Radon is a radioactive gas. It comes from uranium, which is present in rocks, such as granite, shale, phosphate, and pitchblende. When uranium breaks down, it turns into radium and then decays into radon gas. This gas can then easily move up through the soil and into the atmosphere
All homes should be tested for radon, even those built with radon-resistant features. The Environmental Protection Agency (EPA) recommends taking action to reduce indoor radon levels when levels are 4 pCi/L or higher.
Is radon a significant health risk?
People cannot see, taste, feel or smell radon.
When radon enters a home, it decays into radioactive particles that maintain a static charge, which attracts them to air particles. Consequently, these particles can get trapped in your lungs when you breathe. As these radioactive particles break down even further, they release bursts of energy that can damage DNA in lung tissue. In some cases, if the lung tissue does not repair the DNA correctly, the damage can lead to lung cancer.
Not everyone exposed to elevated levels of radon will develop lung cancer, but your risk of getting radon-induced lung cancer increases as your exposure to radon increases, either because the radon levels are higher or you live in the home longer. Smokers who have high radon levels in their homes are at an especially high risk for getting radon-induced lung cancer.
Radon is classified as a Class A carcinogen (known to cause cancer in humans). Some other Class A carcinogens include arsenic, asbestos and benzene.