Image by Olavi Anttila from Pixabay

June 27, 2026 - OAKLAND — On Friday, California Attorney General Rob Bonta issued the following statement on the U.S. Court of Appeals for the District of Columbia Circuit’s decision upholding the Biden Administration Environmental Protection Agency’s (EPA) 2024 rule strengthening the National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5), also known as soot.  The rule was challenged by a coalition of states as well as a coalition of industry and business entities, which asked the Court to strike down the updated soot standard. Attorney General Bonta, joined by the California Air Resources Board (CARB), led a coalition in intervening in the lawsuit to defend the standard. After the Trump Administration came into office, its EPA reversed position and also asked the Court to strike down the 2024 standard.  As the case was pending, the 2024 standard has remained in effect. However, the Trump Administration EPA has unlawfully failed to implement the standard, and Attorney General Bonta and the CARB led a multistate coalition in filing a separate lawsuit against them, which is currently ongoing.

“Today’s ruling reaffirms what we have said all along: this attack on important and legally-required federal health protections was meritless. The 2024 PM2.5 standard was grounded in decades of scientific research clearly showing that stronger standards reducing particulate matter pollution were necessary to save lives,” said Attorney General Bonta. “Despite this, the Trump Administration has failed to implement this life-saving soot standard. We call on them to follow the science and law and implement the standard immediately.”

Under the Clean Air Act, EPA is required to set NAAQS for several pollutants, including PM2.5, at levels that protect 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. Reductions in soot are associated with decreases in the risk of mortality and increases in life expectancy. In 2024, in response to advocacy from California and others, the Biden-era EPA strengthened the soot NAAQS based on overwhelming scientific evidence. According to its own estimates, EPA has reported that the first year alone of full attainment of the 2024 PM2.5 NAAQS will result in significant public health benefits, including avoiding 4,500 premature deaths, 2,000 emergency room visits, 5,700 new cases of asthma, 800,000 cases of asthma symptoms, 290,000 lost workdays, and 1,000 hospital admissions for Alzheimer’s/Parkinson’s diseases. The value of these and other health benefits would outweigh the estimated costs of implementation by $46 billion. 

Source: CA. DOJ