What is radon?

Radon is a cancer-causing radioactive gas. It comes from the breakdown of uranium, which is a natural part of soil and rock. Radon is found in rock, soil, water, building materials (such as granite or shale), and natural gas. Radon cannot be detected by human senses because it is odorless, tasteless, and invisible.

How does radon exposure occur?

Any home, school, office, or other building can have a radon problem. Radon may seep in through cracks and pores in the foundation of a house built on radon-contaminated soil. Radon is found in many homes, new and old, well-sealed or drafty. You don't have to have a basement to have a radon problem. The radon can then become trapped inside, especially if the home is well-insulated.

Radon is found in homes all over the world and has been found in every state in the United States. Studies have shown that nearly 1 out of every 15 homes in the U.S. has unsafe levels of radon.^{1, 2} The U.S. Surgeon General and the U.S. Environmental Protection Agency (EPA) recommended in 2005 that all homes be tested for radon levels.

What are the health effects of radon exposure?

Long-term exposure to radon has been linked with lung cancer. Radon is now the second leading cause of lung cancer, after tobacco smoking. It is estimated to cause about 21,000 lung cancer deaths per year in the U.S.¹ The risk of lung cancer is even higher when these causes are combined: smokers have a significantly higher risk for radon-associated lung cancer than nonsmokers.

Can radon exposure be prevented?

You can greatly reduce levels of radon in home, school, and work environments either by preventing it from entering buildings or by venting it out. When having radon professionally vented from your home or office, it is important to have a reputable company's help in following the guidelines set up by the EPA. If you live outside the United States, you can contact your regional environmental protection office for more information.

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