Assessment of Natural Radioactivity for Some Secondary Ceilings Samples in Iraq
This research focuses on measuring of specific activity of natural radioactive sources (238U, 232Th and 40K) in some types of secondary ceilings that used as a decorate material and available in Iraqi markets. The measurements were done using gamma ray spectroscopy system that based on NaI(Tl) Detector. Also, the radiological hazard indices have been assessed for all samples in present study. The results show that the specific activity vary from 8.7±0.6 to 32.9±2.3 Bq/kg for 238U, 2.9±0.2 to 40.3±1.5 Bq/kg for 232Th, and 117.4±2.6 to 649.1±7.9Bq/kg for 40K. The latter levels were compared with the world mean values that reported by the UNSCEAR 2008. It was found that all values of 238U and 232Th were below the world wide published values, while the values of only two samples of 40K were above the upper range of the world wide published values. Regarding the average values of radiological hazard risk were found to be within the permissible limit according to the OECD, UNSCEAR 2000, and ICRP. It can be concluded that natural radioactivity levels together with radiological hazard risk studied from the most of the secondary ceilings samples available in local markets of Iraq within natural rates of permissible limits and may not cause any danger to the human when being used.