(Utah News Connection) A group of health and environmental advocates has sued the Environmental Protection Agency over its failure to enforce air-pollution protections in 30 large cities across the country. 

The lawsuit, filed by Earthjustice, claims the agency did not enforce its own regulations to reduce toxic ozone levels. The cities, including Salt Lake City, Denver, Phoenix and Las Vegas, all rank among the most polluted in the country. 

The Healthy Environmental Alliance of Utah, also known as HEAL Utah, is a plaintiff in the suit. Executive Director Lexi Tuddenham said nothing is getting done while communities and natural areas along the Wasatch Range continue to endure toxic air pollution.

"This particular suit came to our attention," said Tuddenham, "and we decided to become a part of it because it directly affects the way we, as Utahns, can live our lives, and the way that we not only can, site businesses and have economic opportunities, but just basic quality of life."

The EPA missed a February deadline to certify whether the cities had met standards set forth in the 2015 Clean Air Act. Other plaintiffs include Downwinders at Risk, The Alliance of Nurses for Clean Environments, and the Sierra Club. 

Tuddenham said while the area's year-round "brown cloud" affects everyone in the region, it falls hardest on low-income areas and communities of color.

"We also know that people need to be protected," said Tuddenham, "and that the communities that are most affected within that change need to have access to the resources that they need to continue to live their lives."

She said while cities and the states are also responsible for enforcing clean-air regulations, federal intervention is needed to bring those in noncompliance up to standards. 

"The EPA is the standard and the backbone for what needs to happen," said Tuddenham. "And without them enforcing their own rules, essentially, and sticking to their own timeline, we can't move forward."

The American Lung Association ranks the Salt Lake City, Denver, Phoenix, and Las Vegas metro areas among those with the highest levels of toxic ozone, with Salt Lake and Phoenix also among the worst for particulate pollution.