Radon is an invisible, odorless gas that is the second leading cause of lung cancer. A simple test can tell you if you have elevated radon levels in your home. Do-it-yourself short-term (3-7 day) radon test kits are sold at hardware stores and some departments of health and are also available from the National Safety Council at www.nsc.org/ehc/radon/coupon.htm. Most are less than $15 and include laboratory analysis with the upfront cost.

Testing your home is simple, but it is important to closely follow the manufacturer's instructions. Your test results will be sent to you after you mail in your sample and the lab processes your kit.

EPA has important information on how to test and fix your home if you have elevated levels of radon, at www.epa.gov/radon/.

If you are building a house, you can make your home less likely to have dangerous radon levels from the start. American Lung Association Health House guidelines recommend using EPA's guidance to build radon resistant houses, at www.epa.gov/radon/construc.html.