Radon in natural gas: a systematic review, CFD simulation, and health effects estimation

This study investigates the health risks associated with exposure to radon (Rn) in natural gas (NG) within indoor environments, particularly in spaces equipped with non-flued appliances. Radon, a radioactive gas, poses significant health hazards, yet no comprehensive meta-analysis had previously estimated pooled concentrations and related risks. Following the PRISMA protocol, 16 relevant studies were systematically reviewed and analyzed across different countries and sampling areas. The pooled volumetric activity of radon was found to be 349.071 Bq/m³, with the highest concentrations detected in gas pipelines, followed by gas industries and gas wells. Computational fluid dynamics (CFD) simulations demonstrated that effective ventilation substantially reduces radon levels near the inhalation zone. This reduction translated into a lower annual effective lung dose, decreasing from 5.80E-02 to 6.70E-02, and a decline in estimated lung cancer incidence from 8.93E-07 to 9.85E-07. The findings highlight the critical importance of monitoring radon activity in indoor NG environments. The use of non-flued appliances, such as gas stoves, may exacerbate exposure risks, highlighting the necessity of adequate ventilation systems. Furthermore, public education and awareness campaigns are essential to mitigate inhalation risks and to promote strategies that minimize radon exposure in domestic settings.