Who regulates the air in Houston?

The National Ambient Air Quality Standards (NAAQS) are established under the Clean Air Act. The U.S. Environmental Protection Agency (EPA) is charged with setting the NAAQS values to protect public health and welfare. Those values are set based on scientific knowledge and are reviewed every five years to integrate the most recent data on the health effects from each pollutant. The Texas Commission on Environmental Quality (TCEQ) collects and evaluates … Continued

What is ppb and ppm?

Ozone is measured by the concentration of ozone within the air, and units are recorded in parts per billion (ppb). For example, one ppb is the equivalent of one drop in one billion drops of water or about one drop of water in a swimming pool. Another unit of measurement for some of the air quality standards is parts per million (ppm), and one ppm is the equivalent of about … Continued

Houston meets all other national air quality standards. Why not ozone?

Houston faces several unique challenges. Houston’s summer weather conditions can be ideal for allowing ground level ozone to form. Also, Houston has been challenged in its efforts to meet the ozone standard because the region is home to the largest concentration of petrochemical and refining facilities in the nation. Researchers took many years to develop and design technologies to reduce emissions from industrial sources, but over the years, the industry … Continued

What is ozone?

Ozone is a complex pollutant. While ground level ozone is considered to be an air pollutant, ozone is also naturally present in the Earth’s upper atmosphere and filters the ultraviolet rays of the sun. Ground level ozone is formed when volatile organic compounds and nitrogen oxides – emitted from industrial facilities, power plants, vehicle exhaust, household solvents and trees – react in sunlight under the right weather conditions. Ozone can … Continued

What are the National Ambient Air Quality Standards (NAAQS)?

National Ambient Air Quality Standards (NAAQS) are a set of standards for six air pollutants, known as criteria pollutants: particulate matter ground level ozone carbon monoxide sulfur dioxide nitrogen dioxide lead Criteria pollutants are common air pollutants that are found worldwide at varying levels and can be harmful to human health and the environment. The NAAQS are established by the U.S. Environmental Protection Agency (EPA) under the Clean Air Act. … Continued

What are the sources of air pollution in Houston?

Air pollutants may exist as solid particles, liquid droplets or gases and may originate from: 1 – large stationary sources – refineries, power plants, smelters, boilers, and smaller sources such as dry cleaners and degreasing operations 2 – mobile sources – cars, construction equipment, buses, planes, trucks, marine vessels and trains 3 – naturally occurring sources – wildfires [link to blog post on haze/smoke], wind-blown dust, some tree species, and … Continued

Is Houston’s air quality getting better or worse?

Houston’s air quality has dramatically improved since the late 1980s, and it’s no accident. Despite hot, humid summer weather that makes for ideal ground level ozone formation and being home to the largest concentration of petrochemical and refining facilities in the nation, Houston remains compliant with five out of the six federal health-based standards for common air pollutants. Furthermore, since 2010, the Houston region has added more than 736,000 residents, … Continued

Ozone Levels in 2015: What Can We Learn from the Data?

The greater Houston region has been working for many years to meet EPA’s health-based standard for ozone. Over the past 15 years, we have seen significant decreases in both ozone levels and the number of days that the standard was exceeded in Houston. In fact, 2014 was our cleanest year on record.