Concern regarding radiation around your home and family is well founded. Radiation exists in many items encountered every day. In fact, radiation is probably more prevalent than you think. Radiation in the form of radon gas is found in natural stone, like granite, but rarely in harmful quantities.
Radon is a colorless, odorless, radioactive gas. It is a byproduct of the decay of radium and is actually used in cancer treatment. According to the EPA, radon is the second leading cause of lung cancer in the country. The EPA also states that radon is present in almost all stone, soil and water.
Radon Around the Home
All granite countertops have some level of radon. Those levels, however, are not generally high enough to cause any health problems. Radon gas released from a granite countertop, for example, will quickly dissipate in the air, causing no harm to homeowners. According to the EPA, the highest levels of radon found around homes is in the soil, not in granite countertops, bricks or any other natural building materials.
If you're concerned about the levels of radon in your granite countertops, or anywhere else around your home, testing kits are commercially available and easy to use. Do not use Geiger counters to test radon levels in your home. These devices are sensitive and pick up a wide array of radioactive substances, some of which are not harmful. Using a Geiger counter to test for radon will result in inaccurate test results. Use a charcoal test kit calibrated to measure only radon, and follow testing instructions carefully to achieve the most reliable results.
According to the EPA, homeowners experiencing levels of radon higher than 4pCi/L (picocuries per liter), should consider implementing reduction procedures. If an initial test shows high levels of radon, contact your state's radon specialist. Each state has one, and he or she will help you find a certified contractor to determine why your radon levels are high and help you fix the problem. A radon survey done in 1991 showed that the average level of radon in homes is around 1.3pCi/L -- and the air around homes is around .4pCi/L.