Under what circumstances should test results not be averaged?

The best circumstances for not averaging test results occur specifically when the results are on either side of the action level or if they were obtained at different times or locations. This is crucial because averaging results in these scenarios can mask significant fluctuations in radon levels that might indicate varying levels of risk. If one test shows radon levels above the action level and another shows levels below it, averaging could provide a misleading representation of the overall radon exposure risk. Additionally, tests taken at different times or locations might reflect the true variability in radon concentrations due to environmental factors such as changes in weather, building occupancy, or seasonality, which are critical to assess for accurate health risk evaluation.

Under conditions where results are consistent and below the action level, or if the test results are repeatable compared to previous measurements, then averaging may be more justifiable, as those situations would typically reflect a stable environment for radon exposure and testing. Hence, not averaging when results are inconsistent related to the action level respects the variability and potentially dangerous nature of radon gas exposure.