General Radon Information

Texas specific radon and radon level information can be found throughout this site. You will be able to find information about certified radon inspectors in Texas, as well as detailed radon level information for every county in Texas.

Radon is an odorless, colorless, naturally occurring radioactive gas that decays into radioactive chemically reactive particles which attach to other airborne particles, such as household dust. If they are inhaled, the radioactive particles may cause damage to lung tissues and increase the risk of lung cancer. High levels of naturally occurring radon are most likely found where there are significant amounts of uranium in the soil or rocks.

How does radon enter the indoor environment? It typically penetrates a building's foundation or is released from well water. The equilibrium levels that are achieved depend on rates of replenishment, radioactive decay and ventilation. Although the average indoor domestic radon level in North America is small, great variations exist. Some houses have radon levels higher than the control levels in underground mines. A survey of 11,600 homes in ten states indicates that as many as 21 percent of homes may exceed the maximum radon level suggested by the U.S. Environmental Protection Agency (EPA). Many of these homes are in areas known to have high background levels of natural radiation. However, not all of the homes in such regions are affected, and not all of the affected homes are located in those regions. Cumulative domestic exposure levels, therefore, can be quite variable, depending on the amount of time spent in the home and the percentage of that time spent in the high-radon areas of the home. Outdoors, the concentrations of radon gas are trivial. These variable readings make it so that the only way to know if an individual house has radon is to test that specific house.

Most often, the radon in your home's indoor air can come from two sources, the soil or your water supply. Compared to radon entering your home through water, radon entering your home through soil is usually a much larger risk. If you are concerned about radon and you have a private well, consider testing for radon in both air and water. The devices and procedures for testing your home's water supply are different from those used for measuring radon in air. Generally, radon is not a problem with public drinking water systems because during the water treatment process aeration releases dissolved radon to the atmosphere. However, if the water supply is from a private well, radon levels could be unacceptably high. The recommendation is to test the well water if the air radon concentrations in the occupied dwelling are over 4pCi/l. If you have tested the air in your home and found a radon problem and your water comes from a private well, you should test the water.

In 1991, the Texas Department of Health, Bureau of Radiation Control (BRC) commissioned a statewide survey of indoor residential radon to determine the extent of the problem in Texas, and to identify potential "hot spots." When viewed on a statewide basis, the radon measurements from nearly 2,700 randomly selected Texas homes were relatively low -- averaging 1.0 pCi/l of air. No level of radon is considered absolutely safe, but the US Environmental Protection Agenction (EPA) recommends fixing your home if the results of one long-term test or the average of two short-term tests taken in the lowest lived-in area of the home show radon levels of 4 pCi/L or higher. The higher the radon level, the more quickly you should have your home fixed.

A 1992 study by the Texas Department of Health monitored indoor air for radon in about 2,700 homes across Texas. The department found four areas with a high potential for radon: the West Texas Panhandle region, the Big Bend area, the Llano Uplift area, and inland from the Coastal Bend in South Texas

Nearly 1 out of 15 homes in the US is estimated to have elevated radon levels. In Texas, the average of radon in homes is within national norms; however, when examined on a county-by-county basis, several areas of Texas are identified where local geology is suspected of contributing to the potential for elevated levels of indoor radon.

The Panhandle area of Texas, especially those counties clustered in a band through its center, is shown to have moderate potential for indoor radon. This area of the state is the only area to report any sizable number of homes with radon levels above 20 pCi/l of air, but, on the average, these areas fall within the "Moderate Potential" zone (between 2 to 4 pCi/L). Texas has no areas of "Highest Potential" (greater than 4 pCi/L) according to the United States Environmental Protection Agency standards, but uranium and its radioactive daughter products are ubiquitous in the South Texas tertiary environment.