Determination of natural radioactivity levels and radiation hazards for natural gypsum in Abay gorge, Dejen district, Ethiopia.

Natural gypsum has been studied as a building material, and it has been discovered that it is one of the potential sources of indoor radioactivity due to naturally occurring radioactive elements in it. The levels of radioactive elements obtained in natural gypsum available in Abay gorge Dejen district were accomplished by a well shielded and calibrated gamma spectrometry with high purity Ge detector to evaluate the radiation hazard to workers in Dejen gypsum factories and dwellers in buildings decorated with gypsum products. The results of this study revealed that radioactive elements 238U, 232Th, and 40K are found in raw gypsum samples, with specific activity ranging from 1.47 ± 0.26 to 2.42 ± 0.37 Bqkg−1, 1.10 ± 0.26 to 2.60 ± 0.48 Bqkg−1, and 4.27 ± 1.92 to 44.53 ± 2.84 Bqkg−1, respectively. The mean specific activities are 1.90 ± 0.33 Bqkg−1 for 238U, 1.99 ± 0.39 Bqkg−1 for 232Th, and 28.16 ± 2.57 Bqkg−1 for 40K, which are significantly lower than the intercontinental approved values. All of the calculated radioactive risk indices were significantly lower than the global recommended values for building materials. The values of various radioactive indices indicate that the use of gypsum powder obtained from studied samples in the construction of residences is considered safe. [ABSTRACT FROM AUTHOR]