Are radon decay product measurements variable over time?
If a short-term test is conducted (2-3 days in duration) in accordance with EPA protocols, the result will be indicative of the conditions that existed at the time of the test. Certainly conditions that effect radon entry can be different from season to season, even though short-term testing conditions of all exterior doors and windows being closed serves to force the radon entry levels up, they can still vary. The best measure of exposure is a long-term test, lasting for a minimum of 91 days up to a full year under normal lived-in conditions. PGL now offers a long-term radon and radon decay product test device, for further assurance of radon decay product exposures. In essence, radon decay product levels can vary since the radon entry can vary, but radon decay product measurements (either short or long-term) provide the best characterization of actual risk.
