Radiometric analysis of micas used in many industries and evaluation of radiological hazards

Mica group minerals have been utilized in various industries such as paint, cement, rubber, plastic, paper, automotive, cosmetics, textile, etc. due to their unique electrical, thermal, and mechanical properties. In this study, the radiometric properties of 58 mica samples collected from three quarries operated commercially in Turkey were investigated using gamma-ray spectroscopy with an HPGe detector. The average activity concentrations of Ra-226, Th-232, and K-40 analyzed in mica samples were found as 12, 44, and 2763 Bq kg(-1), respectively. The radon emanation coefficient and radon mass exhalation rate of mica samples varied from 4 to 22% with an average of 10% and 0.4-5.9 mu Bq kg(-1) s(-1) with an average of 2.6 mu Bq kg(-1) s(-1), respectively. The radiological hazard caused by the utilization of mica samples as raw materials in the cement and concrete industry was evaluated for adults by calculating the gamma index and annual effective dose due to external exposure indoor. The study results revealed that there are no significant radiological hazards associated with the utilization of mica samples as building raw materials.