Natural gamma-emiting radionuclides in Pakistani Portland cement.

Studies of the natural gamma-emitting radionuclides in Portland cement manufactured in the North West Frontier Province (NWFP) of Pakistan and the various raw materials which compose the product have been carried out using gamma-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 (40K, 226Ra and 232Th) were found to be 187.8+/-63.5-573.2+/-73.1 Bq kg(-1) (Portland cement); 54.5+/-16.1-183.9+/-31.4 Bq kg(-1) (limestone); 87.1+/-30.7-297.1+/-64.4 Bq kg(-1) (gypsum); 696.4+/-79.1-1043.9+/-85.0 Bq kg(-1) (slate); and 490.9+/-54.5-570.2+/-59.8 Bq kg(-1) (latrite). The average specific activities due to 40K in Portland cement and all the raw materials were found to be higher when compared with 226Ra and 232Th. Such materials do not pose any excess radiological health problem.