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    Air Quality Index

    The ozone that develops at ground-level is created by a chemical reaction between emissions and weather conditions.  The emissions contain volatile organic compounds and nitrogen oxides that are combined with sunlight to later produce ozone.  This newly formed gas is very reactive and capable of damaging our respiratory tract and lungs. 

    There are currently 20 air quality monitors throughout the region that continuously monitor criteria pollutants like ozone.  If air pollution levels actually reach unhealthy levels on monitors, the Texas Commission on Environmental Quality monitoring network will automatically update their exceedance maps to local authorities, news organizations and interested citizens.  The information will be reported visually on an area map utilizing these colors: orange, red, purple and maroon, with maroon being the worst. 

    Our region’s monitors are also used to forecast an Air Pollution Action Day alert.  Air Pollution Action Day alerts are announced when air quality forecasting suggests a high possibility of exceeding the ozone standard of 70 parts per billion for an 8-hour average.  This air quality alert can be used by citizens to reduce ozone forming precursors through increased use of mass transit and other timely pollution prevention efforts.  

    Our region has a partner who has created a comprehensive resource page that allows citizens to easily retrieve local Air Quality Index Maps and Air Pollution Action Day Alert information.  Follow this link to the North Central Texas Council of Governments’ Current Ozone Activity web page.


    The Air Quality Index Chart & Health Message:

    AQI Index chart


    • "Good" The AQI value for your community is between 0 and 50. Air quality is considered satisfactory, and air pollution poses little or no risk.
    • "Moderate" The AQI for your community is between 51 and 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms.
    • "Unhealthy for Sensitive Groups" When AQI values are between 101 and 150, members of sensitive groups may experience health effects. This means they are likely to be affected at lower levels than the general public. For example, people with lung disease are at greater risk from exposure to ozone, while people with either lung disease or heart disease are at greater risk from exposure to particle pollution. The general public is not likely to be affected when the AQI is in this range.
    • "Unhealthy" AQI values are between 151 and 200 is when everyone may begin to experience health effects. Members of sensitive groups may experience more serious health effects.
    • "Very Unhealthy" AQI values between 201 and 300 trigger a health alert, meaning everyone may experience more serious health effects.
    • "Hazardous" AQI values over 300 trigger health warnings of emergency conditions. The entire population is more likely to be affected.