After completing mitigation, when is the earliest that a short-term test can be conducted?

• A. Immediately after mitigation
• B. 1 hour after mitigation
• C. 24 hours after mitigation
• D. 48 hours after mitigation

Answer: (C)

Conducting a short-term radon test is critical after mitigation to ensure that the radon levels have been effectively reduced and remain within acceptable limits. The appropriate timeframe for this test is at least 24 hours after mitigation has been completed. This gap allows for the building's ventilation and other environmental conditions to stabilize following the changes made during the mitigation process.

If testing occurs too soon—such as immediately after mitigation or just one hour later—there may still be residual effects from the mitigation methods that could produce misleading results. By waiting 24 hours, it helps ensure that any radon concentration fluctuations resulting from the recent mitigation actions have settled, and allows for a more accurate representation of the radon levels in the dwelling.

This 24-hour waiting period is important for obtaining a reliable short-term test result, accurately reflecting the effectiveness of the mitigation and the current radon levels within the home.