What should I do when I want to buy a home and a radon test has already been done? It is very important to select your own radon testing company – tests can be skewed.
How can a radon test be beaten? Simply opening windows or doors prior to or during the test, setting the tester or charcoal canister outside, unplugging the electrical cord on a digital monitor can greatly alter the results. Our electronic testers continuously monitor hourly levels and will show it the unit has been tampered with or if the power has been disconnected. If we see spikes or gaps in the readout, it may invalidate the test and require us to retest.
Passive Short Term Testing: Take two short-term tests at the same time in the same location for at least 48 hours. Alternatively, take an initial short-term test for at least 48 hours immediately followed by a second test, using the same device in the same location as the first test. Fix the home if the average of two tests is 4 pCi/L or more.
Active Short Term Testing: Test the home with a continuous electrical monitor for at least 48 hours. Fix the home if the average radon level is 4 pCi/L or more.
For more information: http://www.epa.gov/radon/realestate.html