When reporting results, what indicates that efforts for radon reduction are not complete?

The idea behind indicating that efforts for radon reduction are not complete lies in the effectiveness of the mitigation measures that have been put in place. When radon reduction shows evidence of effectiveness, it suggests that there are still issues that may require further attention or ongoing monitoring, especially if the levels have not been sufficiently reduced to meet safety standards or regulations.

Radon mitigation typically involves a process that aims to bring radon levels down to acceptable levels, ideally below 4 pCi/L, as recommended by the EPA. Evidence of effectiveness might mean that while there has been a reduction, levels remain above recommended thresholds. This indicates the necessity for additional measures or adjustments in the mitigation strategy, suggesting that the initial efforts have not fully achieved the desired result.

In contrast, if a building is still occupied, testing under different conditions, or if initial levels were low, these factors do not necessarily imply an incomplete mitigation effort. They can reflect the circumstances of testing or occupancy but do not signify ongoing issues with radon levels that necessitate further action. Thus, the effectiveness of mitigation is a more direct indicator of whether those efforts are adequately complete.