Air Quality Outreach & Education Programs

Ground-Level Ozone and Air Quality

In the 13-county Alamo region surrounding San Antonio, our major air pollutant is ground-level ozone. Unlike ozone that is high up in the earth’s atmosphere and protects us from the more harmful rays of sunlight, ozone that forms in the air we breathe is harmful to humans and other living things.

Ground-level ozone forms when nitrogen oxides, which are found in vehicle exhaust, mix with volatile organic compounds, which are found in gasoline fumes. Nitrogen oxide and volatile organic compounds mix together in intense sunlight to form ground-level ozone. Ground-level ozone typically forms in this region between March and November, when sunlight tends to be the strongest. Thus, the period of time from March through November is referred to as the Ozone Season.

Among other negative effects, ground-level ozone can cause breathing problems and damage lung tissues. It is particularly harmful to those who already have breathing ailments, to those who are young and whose lungs are still developing, and to those who spend a lot of time outdoors.

Ozone Action Days and Banners

Ground-level ozone is considered to be unhealthy for sensitive groups when it reaches a concentration in the air we breathe that is higher than 70 parts per billion (ppb). When scientists predict that the ozone will reach a concentration higher than 70 ppb in this region, the Texas Commission on Environmental Quality (TCEQ) issues an Ozone Action Day Alert. AACOG sends out notifications by email when the TCEQ issues an alert. If you would like to be added to the Ozone Action Day notification list, please contact Jesse Chadwick.

AACOG's Air Quality Outreach & Education program has available three-foot by five-foot banners that can be displayed during an Ozone Action Day. These banners are ideal for display at schools, workplaces, public areas, and other locations where the public may see it and be informed of the alert. For more information or to order a banner, please click here.

Air Quality Educational Resources

The following education material is available for more information. Please feel free to download and distribute this material.