INITIAL EVALUATIONS OF NATURAL (226Ra, 232Th AND 40K) AND ARTIFICIAL (137Cs) RADIO ISOTOPE ACTIVITIES IN ARZULAR-YITIRMEZ-DÖLEK (GÜMÜSHANE) MINERALIZATION/ALTERATION FIELDS

Within the scope of this study, the first evaluations of natural (226Ra, 232Th and 40K) and artificial (137Cs) radio isotope activities of the Arzular-Yitirmez-Dölek (Gümüşhane) mine/alteration site were carried out. Measurements were carried out with Poptop Ortec gamma rays detector on 22 soil samples collected from the field. When the natural 232Th, 226Ra and 40K activities of the area are compared with the weighted world averages, it has been determined that the 40K and 226Ra activities exceed the world averages in most of the sampling points, and the 232Th activities are below the weighted world average except for a few sampling points. It was observed that the artificial 137Cs activities in the field were above the detection limit and exceeded 2 Bq/kg except for a few sampling points. It has been evaluated that the high 137Cs activities in the field may be associated with a human-induced effect, especially the accident at the Chernobyl nuclear power plant. Parameters such as radiological hazard indices, Ra equivalent activity value, absorbed dose rate and annual effective dose rate were also calculated for the field. Considering the results obtained from these parameters, it was concluded that it would be beneficial to study the Arzular-Yitirmez-Dölek mineralization/alteration field in more detail in terms of natural and artificial radioisotope activities.

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.

Comparing of the Natural Radioactivity in Soil Samples of University at Al-Husseineya and Al-Mothafeen Sites of Kerbala, Iraq

Radioactivity must be studied in soil to see the changes in the doses of human exposure. In this study, natural radioactivity and radiological hazard indices in soil samples of the Faculty of Agriculture (Al-Husseineya site) and the Faculty of Medicine (Al-Mothafeen site) in Kerbala Governorate were determined using gamma-ray spectroscopy. The results showed that the mean values of specific activity (in units of Bq/kg) and standard errors of: 238U, 232Th and 40K at Al-Husseineya site was 21.7±7.2, 9.43±3.2 and 335.8±82.2, respectively, while at Al-Mothafeen site, the mean values and standard errors were 22.4±8.8, 11.2±3.3 and 333.1±70.7, respectively. Radiation maps of natural radioactivity (238U, 232Th and 40K) at Al-Husseineya and Al-Mothafeen sites were mapped using geographic information system (GIS) technology. Moreover, most results in the present study fall within the acceptable levels, as defined by OCDE, UNSCEAR and ICRP. Therefore, there is no significant radiological hazard at the sites which were studied. Keywords: Radiological hazard, Natural radioactivity, Soil, NaI (Tl), Gamma-ray, Karbela University.

Calculation of Radiation Nuclei Concentrations in Fertilized and Unfertilized Plants Samples Using Gamma Spectroscopy

The aim of this work was to estimate the concentrations of natural and artificial nuclides in some fertilized and unfertilized plant samples. These samples were collected and prepared in a petri dish for the measurements using gamma spectroscopy. The average values of 238U, 232Th, 40K, and 137Cs for the unfertilized plant samples were (11.964 ± 3.226, 8.273 ± 2.639, 402.436 ± 18.099, and 2.761 ± 1.613) respectively, and for the fertilized plant samples were (30.434 ± 5.282, 22.584 ± 4.620, 711.332 ± 25.806, and 6.986 ± 2.542) respectively. The average values of radiological hazard indices, Raeq, D, D for 137Cs, (AEDE)in, (AEDE)out, Iγ, Hin, and Hout for the unfertilized plant samples were (54.782 ± 7.216, 27.306, 0.469, 0.134, 0.033, 0.431, 0.180, and 0.148) respectively, and for the fertilized plant samples were (117.502 ± 10.747, 57.364, 1.188, 0.281, 0.070, 0.903, 0.400, and 0.317) respectively. The present results have indicated that the fertilized plant samples have more concentrations than the unfertilized plant samples.

Study of Well Waters from High-Level Natural Radiation Areas in Northern Vietnam

The determination of natural radionuclide concentrations plays an important role for assuring public health and in the estimation of the radiological hazards. This is especially true for high level radiation areas. In this study, 226Ra, 228Ra and 238U concentrations were measured in well waters surrounding eight of the high-level natural radiation areas in northern Vietnam. The 226Ra, 228Ra and 238U activity concentrations vary from <1.2 × 10−3–2.7 (0.46), <2.6 × 10−3–0.43 (0.07) and <38 × 10−3–5.32 Bq/L (0.50 of median), respectively. 226Ra and 238U isotopes in most areas are in equilibrium, except for the DT-Thai Nguyen area. The calculated radiological hazard indices are generally higher than WHO (World Health Organization) recommendations. Average annual effective dose and excess lifetime cancer risk values due to drinking well water range from to 130 to 540 μSv/year and 7.4 × 10−6 to 3.1 × 10−5, respectively.

Measurement of Natural and Artificial Radioactive Elements in Soil at the Southern Al-Dora Region, Baghdad Governorate, Iraq: حساب تركيز النظائر المشعة الطبيعية والصناعية لنماذج تربة جنوب منطقة الدورة في محافظة بغداد، العراق

The specific activity of natural and artificial radioactive elements in nine soil samples at different locations of southern Al-Dora region, Baghdad governorate, Iraq were measured and analysed by using a gamma ray detector NaI (Tl). The average activity concentrations of 238U, 232Th, 40K and 137Cs are found to be 38.22 Bq/Kg, 42.99 Bq/Kg, 16.64 Bq/Kg and 2.92 Bq/Kg, respectively. Several radiological hazard indices including radium equivalent activity (Raeq), absorbed dose rate (D), internal (Hin) and external (Hex) hazard indices, internal (AEDEin) and external (AEDEex) annual effective dose equivalent and gamma ray index (Iγr) are calculated. The findings of all radiological hazard indices are lower than their international values. This study discloses that most locations in study area are safe from any radiological risks.

Assessment of Natural Radionuclides in Local and Imported Cements in Erbil Governorate, Kurdistan Region- Iraq

A total of 10 cement samples were collected from the manufactures and markets. Spectrometry analysis of Sodium Iodide NaI (Tl) detector was used for measuring the samples' specific activity. The obtained specific activities of (226Ra, 232Th and40 K) were (35, 30 and 400) Bq/kg, respectively, which are below the critical values suggested by UNSCEAR2000. The radiological hazard indices of radium equivalent activities (Raeq), the indoor absorbed dose , the internal annual effective dose equivalent (Ein) and the internal index (Hin) were calculated. All of the obtained values were below the world wide recommendation values. Fortunately, from the analyzed results, it was concluded that the local and imported cements in Erbil governorate will make no risk when used in building constructions.

RADIOMETRIC SURVEY OF THE TYAA RIVER SAND MINE IN KITUI, KENYA

Gamma spectroscopic analyses of sand and rock samples from Tyaa River report an average activity concentration of 33 ± 1, 55 ± 2.8 and 812 ± 40.46 Bqkg−1 for 226Ra, 232Th and 40K, respectively in the sand. A similar analysis of rock samples reveals a mean of 21 ± 2.47, 49 ± 2.47 and 782 ± 39.13 Bqkg−1 for 226Ra, 232Th and 40K, respectively. The absorbed dose rate in rocks averaged 75 ± 3.78 nGyh−1, while in the sand was 86.2 ± 4.31 nGyh−1. The ranges and mean radiological hazard indices (radium equivalent, internal and external) were within the permissible limits and the use of sand and rocks from this mine as construction material pose no health risks. Correlation analysis between the radioactivity in the sand and rocks reveals weak non-linear positive relationships suggesting that they might be from different bedrocks.