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Alkaline igneous rocks represent one of the most economically important resources of radioactive minerals and rare metals. New field observations and petrographic studies are integrated with whole-rock geochemical analyses and Gamma ray spectroscopy data of alkaline rocks associated with the Amreit complex. The fieldwork was achieved by the collection of more than forty samples from alkaline granites and alkaline syenites. The youngest rocks cropping out in the study area are the cogenetic alkaline rocks, ranging from alkaline granite to alkaline syenite. These alkaline rocks are composed essentially of K-feldspar, alkali amphiboles (arfvedsonite), and sodic pyroxene, with accessories such as zircon, apatite, and ilmenite. Mineral characterization of the highly radioactive zones in both alkaline granite and alkaline syenite displays enrichment in monazite, thorite, zircon, ferro-columbite, xenotime, and allanite minerals. Geochemical analyses indicate that the Amreit rocks are alkaline with peralkaline affinity and have high concentrations of total alkalis (K2O + Na2O), large ion lithophile elements (LILEs; Ba and Rb), high field strength elements (HFSEs; Y, Zr and Nb), rare earth elements (REEs) and significantly depleted in K, Sr, P, Ti, and Eu, typically of post-collision A-type granites. Typically, the Amreit alkaline igneous rocks are classified as within plate granites and display A2 subtype characteristics. The fractionation of K-feldspars played a distinctive role during the magmatic evolution of these alkaline rocks. The geochemical characteristics indicate that the studied alkaline igneous rocks which were originated by fractional crystallization of alkaline magmas were responsible for the enrichment of the REE and rare metals in the residual melt. The high radioactivity is essentially related to accessory minerals, such as zircon, allanite, and monazite. The alkaline granite is the most U- and Th-rich rock, where radioactivity level reaches up to 14.7 ppm (181.55 Bq/kg) eU, 40.6 ppm (164.84 Bq/kg) eTh, whereas in alkaline syenite radioactivity level is 8.5 ppm (104.96 Bq/kg) eU, 30.2 ppm (122.61 Bq/kg) eTh. These observations suppose that these alkaline rocks may be important targets for REEs and radioactive mineral exploration. [ABSTRACT FROM AUTHOR]

Naturally occurring radionuclides rocks are one of the possible sources of indoor and outdoor radiation. Samples were taken from Kolar taluk in Karnataka in order to evaluate the radioactive hazards and natural radioactivity levels in those samples. The activity concentrations of 226Ra, 232Th, and 40K in these samples were determined using NaI(Tl) gamma ray spectroscopy. The measured ranged from 5.05 to 171.43 (Bq kg-1); 5.04 to 274.64 (Bq kg-1); 287.23 to 2603.45 (Bq kg-1) for 226Ra, 232Th, and 40K. In this study, the yearly effective radiation dosage, air absorbed gamma radiation dose rate, and hazard index (Hin, Hex), gamma index, activity utilization index, annual gonald dose equivalent were estimated. The study's demonstrate that potassium (40K), a naturally occurring radionuclide, is higher than radium and thorium. The levels of the computed radionuclides were compared to other places in Karnataka and world average value. The relationship between radionuclides was examined using correlation and statistical methods, radiation parameters were also computed. Information on background radioactivity levels and the impacts of radiation on locals in the research area under inquiry is what this study aims to deliver. [ABSTRACT FROM AUTHOR]

The main objective of this study is to measure the levels of radioactivity in certain construction material samples by quantifying the amounts of natural radionuclides (238U, 232Th, 40K) and 137Sc using gamma-ray spectroscopy with a High Purity Germanium (HPGe) detector. The selected samples were collected and examined to ascertain the mean quantities of radionuclides present. Subsequently, these findings were juxtaposed with global benchmarks for additional examination. The efficiency results unveiled a spectrum of concentrations for different radionuclides, encompassing 238U with a concentration range of (2.53 - 8.2 Bq/kg) and an average concentration of (4.93 Bq/kg). Similarly, the concentration of 232Th ranged from (0.655 - 3.45 Bq/kg), with an average concentration of (1.74 Bq/kg). The radionuclide 40k exhibited a concentration range of (3.5 -1500 Bq/kg), with an average value of (386.4 Bq/kg). Furthermore, 137Sc displayed a concentration range of (0.51-0.22 Bq/kg) with an average concentration of (0.53 Bq/kg). The radium equivalent concentration was determined to be (40.45 Bq/kg), whereas the absorbed dosage was measured at (18.67 nGy/h). The external hazard index (Hout) was measured to equal (0.11 mSv/y), whereas the internal hazard index (Hin) was determined to be (0.17 mSv/y). Furthermore, the annual equivalent effective dose (AEDEout) was calculated to be (0.09 mSv/year). The annual dosage of (AEDEin) was determined to be (0.02 mSv/year). The gamma radiation index, denoted as Iγ, was determined to be (0.28 Bq/kg). The study results imply that the amounts of radionuclides fall within the defined normal limits worldwide, indicating that the natural radioactivity levels are within the internationally acceptable range. Quantification of both natural and artificial radioactivity in specific building materials employed in constructing dwellings inside Salah Al-Din Governorate. A selection of seven distinct models was made. (Plaster, Bork, and Dust). The concentration of gamma-ray-emitting radionuclides in both the uranium-radium and thorium series, as well as 40K and 137Sc, was measured using a high-purity germanium (HpGe) detector. Subsequently, the spectrum underwent analysis for 3600 seconds. The concentrations of the radionuclides being investigated were determined to be as follows: The mean concentrations of 238U range from (2.53 - 8.2 Bq/kg), while for 232Th the range from (0.65 to 3.45 Bq/kg). The concentrations of potassium 40K range from (3.5 to 1500 Bq/kg), and for 137 Sc the range from 0.51 to 0.22 Bq/kg. [ABSTRACT FROM AUTHOR]

The natural radioactivity concentration was studied for 40 soil samples of the Churchandpur and Ukhrul districts of Manipur, India, by using gamma-ray spectroscopy. The average radioactivity concentration of 226Ra, 232Th and 40K in Churchandpur was found as 39.9 (range: 30–56), 72.1 (range: 57–93) and 564.1 (range:360–867) Bq kg−1 respectively, whereas, in Ukhrul, average radioactivity for the same was found as 30.3 (range: 16–54), 54.2 (range:24–89) and 637.1(range:103–901) Bq kg−1, respectively. The calculated radioactivity parameters were compared with the world average values. The measured radium equivalent activity (R aeq), absorbed dose rate (⁠|$\dot{\mathrm D}$|⁠), annual effective outdoor dose(Ė) and the external hazard index (H ex) were observed as 165 (range: 63.7–234.8) Bq kg−1, 77.6 (36.9–108.0) nGy h−1, 0.11 (0.05–0.13) mSv y−1 and 0.5 (0.1–0.6), respectively. This study aims to provide baseline data for radionuclide present in the Churchandpur and Ukhrul districts of Manipur. [ABSTRACT FROM AUTHOR]

The natural radioactivity of the earth formations of the Soil of the kufa city in Al-Najaf Al-Ashraf governorate has been studied. It currently consists of the northern and southern parts, the center of the old city, Maysan neighborhood, Al-Suhailia, and Al-Barakiya. The area of Maysan, Al-Suhailia, and Al-Barakiya was studied due to its close to the cement factory in Kufa. To calculate the level of radioactivity present and the degree to which it affects the local population these areas by selecting 30 sites to take soil samples from the region, and spectral measurements were made using gamma-ray spectroscopy (NaI(Tl)) ( 3"x3" ). It was found that the specific activity of 238U, 232Th and 40K in the studied ranged between (34.279±1.059) Bq/kg in Maysan neighborhood to (3.423±0.353) Bq/kg in Al-Barakiya with average (16.450) Bq/kg to (8.274) Bq/kg, (21.549±0.864) Bq/kg in Al-Barakiya to (5.050±0.405) Bq/kg in Maysan neighborhood with average (14.105 ) Bq/kg to (13.260) and (433. 948±3.939 ) Bq/kg in Maysan neighborhood to (92.328±1.843) Bq/kg in Al-Barakiya with average ( 338.251) Bq/kg to (245.754) Bq/kg. As The value of the excess lifetime cancer risk (total) it was between (0.802) in Maysan neighborhood to (0.393) in Al-Barakiya with average (0.627) to (0.478). After comparing the current findings with the values taken into account generally, it was found that the radiation levels in the examined samples are within allowable bounds. [ABSTRACT FROM AUTHOR]

The current study aims to assess the radioactive health risks and their levels due to tea consumption. Fresh tea leaves were plucked from different locations in the Gumero tea farmland in Ilubabour zone, Ethiopia. High-resolution gamma-ray spectroscopy was used to measure the activity concentrations of artificial and natural radionuclides (e.g., 40K, 232Th, and 238U) in the samples. Radiological indicators such as committed dose rate (DR) and excess lifetime cancer risk, LCR (i.e., the cancer death risk due to lifetime exposure to carcinogens, ignoring the contribution of natural background risk) were evaluated to ascertain the radioactive risk to humans in the tea samples. DR and LCR, two radiological markers, were assessed to determine the radioactive risk to humans in the tea samples. The finding shows that the radiological hazards assessment of 238U and 232Th revealed that the Gumero tea leaves have natural radioactivity levels within the internationally recommended limit, while that of 40K was higher than the limit. Comparing the current study with other studies, it was found that the yearly effective doses and nuclide radioactivity concentrations in tea leaves were similar. [ABSTRACT FROM AUTHOR]

The distribution of natural series radionuclides 226Ra, 232Th and non-series 40K in the heavy mineral-rich beach sands of highly touristic areas of Cox's Bazar sea beach has been studied. The study is made to evaluate the gamma radiation exposure to individuals with an aim to establish reference data for the presence of naturally occurring radionuclides. The present study reports the probable first attempt of detail and systematic work in the study areas for estimation of activity concentration in the recent beach sand samples. Radiometric analysis was performed using gamma ray spectroscopy system based on HPGe detector. The mean activity levels of 226Ra, 232Th and 40K in Laboni beach sands were ranged from 255.69±64.57, 336.83±93.96 and 1785.91±89.60 Bq kg-1, respectively. While in Kolatoli beach sands, the respective values were 166.42±35.99, 157.35±35.90 and 1894.42±74.07Bq kg-1, respectively. The mean values of 226Ra and 232Th concentrations in the investigated beach sands were estimated to be very much higher than the corresponding world average values and comparable to those found in high background radiation areas in the world. The heavy minerals seem to control the activity concentrations of 226Ra and 232Th in sand samples, showing some variances based on uranium and thorium bearing minerals. Various radiation health hazard indicators were found to be extremely higher when compared to the recommended values. Hence, heavy mineral-rich sands may pose a significant radiological health risk to the people. The descriptive statistics indicating the radionuclides of 226Ra, 232Th and 40K are uniformly and symmetrically distributed in the Cox's bazar beach sand. Multivariate statistical analysis showing the radioactivity and estimated radiological parameters are strongly positively correlated with 226Ra and 232Th, while weakly correlated with 40K, signifying that radiological risk is mainly associated and controlled by the radioactivity levels of uranium and thorium series radionuclides. [ABSTRACT FROM AUTHOR]

River sand is a one of the important and commonly used building material in India and hence in the present study, activity concentration of natural radionuclides such as 226Ra, 232Th and 40 K have been measured in sand samples collected from Ponnai river, Tamilnadu using HPGe detector-based gamma ray spectroscopy. The measured activity concentrations vary from 13.30 to 54.83 Bq kg−1 with a mean value of 31.07 Bq kg−1 for 226Ra, from 26.15 to 245.33 Bq kg−1 with a mean value of 83.61 Bq kg−1 for 232Th, from 218.76 to 581.88 Bq kg−1 with a mean value of 416.36 Bq kg−1 for 40 K. These mean values of activity concentration of radionuclides have been compared with recommended limit and other similar work carried in the world. In order to assess the radiation associated with sands, radiological parameters such as air absorbed dose rate, annual indoor and outdoor effective dose rate, excess lifetime cancer risk, were calculated. The result shows that excess lifetime cancer risk (ELCR) for the indoor exposure varied from 0.775 × 10−3 to 3.216 × 10−3 with an average value of 1.440 × 10−3. An average ELCR for Ponnai river sand samples is slightly higher than the world average value of 1.16 × 10−3 mSv y−1. Finally, to assess the delivery of gamma radiation to organs, effective dose to body organ (Dorgn) was calculated for all river sand samples in the study area. [ABSTRACT FROM AUTHOR]

• PM 2.5 levels exceeded WHO's limits; significant concentrations of 226Ra and 232Th found. • High particulate matter and radionuclides pose health risks, especially through inhalation. • Detailed methods for sample collection and radionuclide measurement using gamma-ray spectrometry. • Effective inhalation dose calculated for different age groups, indicating health impact. • Assessed lifetime cancer risk due to radiation exposure from radionuclides. This research focused on measuring the concentration of particulate matter (PM 2.5) aerosols and radionuclides (226Ra, 232Th, and 40K) in road dust collected using glass fiber filters from busy roads and populated areas in Islamabad and Rawalpindi, Pakistan. The measured concentrations ranged between 551.0 and 2025.7 µgm−3 for PM 2.5 aerosols, 32.4 and 54.7 mBqm−3 for 226Ra, 15.8 and 26.8 mBqm−3 for 232Th, and 239.0 and 316.4 mBqm−3 for 40K. The study found that PM 2.5 levels surpassed the WHO's recommended limit of 25 µgm−3. Additionally, concentrations of 226Ra and 232Th were considerably higher than the global average values of 1 and 0.5 µBqm−3, respectively, in dust. The total inhalation effective dose in all samples exceeded the ICRP's acceptable limit of 2 mSvy-1, except in the infant and 1-year-old age groups (considering F, M, and S-type modes). Notably, 232Th was identified as the primary contributor, accounting for 36.5 % to 99.4 % of the total inhalation effective dose. [ABSTRACT FROM AUTHOR]

The concentration levels of 226Ra, 232Th and 40K in soil have a great concern in the recent decades, due to its effect on the human health. The radioactivity of some soil samples taken from selected locations in Sylhet District have been measured using a High Purity Germanium Detector based on gamma ray spectroscopy. The present investigation shows that the level of natural radioactivity for 226Ra, 232Th and 40K in such soil is slightly higher than World average value of UNSCEAR, 2000. The artificial radionuclide 137Cs was not observed in statistically significant amounts above background level in this study. The radiological hazard parameters i.e., radium equivalent activity, absorbed dose rate, external hazard index, internal hazard index, representative level index and annual effective dose equivalent are calculated from the measured activity concentrations of the radionuclides 226Ra, 232Th and 40K from soil samples in this study and compared with the world averages. The experimental soil data were subjected to statistical analysis using IBM SPSS software (version 20). Descriptive statistics of the radionuclides of the soil, Pearson's correlation matrix and Cluster Analysis have been carried out in this study. [ABSTRACT FROM AUTHOR]

Using gamma ray spectroscopy with high purity germanium detector, the activity concentrations of 238U, 232Th and 40K radionuclides in drinking water samples from two areas in Bordj-Bouarreridj, east of Algeria were measured. The mass concentrations were found to range 10.46–63.56 µg/L for 238U, not determined value to 9.83 µg/L for 232Th and 5.29–6.80 µg/L for 40K. The chemical and physical characteristics of the drinking water samples were determined. The human radiological risk was calculated on the lifetime consumption of the population of the studied area based on the results obtained. [ABSTRACT FROM AUTHOR]

This paper focuses on the natural radioactivity concentrations of 238U, 232Th, and 40K in the eruptive products of the Gölcük Volcano (SW Turkey) and its environmental radiation risks. Concentrations of these radionuclides (238U, 232Th, and 40K) have been measured on different igneous rocks, using a portable gamma-ray spectrometer at 450 points. Based on the obtained data, distribution maps of these radionuclides and the maps showing the absorbed dose rate in the air and radiogenic heat production (RHP) have been generated. We conclude that tephriphonolite and trachytes in potassic-ultrapotassic character display high radioactivity levels. On the other hand, it is revealed that the absorbed dose rate in the air ranging from 21 nGy/h to 482 nGy/h has been calculated as 8 times more than the world average (55 nGy/h). The results indicate that this region has crucial importance on human health and the environment. Therefore, the area requires special attention in terms of radiological hazards and further research should be done in the area regarding this issue. • Radionuclide concentrations definition using the gamma-ray spectrometer in Gölcük volcano. • The comparison of radionuclide concentrations with geology. • The absorbed dose rate in the air has been calculated as 8 times more than the world average. • Radiological hazards on human health and the environment have been determined. [ABSTRACT FROM AUTHOR]

In this work, the activity concentrations of natural radionuclides 226Ra, 232Th and 40K in soil samples from Erbil governorate, Iraqi Kurdistan were investigated by a gamma-spectroscopy system based on high-purity germanium (HPGe) detector. This is to assess the dose of radionuclides exposure to the population, knowing the health risks and to have a baseline for future changes in the environmental radioactivity. It was found that the activity concentrations of 226Ra, 232Th and 40K were ranged from (14.6 ± 1.6 to 38.2 ± 2.8 Bq.kg-1), (4.5 ± 1.4 to 52.4 ± 5.8 Bq.kg-1) and ( 302.8 ± 12.6 to 388.6 ± 12.8 Bq.kg-1), respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and with the worldwide average activity of soil. Radium equivalent activities, absorbed dose rate, excess lifetime cancer risk and the values of hazard indices were calculated for the measured samples to assess the radiation hazard of the natural radioactivity in all samples to the people. It was concluded that the radium equivalent activities of the studied samples are below the internationally accepted values. These results show that annual effective dose absorbed via occupant from activity construction of soil samples used in the under place is below 1.0 mSv.y-1. It is concluded that the assessment radioactivity of soil are within acceptable levels and does not pose any health hazard to the population.

Human being exposed to naturally occurring ionizing radiation throughout their lives as these radionuclides are present in different amounts in our environment. Gamma radiation emitted from uranium (U), thorium (Th), radium (Ra), potassium (K) and cesium (Cs) radionuclides and their decay products represents the essential external source of radiation to human beings. The amount of these radioactive elements differs from one region to another. These radioactive nuclides may enter into the human body through air inhalation or by eating and drinking. When the concentration of these radioactive elements reaches hazardous limits, it may cause cancer like lung, stomach and blood cancers. For purposes of monitoring the health hazards caused by the ionizing radiation, radionuclide activity concentrations are being measured in soil, sand, water, rocks, air etc. In Iraq and different regions around the world pollution of soil is a major concern with respect to its contaminant, existing in the food chain and persistence in the environment. In this work, several data have been reported and reviewed from a number of studies that measure 238U, 226Ra, 232Th, 137Cs and 40K radionuclides activity in the soil of Iraq, specifically in Salahadeen, Bsrah, Erbil, Sulaimanya, Najaf, Nineveh, Kirkuk, Babylon, Thi-Qar, Al Anbar, Al-Muthanna, Karbala and Hilla governorates. In all articles, NaI (Tl) and high-purity germanium (HPGe) detectors are used for radioactivity measurements. From this review, it can be deduced that the average activity concentrations for the measured radionuclides in soil were below worldwide average levels established by UNSCEAR except in Sulaimany, Basrah and Baghdad where elevated levels of 238U, 226Ra and 40K were noticed. Additionally, 137Cs has been recorded in some Iraqi regions. [ABSTRACT FROM AUTHOR]

Due to the declining number of available nuclear reactors capable of Tc-99m production and tight regulations related to uranium enrichment, cyclotron-based Tc-99m production has recently been suggested as a new method to help ease Tc-99m supply shortages. In this investigation, a solid natural MoO3 target was irradiated using 11-MeV proton beams at variable proton doses. The proton doses were varied by varying the irradiation time while keeping the proton beam current constant at 20 gA. At the end of the bombardment, the post-irradiated solid MoO3 targets were analyzed for their radioactive contents using a portable gamma ray spectroscopy system. The analysis was also performed for the post-irradiated targets after dissolving the solid MoO3 in a 6M NaOH solution. The experimental results indicated that as much as 75.71% of Tc-99m radioactivity was directly generated via a 100Mo(p,2n)99mTc nuclear reaction, while the rest of the Tc-99m radioactivity was a result of a 98Mo(n.Y)99Mo^99mTc nuclear reaction. Apart from Tc-99m and Mo-99 radionuclides, some other radionuclides such as N-13, Tc-96 and Nb- 96 were also recorded following temporal observation of the NaOH-dissolved MoO3. These experimental results open up the possibility of direct production of Tc-99m using a proton-accelerating cyclotron. [ABSTRACT FROM AUTHOR]

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96 aerosol samples were collected in north China and analyzed by gamma spectrometry. The activity concentrations of Pb-210 ranged from 97 to 27,955 μBq/m3, with average of 879, 3389 and 813 μBq/m3 in Beijing, Changbai and Hunchun, respectively. Annual effective dose for inhabitants due inhalation varied from 0.68 to 5.94 μSv. There was a positive correlation between Pb-210 and PM2.5 in Beijing. Seasonal variation of Pb-210 concentration was observed in Changbai and Hunchun. Analysis of their correlation with meteorological parameters could help to assess the effects of present pollutant emission and provide scientific support for prevention strategy. [ABSTRACT FROM AUTHOR]

A methodology that extends the usability of low and medium resolution γ-ray detectors to a wide range of energies that appear in environmental radioactivity measurements is described. Results of the implementation of the methodology in the analysis of 20 granite samples measured with a (3″ × 3″) NaI(Tl) are presented. A comparison with the activity results obtained by a high-resolution detector (HPGe) for two samples was found in good agreement, within the uncertainties, validating the results of the proposed method. [ABSTRACT FROM AUTHOR]

Production of medical isotopes has recently been developed at the Institute of Modern Physics (IMP) in China and many aqueous samples containing produced radioisotopes at wide range of volume were generated. Evaluation of radionuclidic purity and quantification of radioactivity for these samples are of significant importance, especially for medical purpose. High purity germanium (HPGe) detectors and gamma spectrometry are widely used in radionuclidic purity evaluation due to the high energy resolution. However, radionuclidic purity assessment and determination of radioactivity cannot be accurately conducted by using the HPGe detector installed at Laboratory of Nuclear Chemistry in IMP due to the lack of competent calibration standard sources. Therefore, an efficient method based on Geant4 simulation was proposed to calculate the detection efficiency curve for samples with different geometry, composition and source-to-detector distance. A set of efficiency data measured with a point-like standard source containing multi-radionuclides was used to determine the dimension of germanium crystal and thickness of dead layers. Afterwards, a point-like and 3 volumetric standard sources (5 ml, 10 ml and 20 ml, respectively) containing 152Eu were measured at 5–50 cm source-to-detector distances. The EFFTRAN code was applied to calculate the correction factor of coincidence summing for all measurements. The full energy peak (FEP) efficiencies with energy range of 121–1408 keV were calculated and compared with the values obtained from simulations. The simulated FEP efficiency values were in good agreement with experimental results, which illustrated a satisfactory precision of the Geant4 simulations. The feasibility of obtaining detection efficiency for point-like and volumetric samples by means of Geant4 simulations was confirmed. This method can be applied to address the efficiency problem caused by sample geometry and composition. • An accurate model of HPGe detector was built in a Geant4 simulation. • The simulated efficiencies are in good agreement with experimental values for all samples at large detection distances. • Precise results are obtained from simulation with most of the deviation (between simulation and experiments) < 10%. • This method can be used to address efficiency calibration problem caused by the geometry and composition of samples. [ABSTRACT FROM AUTHOR]

Activity concentrations of 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K in 64 mushroom samples collected in China from Yunnan, Fujian and Heilongjiang Provinces, were measured. Gamma-ray emissions were determined by using high-purity germanium (HPGe) γ spectrometry. The range of concentrations (Bq kg −1 dry weight) for 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K in all investigated mushroom samples were from 0.12 to 12, 0.05 to 7.5, 0.14 to 14, MDC(<0.01) to 339, and 396 to 1880, respectively. Activity concentrations of 137 Cs in mushrooms showed some variation between species sampled at the same site. To calculate soil to mushroom transfer factors, levels of radionuclide in 15 paired soil samples and mushrooms were also investigated. The median transfer factors for 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K were 8.32 × 10 −2 , 3.03 × 10 −2 , 6.69 × 10 −2 , 0.40 and 1.19, respectively. The results were compared with values of other areas. [ABSTRACT FROM AUTHOR]

The study on natural radioactivity level in the soil plays a significant role in health physics. The present study has been carried out with the aim of estimating activity concentration of radionuclides in soil samples collected at 30 places around Kolar Gold Fields, Kolar district using gamma ray spectrometry. Average values of activity concentration of Ra, Th and K in soil samples of the present study are 27.3 ± 1.8, 63.1 ± 2.5 and 818 ± 6 Bq kg, respectively. The average radium equivalent activity (Ra), absorbed dose rate and annual effective dose have been calculated and compared with the referred safe values. [ABSTRACT FROM AUTHOR]

A current need in nuclear security is an economical, yet high energy resolution (near 2%), scintillation detector suitable for gamma-ray spectroscopy. For current scintillators on the market, there is an inverse relationship between scintillator energy resolution and cost of production. A new promising scintillator, KSr 2 I 5 :Eu 2+ , under development at the University of Tennessee, has achieved an energy resolution of 2.4% at 662 keV at room temperature, with potential growth rates exceeding several millimeters per hour. However, the internal background due to the 40 K content could present a hurdle for effective source detection/identification in nuclear security applications. As a first step in addressing this question, this paper reports on a computational investigation of the intrinsic differential pulse height spectrum (DPHS) generated by 40 K within the KSr 2 I 5 :Eu 2+ scintillator as a function of crystal geometry. It was found that the DPHS remains relatively equal to a constant multiplicative factor of the negatron emission spectrum with a direct increase of the 1.46 MeV photopeak relative height to the negatron spectrum with volume. Further, peak pileup does not readily manifest itself for practical KSr 2 I 5 :Eu 2+ volumes. [ABSTRACT FROM AUTHOR]

Naturally occurring radionuclides of the 226Ra, 232Th, and 40K present in the lignite samples was measured by using a low-background Pb-shielded gamma spectroscopic counting assembly utilizing NaI(Tl) detector for the measurement and to evaluation the radiation hazard indices and excess life time cancer risk. The average values of specific activity concentrations in the investigated lignite samples was found to be 45.36 Bq kg−1 for 226Ra, 21.42 Bq kg−1 for 232Th, 40.51 Bq kg−1 for 40K and 79.11 Bq kg−1 for Raeq respectively. The average value excess life time cancer risk was found to be relatively higher than the world average. Moreover, the correlation analysis shows the strong dependence of excess lifetime cancer risk on measured dose and the radium equivalent activity. [ABSTRACT FROM AUTHOR]

The distribution of 226Ra, 232Th, and 40K in 70 granite samples obtained from 13 Western Anatolian plutons (Turkey) was measured by using γ-ray spectroscopy. The activities of the measured radionuclides varied up to 259 Bq kg-1 for 226Ra, up to 241 Bq kg-1 for 232Th, and up to 2518 Bq kg-1 for 40K, with mean values of 66 (±44), 90 (±47), and 1097 (±410) Bq kg-1, respectively, which are smaller than the mean values given for granites worldwide. The mean value of the increase on the external γ-radiation effective dose rate is 0.21 (±0.09) mSv year-1, varying by <1 mSv year-1. The mean value of the internal α-radiation was 0.15 (±0.10) mSv year-1, varying <0.5 mSv year-1. Most of the samples cause an increase to both the external and internal dose by <30%, which is smaller than the permitted limit. Therefore, there is no radiological risk from the usage of the samples studied as decorative and ornamental building materials. [ABSTRACT FROM AUTHOR]

To evaluate the state of the environment in Kopaonik, a mountain in Serbia, the activity concentrations of 4 K, 226 Ra, 232 Th and 137 Cs in five different types of environmental samples are determined by gamma ray spectrometry, and radiological hazard due to terrestrial radionuclides is calculated. The mean activity concentrations of natural radionuclides in the soil are higher than the global average. However, with an exception of two sampling locations, the external radiation hazard index is below one, implying an insignificant radiation hazard. Apart from 40 K, content of the natural radionuclides is predominantly below minimum detectable activities in grass and cow milk, but not in mosses. Although 137 Cs is present in the soil, grass, mosses and herbal plants, its specific activity in cow milk is below minimum detectable activity. Amongst the investigated herbal plants, Vaccinium myrtillus L. shows accumulating properties, as a high content of 137 Cs is detected therein. Therefore, moderation is advised in consuming Vaccinium myrtillus L. tea. [ABSTRACT FROM AUTHOR]

Soil and vegetables grown in Iringa rural in Tanzania were analysed for radioactivity associated with the use of phosphate fertilizer in farming. The activity concentrations of Ra, Ra and K were determined using gamma spectrometry of Tanzania Atomic Energy Commission, Arusha. Higher activity concentrations of Ra and Ra in both types of samples were found in samples from fertilized farms than in samples from control. Hence, regular monitoring of radioactivity level in farm soils and agricultural products is recommended. [ABSTRACT FROM AUTHOR]

We fabricated a small-sized, flexible, and insertable fiber-optic radiation sensor (FORS) that is composed of a sensing probe, a plastic optical fiber (POF), a photomultiplier tube (PMT)-amplifier system, and a multichannel analyzer (MCA) to obtain the energy spectra of radioactive isotopes. As an inorganic scintillator for gamma-ray spectroscopy, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) crystal was used and two solid-disc type radioactive isotopes with the same dimensions, cesium-137 (Cs-137) and cobalt-60 (Co-60), were used as gamma-ray emitters. We first determined the length of the LYSO:Ce crystal considering the absorption of charged particle energy and measured the gamma-ray energy spectra using the FORS. The experimental results demonstrated that the proposed FORS can be used to discriminate species of radioactive isotopes by measuring their inherent energy spectra, even when gamma-ray emitters are mixed. The relationship between the measured photon counts of the FORS and the radioactivity of Cs-137 was subsequently obtained. The amount of scintillating light generated from the FORS increased by increasing the radioactivity of Cs-137. Finally, the performance of the fabricated FORS according to the length and diameter of the POF was also evaluated. Based on the results of this study, it is anticipated that a novel FORS can be developed to accurately measure the gamma-ray energy spectrum in inaccessible locations such as narrow areas and holes. [ABSTRACT FROM AUTHOR]

The present work is directed to characterize the phosphogypsum (PG) wastes by means of in situ atmospheric radon measurements, gross-alpha and gamma-ray spectrometry measurements. The average radon concentrations in three locations: Valea Calugareasca, Navodari and Turnu Magurele are 21.88 ± 3.19, 26.56 ± 2.90 and 33.43 ± 3.64 (Bq × m), respectively. The γ-ray measurements showed that the total activities are 1510.62 ± 148.08, 1838.77 ± 165.04, 1363.83 ± 147.96 (Bq × kg). The results shows in all cases elevated levels of radon and Ra for PG samples, indicating the necessity to find suitable routes to reduce its radiation impact on the surrounding environment. [ABSTRACT FROM AUTHOR]

Dust storms in the Middle East are common during spring. Some of these storms are massive and carry a large amount of dust from faraway regions, which pose health and pollution risks. The huge dust storm event occurred in early May, 2012 was investigated for its radioactive content using gamma ray spectroscopy. Dust samples were collected from Northern Jordan and it was found that the storm carried a large amount of both artificial and natural radioactivity. The average activity concentration of fallout 137 Cs was 17.0 Bq/kg which is larger than that found in soil (2.3 Bq/kg), and this enrichment is attributed to particle size effects. 7 Be which is of atmospheric origin and has a relatively short half-life, was detected in dust with relatively large activity concentrations, as it would be expected, with an average of 2860 Bq/kg, but it was not detected in soil. Despite the large activity concentration of 7 Be, dose assessment showed that it does not contribute significantly to the effective dose through inhalation. The concentrations of the primodial nuclides 40 K, 232 Th and 238 U were 547, 30.0 and 49.3 Bq/kg, respectively. With the exception of 40 K, these were comparable to what was found in soil. [ABSTRACT FROM AUTHOR]

Radioactivity of nuclides 238U, 226Ra, 232Th and 40K was measured in soil by γ-ray spectrometry using a NaI (Li) detector. A criterion was set in order to analyze sludge samples from oil fields and oil well-cores in southern Basrah, in the Iraq oil fields. More than 3 γ-ray energy peaks were used for the determination of 226Ra and 232Th activity concentrations to obtain results that are more accurate. Relationships between the measured radionuclides were discussed. Radionuclides 238U and 226Ra were found in disequilibrium with ratio of specific activities (238U/226Ra) less than unity for most of the sludge and core samples. The content of radioactive elements in the sludge, scale and well core is found within the range of other petroleum countries in the region. [ABSTRACT FROM AUTHOR]

Abstract: Common building materials collected from Aden, Yemen were analyzed for the natural radioactivity of 226Ra, 232Th and 40K using gamma-ray spectroscopy. The average activity concentrations of 226Ra, 232Th and 40K in the studied building materials range from 20.78 to 68.6, from 15.48 to 95.08 and from 116.7 to 2636.68Bqkg−1, respectively. The measured activity concentrations for these radionuclides were compared with chemical data obtained by XRF analysis and with the reported data of other countries and compared also with the worldwide average activities. The radium equivalent activities of the studied samples that range from 69 to 369.3Bqkg−1 are below the internationally accepted values (370Bqkg−1), except those of Hapach hard rock (407.6Bqkg−1). The external and internal hazard indices that range from 0.2 to 1.1 and from 0.3 to 1.3, respectively, of all analyzed building materials are less than unity, except those of Hapach hard rock (Hex =1.1 and Hin =1.3) and hard rock of Crater (Hin =1.2). The mean values of indoor absorbed dose rate for all building materials range from 30.7 to 199.8nGyh−1 except those for cement, macadam, hard rock of Habaylin and hard rock of Abyan which are higher than the world population-weighted average of 59nGyh−1 and the total annual effective dose values of building materials that range from 0.15 to 0.98mSvy−1 are lower than 1mSvy−1 except for the samples of Hapach hard rock (0.98mSvy−1) which have the closed value (the limit of accepted value (1mSvy−1) reported in the UNSCEAR (2000)). The study shows that the measured radioactivity for building materials does not pose as significant source of radiation hazard and is safe for use in the construction of dwellings, while when using Hapach hard rock and hard rock of Crater for construction, their natural radioactivity level should be monitored. [Copyright &y& Elsevier]

The natural radiological characteristics and their respective annual effective dose (AED) rates, produced by Ra, Th and K in coal, fly ash and bottom ash from two large coal-fired power plants (CFPPs) of Xi'an were determined by means of γ-ray spectrometry. The average activity concentrations of Ra, Th and K in all ash samples (fly ash and bottom ash samples) from the two CFPPs were 67.6, 74.3 and 225.3 Bq kg, respectively. The results are compared with data from other locations. To evaluate the radiological hazards of the natural radioactivity, the radium equivalent activity (Ra), air absorbed dose rate ( D), AED and external hazard index ( H) are compared with internationally accepted values. Ra and H of all samples except three fly ash samples were less than the limits of 370 Bq kg and unity, respectively. The average D and AED for ash samples were 86.8 nGy h and 0.11 mSv y, respectively, which exceed the world average and Xi'an average values. [ABSTRACT FROM AUTHOR]

Herbs in Egypt are imported from different countries and widely used in different forms. Owing to their different origins, the measured radioactivity levels show a broad range. For example, the radium concentrations in the studied herbs ranged from 7.71±0.25 Bq/kg in green tea to 115.08±0.49 Bq/kg in gawafa. 137Cs concentrations were found to be quite different from one herb to another, ranging from below the minimum detectable limit to 12.62±0.42 Bq/kg. Some values are much greater than the UNSCEAR reported values for grain products and vegetables. The external exposure and the uptake of naturally occurring radionuclides were studied in terms of the annual effective absorbed dose and the annual ingestion dose, respectively. The herb store workers are externally exposed due to natural radiation in the herbs. The annual effective absorbed dose was calculated as 282.8 μSv for tilia, a dose which is over half the total annual effective dose due to terrestrial radiation (which is 410 μSv). Thus, it is potentially possible to accumulate excess doses from all herbs in the store which constitute a health hazard to the workers. For internal exposure, assuming a 1 kg/year annual intake for each herb, the annual ingestion doses are lower than the global value and can be further diminished if herbs with lower concentrations of radionuclides are consumed. [ABSTRACT FROM AUTHOR]

Background. In arid regions water is vital and large bodies of waste water that are returned to the environment penetrate the ground and re-emerge as surface water to be used for domestic purposes. Results. Waste water from oil is disposed of in this way and this study showed that waste water from this origin produced activities of 40K that exceeded the domestic admissible limit of 0.2 Bq L-1. This was used as an indicator to evaluate the threat of contamination to underground aquatic supplies. Several samples were collected and monitored for gamma rays for a period of 1 year. In some cases 40K levels were as high as 100 Bq L-1. Conclusions. The potential impact of these raised levels on aquatic resources and the general environment is discussed. The thrust of this paper is of considerable benefit to oil-producing countries throughout the world from the perspective of potential contamination by 40K from produced water that is returned to the environment. [ABSTRACT FROM AUTHOR]

A comprehensive study was conducted to determine the radioactivity concentrations of beach sand samples from different sites along the coast of Tripoli, northwest Libya, using high resolution γγ-ray spectroscopy. Collection of samples was carried out during low tide, where it was possible to collect sediments from the wet region that was covered by sea water during high tide. From the measured γ-ray spectra, elemental concentrations were determined for 226Ra, 232Th, 40K, and 210Pb at depths 5-10 and 50-70 cm from the surface. The activity concentration ratios of 210Pb/226Ra for some samples were calculated to show the disequilibrium between the 210Pb and its parent nuclei 226Ra in the coastal marine sediments. The mean value of the absorbed dose rates in air obtained in the studied area was 4.4 ± 1.3 nGy h-1, which is lower than the world average (55 nGy h-1). [ABSTRACT FROM AUTHOR]

Low-level actinium contamination (228Ac) of petroleum sludge is reported. The sludge is earmarked for road-building and soil enrichment, hence long-term radiation in low doses is not desirable. We subsequently investigated the distribution of this radioactivity over a one-year period. Collection was conducted at different sites, and the sludge was subjected to high-resolution gamma-ray measurement with a Geenlarge this page detector. Samples of 1 kg dry weight were prepared in suitable Marinelli beakers and counted for 12 h. The approximate literature guideline for this radioistope in soil and regular sludge is about 60 Bq/kg. The levels in many of our samples were several times higher, and activities up to 600 Bq/kg were observed. The general distribution was studied; and suggestions for possible preventative remediation to deplete the activity levels in the sludge prior to its use as a building material and on sludge-farms are outlined. The study, therefore, formed an interesting contribution to research associated with radioactivity in the environment. [ABSTRACT FROM AUTHOR]

Elevated levels of 214 Pb and 214 Bi activity were observed in oily sludge samples and the possible risk they could pose to the environment are investigated. 214 Pb and 214 Bi levels can be used to estimate indirectly the prominence of radon ( 222 Rn), which is considered to be significant ecological hazard at abnormal levels. The sludge itself is regarded as prospective building material for constructing pavements, carparks and shopping malls; and is also disposed off on ‘sludge‐farms’ to enrich soil. The approximate literature guideline for these radioistopes in soil and regular sludge is around 200 Bq/kg. Levels in the samples investigated were more than four times this level. The distribution of this radioactivity was subsequently investigated over a one‐year period extending from January 2004 to December 2004. [ABSTRACT FROM AUTHOR]

In this work we investigate and quantify how effectively the noble gas 222Rn is trapped inside measurement beakers used in high-resolution gamma-ray spectrometry. We test six types of different beakers commonly utilized in γ spectrometry, including one novel construction, the γBeaker. We assessed 222Rn leakage by injecting 222Rn rich air into the examined beakers and investigated the abnormal decrease in 222Rn daughters – 214Pb and 214Bi. The measured decay times were used to estimate the 222Rn leakage. In addition, we investigated the influence of an additional beaker sealed with tape. However, the additional beaker sealing only slightly reduced the 222Rn escape and was not reproducible. Almost every tested beaker exhibited heavy 222Rn leakage. This may lead to an underestimation and radioactivity over-dispersion of 238U decay chain members when they are measured via their 222Rn daughter products. • We quantify how effectively noble gas 222Rn is trapped inside HPGe measurement beakers. • We test six different beakers used in HPGe γ spectrometry. • Up to 99% of 222Rn leakage. • New 222Rn tight beaker is proposed. [ABSTRACT FROM AUTHOR]