Radon Exposure: A Comprehensive Review of the Health Risks and Therapeutic Potentials

Radon, a naturally occurring radioactive gas, is classified as a Group 1 carcinogen by the World Health Organization (WHO) and remains a significant environmental health hazard. Traditionally linked to lung cancer, radon exposure is the second leading cause of lung cancer worldwide. Emerging evidence also suggests that radon exposure may contribute to other diseases such as chronic obstructive pulmonary disease, hematological disorders, and skin diseases. This review explores the broad spectrum of health risks associated with radon exposure, including its biological effects at histopathological, cellular, and molecular levels, with a focus on unique radiation effects such as the bystander effect and inverse dose-rate effect. Despite its harmful effects, radon has shown potential therapeutic benefits under controlled exposure conditions. Known as radon therapy, it has been investigated for treating rheumatic diseases, neurological disorders, and even cancer metastasis. The biological mechanisms of radon therapy, including its regulation of oxidative stress, immune modulation, and redox balance, are discussed. The effects of radon-whether harmful or therapeutic-are highly dependent on factors like dose, exposure duration, and individual susceptibility. This review concludes by highlighting key areas for future research to refine our understanding of both the risks and therapeutic applications of radon.