing,” warning that “harms to children’s brain development will increase and risks of respiratory conditions like asthma will become worse” without the 2024 standards.
The environmental implications extend beyond individual health impacts. Minnesota’s attorney general argues the federal rollback will lead to increased pollution, particularly from lignite-burning power plants in nearby North Dakota, and worsen contamination in Minnesota’s lakes and rivers. According to Minnesota state environmental data, the state already has roughly 1,700 bodies of water impaired by mercury, much of it carried by air pollution from out of state.
Tuesday’s dual lawsuits represent the latest challenge to the Trump administration’s regulatory rollbacks, with environmental and health advocates preparing for what many expect to be an extended legal battle over federal pollution standards.