Norm and associated radiation hazards in bricks fabricated in various localities of the North-West Frontier Province (Pakistan)

The activity concentrations of natural gamma-emitting radionuclides and associated radiation hazards due to K-40, Ra-226 and Th-232 have been measured in baked brick samples, collected from six highly populated areas of the North-West Frontier Province (NWFP) of Pakistan. For the detection, analysis and data acquisition, a high purity germanium (HPGe) detector coupled with a high resolution multichannel analyser (MCA) was used. The range of the average values of the activity concentrations due to K-40, Ra-226 and Th-232 were found to be 680.3 +/- 22.2-784.4 +/- 30.7 Bq kg(-1), 36.9 +/-3.5-51.9 +/-3.3 Bq kg(-1) and 52.5 +/-3.6-67.6 +/-3.1 Bq kg(-1) respectively. Radium equivalent (Ra-eq) activities and various hazard indices were also calculated to assess the radiation hazards. All the brick samples showed Ra-eq activities within the limit (370 Bq kg(-1)) set by the Organization for Economic Cooperation and Development (OECD) countries. The results of different criterion formulae also complemented each other in this study. The derived data have been compared with the reported values for other countries of the world. (C) 2001 Elsevier Science Ltd. All rights reserved.