Attorney General Peter F. Neronha announced on Mar. 31 that he has joined a coalition of 21 states and local governments in filing a lawsuit against the Trump administration’s repeal of the 2024 Mercury and Air Toxics Standards (MATS) Rule, which had imposed limits on toxic air pollutants from coal- and oil-fired power plants.
The lawsuit challenges the decision to return to earlier standards, arguing that it will harm both the environment and public health by allowing increased emissions of substances such as mercury, arsenic, lead, acid gases, hydrogen chloride, and formaldehyde. The MATS Rule was updated in 2024 after advancements in pollution control technology enabled stricter regulation.
“Public health and safety should be the top priority of any government,” said Attorney General Neronha. “Here, we have the Trump Administration once again acting recklessly and without good reason in rolling back important emissions standards that help mitigate the potentially disastrous health effects of toxic air pollutants associated with power plants like mercury and arsenic. Americans should be able to trust that their government is working to make their lives better, but unfortunately this Administration has proven time and time again that the safety and quality of life of the American people doesn’t factor into their decision making. Nevertheless, we will fight hard to reverse this irresponsible decision.”
The coalition highlights concerns about mercury exposure from power plant emissions, noting its particular risks for pregnant women and children due to potential lifelong developmental harms or neurological disorders. Mercury also contributes significantly to contamination in U.S. waterways affecting fishing economies as well as tribal nations relying on subsistence fishing.
According to the lawsuit filed by Neronha’s office alongside attorneys general from several other states—including Arizona, Connecticut, Delaware, Illinois, Maine, Maryland, Massachusetts—and major cities such as New York City and Chicago as well as Harris County in Texas—the Environmental Protection Agency failed to provide adequate justification for repealing updated standards or consider recent technological advances.
The coalition is seeking a court determination that would reverse what they describe as an unlawful rule change.
