February 9, 2024 – OAKLAND, CA – California Attorney General Rob Bonta on Wednesday issued the following statement celebrating the U.S. Environmental Protection Agency (EPA)’s announcement of stronger National Ambient Air Quality Standards for fine particulate matter (PM2.5), also known as soot. In its decision to strengthen these 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 strengthened standards will support California and others in their efforts to reduce emissions of PM2.5 from a wide variety of sources, including heavy-duty vehicles, refineries, factories, and construction sites. Limiting PM2.5 pollution to the level of these standards is expected to save lives each year; reduce hospital visits, heart attacks, strokes, asthma attacks, and many other harmful effects; and result in tremendous economic benefits.

“Today’s announcement is a major victory for environmental justice,” said Attorney General Bonta. “Across California and beyond, too many people suffer from the high levels of particulate matter pollution in their neighborhoods. The Biden Administration, simply by recognizing that fact, has taken a key step that will support states in their efforts to clean up their air and protect the public, especially overburdened communities.”

Wednesday’s rule finalizes U.S. EPA’s reconsideration of a decision made in the last days of the Trump Administration to keep the PM2.5 standards at their prior level, over the advice of U.S. EPA staff and a panel of scientific experts the Trump Administration had disbanded. California led a multistate coalition that sued the Trump Administration to challenge the refusal to update the standards, and then successfully petitioned the incoming Biden Administration to reconsider that refusal. When U.S. EPA proposed in 2023 to strengthen the standards, Attorney General Bonta, leading a multistate coalition, and the California Air Resources Board (CARB) each submitted comments providing further scientific evidence in support of that decision.