Natural gamma-emiting radionuclides in Pakistani Portland cement

Studies of the natural gamma-emitting radionuclides in Portland cement manu factured in the North West Frontier Province (NWFP) of Pakistan and the var ious raw materials which compose the product have been carried out using ga mma-spectrometric techniques. For data acquisition a high-purity germanium detector (HPGe) was used. The range of the total specific activity (minimum and maximum values) due to all the three radionuclides (K-40, Ra-226 and T h-232) were found to be 187.8 +/- 63.5-573.2 +/- 73.1 Bq kg(-1) (Portland c ement); 54.5 +/- 16.1-183.9 +/- 31.4 Bq kg(-1) (limestone); 87.1 +/- 30.7-2 97.1 +/- 64.4 Bqkg(-1) (gypsum); 696.4 +/- 79.1-1043.9 +/- 85.0 Bqkg(-1) (s late); and 490.9 +/- 54.5-570.2 +/- 59.8 Bqkg(-1) (latrite). The average sp ecific activities due to K-40 in Portland cement and all the raw materials were found to be higher when compared with Ra-226 and Th-232. Such material s do not pose any excess radiological health problem. (C) 2001 Elsevier Sci ence Ltd. All rights reserved.