Background: The decay of uranium and thorium is the primary source of radon emissions, a radioactive gas. The transfer and accumulation of this gas indoors pose serious health risks. Methods: This study investigated indoor radon concentrations in buildings located in areas with different geological characteristics. Thirty-six buildings were examined across three locations in Larijan, Iran, with samples collected from living rooms and bedrooms over a three-month period. Results: The average radon concentrations in bedrooms and living rooms were 114.40 Bq/m3 and 128.35 Bq/m3 , respectively. Indoor radon levels in buildings near hot springs were 24.66% higher than those in buildings close to, and 45.31% higher than those in buildings far from, hot springs. Seasonal variation was also observed: the average concentration in winter was 112.05 Bq/m3 , compared with 130.89 Bq/m³ in summer. These findings indicate that both climatic and geological conditions significantly influence indoor radon levels. Conclusion: Since radon concentrations in most buildings exceeded the World Health Organization (WHO) guideline of 100 Bq/m3 , implementing exposure control programs in residential buildings is essential.
Dadashpoor et al. (Sun,) studied this question.