Radiation dose estimation from the radioactivity analysis of lime and cement used in Bangladesh

The radioactivity concentrations of 232Th, 226Ra, 40K and 137Cs were measured using high-resolution γ-ray spectrometry in limestone, powdered lime, by-product lime and cement used in Bangladesh. The activity concentrations, Ra equivalent activities, representative level index values for all samples and the effective dose equivalents due to the intake of the above-mentioned radionuclides in limestone and powdered lime by the adult group were estimated. The mean activity concentrations of 232Th, 226Ra and 40K were 60.8, 60.2 and 928 Bq kg-1, respectively for limestone, 107, 68.0 and 1660 Bq kg-1, respectively, for powdered lime and 83.0, 31.0 and 972 Bq kg-1, respectively, for by-product lime. For cement, the mean activity concentrations of 232Th, 226Ra and 40K were observed to be 54.3, 29.7 and 523 Bq kg-1, respectively. The presence of 137Cs was not detectable in any of the studied samples. The measured average activities of 232Th, 226Ra and 40K for all samples were relatively higher than the world typical values except for 226Ra in cement and by-product lime. The calculated mean Ra equivalent values for limestone, powdered lime, by-product lime and cement were 219, 349, 224 and 148 Bq kg-1, respectively. The corresponding representative level index values were found to be 1.63, 2.63, 1.68 and 1.09, respectively. The mean effective dose equivalent values of 232Th, 226Ra and 40K for limestone were 56.5×10-7, 41.6×10-8 and 50.8×10-10 Sv g-1, respectively, and those for powdered lime were 99.5×10-7, 46.9×10-8 and 91.3×10-10 Sv g-1, respectively.