Attorney General Bonta Leads Multistate Coalition to Defend Biden Administration’s Rule to Strengthen Standards Regulating Particulate Matter Pollution

OAKLAND – Leading a multistate coalition of 17 attorneys general and the city of New York, California Attorney General Rob Bonta on Friday filed a motion to intervene on behalf of the state of California and the California Air Resources Board (CARB) in the United States Court of Appeals for the D.C. Circuit to defend the U.S. Environmental Protection Agency (EPA)’s final particulate matter (PM) standards rule. Last month, EPA finalized this rule to strengthen National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5), also known as soot. Currently, the rule is being challenged by a coalition of 24 states, led by Kentucky and West Virginia; separate challenges have also been filed by the U.S. Chamber of Commerce and industry associations, the state of Texas, and the Arizona Chamber of Commerce. These challenges aim to weaken the new PM2.5 standards and, if successful, would curtail the many health, environmental, and economic benefits of the rule, and disproportionately harm low-income communities and communities of color.

“Yet again, we are seeing meritless attacks not grounded in facts. Study after study shows that stronger standards reducing particulate matter pollution not only protect the health and well-being of Americans across this country, but also result in robust economic benefits,” said Attorney General Rob Bonta. “That’s why I will continue to fight to ensure that science and the law are heeded.” 

“Research shows elevated PM2.5 exposure has serious health effects for all communities and particularly impacts communities of color, children, seniors and other vulnerable groups,” said California Air Resources Board Chair Liane Randolph. “Each year in California, PM2.5 pollution contributes to over 5,000 premature deaths and thousands of hospitalizations for heart and lung disease, including asthma. A strong annual PM2.5 standard, along with federal, state, and local actions to attain that standard, is critical to protecting public health in California and beyond.” 

Exposure to PM2.5 causes significant health impacts, including increased rates of heart disease, serious respiratory impacts, and increased death rates. In particular, PM2.5 particles can travel deep into the lungs and the finest particles can even reach the bloodstream, therefore posing a greater health risk than larger particles.

Under the Clean Air Act, EPA is required to set NAAQS for several pollutants, including PM2.5, at a level that protects public health and welfare. The standards do not control emissions from any particular sources; once the NAAQS are set, states are tasked with implementing those standards. In its decision last month to strengthen standards, EPA acknowledged that the concentration of PM2.5 allowed under the previous standard did not meet the Clean Air Act’s requirement that standards be set at a level necessary to protect public health and welfare, with an adequate margin of safety. EPA’s decision is based on more than a decade of scientific research showing that PM2.5 is more harmful than previously known. The Trump Administration refused to lower the standards despite overwhelming evidence that the standards then in effect failed to protect the public health and welfare. In 2021, the California Department of Justice, leading a coalition of states, sued the Trump Administration over its refusal to update the PM NAAQS, and has since successfully petitioned EPA to reconsider that decision.  

Attorney General Bonta and CARB are joined by the attorneys general of Arizona, Connecticut, Illinois, Maryland, Massachusetts, Michigan, Minnesota, New Jersey, New York, New York City, Oregon, Pennsylvania, Rhode Island, Vermont, Washington, Wisconsin, and the District of Columbia in filing the motion.

A copy of the motion can be found here.