Soil radioactivity and radiotoxic risks of uranium in drinking water. A case study of Jos Plateau, Nigeria

Protection and assessment of any radiation pollution resulting from the use and disposal of radioactive materials to the large extent depend on the knowledge of natural radioactivity level of an environment. This work determined the activity concentration of terrestrial radionuclides 226Ra, 232Th and 40K in top soil samples of Jos Plateau using high resolution HPGe detector. Inductive Coupled Plasma (ICP) Mass Spectrometer was used to determine the chemical concentrations of uranium (238U) in drinking water samples collected from the area.  The activity concentration of 226Ra varied between 34±1 and 1006±18 Bq/kg, 67±2 and 1695±37 Bq kg−1 for 232Th and between 67±4 and 2465±45 Bq/kg for 40K. Chemical concentration of 238U in water samples was found to vary from 1.4 to 35 μg/ L. The values of radiological risks due to radioactivity and chemical risks of mortality and morbidity due concentration of 238U in drinking water were estimated. The risk values for some samples are found to be within safe limits provided by health and environmental protection agencies (ICRP, WHO and USEPA). The radiometric data could be useful for geochemical exploration and diagnosis and prognosis of uranium persuaded diseases for the local inhabitants in the study area

Assessment of natural radionuclides at Kinta River, Malaysia: relationship between the turbidity to uranium and thorium concentrations

This study aims to investigate the relationship between the turbidity to uranium and thorium concentrations. Since the radionuclides analysis is complex and time consuming, turbidity monitoring on river is proposed to be an indirect indicator for uranium and thorium concentration. Eighteen water samples were collected and turbidity measurements were conducted at several locations from Kinta River. The concentration of uranium and thorium were analyzed using inducted coupled plasma mass spectrometer (ICP-MS). The concentrations of thorium were varied from 44 ng L?1 to 787 ng L?1 while the concentration of uranium varied from 45 ng L?1 to 371 ng L?1. Statistical analyses were applied to determine the relation between turbidity and concentrations of uranium and thorium at Kinta River. The correlation coefficients (R) show a strongly correlation, with R values of 0.915 and 0.881 for turbidity with concentrations of uranium and thorium, respectively

Thermoluminescence responses of photon- and electron-irradiated lithium potassium borate co-doped with Cu+Mg or Ti+Mg

New glasses Li2CO3–K2CO3–H3BO3 (LKB) co-doped with CuO and MgO, or with TiO2 and MgO, were synthesized by the chemical quenching technique. The thermoluminescence (TL) responses of LKB:Cu,Mg and LKB:Ti,Mg irradiated with 6 MV photons or 6 MeV electrons were compared in the dose range 0.5–4.0 Gy. The standard commercial dosimeter LiF:Mg,Ti (TLD-100) was used to calibrate the TL reader and as a reference in comparison of the TL properties of the new materials. The dependence of the responses of the new materials on 60Co dose is linear in the range of 1–1000 Gy. The TL yields of both of the co-doped glasses and TLD-100 are greater for electron irradiation than for photon irradiation. The TL sensitivity of LKB:Ti,Mg is 1.3 times higher than the sensitivity of LKB:Cu,Mg and 12 times less than the sensitivity of TLD-100. The new TL dosimetric materials have low effective atomic numbers, good linearity of the dose responses, excellent signal reproducibility, and a simple glow curve structure. This combination of properties makes them suitable for radiation dosimetry

NORMs distribution in coastal soils and sediments of River Yobe, north-eastern Nigeria: an evaluation of the potential radiological hazards

A preliminary study which aimed to establish a reference data on naturally occurring radioactive materials (NORMs) for River Yobe has been conducted. Soil and sediment samples were collected along the coastal areas of the river and analyzed to determine the specific activities of NORMs such as 238U, 232Th and 40K. Gamma spectrometry technique using NaI (Tl) detector was employed to determine the specific activities f the natural radionuclides. The mean activity concentration in the soil samples for 238U, 232Th and 40K were found to be 23±1.5, 36±2.5 and 395±9.1Bq kg−1 and for the sediment samples are 60±2.6, 45±3.6 and 324±6.8Bq kg−1 respectively. These values, in some cases exceed the world reference values of 30, 35 and 400 Bq kg−1 for 238U, 232Th and 40K respectively. Parameters of radiological hazard, were also estimated based on specific activity of the radionuclides to assess the radiological impacts due to exposure on the users of the river. The results were found to be within the worldwide recommended safety limits.Keywords: Annual effective dose, NORMs,238U.232Th.40K. River Yob

Determination of surface radiation dose-rate in the environment of Kelantan State, Malaysia

Measurements of environmental surface radiation dose rate in Kelantan state, Malaysia was carried out using a portable hand held radiation survey meter and Global Positioning System (GPS). The surface radiation dose rates ranged from 44 to 500 nGy h-1. The measurements were done based on geology and soil types of the area. The mean radiation dose rate was found to be 209 ± 8 nGy h-1. Few areas of relatively enhanced activity were located in Pasir Mas, Tanah Merah and Jeli districts which have external gamma dose rates between 300 to 500 nGy h_1. An Isodose map of the state was produced using ArcGIS10 software version 10.1. To evaluate the radiological hazard due to terrestrial gamma dose, the annual effective dose equivalent (AEDE), the mean population weighted dose rate and cancer risk factor were calculated and found to be relative excess lifetime cancer risks were 1.280 mSv y-1, 18 mSv and 1.04×10-3 respectively

Nigeria research reactor-1 : vertical detector efficiency calibration using conventional and semi-empirical approach for large samples NAA implementation

Detector efficiency calibration is mandatory for accurate measurement of induced activity in irradiated samples and for safe operation of the reactor with minimal uncertainty. This paper reported the efficiency calibration of vertically dIpstick High Purity Germanium detector, installed at the Centre for Energy Research and Training, Ahmadu Bello University Zaria for the purpose of large sample Neutron Activation Analysis (NAA) using Nigeria research reactor-1 (NIRR-1). The performance of the detector was evaluated for the radioisotope activity measurements during the reactor operation for large samples neutron activation analysis. The detector performance in terms of radioisotopes detection ability was inspected using the standard conventional and semi-empirical approaches. The full energy peak efficiencies were determined at the corresponding energies for three different geometries (source to detector distance of 1, 5 and 10 cm). The semi-empirical approach produced better and precise results that logically rhymed with theory than the traditional approach. Besides that, a consistency in the nature of the graphs and values were evidenced. The determined efficiencies and their corresponding energies revealed encouraging outcome and ensured the successful NAA for large samples of different material compositions

Dosimetric characteristics of a LKB:Cu,Mg solid thermoluminescence detector

We present the main thermoluminescence characteristics of a newly borate glass dosimeter modified with lithium and potassium carbonate (LKB) and co-doped with CuO and MgO. An enhancement of about three times has been shown with the increment of 0.1mol% MgO as a co-dopant impurity. The effects of dose linearity, storage capacity, effective atomic number and energy dose response are studied. The proposed dosimeter shows a simple glow curve, good linearity up to 103 Gy, close effective atomic number and photon energy independence. The current results suggest using the proposed dosimeter in different dosimetric applications

Pixel intensity-based contrast algorithm (PICA) for image edges extraction (IEE)

In this paper, images' pixels are exploited to extract objects' edges. This paper has proposed a Pixel Intensity based Contrast Algorithm (PICA) for Image Edges Extraction (IEE). This paper highlights three contributions. Firstly, IEE process is fast and PICA has less computation time when processing different images' sizes. Secondly, IEE is simple and uses a $2\times 4$ mask which is different from other masks where it doesn't require while-loop(s) during processing images. Instead, it has adopted an if-conditional procedure to reduce the code complexity and enhance computation time. That is, the reason why this design is faster than other designs and how it contributes to IEE will be explained. Thirdly, design and codes of IEE and its mask are available, made an open source, and in-detail presented and supported by an interactive file; it is simulated in a video motion design. One of the PICA's features and contributions is that PICA has adopted to use less while-loop(s) than traditional methods and that has contributed to the computation time and code complexity. Experiments have tested 526 samples with different images' conditions e.g., inclined, blurry, and complex-background images to evaluate PICA's performance in terms of computation time, enhancement rate for processing a single image, accuracy, and code complexity. By comparing PICA to other research works, PICA consumes 5.7 mS to process a single image which is faster and has less code complexity by $u\times u$. Results have shown that PICA can accurately detect edges under different images' conditions. Results have shown that PICA has enhanced computation time rate for processing a single image by 92.1% compared to other works. PICA has confirmed it is accurate and robust under different images' conditions. PICA can be used with several types of images e.g., medical images and useful for real-time applications

Binary nickel and silver oxides by thermal route: preparation and characterization

Many studies have concentrated on exploring behaviors of nickel silver oxide nanoparticles using various routes of fabrication. Thermal treatment technique has never been utilized to fabricate nickel oxide silver oxide nanoparticles. In this research, binary (NiO)0.4 (Ag2O)0.6 nanoparticles were synthesized using the thermal treatment method due to its attractive advantages such as low cost, eco-friendly, and purity of nanoparticles. The structural, morphological, and optical behaviors of these nanoparticles were investigated at different calcined temperatures. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible spectroscopy (UV–Vis), and photoluminescence (PL) were the techniques used to characterize the synthesized nanoparticles. XRD was conducted at different calcined temperatures. The crystallite size was increased from 25.4 nm to 37.0 nm as the calcined temperature increased from 500 °C to 800 °C. Also, TEM results verified that the mean particle size was enlarged as the calcined temperatures increased. Two band gaps were found for each temperature, which were decreased from (3.05, 2.45) to (2.70, 1.95) eV as the temperature varied from 500 to 800 °C, respectively. Broadbands were observed by PL spectra, and the intensity of two emission peaks was also increased at higher temperatures. The results approved the successful formation of binary (NiO)0.4 (Ag2O)0.6 nanoparticles by a novel facile synthesis route. These nanoparticles are likely to have various applications, especially optical applications due to the formation of two band gaps

Nanofabrication of (Cr2O3)x (NiO)1-x and the impact of precursor concentrations on nanoparticles conduct

This study aims to synthesize the (Cr2O3)x (NiO)1-x nanoparticles at lower and higher precursor values using the calcination method. There is a lack in regard to investigating the lower and higher precursor values on structural and optical properties of the (Cr2O3)x (NiO)1-x nanoparticles. To synthesize the (Cr2O3)x (NiO)1-x nanoparticles, Cr (III) acetate hydrate and Ni (II) acetate tetrahydrate were reacted with poly (vinyl alcohol). Several techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR), have been employed to characterize the synthesized sample. The XRD pattern analysis indicated that, following calcination, nanoparticle formation occurred, indicating hexagonal crystalline structures (HCP) and face-centred cubic (FCC) of (Cr2O3)x (NiO)1-x nanoparticles. FT-IR verified the existence of Ni-O and Cr-O as the original compounds of ready (Cr2O3)x (NiO)1-x nanoparticle samples. In term of average particle size, this varied from 5 to 16 nm when the precursor concentration rised from x = 0.20 to x = 0.80, as reflected in the TEM results. X-ray photoelectron spectroscopy (XPS) was employed to measure the valence state and surface composition of the prepared product nanoparticles. To identify the optical band gap using the Kubelka-Munk equation, diffuse UV-visible reflectance spectra were employed, which revealed that the energy band gap fell with a rise in the value of x. In addition, photoluminescence (PL) spectra indicated that the photoluminescence intensity was related to a directly proportional way to particle size. Hence, the results can be employed with a broad range of applications in solar cell energy applications at higher x values and antibacterial activity at lower x values