What is true regarding short-term tests and closed-building conditions?

Short-term radon tests are designed to provide quick assessments of indoor radon levels, particularly in real estate transactions or urgent situations. For these tests to yield accurate and reliable results, it is essential to maintain closed-building conditions, meaning all windows and doors should remain closed for at least 12 hours prior to and during the testing period. This minimizes external influences on radon levels, such as incoming outdoor air that could dilute or affect the concentration measured during the test.

When closed-building conditions are maintained, the results from short-term tests are more likely to reflect the actual radon levels present in the home or building. If these conditions cannot be maintained, such as in cases of ongoing construction or excessive ventilation, the test results may become unreliable and may not accurately indicate the radon levels one would expect in typical living conditions.

Other options suggest scenarios that do not promote the accuracy and reliability of short-term tests. The requirement for closed-building conditions underscores the necessity for controlled testing environments to obtain valid data on radon levels.