Air Pollutants

The Clean Air Act identifies six common air pollutants that are found all over the United States and can injure health, harm the environment or cause property damage. These pollutants include:

The United States Environmental Protection Agency (EPA) has established National Ambient Air Quality Standards (NAAQS) for each of these pollutants. If the air quality in a geographic area meets the NAAQS, it is called an attainment area; areas that do not meet the NAAQS are called nonattainment areas and must develop comprehensive state plans to reduce pollutant concentrations to a safe level.

Air Quality Standard Status

In the 1990s, Davis, Salt Lake, and Utah Counties failed to attain the NAAQS for ozone, particles, carbon monoxide, and sulfur dioxide. However, Salt Lake and Davis Counties were officially re-designated to attainment status for ozone by the EPA in 1997; Salt Lake, Ogden, and Provo Cities were re-designated to attainment for carbon monoxide in 1999, 2001,and 2006 respectively. Requests to re-designate Salt Lake County and part of Tooele County to attainment for sulfur dioxide, and to re-designate Salt Lake and Utah Counties and Ogden City to attainment for PM10 were submitted to the EPA in 2005.

On September 21, 2006, the EPA issued revisions to the NAAQS for particle pollution. The EPA strengthened the 24-hour PM2.5 standard from the 1997 level of 65 µg/m3 to 35 µg/m3, and retained the current annual fine particle standard at 15 µg/m3. See Utah’s Area Designation Recommendation for the 2006 PM2.5 NAAQS (1.9 MB).

In October 2008, the EPA strengthened the NAAQS for lead to increase protection of public health and the environment. The ambient air lead standards—both the primary (health-based) and secondary (environment-based) standards—have been revised to 0.15µg/m3 (micrograms per cubic meter of air). The previous NAAQS issued by the EPA in 1978 were ten times higher (1.5µg/m3).

Air monitoring stations collect representative data that indicates how much of a pollutant is in the air. Currently, 24 air-monitoring stations are strategically located across the Wasatch Front and in Southwestern Utah.

Trend plots have been developed for:

  • Ozone (14 KB) (8 hr averaging time)
  • Carbon Monoxide (51 KB) ( 8-hr averaging time)
  • Particulate Matter
    • PM10 (13 KB), 24-hr averaging time
    • PM2.5 (12 KB), 24-hr averaging time
  • Sulfur Dioxide (13 KB) ( 24-hr averaging time)
  • Lead (41 KB) (24-hr averaging time)

Air pollution concentrations are a function of meteorology and emissions. While meteorology cannot be controlled, the emissions inventory can be controlled and is the focus of air quality control strategies for automobiles and industrial facilities.