PHOENIX -- Maricopa County dust levels are meeting federal standards for the first time in more than 40 years.
The U.S. Environmental Protection Agency on Friday announced its approval of the county's Five Percent Plan.
The plan, which was last submitted to the EPA in 2012 with revisions, sought to reduce dust emissions of at least 5 percent each year between 2007 and 2013.
Officials in Phoenix and surrounding cities say they have been implementing aggressive dust control policies. They say the plan includes more than 53 measures.
Maricopa County air quality officials say the county had failed to meet federal standards for dust since the Clean Air Act was amended in 1970.
The EPA says dust is a public health concern because particulate matter affects the respiratory system.