ALBUQUERQUE, N.M. — An environmental group filed a petition with the U.S. Environmental Protection Agency on Tuesday to force 16 Western states to revise their air quality regulations in an effort to trim ozone pollution.

WildEarth Guardians contends in its 25-page filing that large cities throughout the West have already violated clean air standards limiting ozone and the problem is spreading.

“The Western states are facing an unprecedented challenge in addressing the impacts of ozone air pollution. For the sake of public health, it is a challenge that must be met aggressively,” Jeremy Nichols, WildEarth Guardian’s climate and energy program director, wrote in the petition.

Ground-level ozone forms when emissions from tailpipes and smokestacks mix with sunlight. The colorless gas can irritate the respiratory system.

WildEarth Guardians is asking the EPA to force New Mexico, Arizona, California, Colorado, Idaho, Kansas, Montana, Nebraska, Nevada, North Dakota, Oklahoma, Oregon, South Dakota, Utah, Washington and Wyoming to revise their air quality regulations to strengthen ozone safeguards by 2013.