干旱区生态环境知识资源中心

A part of Mansehra Granite was selected for the assessment of radiological hazards. The average activity concentrations of Ra-226, Th-232 and K-40 were found to be 27.32, 50.07 and 953.10 Bq kg(1), respectively. These values are in the median range when compared with the granites around the world. Radiological hazard indices and annual effective doses were estimated. All of these indices were found to be within the criterion limits except outdoor external dose (82.38 nGy h(1)) and indoor external dose (156.04 nGy h(1)), which are higher than the worlds average background levels of 51 and 55 nGy h(1), respectively. These values correspond to an average annual effective dose of 0.867 mSv y(1), which is less than the criterion limit of 1 mSv y(1) (ICRP-103). Some localities in the Mansehra city have annual effective dose higher than the limit of 1 mSv y(1). Overall, the Mansehra Granite does not pose any significant radiological health hazard in the outdoor or indoor.