If a short-term test result exceeds the action level but is less than twice the action level, what should follow?

When a short-term radon test result exceeds the action level but is less than twice the action level, the recommended protocol is to conduct a second short-term test. This step is crucial because it allows for confirmation of the initial result, ensuring that the measurement is accurate and not a false positive due to temporary fluctuations in radon levels.

Short-term tests, which can last from a couple of days to a week, can be influenced by various factors such as weather conditions, household activities, or even the placement of the testing device. By performing a second short-term test, you have the opportunity to verify if the elevated radon level is persistent or if it was an anomaly. If the second test also shows elevated levels, further investigation or remediation would be warranted.

Choosing to do a long-term test or using a continuous monitor may not be appropriate at this stage because these methods are generally reserved for obtaining a more comprehensive understanding of radon levels over time or for confirming long-term exposure risks, rather than for immediate verification following a short-term test result. Therefore, conducting a second short-term test is the best course of action to ensure accuracy in the assessment of radon presence.