Measurement of Natural Radioactivity in Coal, Soil and Water Samples Collected from Barapukuria Coal Mine in Dinajpur District of Bangladesh

The activity concentrations of naturally occurring radionuclides Ra-226, Th-232 and K-40, were measured by using a gamma ray spectrometry for coal, soil and water samples collected from the Barapukuria coal mine in Dinajpur district of Bangladesh. The average activity concentrations of Ra-226, Th-232 and K-40 in coal samples were found to be 6.21±3.68, 10.69±7.5 and 185.76±138.86 Bqkg, respectively; and those for active soil samples were found to be 23.54±2.6, 52.10±4.73 and 603.17±66.40 Bqkg, respectively; and for passive soil samples were 36.75±3.38, 76.79±5.53 and 607.18±83.50 Bqkg, respectively. The results for both the soil samples obtained for the corresponding nuclides are slightly higher than the worldwide average values of 35, 30 and 400 Bqkg respectively except that of Ra-226 for active soil samples. The activity contents of the water samples did not show any evidence of enhancement due to the min ing activit ies. The average absorbed dose rate (D) and outdoor annual effect ive dose (E), were observed to be 12.05 nGyh and 0.015 mSvyr for coal, respectively. The values were 67.14 nGyh and 0.083 mSvyr respectively for active soil and 88.86 nGyh, and 0.11 mSvyr, respectively for passive soil. The average absorbed dose rates were h igher than worldwide average values for soil samples. Whereas, the radium equivalent activity and external hazard indices were less than the world average values.