What is radon? Where does it come from?
Radon is a colorless, odorless gas that is produced as one of the stages of the natural decay of uranium into lead. Because soil in many areas contains minute traces of uranium, trace amounts of radon can seep into your house through cracks or holes in the basement, from your crawl space, or from high radon levels in well water.
Why should I be concerned about radon?
Radon is radioactive. It can also get caught up with dust and get stuck in the mucus in your lungs. As the radon continues to decay it produces high energy alpha particles, which can damage your lung tissue and cause cells to mutate. For short periods of time, low or moderate exposure to radon is not overly harmful. But if you are exposed every day in your house or business, the exposure can add up over time to an increased chance of your getting lung cancer. Studies have been done to determine just how harmful normal exposure to radon is. Careful government studies have also shown that radon is currently the second leading cause of lung cancer, second only to cigarette smoking. Thus, elevated levels of radon in your house or business are something to be concerned about.
What are safe levels of radon?
The EPA (US Environmental Protection Agency) has set a threshold for the Radon concentration above which their tests show that an individual has an increased risk for lung cancer over a lifetime of exposure. The EPA's current threshold concentration for radon is 4.0 pCi/L. This is read as “4 picoCuries per liter” of air. This is a very small amount. If your house test results are above this amount, it is suggested that actions be taken to reduce radon concentrations.
Note: Sometimes test results are expressed in Working Levels (WL) rather than picoCuries per liter (pCi/L). 4 pCi/L is equal to 0.02 Working Levels.
Across the US, the average indoor radon level is estimated to be about 1.3 pCi/L, and about 0.4 pCi/L of radon is normally found in the outside air. The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. While this goal is not yet technologically achievable in all cases, most newer homes today can fairly easily be reduced to below 4 pCi/L.