Ozone Information

 Reducing Ozone | Ozone Monitoring | Eight-Hour Ozone Information | Links

The Missouri Department of Natural Resources monitors ozone across the state during the ozone season, which begins April 1 and ends Oct. 31. Naturally occurring ozone in the upper atmosphere protects the earth from the sun's harmful rays. Ground-level ozone, commonly known as smog, is a gas that is created when pollution from vehicles, businesses and power plants combine in the presence of sunlight. The pollutant is formed when heat and sunlight mix with Volatile Organic Compounds, or VOCs, and nitrogen oxides, or NOx, in the lower  atmosphere. Typically, ozone pollution is more of a problem in the hot summer months because sunlight and warm temperatures speed up the formation of ground-level ozone.

Exposure to ground-level ozone can contribute to health and environmental problems. Ground-level ozone is an irritant that damages lung tissue and aggravates respiratory disease. Ozone can trigger a variety of health problems. Those most susceptible to ozone include children, the elderly and individuals with pre-existing respiratory problems. Children are at increased risk from exposure to ground-level ozone because their lungs are still developing. Healthy adults can experience problems breathing, especially those who exercise or work outdoors.

Reducing Ozone
Simple everyday steps can help reduce the emission of harmful pollutants that are derived from vehicles and coal-fired power plants that produce our energy. These emissions contribute to the formation of ground-level ozone.

Ozone-reducing activities include:

• Keep tires properly inflated.
• Use mass transit, carpool, bike or walk.
• Do not top off gas tanks. Stop at the first click.
• Do not use gas-powered lawn equipment on hot, sunny days with little or no wind. Consider waiting until early evening to mow your lawn.
• Conserve energy by turning off lights and appliances when leaving a room to reduce emissions from power plants. Purchase Energy Star® appliances.
• Set goals to reduce utility bills by two percent. This can save money and protect air quality.

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Ozone Monitoring
The department maintains and collects data from air monitors across Missouri to see if Missouri’s air quality meets the Environmental Protection Agency’s National Ambient Air Quality Standards. If an area monitors or contributes to violations of the ozone standard, actions must be taken to reduce the emissions that contribute to the formation of ground-level ozone. The department works with affected areas to develop emission reducing measures that are the most effective in terms of cost and emission reductions.

Ozone Monitoring Data

• Missouri Air Quality Data System. Today's Ozone Levels
• Summary of Monitored Ozone Values.

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Eight-Hour Ozone Information
The U.S. Environmental Protection Agency has proposed a more protective eight-hour average ozone standard. This new standard is expected to fall within the range of 60 to 70 parts per billion, or ppb, of ozone and is expected to be finalized in July, 2011. EPA’s current primary eight-hour average ozone standard promulgated in 2008 is 75 parts per billion, or ppb. In 2010, after the 2008 standard was proposed for reconsideration, the department held three stakeholder meetings.  These three meetings were held in St. Louis, Kansas City and Springfield. The agendas for these meetings and the presentations are posted below.

• Stakeholder Meetings
  • St. Louis Area Meeting - Aug. 24, 2010
    • Agenda.
    • Presentation.
  • Kansas City Area Meeting - Aug. 19, 2010
    • Agenda.
    • Presentation.
  • Springfield Area Meeting - Nov. 17, 2010
    • Agenda.
    • Presentation.
• Revised 2008 8-Hour Ozone Standard Boundary Recommendation

Revised 2008 8-hour Ozone Standard Boundary Recommendation (12/11)

On Sept. 22, 2011, the U.S. Environmental Protection Agency released a memorandum to clarify for states the status of the 2008 Ozone National Ambient Air Quality Standard. In this document, EPA explicitly stated that the current standard is 0.075 parts per million, or 75 parts per billion. EPA also announced their intentions to move forward with designations under the 2008 National Ambient Air Quality Standard, starting with the recommendations made by states in 2009, and then updating them with the most current, certified air quality data from the 2008 to 2010 monitoring period.   

• 2008 Boundary Designations

Boundary Recommendation Letter to the U.S. Environmental Protection Agency
The 2008 Eight-Hour Ozone Boundary Recommendation Documents
The 2008 Eight-Hour Ozone Boundary Designation Process

• 2003 Boundary Designations
  Missouri Response to EPA Letters Dated Dec. 4 and 12, 2003  (02/04)
  Eight-Hour Ozone Designation EPA Response Letter for Missouri

• State Implementation Plan Development Process
  St. Louis Eight-Hour Ozone and PM2.5 State Implementation Plan, or SIP, Workgroup
  Missouri Status on Implementation of the Eight-Hour Ozone Standard, Fact Sheet (05/03)

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Other Ozone Links

EPA Ozone webpage
St. Louis Regional Clean Air Partnership - St. Louis Air Quality Forecast
Kansas City AirQ - Kansas City Air Quality Forecast
APCP Calendar of Events
Missouri Air Quality Monitoring Network
Other Environmental Links

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