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

Abstract

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.