RADIOLOGICAL HAZARDS DUE TO NATURALLY OCCURRING RADIONUCLIDES IN THE SELECTED BUILDING MATERIALS USED FOR THE CONSTRUCTION OF DWELLINGS IN FOUR DISTRICTS OF THE PUNJAB PROVINCE, PAKISTAN

摘要

This paper presents the finding of a study undertaken to determine the naturally occurring radionuclides present in commonly used building materials for dwellings and workplaces in four districts of the Punjab Province, Pakistan. The concentrations of ~(226)RA, ~(232)TH and ~(40)K were measured by using gamma-ray spectroscopy. A total of 80 samples of building materials were collected from various manufacturers and suppliers of the studied area. The specific activities of ~(226)Ra, ~(232)TH and ~(40)K were measured in building samples, and results ranged from minimum values of 9+ 1, 9 + 2 and 27 + 8 Bq kg"' to maximum values of 106 ± 5, 133 ± 5 and 914±21 Bq kg~(-1) with mean values of 42 ± 3, 48 ± 3 and 376±16 Bq kg~(-1), respectively. From the measured activity concentrations, equivalent radium (Ra_(eq)), terrestrial absorbed dose rate, annual effective dose as well as external and internal hazard indices were calculated and found to range from 52 ±7 to 274± 15 Bq kg~(-1), 23 ± 3 to 130 6 nGy h~(-1), 0.15 ± 0.02 to 0.80 ± 0.03 mSv, 0.14 ± 0.02 to 0.75 ± 0.04 and 0.2 ± 0.02 to 0.98 ± 0.05, respectively. These results were comparable to the results of similar studies undertaken locally and in other countries. The samples considered were safe for use in construction of dwellings in the study area and do not pose any significant source of radiation hazard.