Sources of Radon - Radon Testing

The U.S. Environmental Protection Agency and the Surgeon General of the United States have recommended that all houses should be tested for radon. For more information on radon testing, call the National Radon Information Line at 1-800-SOS-Radon or 1-800-767-7236. As with a home inspection, if you decide to test for radon, you may do so before signing your contract, or you may do so after signing the contract as long as your contract states the sale of the home depends on your satisfaction with the results of the radon test.

What are the Health Effects From Exposure to Radon

No immediate symptoms. Based on an updated Assessment of Risk for Radon in Homes, radon in indoor air is estimated to cause about 21,000 lung cancer deaths each year in the United States. Smokers are at higher risk of developing Radon-induced lung cancer. Lung cancer is the only health effect which has been definitively linked with radon exposure. Lung cancer would usually occur years (5-25) after exposure. There is no evidence that other respiratory diseases, such as asthma, are caused by radon exposure and there is no evidence that children are at any greater risk of radon induced lung cancer than adults.

How do we know radon is a carcinogen?

The World Health Organization (WHO), the National Academy of Sciences, the US Department of Health and Human Services, as well as EPA, have classified radon as a known human carcinogen, because of the wealth of biological and epidemiological evidence and data showing the connection between exposure to radon and lung cancer in humans.

There have been many studies conducted by many different organizations in many nations around the world to examine the relationship of radon exposure and human lung cancer. The largest and most recent of these was an international study, led by the National Cancer Institute (NCI), which examined the data on 68,000 underground miners who were exposed to a wide range of radon levels. The studies of miners are very useful because the subjects are humans, not rats, as in many cancer research studies. These miners are dying of lung cancer at 5 times the rate expected for the general population. Over many years scientists around the world have conducted exhaustive research to verify the cause-effect relationship between radon exposure and the observed increased lung cancer deaths in these miners and to eliminate other possible causes.

In addition, there is an overlap between radon exposures received by miners who got lung cancer and the exposures people would receive over their lifetime in a home at EPA's action level of 4 pCi/L, i.e., there are no large extrapolations involved in estimating radon risks in homes.

When will we know for sure about radon's health risk?

We already have a wealth of scientific data on the relationship between radon exposure and the development of lung cancer. The scientific experts agree that the occupational miner data is a very solid base from which to estimate risk of lung cancer deaths annually. While residential radon epidemiology studies will improve what we know about radon, they will not supersede the occupational data. Health authorities like the Centers for Disease Control (CDC), the Surgeon General, the American Lung Association, the American Medical Association, and others agree that we know enough now to recommend radon testing and to encourage public action when levels are above 4 pCi/L. The most comprehensive of these efforts has been the National Academy of Science's Biological Effects of Ionizing Radiation (BEIR VI) Report. This report reinforces that radon is the second-leading cause of lung cancer and is a serious public health problem. As in the case of cigarette smoking, it would probably take many years and rigorous scientific research to produce the composite data needed to make an even more definitive conclusion.

A Citizens guide to Radon