The EPA recommends that all residences below the third floor level be tested for radon. In addition, the EPA also recommends testing all rooms in contact with the ground or over crawlspaces in schools. If you have tested your home, you should retest every two years since radon levels can change with structural changes in the home. If you decide to use a lower floor of your home, such as a basement, you should test this level before occupancy. In addition, you should always test prior to the purchase of a home.
Short term charcoal tests measure radon levels for exposure periods of 2 days to 7 days. Short term testing is extremely useful when you need results quickly such as during a real estate transaction. Each charcoal canister contains activated charcoal. Radon is adsorbed onto the charcoal and then measured at our lab by counting with a sodium iodide detector.
Using a test kit that meets the EPA requirements, place the test kit in the lowest level of the home suitable for occupancy, at least 20 inches above the floor. The test kit should not be placed in the bathroom or kitchen, where the humidity and use of fans could effect the test results. If a short term test lasting less than 4 days is conducted, doors and windows should be closed 12 hours prior to and throughout the testing period. If the test lasts up to 7 days closed house conditions are recommended. Short term testing should not be done during severe storms or periods of unusually high winds. Place the test kit in an area that will not be disturbed and away from drafts, high heat, high humidity and exterior walls that may have windows or doors. Carefully follow the directions in the test kit and leave it in place for the time period noted in the instructions.