Office of the
Illinois Attorney General
Kwame Raoul

Chicago – Attorney General Kwame Raoul today co-led a coalition of 21 states and local governments filing a lawsuit challenging the Trump administration’s repeal of the 2024 Mercury and Air Toxics Standards (MATS) Rule and reversion to outdated standards that harm the environment and public health.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 standard, allowing for more of these dangerous emissions to be released into the air.

“The Trump administration has made a significant step backwards, allowing more toxic air pollution that will harm our communities,” Raoul said. “Mercury and other types of pollution from fossil fuel power plants cause serious negative health effects, especially for children. I’m committed to fighting back against this administration’s attacks on crucial protections for our health and the environment.”

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 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. 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, including parts of Lake Michigan in Illinois. 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.

Raoul and the coalition argue 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. Raoul and the attorneys general are asking the court to determine that the rule is unlawful and must be reversed.

Attorney General Raoul co-led the coalition with Minnesota Attorney General Keith Ellison. Joining Raoul and Ellison in filing the legal challenge are the attorneys general of Arizona, Connecticut, Delaware, the District of Columbia, Maine, Maryland, Massachusetts, Michigan, 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.