Abstract
INTRODUCTION: This study aimed to establish a new predictive model for indoor radon concentrations. METHODS: We constructed a radon experimental model using prefabricated block walls and measured surface radon exhalation rates across multi-layer walls. The geometric parameters of various building envelopes (walls, floors, and roofs) were incorporated to calculate indoor radon concentrations from each source. Natural ventilation rates were also considered in developing the indoor radon concentration prediction model. RESULTS: Using closed-loop measurements, we determined the surface radon exhalation rates of prefabricated block walls and established fitting functions for multiple walls under varying temperatures and thicknesses. Based on indoor geometric parameters and natural ventilation rates, we developed a comprehensive prediction model for indoor radon concentrations. The model accurately predicted indoor equilibrium radon concentrations from prefabricated walls (thickness 0.155-0.268 m) at 23 ℃, with deviations less than 10% from measured values within ventilation rates of 0.115±0.015 /h. CONCLUSIONS: This scientifically rigorous and practical approach to predicting radon concentration, based on building composition and measurements of radon exhalation rates, enables proactive assessment of indoor radon concentrations and facilitates evidence-based health risk prevention strategies.