Radon-enriched hot spring water therapy for upper and lower respiratory tract inflammation

Background Radon-222-enriched hot spring therapy, which is characterized by a safe level of radioactivity, is used for the treatment of rheumatic disorders, and its efficacy has already been studied in several clinical trials. Radon-water inhalation therapy for the treatment of upper and lower airway inflammatory diseases is used in many hot springs centers. However, its application has not been reviewed to date. Methods We systematically searched the PubMed and Scopus databases for clinical trials published in the last 20 years in which objective parameters of upper and lower airway function had been tested before and after radon-enriched inhalation treatment. Results Four prospective studies were found: 1 asthma trial, 1 placebo-controlled chronic rhinosinusitis trial, 1 upper respiratory tract inflammation with nasal obstruction trial, and 1 case-control allergic rhinitis trial. Patients were treated with nasal inhalations of radon-enriched water for 12 to 28 days and were assessed at baseline and after therapy. After 2 weeks of treatment, nasal resistance decreased, flow increased, mucociliary clearance was enhanced, ciliated-to-muciparous cell ratio increased, and %FEV1 increased in asthmatic patients. Conclusion Radon-enriched inhalation therapy improves objective indicators of nasal function in allergic rhinitis and chronic rhinosinusitis, and causes relief of pulmonary obstruction in asthma.