WHAT IS RADON?

Radon is a radioactive gas. It's colorless, odorless, tasteless, and chemically inert. Unless you test for it, there is no way of telling how much is presently in your home.

Radon is formed by the natural radioactive decay of radium and uranium in rock, soil, and water. Naturally existing, low levels of uranium occur widely in the Earth's crust. It can be found in all 50 states. Once produced, radon moves through the ground to the air above. Some remains below the surface and dissolves in water that collects and flows under the ground's surface.

Radon has a half-life of about four days - half of a given quantity of it breaks down every four days. When radon undergoes radioactive decay, it emits ionizing radiation in the form of alpha particles. It also produces short-lived decay products, often called progeny or daughters, some of which are also radioactive. Unlike radon, the progeny are not gases and can easily attach to dust and other particles. Those particles can be transported by air and can also be breathed. The decay of progeny continues until stable, non-radioactive progeny are formed. At each step in the decay process, radiation is released.

HOW DOES RADON GET INTO YOUR HOME?

Most indoor radon comes into the building from the soil or rock beneath it. Radon and other gases rise through the soil and get trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings. Once inside, the radon can become trapped and concentrated.

Openings which commonly allow easy flow of the gases into your home:

*Cracks in floors and walls

*Gaps in suspended floors

*Openings around sump pumps and drains

*Cavities in walls below grading

*Gaps around utility penetrations (pipes and wires)

*Crawl spaces that open directly into the building

Radon may also be dissolved in water, particularly well water. After coming from a faucet, about one ten thousandth of the radon in water is typically released into the air. The more radon there is in the water, the more it can contribute to the indoor radon level. Trace amounts of uranium are sometimes incorporated into materials used in construction. These include, but are not limited to concrete, brick, granite, and drywall. Though these materials have the potential to produce radon, they are rarely the main cause of an elevated radon level in a building. Outdoor air that is drawn into a building can also contribute to the indoor radon level.

The average outdoor air level is about 0.4 pCi/L, but it can be higher in some areas. While radon problems may be more common in some geographic areas, any home may have an elevated radon level. New and old homes, well-sealed and drafty homes, and homes with or without basements can have a problem.

Radon levels can be higher in homes that are well insulated, tightly sealed, and/or built on uranium-rich soil. Because of their closeness to the ground, basement and first floors typically have the highest radon levels. All homes below the third floor of a multi-family building are particularly at risk.

Health effects associated with Radon exposure?

There have been no reports of short-term effects or symptoms caused by radon exposure. The only reported long-term effect is lung cancer. The Surgeon General has warned that radon is the second leading cause of lung cancer in the United States. There are currently no conclusive data on whether children are at greater risk than adults from radon. No specific subtype of lung cancer is associated with radon exposure. Scientists estimate that approximately 15,000 to 22,000 lung cancer deaths per year are related to radon.

Radon is present in nearly all air. Everyone breathes in radon every day, usually at very low levels. However, people who inhale high levels of radon are at an increased risk for developing lung cancer. If you inhale a radon atom, the atom can disintegrate while it is in your lungs. When it disintegrates, it becomes polonium-218, which is a metal. This metal atom can get trapped in your lungs, and over the next hour or so it will emit a number of alpha particles, beta particles and gamma rays.

It eventually turns into lead-210 with a half-life of 22 years, which is fairly stable in this context. But now you have an atom of lead in your system, which causes its own problems. It?s the quick, hour-long sequence of alpha, beta and gamma emissions that can lead to the mutations in the lung tissue, which can cause lung cancer over the course of your lifetime.

Smoking enormously increases the risk of lung cancer from radon exposure. If you smoke and you are exposed to elevated radon levels, your risk of lung cancer is especially high. Stop smoking now and lower your radon level to reduce your lung cancer risk. Not everyone exposed to elevated levels of radon will develop lung cancer, and the amount of time between exposure and the onset of the disease may be many years. Breathing radon does not cause any short-term health effects such as shortness of breath, coughing, headaches, or fever.

So, you can see that a high concentration of radon gas, despite the fact that it is completely natural, is not something you want in your home.

WHAT IS THE "ACCEPTABLE" LEVEL OF RADON IN AIR?

4.0 pCi/L or LESS (According to the EPA)

HOW OFTEN IS INDOOR AIR A PROBLEM?

Nearly one out of every 15 homes in the United States has a radon level EPA considers to be elevated - 4 pCi/L or greater. The U.S. average radon-in-air level in single family homes is 1.3 pCi/L. Because most people spend as much as 90 percent of their time indoors, indoor exposure to radon is an important concern.

Radon Risk Comparison Charts

Radon Risk If You Smoke

Radon Risk If You've Never Smoked