Natural radioactivity measurements in some Indian building materials

The present work deals with the radioactivity measurements of some Indian building materials using gamma ray spectrometry. The activity concentration obtained for 226Ra, 232Th and 40K ranged from 8.3 to 88.47, 8.45 to 95.29 and 23.43 to 155.46 Bq kg-1, with the mean values of 42.57, 34.85 and 63.25 Bq kg-1 respectively. To assess the radiological hazard of the natural radioactivity in the samples, the radium equivalent activity the absorbed dose rate and the external hazard index were also calculated. The study yields an annual effective dose equivalent in the range of 0.6 to 11.73 x 10-5 Sv with a mean value of 5.77 x 10-5 Sv. The results suggest that the use of such building materials in the construction of domestic dwellings or workplaces in India is unlikely to give rise to any significant radiation exposure to the occupants. The uranium calculated using fission track registration technique and the values ranged from 0.69 to 2.28 ppm. (author)