New Ozone Rule Presents Difficulties for Arizona, Officials Say

Oct 2, 2015

The U.S. Environmental Protection Agency tightened its ozone standard yesterday. State officials say that puts many counties in Arizona out of compliance. 

Cars are the major source of ground-level ozone pollution in Arizona.
Credit US Census Bureau

Nine of the ten counties in Arizona monitored for ozone levels exceed the new standard more often than allowed. Officials with the Arizona Department of Environmental Quality say it will be difficult to correct the problem.

Eric Massey, the agency’s air quality director, says Arizona doesn’t have the authority to regulate vehicle emissions, which is the state’s main source of ozone. He also says pollution drifting across state lines is another source that’s hard to curb.

Ozone is formed when pollutants from cars and other sources react with sunlight. It’s linked to respiratory issues and asthma attacks. Levels typically rise in the summer. Some critics say the EPA’s tightened standard still isn’t enough to protect public health.