Radon is a naturally occurring radioactive gas produced by the breakdown of uranium in rocks and soils. Radon gas is tasteless, colorless and odorless. The only way to know if it is in your home is to test for it. Our Healthy Homes Website provides more information about keeping your home safe from radon.
For more information on radon, see our Healthy Homes page.
Radon gas has been identified as the second leading cause of lung cancer, second only to cigarette smoking. Radon is responsible for about 20,000 lung cancer deaths every year.
Our radon data come from a contract between the Tennessee Department of Environment and Conservation (TDEC) and Air Check, a private testing laboratory. Many of the test results were performed using free radon test kits offered by TDEC through their cooperative agreement with the U.S. Environmental Protection Agency. Some of data represent tests performed privately by individuals or radon professionals.
Radon is measured in picocuries per liter of air (pCi/L). The average concentration of radon in outdoor air is 0.4 pCi/L. The average radon concentration in the indoor air of America’s homes is about 1.3 pCi/L. The U.S. Environmental Protection Agency has established 4 pCi/L as an action level in which one should initiate measures to reduce the amount of radon in a home. However, there is no safe level of radon.
The data are shown as radon test results aggregated by zip code. All testing was done voluntarily, not at random.
Radon data include:
- Measurement results in picocuries of radon per liter of air (pCi/L)
- State, county and zip code
Limitations inherent with our radon data:
- Data do not represent a random sample
- Data do not show variability from seasonality, if present
- Data are not inclusive of all zip codes
- Data may not represent many tests within a particular zip code
- Data were cleaned for duplicates, although some duplicates will persist
Centers for Disease Control and Prevention (CDC)
Tennessee Department of Environment and Conservation (TDEC)
Online test kit request
U.S. Environmental Protection Agency (EPA)
Agency for Toxic Substances and Disease Registry (ATSDR)