The EPA and the surgeon general state that radon is the second leading cause of cancer, second only to smoking. If a house has elevated levels of radon, the levels can be reduced to below the EPA aciton level of 4 pCi/L for the sam price as replacing a furnace. A bad furnace should not kill a deal. Neither should elevated levels of radon.
Here a checklist for proper testing of a radon test.
1. Closed House Conditions In a real estate transaction the minimum amount of time for a radon test is two days. For this two-day test the windows are to remain closed 12 hours before the start of the test and during the two-day test. The doors can be opened and closed momentarily for normal entry and exit. Closed house conditions does not mean hermitically sealed.
2. Test Location The test should be done in the lowest livable area without renovation. This means a basement either finished or unfinished. It does not mean crawl space, or cellars (low ceilings). A habitable area does not mean a closet or a storage room. There is no requirement for the door to the room being tested to be closed. If the radon tester is doing this, the testers is making up their own rules and beyond those of the EPA radon measurement protocol.
3. Test Device Placement The radon device(s) should be at least 3 feet away from an outside window or outside door. It should be at least 2 feet above the ground. If an hourly continuous radon monitor is being used it can be a single device. If charcoal devices are used, the EPA protocol for real estate transactions required two devices side by side or in serial 2-day tests. The AirChek packets can be hung from a string off a ceiling light or off an inside wall. Some will argue that it must be 4" away from and object. If you use charcoal canisters they sit on a table, stand or other device. This is within 4". They are not suspended in mid air!
3. Homeowner Sign-off It is a good idea to write up the test conditions as state in number 1; and furthere state that the radon test device(s) will not be touched, moved or interferred with. Then have the home owner sign this document.