Radon, the primary constituent of natural radiation, is the second leading environmental cause of
lung cancer after smoking. To confirm a relationship between indoor
radon exposure and
lung cancer, estimating cumulative levels of exposure to indoor
radon for an individual or population is necessary. This study sought to develop a model for estimate indoor
radon concentrations in Korea. Especially, our model and method may have wider application to other residences, not to specific site, and can be used in situations where actual measurements for input variables are lacking. In order to develop a model, indoor
radon concentrations were measured at 196 ground floor residences using passive alpha-track detectors between January and April 2016. The arithmetic mean (AM) and geometric mean (GM) means of indoor
radon concentrations were 117.86±72.03 and 95.13±2.02 Bq/m3, respectively. Questionnaires were administered to assess the characteristics of each residence, the environment around the measuring equipment, and lifestyles of the residents. Also, national data on indoor
radon concentrations at 7643 detached houses for 2011-2014 were reviewed to determine
radon concentrations in the soil, and meteorological data on temperature and wind speed were utilized to approximate ventilation rates. The estimated ventilation rates and
radon exhalation rates from the soil varied from 0.18 to 0.98/hr (AM, 0.59±0.17/hr) and 326.33 to 1392.77 Bq/m2/hr (AM, 777.45±257.39; GM, 735.67±1.40 Bq/m2/hr), respectively. With these results, the developed model was applied to estimate indoor
radon concentrations for 157 residences (80% of all 196 residences), which were randomly sampled. The results were in better agreement for Gyeonggi and Seoul than for other regions of Korea. Overall, the actual and estimated
radon concentrations were in better agreement, except for a few low-concentration residences.