Radiation Protection Dosimetry Advance Access originally published online on June 30, 2006
Radiation Protection Dosimetry 2006 121(4):466-468; doi:10.1093/rpd/ncl065
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TECHNICAL NOTES
Natural background dose and radium equivalent measurements at Ikogosi warm spring, Nigeria
1 Department of Physics, University of Ado-Ekiti, Ekiti State, Nigeria
2 Department of Physics, Adekunle Ajasin University, Akungba-Akoko, Nigeria
* Corresponding author: niyikaye2002{at}yahoo.com
Received February 20, 2006, amended April 21, 2006, accepted May 7, 2006
| Abstract |
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The natural background dose and the radium equivalent due to the natural radioactivity levels in rocks and sediments collected around Ikogosi warm spring, Nigeria, has been determined in this study using a highly sensitive HpGe detector. The mean activity concentration of 40K, 226Ra and 228Ac were measured to be 585.50 ± 17.40 Bq kg1, 66.91 ± 5.23 Bq kg1 and 48.91 ± 2.10 Bq kg1, respectively, in rock samples while in sediment samples the activity concentrations were found to be 113.89 ± 5.64 Bq kg1 for 40K, 21.47 ± 5.14 Bq kg1 for 226Ra and14.20 ± 1.07 Bq kg1 for 228Ac. This mean values give rise to average absorbed dose rate of 85.87 nGy h1 at a distance of 1.0 m above the ground level and a mean human effective dose equivalent of 0.53 man Sv y1 for rock samples. A radium equivalent of 50.55 Bq kg1 was measured for the sediment samples. The radium equivalent value is far less than the 370 Bq kg1 limit for materials that can be used as building materials while the human effective dose equivalent falls below the world average background dose of 2.4 man Sv y1.