What is already known about this topic? Indoor radon is the second leading cause of lung cancer after smoking, but previous studies in China have mainly focused on urban areas, with limited data from rural areas. What is added by this report? A survey of 20 cities from 2023–2025 shows that median indoor radon concentrations in rural areas (72 Bq/m3) are higher than in urban areas (65 Bq/m3). Higher levels are also associated with northern regions, low floor levels, brick-wood structures, and energy-efficient buildings. What are the implications for public health practice? It is recommended to control radon release from building materials at the source, improve ventilation, seal cracks in walls and floors, and pay attention to rural and cold climate regions.
Bowei et al. (Thu,) studied this question.