Assessment of indoor radon exposure in kermanshah’s educational facilities, and its determinants, health risks, and mitigation strategies

Ensuring a healthy indoor environment for children is crucial, as they are particularly vulnerable to environmental hazards. Indoor radon exposure is a significant concern due to its carcinogenic effects. This study assessed radon concentrations in primary schools and kindergartens in Kermanshah, Iran, estimated the annual effective dose, and evaluated potential health risks. This cross-sectional study randomly selected 24 primary schools and kindergartens across Kermanshah. Radon concentrations were measured seasonally using a radon meter (SARAD, RTM1688). Air samples were collected at breathing height and at least 40 cm from walls. Building characteristics were recorded using a checklist, and meteorological parameters were measured during sampling. Statistical analysis was conducted using SPSS version 25. The average annual radon concentration was 37.1 ± 6.1 Bq/m² in kindergartens and 30.9 ± 6.5 Bq/m² in primary schools. The highest concentration was recorded in winter (39.4 ± 4.9 Bq/m²) and the lowest in summer (30.6 ± 6.1 Bq/m²). Radon concentrations correlated significantly with classroom size and relative humidity (p ≤ 0.01) but not with building age. Ground-floor rooms had higher concentrations, particularly in winter. Rooms with granite walls exhibited the highest radon concentrations (39.15 Bq/m²), while those with plaster and paint had the lowest (28.5 Bq/m²). The estimated annual effective lung dose was 0.28 mSv/y in kindergartens and 0.23 mSv/y in primary schools, both below the UNSCEAR recommended limit of 1.15 mSv/y. Indoor radon concentrations in Kermanshah's primary schools and kindergartens were below WHO and ICRP safety thresholds. However, as radon's effects build up over time, even low levels can contribute to a higher lifetime dose of radiation, increasing health risks over decades and the World Health Organization (WHO) recommend mitigation even at relatively low levels. Therefore, efforts should be made to increase public awareness, and policymakers must implement radon-resistant building codes while maintaining adequate ventilation systems. Further research is needed to identify influencing factors and develop mitigation strategies.