Distribution of natural radioactivity and assessment of radioactive dose of Western Anatolian plutons,Turkey

The distribution of²²⁶Ra,²³²Th,and⁴⁰K in 70 granite samples obtained from 13 Western Anatolian plutons (Turkey) was measured by using γ-ray spectroscopy. The activities of the measured radionuclides varied up to 259 Bq kg^–1 for²²⁶Ra,up to 241 Bq kg^–1 for²³²Th,and up to 2518 Bq kg^–1 for⁴⁰K,with mean values of 66 (±44),90 (±47),and 1097 (±410) Bq kg^–1,respectively,which are smaller than the mean values given for granites worldwide. The mean value of the increase on the external γ-radiation effective dose rate is 0.21 (±0.09) mSv year^–1,varying by <1 mSv year^–1. The mean value of the internal α-radiation was 0.15 (±0.10) mSv year^–1,varying <0.5 mSv year^–1. Most of the samples cause an increase to both the external and internal dose by <30%,which is smaller than the permitted limit. Therefore,there is no radiological risk from the usage of the samples studied as decorative and ornamental building materials.