Ozone

History

In 2018, the US Environmental Protection Agency (EPA) designated nine counties in North Central Texas as "marginal" nonattainment for the 2015 8-hour ozone National Ambient Air Quality Standard (NAAQS). These standards are designed to protect human and environmental health, and ground-level ozone is monitored and targeted for reductions due to its potentially harmful effects.

The region has made significant progress since first being designated nonattainment in the 1990s. Information about the current ozone concentration and trends can be found here. The North Central Texas Council of Governments will continue to work with partners and encourage the involvement of residents and employees to meet the 2015 standard of 70 ppb or less to ensure a good quality of life for people of all ages.

Ozone Basics

Ozone forms when nitrogen oxides (NOx) and/or volatile organic compounds (VOCs) combine with sunlight and intense heat. Primary emissions sources include:

Off-road vehicles such as construction equipment, lawn equipment, aircraft and locomotives
Point area sources such as cement and power plants
On road vehicles such as cars, trucks and buses
Area sources such as oil and gas drilling, bakeries, paint shops and dry cleaners
Biogenic sources like vegetation and forest fires

Historical emphasis has indicated that NOx reductions are the most appropriate way the region can lower ozone levels. On-road vehicle activities account for nearly half of the NOx inventory.

Ozone & Health

Inhaling ground-level ozone is especially dangerous for people who have asthma or respiratory problems, and they may experience increased frequency of asthma attacks and health care needs. Young children may also be at risk for developmental problems associated with ozone exposure. People without respiratory problems or asthma can also experience health effects from ozone exposure, such as the following.

Coughing
Throat irritation
Chest tightening
Pain, burning or discomfort when taking a deep breath
Shortness of breath

Become familiar with the Air Quality Index (AQI) to better understand the severity of pollution and related health impacts. The AQI is used for reporting daily air quality levels. Colors indicate how polluted the air is and how to protect your health.

Click on the colors to learn more.

When the AQI is green, air quality is good and safe for everyone.

When the AQI is yellow, air quality is moderate. Unusually sensitive groups should consider limiting prolonged or heavy outdoor exertion.

When the AQI is orange, air quality is unhealthy for sensitive groups. Active children and adults, along with those with respiratory diseases such as asthma, should reduce prolonged or heavy outdoor exertion.

When the AQI is red, air quality is unhealthy. Active children and adults, along with those with respiratory diseases such as asthma, should avoid prolonged outdoor exertion. Everyone else should reduce prolonged or heavy outdoor exertion.

When the AQI is purple, air quality is very unhealthy. Active children and adults, along with those with respiratory diseases such as asthma, should avoid all outdoor exertion. Everyone else should avoid prolonged or heavy outdoor exertion.