Mitigating Indoor Radon Exposure: The Effect of Air Purifiers on Radon Progeny

Radon is one of the leading causes of lung cancer worldwide. Following the implementation of the European Council Directive 2013/59/EURATOM, regular measurements of radon concentrations in workplaces have been carried out in European countries for approximately ten years. This provides a basis for assessing the exposure of workers and the general population to radon, as well as for determining the need to implement measures aimed at reducing this exposure. In addition to commonly used methods that focus on eliminating radon sources or minimizing its ingress into buildings, there are also temporary measures available, such as using air purifiers to improve indoor air quality. Although they are not recommended as a standalone or definitive solution, they can be useful as an interim measure—until appropriate actions to reduce indoor radon concentrations are implemented. In this study, five commercially available air purifiers were tested under controlled laboratory conditions to assess their impact on radon and its decay products. The results show that none of the tested devices significantly reduced gaseous radon concentrations. However, the air purifiers were highly effective in removing radon progeny, achieving a 95–99% reduction in potential alpha energy concentration (PAEC) and reducing the equilibrium factor from 48 to 76% to 0–2%. From a sustainability perspective, these findings are relevant for public health protection, responsible consumer decision-making, and evidence-based indoor air quality management. By distinguishing between ineffective radon gas removal and effective reduction of dose-relevant decay products, this study supports sustainable risk mitigation strategies and helps prevent the misuse of energy- and resource-intensive technologies for purposes they cannot fulfill.