The short and simple answer to the question "What are the signs of radon in my home?" is that there are none. Radon leaves no traces of itself. It does not damage floors, does not discolor walls and leaves no haze in the air. Radon may not be undetectable, but it maintains a low profile, and that low profile compounds its danger.

Radon normally enters your home through the basement.

What is Radon?

Radon is an inert gas, in the same family of "noble gases" as argon, helium, neon, krypton and xenon. Like all of the noble gases, radon is colorless, odorless and chemically nonreactive. But because radon is the byproduct of uranium decay (via the subsequent decay of radium), it is dangerously radioactive, and a clear connection has been established between breathing elevated concentrations of radon and the occurrence of lung cancer. The U.S. Environmental Protection Agency says that radon exposure is the leading cause of lung cancer in nonsmokers.

How Does Radon Enter My Home?

According to Dick Kornbluth, president of Radon Home Services, of Syracuse, NY, and a nationally certified radon mitigator since 1986, the gas typically takes advantage of pressure differentials between the air in your home's basement and the ambient pressure in the ground surrounding it. "Molecules of radon gas are heavier than air, but are small enough to go through cracks in concrete that are too small to see," Kornbluth said.

How is Radon Detected?

Radon is normally detected by the use of either activated charcoal kits or with electronic monitoring devices, over approximately 48 to 96 hours of testing. Although doors may be opened and closed for normal entry and exit, your home should otherwise remain sealed. Keep windows closed for at least 12 hours before the test begins (so that any radon present remains in place), and leave them closed for the duration of the test. The lowest living space of your home should have radon levels no higher than 4.0 picocuries per liter of air.

How is Radon Removed?

Removal and further prevention of radon incursion -- "mitigation," in the vernacular of the trade -- requires a combination of techniques. Holes and visible cracks in basement floors and walls should be sealed to minimize further incursion of the gas. Additionally, a method called sub-slab depressurization -- in which a moderate vacuum is created in a small excavation beneath the basement floor and is then vented to a spot above the roof's eaves -- collects radon and expels it before it can enter your home's basement. Homeowners should contact a certified radon mitigation specialist to learn more about SSD.