Carbon Monoxide Exceedances in Arizona
The data show the number of nonoverlapping 8-hour values above the level of the standard. The National Standard for this criteria pollutant is 9.0 parts per million (ppm). There have been no reported carbon monoxide exceedances this decade. On January 5, 2005, EPA finalized the rule to redesignate the Phoenix metropolitan area in Arizona to attainment for the National Ambient Air Quality Standard (NAAQS) for carbon monoxide (CO), as well as to approve the attainment demonstration and maintenance plan showing maintenance of the CO standard through 2015 (from http://www.epa.gov/region09/air/phxco/index.html).
Data were collected in February 2009 by Arizona State University's Decision Center for a Desert City (DCDC) using records from the U.S. Environmental Protection Agency's Monitor Trends Report - Criteria Air Pollutants for Arizona Counties for years 1998-2008.
Air pollutants contribute to numerous health and visual impairments such as asthma, heart disease, and regional haze. Ozone, carbon monoxide, and particulate matter (PM10--particles between 2.5 and 10 microns in size) are three of the six common air pollutants identified by the EPA as being critical to assessing environmental health of a place.
Readers are cautioned not to infer a qualitative ranking order of geographic areas based on AirData reports. Air pollution levels measured in the vicinity of a particular monitoring site may not be representative of the prevailing air quality of a county or urban area. Pollutants emitted from a particular source may have little impact on the immediate geographic area, and the amount of pollutants emitted does not indicate whether the source is complying with applicable regulations.
Disclaimer: AirData reports are produced from a monthly extract of EPA's air pollution database, AQS. They represent the best information available to EPA from state agencies on that date. However, some values may be absent due to incomplete reporting, and some values subsequently may be changed due to quality assurance activities. The AQS database is updated daily by state and local organizations who own and submit the data. Please contact the pertinent state agency to report errors.