What factor is essential for determining the effectiveness of a radon mitigation system?

The concentration of radon before mitigation is essential for determining the effectiveness of a radon mitigation system because it establishes a baseline level of radon present in the environment prior to any intervention. By knowing the initial concentration, mitigation specialists can gauge how effective the system has been in reducing radon levels once it is installed. This assessment is crucial because it allows for the evaluation of whether the mitigation system has adequately reduced radon to acceptable levels as per health guidelines.

Moreover, the success of any mitigation strategy is ultimately measured by its ability to bring radon concentrations down from a higher, potentially hazardous level to the safer recommended levels, which reinforces the importance of having a clear understanding of the pre-mitigation radon concentration. Monitoring these levels post-mitigation further informs adjustments that might be needed for ongoing effectiveness.