Radiation Dose Assessment to Workers Due to NORM Inhalation in the Korean Phosphate Industry

Radiological risks to workers in the phosphate processing industry have not been adequately addressed in Korea. The objectives of the present study were to measure radioactivity concentration of phosphate materials processed within the Korean phosphate industry and to assess internal radiation dose to workers as a result of inhalation. The radioactivity concentration in the phosphate rocks ranged from 92 - 1,100 Bq kg −1 for uranium series and 0.7 - 9 Bq kg −1 for thorium series. Annual inhalation dose varied with processing area and raw materials, widely ranging from 3.58 × 10 −4 to 4.81×10 −1 mSv yr −1 . Particulate concentration in the air and radioactivity concentration of the particulates were critical determinants of worker inhalation dose. The study results can be used as basic data for the development of a safety standard and guide and for practical radiation safety management in the phosphate industry.