If you live in certain parts of the United States, you might be aware of the threat that radon gas poses. Radon gas is radioactive, and in tightly insulated houses it can accumulate to concentrations that pose a health threat. If you inhale the gas into your lungs, its decay can increase your chance of getting lung cancer. A study reported in 1990 by the National Safety Council estimated that about 14,000 deaths a year could be attributed to radon, and that the number could range from 7,000 to 30,000.

In this edition of How Stuff Works, we'll talk about what radon is, how you can find it in your home and what the health risks are for it.