Press Release: 4/1/2026
AG Campbell Sues To Block Rollback Of Limits On Mercury And Other Hazardous Power Plant Emissions
FOR IMMEDIATE RELEASE:
3/31/2026
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Allie Zuliani, Deputy Press Secretary
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Call Allie Zuliani, Deputy Press Secretary at (617) 727-2543
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Email Allie Zuliani, Deputy Press Secretary at Allie.Zuliani@mass.gov
BOSTON — Massachusetts Attorney General Andrea Joy Campbell today joined a coalition of 21 states and local governments in filing a lawsuit challenging the Trump Administration’s repeal of the 2024 Mercury and Air Toxics Standards (MATS) Rule and return to outdated standards that harm the environment and public health.
The 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. In 2024, following significant developments in the technologies used to control pollution, the Environmental Protection Agency (EPA) updated the standards for emissions of these hazardous air pollutants from power plants. Last month, the Trump Administration rolled back the updated standards, allowing for more of these dangerous pollutants to be released into the air and eliminating important air monitoring requirements.
“Massachusetts residents deserve to live, work and play in safe environments, free from exposure to highly toxic pollutants like mercury, and the federal government has a responsibility to regulate these pollutants and protect our communities,” said AG Campbell. “The Trump Administration must stop ignoring the science and start prioritizing public health by immediately reinstating these critical standards that keep us safe.”
While mercury and other hazardous air pollutants disproportionately harm people who live near coal- and oil-fired power plants, the emissions can also travel great distances and be deposited into other states. Mercury is a potent neurotoxin that poses serious dangers to public health, especially for pregnant people and children who consume mercury-contaminated fish. 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. Exposure to mercury also increases the risk of cardiovascular disease, diabetes and autoimmune dysfunction in adults.
Mercury emissions from power plants are also a major contributor to mercury contamination in U.S. waterways. More than 200 Massachusetts waterbodies are listed as impaired due to mercury contamination. Mercury pollution in lakes and rivers harms the local commercial and recreation fishing economies, as well as tribal nations and indigenous peoples that rely on fishing for subsistence.
AG Campbell and the coalition will argue that the repeal is unlawful because 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 Massachusetts Attorney General’s Office has long led in advocating for the standards now being repealed. This lawsuit is AG Campbell’s latest effort to protect Massachusetts residents’ health and environment from the Trump Administration’s dangerous rollback of environmental and public health regulations. Earlier this month, AG Campbell led a broad coalition of states, counties and cities across the country to challenge EPA’s unlawful attempt to rescind its 2009 Endangerment Finding – the agency’s seminal determination that greenhouse gas pollution from motor vehicles drives climate change and endangers public health and welfare.
Joining AG Campbell in filing this legal challenge are the attorneys general of Arizona, Connecticut, Delaware, the District of Columbia, Illinois, Maine, Maryland, Michigan, Minnesota, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Washington, and Wisconsin, along with the city of Chicago, the city of New York and Harris County, Texas.