On February 21, 2023, the EPA and the Center for Biological Diversity (CBD) reached an agreement for the Agency to meet deadlines for reducing smog in parts of California and Texas that have some of the nation’s worst air pollution, according to the CBD.

The agreement was the result of a lawsuit filed by the CBD and Center for Environmental Health challenging the EPA’s failure to ensure that San Diego County and eastern Kern County, California, and Texas’s Dallas-Fort Worth area have plans to address “serious” nonattainment of smog standards. The lawsuit was filed in the U.S. Northern District of California court.

Under the National Ambient Air Quality Standards (NAAQS) of the Clean Air Act (CAA), the EPA is required to set NAAQS for six pollutants that are common in outdoor air, are considered harmful to public health and the environment, and come from numerous and diverse sources. The pollutants are:

• Carbon monoxide
• Lead
• Particulate matter (PM)
• Ozone
• Nitrogen dioxide
• Sulfur dioxide

“The Clean Air Act (CAA) requires that EPA review the NAAQS every five years to ensure their adequacy,” a post by the Environmental & Energy Law Program at Harvard Law School says. “The review process is a multi-stage, robust review of the current science that requires significant expert input. If a standard is tightened, there is a cascading effect on air quality policies and programs across the country. States and local regions must ensure that the sources of pollution in their jurisdiction decrease their emissions, so that the region can meet the new, more stringent national standard.

“Under the Trump administration, EPA weakened the five-year review of the NAAQS, by eroding the science-based review process and altering the membership requirements of the Clean Air Science Advisory Committee (CASAC). The Biden administration’s EPA has reinstated the CASAC membership requirements and is reviewing the science underlying the 2020 ozone and particulate matter (PM) NAAQS.”

Ground-level ozone, commonly known as smog, is linked to human health problems like asthma attacks and can cause premature death. Those most at risk include older adults, children, and people who work outdoors. Ozone pollution also contributes to the climate crisis by harming plants and limiting their ability to reduce greenhouse gas pollution.

“We’re pleased that people suffering from some of the nation’s worst air pollution will finally get some relief,” says Victoria Bogdan Tejeda, a staff attorney with the CBD, in a CBD press release. “This agreement starts the process of ensuring that states and the EPA will do the work required by the Clean Air Act to clean up this dangerous pollutant.”

“This agreement gets the EPA back on track in addressing the dangers of smog pollution in communities and regions that desperately need cleaner air,” notes Kaya Allan Sugerman, illegal toxic threats program director with the Center for Environmental Health, in the press release. “We shouldn’t have to sue the EPA to ensure that no one has to breathe air that fails to meet even the most basic health standards set by law. But we are committed to making sure the agency does its job to clean up dangerous air pollution.”