WASHINGTON— In response to a lawsuit filed by environmental groups, the Environmental Protection Agency committed today to steps that will ensure parts of California and Colorado have effective plans to reduce smog.

Today’s agreement addresses California’s Coachella Valley and Kern County, which has the state’s highest oil production and some of the worst air quality in the nation. The suit, which was filed by the Center for Biological Diversity and Center for Environmental Health, also addressed the Metro Denver area and the Front Range in Colorado. These areas are home to over 6 million people.

“We are pleased that the EPA has agreed to take steps to reduce asthma-causing smog,” said Ashley Bruner, an attorney at the Center for Biological Diversity. “As we transition to cleaner energy, we need to do everything we can to reduce the air pollution from fossil fuels.”

The agreement requires that California and Colorado have plans in place to clean up the dangerous ozone air pollution from numerous sources, including from the petroleum and the oil and fracked-gas industries.

Excess ground-level ozone, the principal component of smog, impairs lung function, causes asthma attacks and aggravates respiratory diseases such as bronchitis and emphysema, which can lead to premature death. Children, older people, people who work or exercise outside, and those with respiratory conditions are most at risk.

Every year that smog continues to violate the national standards up to 390,000 more asthma attacks will occur in children. In 2013 children missed 13.8 million school days because of asthma — making it the top cause of missed school days in the United States.

“Children breathe easier with less smog in the air,” said Kaya Sugerman with the Center for Environmental Health. “We will continue to ensure that the EPA puts the interests of kids and families ahead of the profits of polluters.”

Beyond the human health concerns, ozone pollution also harms wildlife and plants. Ozone hurts forests by damaging needles and leaves and increasing forest fires, disease and insect infestations. Sensitive tree species at risk from ozone exposure include aspen, ponderosa pine and cottonwood, all of which provide essential habitat for imperiled birds and butterflies.

Ozone even impacts majestic national parks, where the ground-level ozone concentrations are often indistinguishable from those found in major cities. In 2020, 26 national parks, including Rocky Mountain National Park in Colorado and Sequoia and Kings Canyon national parks in California, had at least one day when ozone concentrations were dangerously high.