Mitigation decisions in radon measurement should be based on which of the following?

Mitigation decisions in radon measurement should be based on the average result from a continuous monitor because this approach provides a more reliable and comprehensive understanding of radon levels over time. Continuous monitoring allows for an ongoing assessment of radon concentration, capturing fluctuations that may occur due to changes in weather, occupancy, or ventilation.

Using the average from a continuous monitor is beneficial because radon levels can vary significantly during different times of the day or year. This method smooths out those variations and helps to give a clearer picture of long-term exposure, which is crucial for making informed decisions about mitigation.

In contrast, relying solely on the results of the first short-term test might not represent the true radon levels in a home, as short tests can be influenced by temporary conditions. Similarly, averaging two test results from different locations may not provide an accurate assessment of exposure throughout the entire dwelling. Random test results collected from different seasons could also lead to misleading conclusions due to the natural seasonal variations in radon levels. Therefore, the average result from a continuous monitor stands out as the most sound basis for making mitigation decisions.