On the basis of previous survey results of indoor radon for schools, detailed radon survey was conducted in one hundred three selected schools in Korea during the second semester in 2010. According to the results of effective dose assessment due to inhaled radon of during occupancy time, fourteen schools for requiring urgent mitigation action were selected, and recommended to the government.

Seasonal indoor radon concentration was surveyed, and the annual effective dose was estimated for the residents in some dwellings near the registered uranium mining lot areas, considered as one of the potential radon-prone area. The range of indoor radon concentration in each dwelling was from 17.7 to 1,610 Bq⋅m−3. The range of annual effective dose due to inhaled radon of the resident in each dwelling was from 0.93 to 20.5 mSv.

The phosphogypsum is produced as a by-product of the manufacturing phosphoric acid or phosphate fertilizer from the phosphate rock on the wet process. In general, it contains relatively high concentrations of uranium series radionuclides such as 226Ra. This study surveyed overall radioactivity of the naturally occurring radionuclides in a facility using phosphate rock and evaluated the impact on the vicinity environment by the phosphogypsum.