Texas Environmental Regulators Report Cleaner Air

This action eliminates two areas from the state's Air Pollutant Watch List, APWL, and one pollutant from the third area. Both chemicals are emitted by petroleum refining.

"The TCEQ is constantly undertaking a variety of efforts to improve air quality for the people of Texas," said TCEQ Chairman Buddy Garcia today. "In these watch list areas, we can focus all appropriate resources, and the result is cleaner air."

"We are proud of these emissions reductions," said TCEQ Commissioner Bryan Shaw. "TCEQ has many ongoing air quality efforts, and we are always looking at new science and technology to improve our programs."

Petroleum refineries in Houston, Texas, September 2006. (Photo by Ajay Galdhar)

Because of the relatively large number of air monitoring sites in the Houston and Beaumont areas, the TCEQ is able to examine pollution levels of specific compounds at specific locations in order to address potential issues.

The TCEQ maintains an Air Pollutant Watch List - a list of areas in the state where specific pollutants were measured at levels of concern.

When an area is listed, the state agency works with the regulated industry in the area to identify and reduce emissions and focuses agency resources such as facility inspections, field investigations, and enforcement activities.

Additionally, permitting of new or modified sources of these emissions undergo a more stringent review, encouraging reductions by means of the permitting actions.

Because of the successful reductions in air pollution of these specific compounds, the monitored levels of these compounds have dropped below levels of concern.

1,3-Butadiene is a chemical made from the processing of petroleum. A colorless gas with a mild gasoline odor, it is the 36th highest volume chemical produced in the United States.

About 75 percent of the manufactured 1,3-butadiene is used to make synthetic rubber, which is widely used for tires on cars and trucks. The chemical is also used to make plastics and small amounts are found in gasoline.

Levels of 1,3-butadiene near Merriman Street in Port Neches and near Milby Park in Houston have been measured at levels of concern in the past, prompting their listing on the state's Air Pollutant Watch List.

Exposure to 1,3-butadiene occurs mainly from breathing contaminated air. Effects on the nervous system and irritations of the eyes, nose, and throat have been seen in people who breathed air contaminated with this chemical.

Levels have fallen 75 percent in Port Neches since 1996 and in Houston since 2004 and are therefore no longer a concern in these areas, according to the TCEQ.

Hydrogen sulfide occurs naturally in crude petroleum and natural gas and can also result from industrial activities, such as petroleum refineries.

Hydrogen sulfide is a flammable, colorless gas with a characteristic odor of rotten eggs. It is commonly known as hydrosulfuric acid, sewer gas, and stink damp. People can smell it at low levels.

Just a few breaths of air containing high levels of hydrogen sulfide gas can cause death, according to the federal Agency for Toxic Substances. Lower, longer-term exposure can cause eye irritation, headache, and fatigue.

In Beaumont, hydrogen sulfide was measured prior to 2005 at Carroll Street Park at levels that exceeded the TCEQ state standard. Since 2005, no exceedances were measured, therefore the agency has determined that hydrogen sulfide concentrations are no longer a concern in this area.

The commissioners say the TCEQ will continue to monitor these compounds to ensure that concentrations remain below the level of concern.

Copyright Environment News Service, ENS, 2009. All rights reserved.