Geremew, Hailu2020-11-162023-11-092020-11-162023-11-092020-02-02http://10.90.10.223:4000/handle/123456789/23275Natural radioactive materials can be originated from various geological materials enriched with radio elements. Commonly known natural radioactive materials are primordial radionuclides, 238 92 U, 235 92 U, 232 90 Th and 40 19K, which are known for their long half lifetime. Parts of the earth or earth surface like sedimentary rock, limestone and sandstone, and clay rocks are the known geological materials in hosting such radioactive materials. The distribution of radio elements in earth crust depends on geo-chemical conditions of their hosts, weathering, human actions, and the like factors. Therefore, their distribution in and/or on earth surfaces is not homogeneous, vary from places to places. Radionuclide hosting materials can be used for different purposes in different factories as a raw material. Cement factories are the known consumer of such raw materials in the production of Portland cement. In this study, the levels of activities and health hazard indices in raw materials and final products of Portland cement samples were measured at cement factories in west Shoa Oromia regional state, Ethiopia. Besides, activities and health hazard indices of related environmental samples, soil, were measured. The study had been accomplished using high efficiency gamma ray spectrometer with Digital Signal Analyser, (DSA) coupled with High Purified Germanium detector and high efficiency gamma ray spectrometer with modular detector electronics, coupled with Thallium activated Sodium Iodide (NaI(Tl)) detector. The gamma ray spectrometers are controlled by GENIE2K-high channel number performance, computer software, and out put results are displayed on coupled personal computer. The activity levels and corresponding health hazard indices of 238 92 U, 232 90 Th and 40 19K in the main cement raw materials (Limestone, Sandstone, and Clay rocks), additive raw materials (Coal, Pumice and Gypsum) and final cement product (Ordinary Portland cement, Pozzolana Portland cement and semi-processed cement called clinker) samples were measured. As the main cement raw materials, maximum activities were measured in clay samples, 50:58_ 2:42, 150:40_7:41 and 365:00_17:11 Bq=Kg, for 238 92 U, 232 90 Th and 40 19K respectively, where low activity concentrations were measured in Limestone samples, 7:43_0:35, 1:75_0:29 and 17:02_1:56 Bq=Kg respectively, for 238 92 U, 232 90 Th and 40 19K. In additive cement raw material samples, maximum activity concentrations were measured in pumice samples as 78:00_4:00, 107:53_5:49 and 1307:65_60:70 Bq=Kg, for vi 238 92 U, 232 90 Th and 40 19K radio elements respectively. Low activities were measured in gypsum samples, 1:56_0:14, 1:79_0:33 and 28_2:0 Bq=Kg, for 238 92 U, 232 90 Th and 40 19K respectively. In the same way, the final product of cement, Portland cement, got a maximum reading of 31:63_1:46, 45:87_2:30 and 369:71_16:94 Bq=Kg for 238 92 U, 232 90 Th and 40 19K respectively. The related environmental samples, collected from floriculture industry near Holeta town, Oromia special zone, gave activity concentration readings for 238 92 U, 232 90 Th and 40 19K, as 197:18_16:88, 8:00_0:29 and 360:40_21:20 respectively. The elemental concentration values for natural radio elements in above were also calculated for additive cement raw material and floriculture soil samples. The results have a direct relation with activity concentrations, maximum activity concentration will give maximum elemental concentration values. The health hazard indices, Radium equivalent activity (Raeq), Absorbed dose (DR), Annual dose rate (ADR), External hazard index (Hex) and Internal hazard index (Hin) were calculated for each studied sample. These parameters have a direct relation with activity concentrations that maximum activity concentrations will induces maximum health hazards to the environments. The measured activity values were compared with other’s work investigations for the same sample types and world average values given by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR-2000). It was found that results from some samples (Pumice, Coal and Clay) were crossed the values given by the committee, and others are with in the permissible values given by this committee.enInvestigationsNatural Radioactivity LevelsCementCement’s Raw MaterialsSome RelatedEnvironmental SamplesUsing GammaRay SpectrometerThesis