The MPO monitors local air quality, warns the public when poor air quality is predicted in the coming days, and promotes ways we can all work to reduce air pollution.

What Are Air Pollutants?

There are three major air pollutants/irritants.

Ozone (O3) – occurs in the Earth’s upper atmosphere and at ground level. Ozone in the upper atmosphere protects us from the sun’s harmful ultraviolet rays is considered “good” ozone. In the lower atmosphere or ground level, ozone is harmful to human health and the environment and is considered “bad” ozone. The MPO monitors ground level ozone.

Particulate Matter (PM10 and PM2.5) – is a mixture of solids and liquid droplets found in the air. Coarse dust particles (PM10) which are defined as less than 10 micrometers in diameter – about the width of a single human hair – can get into lungs causing health problems. Sources of PM10 include dust stirred up by vehicles and crushing and grinding operations. Fine particulates (PM2.5) are less than 2.5 micrometers in diameter and are caused by all types of combustion such as motor vehicles, power plants, residential wood burning, forest fires, and agricultural burning.

Climate Change or Greenhouse Gases – are gases that trap heat within the earth’s atmosphere and occur naturally and are generated by human activities including fuel combustion. Some GHG are necessary to keep the earth hospitable for life, but rising levels have been tied to changes in the planet’s temperatures which could lead to harmful effects such as sea-level rise and changes in weather patterns. The transportation sector is estimated to contribute 25-30% of the nation’s greenhouse gas production.

More information on air pollutants and greenhouse gases can be found at and

Air Quality Forecasts and Health Alerts

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The MPO staff utilizes an ozone and particulate matter air pollution forecasting model to predict the Air Quality Index (AQI) level for the next day. A 3-day forecast is completed on Fridays. The models are used during the ozone season (May 1 – Sept. 30) which has the highest rates of ground-level ozone pollution. Warm temperatures and sunlight heat up emissions from cars, factories, and power plants. When pollution is expected to reach a certain level that is unhealthy for sensitive groups, an Air Quality Advisory Alert is issued. If the air quality forecast exceeds the standard set by the EPA, an Air Quality Action Day Alert is issued to let the community know what they can do to help reduce air pollution that day.

Ways We Can Help Reduce Air Pollution

  • Reduce you driving and fuel consumption by using public transportation, walking, carpooling, or riding a bike;
  • Ask your employer to consider flexible work schedules or telecommuting.
  • Trip-chain (plan your daily trips or errands to reduce excess driving).
  • Fill your gas tank during cooler evening hours to cut down on evaporation.
  • Avoid spilling gas and don’t “top off” the tank. Replace gas tank cap tightly.
  • Avoid waiting in long drive-thru lines, for example, at fast-food restaurants or banks. Park your car and go in.

Air Quality Advisory Committee

AQAC is a subcommittee of the Lexington Area MPO and meets periodically (usually 3-4 times per year) to work to reduce air pollution, promote and improve community health, quality of life and livability. The meetings are open to the public and anyone with interest in air quality topics which typically include:

  • federal and state air pollution activities
  • outreach activities
  • upcoming air quality events and milestones
  • reporting on Fayette and Jessamine County air pollution monitor readings

Please contact the MPO office for meeting details or if you would like to be added to the AQAC mailing list.