Efficacy of zeolites in radon adsorption: state of the art and development of an optimized approach.

Radon is a radioactive noble gas omnipresent in the environment, being part of the 238 U and 232 Th decay chains present in the Earth's crust. The gas can easily leak through the ground but also be present in natural construction materials and migrate into indoor places where it can be a carcinogen when inhaled. Studying the content and removal of indoor radon is crucial for the evaluation and mitigation of its radiological risks to public health. For more than 100 years, the removal by adsorption of the radon has been performed on activated charcoal. There is little progress in the field of radon adsorption at ambient conditions; the main progress is in the use of zeolite materials, having well-defined three-dimensional porous structures and radiation resistance. This study concerns a report on the state of the art of the application of zeolites in radon adsorption. Furthermore, an optimized approach for measuring the radon content in indoor environments and, consequently, its removal has been proposed. Adsorption systems based on zeolites have the potential to replace activated charcoal as a material of choice, allowing to facilitate the development of simple and compact radon adsorption systems.