Air Quality is measured by the number of days per year that exceed the federal Environmental Protection Area standard for maximum pollutant concentrations. Measures are only available in areas that are considered “Nonattainment Areas.” Depending on the area, ozone and particulate matter are measured.

Since the enactment of environmental laws in the 1970s, including the Clean Air Act and National Environmental Policy Act, cities have made many efforts to improve air conditions. Poor air quality, especially the presence of particulates, is closely related to the incidence of respiratory diseases such as asthma. In addition to other sources of particulates and ozone, Arizona’s natural environment contributes to air quality concerns. Arizona’s intense sunlight reacts with organic compounds to create ground-level ozone, while desert dust can contribute to particulate matter pollution. In general, urban areas, including Yuma, Nogales, Tucson, and Phoenix, are challenged to address poor air quality to improve health conditions and quality of life.

Air Quality data are updated annually and are available for nonattainment areas.