Air Monitoring Reports

Air monitoring helps us understand the quality of our environment and protects the environment and human health. It involves collecting particles and gases in the ambient (outdoor) air and analyzing how weather affects pollutants at specific sites.

The Clean Air Act establishes national ambient air standards for six commonly occurring chemicals, known as criteria pollutants, which can cause harm to humans and the environment. TCEQ monitors concentrations of these and other pollutants at sites across Texas in compliance with federal regulations.

During ozone season, a network of 23 monitors measures ozone, particle pollution (PM2.5 and PM10), lead, sulfur dioxide, nitrogen oxides, carbon monoxide and volatile organic compounds (VOC). Observations of these chemical species are used to form an index of the air’s ability to meet ozone NAAQS. The ozone index is reported on a color-coded basis as an Air Quality Index, or AQI, with green being the best and red the worst. The index is updated every hour.

The AQI is used to communicate air quality levels to the general public. It is an indicator of how bad the air is, and it also tells people what they can do to reduce their exposure.

All monitoring data from the Air Quality Index is published online as a table of results and a map. This data is available to anyone at no cost. It is easy to use and provides information about the air quality at a location on a particular day, and how it compares to ozone and particulate guidelines.

In addition to the statewide monitoring network, DEC conducts special studies to examine specific pollutants in different neighborhoods. For example, the New York City Community Air Survey evaluates how pollution differs between low-income and high-income neighborhoods. The survey monitors pollution from traffic, buildings (boilers and furnaces), and other sources.

EPA’s National Ambient Air Quality Tracking System (leaves DEC website) includes monitors that measure ozone, nitrogen oxides, VOCs, and carbon monoxide. This system is used to determine whether ozone and particulate pollution levels are within the NAAQS, support modeling of pollution control strategies, and contribute to long-term health assessments and ongoing reviews of the NAAQS.

Detailed data for these and other pollutants can be found in the AP-33 air monitoring reports (leaves DEC website). The AP-33 reports also contain historical trend charts of air quality levels.

The EPA’s AirNow website (leaves DEC website) displays real-time ozone and PM levels for the United States, and for several other locations around the world. In addition, AirNow provides forecasted ozone and PM levels for the coming days. The website is also linked to a mobile app that allows you to find near-real time air monitoring data from stations throughout the United States. The app and web pages are free to use.