Gamma Spectrometer Research Articles

Estimation of Natural Radioactivity Concentrations of 238u, 232th and 40k in Soil Samples from Belagavi District, Karnataka, India

The natural radioactivity concentrations of Uranium (238U), Thorium (232Th), and Potassium (40K) in soil samples from Belagavi District in Karnataka, India were measured to assess the radiological impact on the environment and public health. Soil samples were collected from two different locations within the district, and the radioactivity levels of U, Th, and K were determined using NaI (Tl) a High-Resolution Gamma Spectrometer. The average activity concentrations of Uranium, Thorium, and Potassium were found to be 26.84 ± 0.16 Bq/kg, 48.33 ± 0.09 Bq/kg, and 150.71 ± 1.61 Bq/kg, respectively, in Savadatti soil samples, and 22.87 ± 0.19 Bq/kg, 54.43 ± 0.11 Bq/kg, and 219.99 ± 1.77 Bq/kg, respectively, in Belavadi soil samples. These results were compared with global and regional reference values to evaluate the radiological risk. The calculated Radium Equivalent Activity (Ra eq), External Hazard Index (H ex), were used to assess the potential health risks associated with the radioactivity levels in the soil. The study revealed that the radiological indices in the soil samples were within the safe limits, although certain areas showed slightly elevated concentrations. This study contributes to the understanding of natural radioactivity in the selected region and emphasizes the need for continuous monitoring to safeguard environmental and public health. The findings are compared with global safety limits set by international organizations like UNSCEAR.

Fuzzy logic modelling of the pollution pattern of potentially toxic elements and naturally occurring radionuclide materials in quarry sites in Ogun State, Nigeria

The accumulation pattern of some inorganic pollutants in quarry sites around Ogun State was modeled using a Fuzzy comprehensive assessment (FCA). Potentially toxic elements (PTEs) and naturally occurring radionuclides materials (NORMs) were assessed from soil samples collected from ten quarry sites in three districts (Odeda, Ajebo, and Ijebu Ode) in Ogun State. Three (3) NORMs (40 K, 238U, and 232Th) were assessed using gamma spectrometer with a NaI detector while ten (10) PTEs (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were determined by digestion method using Inductively coupled plasma optical emission spectrophotometer. The FCA was used to evaluate soil contamination, and SPSS version 21.0 was used for statistical analysis. Concentration range of PTEs(mg/kg) and NORMs(Bq/kg) in all the site are: As (5.62 ± 0.85 – 15.93 ± 2.40), Cd (BDL—1.26 ± 0.60), Co (5.56 ± 1.34 – 27.25 ± 1.14), Cr (18.68 ± 1.54 -61.43 ± 6.33), Cu (12.40 ± 1.31—82.43 ± 7.94), Fe (15,035.00 ± 81.12 – 36,520.00 ± 292.20), Mn (168.97 ± 5.93 – 353.30 ± 20.84), Ni (5.63 ± 1.99- 25.54 ± 2.50),),Pb (4.44 ± 0.8 – 17.87 ± 2.80) and Zn (42.97 ± 413 – 147.00 ± 7.50); 40 K (76.78 ± 44.76—2647.88 ± 179.44), 238U (3.24 ± 1.82—55.42 ± 24.88),and 232Th (5.24 ± 3.90—244.36 ± 89.84). The results were modeled into a membership function matrix of three pollution classes. The FCA of NORMs revealed that 30, 10, and 60% of the sites were pristine, moderately polluted, and heavily polluted.In comparison, the FCA of PTEs confirmed 100% of the sites to be heavily polluted due to the accumulative effect of the PTEs. A high percentage of membership in the extremely impacted class is linked to a high concentration of Fe in all the sites due to the soil's geological structure and natural activities. At the same time, 40 K and 238U have high-impact membership in all the quarry sites. Based on the findings, there is a need for stringent pollution control measures, targeted monitoring of PTEs and NORMs and the development of region-specific environmental regulations to protect both public health and ecosystems.

Application of Tradescantia-based test systems for the assessment of genotoxic effects of environmental radioactivity of undisturbed mountain soils (Aragats Massif, Armenia)

ABSTRACT Plant test systems are a sensitive way to detect the genetic effects of various contaminants in environmental compartments: water, soil and sediments. Biotesting of the genotoxicity of soil samples with various activity concentrations of naturally occurring (226Ra, 232Th, 40K) and artificial (137Cs) radionuclides in soil, from the territory of the Aragats Massif (Armenia) was carried out with the application of the Tradescantia micronucleus (Trad-MСN) and stamen hair mutation (Trad-SHM) bioassays of Tradescantia (clone 02) model test-object in the soil – plant system. Undisturbed soil sampling was performed in the southern slopes of the Aragats Massif, from different altitudes (from 1000 to 3200 m above sea level). The soils of the Aragats Massif exhibited a background level of naturally occurring materials (NORM) activity. The highest variability was indicated for 40K. The activity concentration of 137Cs in soils exhibited a naturally increased as the altitude increased. Tradescantia (clone 02) was grown on the undisturbed soils in the greenhouse. To determine the level of genotoxicity of the studied soil samples, the Tradescantia-based Trad-MCN and Trad-SHM tests were applied. The activity concentrations of NORM and artificial 137Cs in soil and phytomass were determined using an HPGe detector-based gamma spectrometer (Canberra). Tradescantia (clone 02) accumulated mainly 40K, accumulation of 226Ra observed in one soil sample. In the areas with elevated activity of NORM, levels of genotoxicity were significantly higher compared to the control soil sample with the low rate of spontaneous mutation frequency. The positive correlation between genetic damages of Tradescantia (MCN and SSH) and contents of 40K and 226Ra in soils was revealed. The obtained results indicated the possibility of using Trad-MCN and Trad-SHM tests of Tradescantia (clone 02) for biotesting of background radioactivity in natural areas.

Evaluation of Scintillation Counter Detector Using Gamma Radiation for Gold Detection

The aim of this work is to evaluate the efficiency of a new gamma spectrometer technology using a scintillation counter detector. This technique can detect the backscattered gamma radiation emitted from the samples. All rock samples were collected and irradiated by two gamma sources, Co60 and Cs137. The existence of gold (Au) was confirmed by displaying the spectrum of one standard made of pure gold and comparing the coincidence of their peaks with that of the rock samples. The spectrum of samples was displayed using the Cassy lab software program. The results indicated that Cs137 gamma spectra showed the same peak for the gold element, while the Co60 gamma spectra indicated the existence of gold radiation. Then, an energy dispersive X-ray (EDX) was done to compare and verify all results.

THE USE OF A XENON GAMMA SPECTROMETER FOR DOSIMETRY IN BORON-NEUTRON CAPTURE THERAPY

One of the main problems associated with the implementation of neutron capture therapy in clinical practice, requiring a solution, is the determination of absorbed dose. The only method that directly allows measuring the absorbed dose is gamma spectrometry, based on the registration of gamma rays with an energy of 478 keV. This article considers the possibility of using a xenon gamma spectrometer, which has high radiation resistance to neutron fluxes. The GEANT4 software package was used to study the neutron capture therapy process and conduct corresponding calculations.

Development of a CLYC-based wide dose rate range portable neutron-gamma detector.

This paper describes the development of a portable neutron-gamma detector for environmental radiation monitoring based on the CLYC crystal. It can function as a gamma spectrometer, gamma dosimeter, and thermal neutron counter. The upper measurement limit of gamma dose rate is approximately 6 mSv/h by using the proposed current mode in CLYC crystal and PMT. Meanwhile, the detector has a gamma energy resolution of 4.86% at 662 keV, and a figure of merit (FOM) of 3.32±0.04 for gamma and neutron pulse shape discrimination. In the initial phase of applications, the detector was used to measure the gamma and neutron radiation levels around the beamline of the associated Proton beam Experiment Platform (APEP) and R-dump room at the China Spallation Neutron Source (CSNS).

Real-time diagnosis of sampled lesions in targeted biopsy of prostate Cancer using a novel tracer [64Cu] Cu-DOTA-PSMA-3Q: a pilot preclinical study.

Prostate-specific membrane antigen positron emission tomography (PSMA-PET) guided targeted biopsy has shown potential for detecting more prostate cancer (PCa) cases. However, relying exclusively on imaging may risk missing lesions, an issue that could be addressed by incorporating radiation-guided technology. Accordingly, we aimed to develop a novel PSMA radiotracer with a long half-life, [64Cu]Cu-DOTA-PSMA-3Q, and evaluate its targeting accuracy. Additionally, this research explored the practicability of real-time lesion verification during surgical interventions. In this study, we synthesized the radiotracer [64Cu]Cu-DOTA-PSMA-3Q and verified its PSMA specificity and safety. We prospectively enrolled 18 patients with suspected PCa for PET/CT imaging to assess the efficacy of PCa detection; 10 patients underwent targeted biopsy combined with standard template biopsy at an interval of 24h after injection. The radioactivity of the biopsy tissue was quantified in counts per minute (CPM) using a gamma spectrometer intraoperatively. The efficacy and specificity of [64Cu]Cu-DOTA-PSMA-3Q were confirmed through preclinical cell and animal studies. In clinical settings, PET/CT imaging performed 2h after injection visualized all of the PSMA-positive lesions both within and outside the prostate. The assessment of human organ radiation exposure indicated that the kidneys received the highest absorbed dose, followed by the bladder wall, salivary glands, and liver. In 10 patients, a total of 132 biopsy cores were extracted, with 53 cores histologically confirmed as PCa. The median CPM for PCa tissues was significantly greater at 134,148 CPM compared to 18,39 CPM for normal prostate tissues (P < 0.001). Receiver operating characteristic (ROC) curve analysis yielded an AUC of 0.8837, suggesting high diagnostic accuracy. The optimal diagnostic cut-off was established at 66 CPM, achieving a sensitivity of 77.36%. Radiation-guided technology using [64Cu]Cu-DOTA-PSMA-3Q improves the reliability of PSMA-PET image-guided biopsy, enables instant confirmation of sample lesions during surgical procedures, and holds potential for achieving optimized puncture outcomes. Chinese Clinical Trial Registry ChiCTR2300072655, Registered 20 June 2023.

The effectiveness of implementing the HACCP system to ensure the quality of food products in regions with ecological problems

This study developed and implemented a specific HACCP plan for the meat pate “Phirmennyi” at the small meat processing enterprise “Alteev” in Semey, Kazakhstan. The research, conducted in collaboration with the Department of Food Production Technology and Biotechnology at Shakarim University, was carried out in an area affected by the ecological consequences of the former Semipalatinsk Nuclear Test Site. The study aimed to identify critical control points (CCPs) and assess potential risks following the Technical Regulations of the Customs Union. Additionally, it evaluated the effectiveness of the HACCP plan in reducing contaminants, such as heavy metals, radionuclides, and pesticides, while considering the region’s environmental impact on food safety and quality. Standard procedures were followed for hazard analysis, CCP identification, setting critical limits, monitoring, corrective actions, verification, and record-keeping. Heavy metals were measured using inductively coupled plasma mass spectrometry, while Cs-137 radionuclides were analyzed with scintillation and semiconductor gamma spectrometers. Statistical analysis was conducted in Microsoft Excel to compute mean values, standard deviations, and correlations, with significance defined at p ≤ 0.05. Five CCPs were identified during the production of an experimental batch of meat pâté, including raw material acceptance, blanching, cooking, cooling, and packaging/storage. Implementing this plan resulted in a reduction in contaminants, including a decrease in lead from 0.55 to 0.51 mg/kg, arsenic from 0.12 to 0.07 mg/kg, and Cs-137 from 7.2 to 6.8 Bq/kg. By addressing both the contaminants and the specific environmental context of the region, this research demonstrates the critical role of a well-structured food safety plan. The HACCP system not only improved food quality but also ensured compliance with safety standards, providing reassurance to consumers. This case study advocates for broader adoption of food safety management in regions with similar ecological challenges, promoting a more sustainable and secure food supply chain.

Characterization of proton-induced neutron spectrum on Ti-nat target in 11 MeV cyclotron using a passive single moderator neutron spectrometer

The neutron spectrum resulting from the interaction of protons with the materials in the cyclotron must be characterized to predict the effects of neutron activation on the various cyclotron component materials. Neutron spectrum measurements were carried out using a single moderator neutron spectrometer (SCNS) with an Au activation foil detector to analyze proton-induced effects on a natural titanium target in a self-shielding 11 MeV cyclotron. During the experiment, a disk-shaped Ti-nat target, 5 mm in diameter and 1 mm thick, was irradiated with proton beam at a current of 15 μA for 5 min. The neutron spectrometer, located inside the self-shielding, was then used to measure the 198Au activity of each Au foil employing an HPGe detector of gamma spectrometer. The neutron spectrum was determined using UMG software based on the 198Au activity values measured from each foil and the calculated response values for each foil detector. The obtained neutron spectrum showed a maximum energy of 8.5 MeV and a peak fast neutron energy of 2.5 MeV, with a total flux of (5.72 ± 0.40) × 105 n/cm2·s, consisting of 75% fast neutrons, 20% epithermal neutrons, and 5% thermal neutrons. The results of measuring the neutron spectrum using SCNS–Au are quite accurate because they only have a 10% difference compared to the simulation results using PHITS software.

Contributions of cosmic-ray components to the HPGe gamma spectrometer background spectrum within the 0°–45° Zenith angle range

This study investigates the contributions of various cosmic-ray-induced components to the energy response of a High-Purity Germanium (HPGe) gamma spectrometer within the 0°–45° zenith angle range. The analysis focuses on muons, neutrons, protons, electrons, positrons, and photons. It also examines the impact of particle showers induced by muons interacting with the lead chamber and reaching the HPGe detector. Utilizing the GEANT4 simulation toolkit, we provide a detailed examination of these components' influence on the spectrum. The results confirm that within this zenith angle range, muons account for approximately 91% of the recorded cosmic-ray induced energy spectrum and contribute 54.6% to the overall cosmic-ray-induced background spectrum. The study also highlights the significant role of showers, especially those resulting from muon interactions with the lead shielding, in shaping the low-energy spectrum below 3 MeV.

Evaluation of Radioactivity Concentration and Hazard Indices in ash Some Hospitals Incinerators in Baghdad / Al Resafa

Due to their harmful effects on human health and their tendency to cause cancer, radionuclide concentrations and risk indicators have been measured in hospital incinerator ash. This was done by collecting samples ash of Hospitals Incinerators, examining them, and identifying the risks that emerged from the examination. Three samples Only taken for the study from certain hospitals affiliated with the Baghdad Al-Rusafa Health Department. High purity germanium gamma spectrometer (HPGe) were used to analyze the samples. The concentrations of potassium isotopes (K-40) range from (147.1±16.5 to 214.4±21.1 Bq/kg), While the range of concentrations for Ra-226 isotopes is (7.52±1 to 19±1.8 Bq/kg), and lead (Pb-212) isotope concentrations ranged from (10.1±1.1 to 11.1±1.5 Bq/kg). In addition, the isotope concentration of actinium (Ac-228) is 8.05±1. Radium equivalent (), risk index , annual effective dose equivalent radioactivity level index ), absorbed dose rate D, and lifetime cancer risk were calculated. The results showed that no radiation risk Only indicated by any of the risk indicators. This indicates that the ash from the hospital incinerator does not pose any radioactive danger.

Production cross sections of 102mRh and 108mAg in proton bombed natPb target with 400 MeV energy

The accelerator-driven subcritical system (ADS) is a competitive option for next-generation nuclear energy systems. Production cross sections of long-lived residual radioactive nuclides in a proton-nuclide reaction are basic quantities for the calculation of accumulated radioactivity in the use of ADS systems. This work presents the production cross sections of 102mRh and 108mAg in a natural lead (natPb) target activated by 400 MeV protons. The natPb target was irradiated by a 400 MeV proton beam in NRC “Kurchatov Institute” and measured two decades later by a low background gamma spectrometer in China Jinping Underground Laboratory (CJPL). A spectrum analysis method based on simulated single-isotope spectrum and Bayesian peak fitting was employed to compute the activities and production cross sections of the residual nuclides. The experimentally measured cross-sections for 102mRh and 108mAg were 0.72 ± 0.05 mb and 0.76 ± 0.09 mb respectively. These values are approximately twice as high as those predicted by the QGSP_INCLXX_HP model and fall within the range predicted by the INCL4+ABLA and LAQGSM+GEM2 models for mass numbers A=102 and A=108. These findings offer new experimental insights for ADS research and provide a practical benchmark for theoretical models concerning proton-lead interactions.

Activity concentrations of 60 Co, 137Cs and 241Am in sieved soil and soil inclusions from the «Taiga» peaceful nuclear explosions site

The article presents results of comparative study of 137Cs, 60Co, and 241Am activity concentrations in components of the soil samples collected in 2009 on the territory adjacent to the «Taiga» peaceful nuclear explosions site (the Perm region, Russia). The objective of the study was to identify differences between: 1) non fractionated native soil, 2) the soil passed through a sieve with a mesh size of 1.2 mm, and 3) the screened out coarse components. Measurements of the radionuclides activities in counting samples were performed using a semiconductor gamma spectrometer. Statistically significantly lower activity concentrations of 137Cs (factor of 1.2), 60Co (factor of 2.2) and 241Am (factor of 2.6) were found in the finely dispersed sieved fraction of soil compared to the native soil. On the opposite, in the solid radioactive inclusions selected from the screened out coarse fraction, the activity concentrations of 137Cs, 60Co and 241Am were significantly higher compared to those in the native soil. Especially large differences (up to a factor of 10 and more) between the native soil and radioactive inclusions were observed for the refractory and low-volatile 60Co and 241Am. Presumably, these radionuclides were concentrated predominantly in the glassy substance of the radioactive inclusions. For 137Cs, the unevenness in the contamination of different soil components was less pronounced. The results obtained will be used to standardize methods for assessing radioactive contamination of the territory at the sites of peaceful nuclear explosions

Radiological Risk Assessment of Building Materials Used in Federal College of Education (Technical) Akoka, Lagos State, Nigeria

Multiple building constructions necessitating a regular influx of different soils for building purposes within Federal College of Education (Technical) Akoka, in Lagos State, Nigeria spurred a radiological risk assessment of selected soil samples. Five (5) construction points were identified and ten (10) soil samples were collected. A gamma spectrometer was used to evaluate the natural radionuclides (226Ra, 232Th, and 40K) present in the soils. IAEA-certified standard materials of RGU-1, RGTh-1, and RGK-1 were used to determine the full peak efficiencies of gamma energies 609, 1120, and 1764 keV for 238U, 2614 keV for 232Th and 1460 keV for 40K. Activity concentration, absorbed dose, annual effective dose equivalent, hazard indices, and excess lifetime cancer risk (ELCR) were estimated to assess possible radiological risks in the building soil samples. Results from the analysis revealed the highest radioactivity among soil samples was 674.3 Bq/kg from 40K and the lowest was 18.5 Bq/kg from 226Ra. The absorbed dose (D) varies from 65.8 nGy/h to 215.3 nGy/h with an average value of 136.6 nGy/h, and the annual effective dose equivalent ranged from 0.081 mSv/y to 0.264 mSv/y with an average value 0.168 mSv/y. The internal and external hazard index ranged from 0.49 −1.46 and 0.39 − 1.32 respectively which is not completely below the hazard index threshold value ≤ 1 as recommended by UNSCEAR. The ELCR values ranging from 0.222 × 10-3 − 0.726 × 10-3 with an average value of 0.461 × 10-3 predicted an insignificant carcinogenic risk with the probability of four persons in every 10,000 persons.

Simulation and Performance of 99Mo/99mTc Radioisotope Separation by Modified Extraction Method

Abstract Technetium-99m (99mTc) is a nuclide in nuclear medicine, commonly derived as a decay product from molybdenum-99 (99Mo). Unfortunately, Japan and Indonesia rely entirely on imports for their 99Mo/99mTc supply. This study aims to determine the distribution coefficient (Kd) for the 99Mo/99mTc production process and assess the efficiency of Methyl Ethyl Ketone (MEK) as a solvent in the extraction process. The method Initial tests using Rhenium (Re) as a substitute for 99mTc, conducted in collaboration with the Japan Atomic Energy Agency (JAEA), revealed optimal conditions: a standing time of 5 to 15 minutes, a mixing time of 3 minutes with a motor speed of 250 rpm, and a MEK volume exceeding 20 ml. These conditions yielded a Re extraction efficiency exceeding 85.14%, with a Re elution yield of up to 98.73%. These findings served as a database for experiments involving 99Mo/99mTc conducted at the National Research and Innovation Agency (BRIN). In hot experiments, the 99mTc recovery rate through MEK exceeded 100%, while the elution process achieved a recovery rate of 97.81%. Through simulation and facility enhancements in the hot cell, the 99mTc extraction recovery increased to 44.86%, and elution recovery ranged from 90.62%. From the calculation results, the distribution coefficient value database (Kd-99mTc) was 0.45. Radionuclide and radiochemistry purity of the 99mTc solution were assessed using the Gamma Spectrometer and TLC Scanner, resulting in purity of 99.90% and 99.80%, respectively. These results underscore the potential for domestic production 99mTc, reducing reliance on imports.

Use of a Xenon Gamma Spectrometer for Dosimetry in Boron–Neutron Capture Therapy

Use of a Xenon Gamma Spectrometer for Dosimetry in Boron–Neutron Capture Therapy

Environmental Radioactivity Monitoring and Radiological Impact Assessment of Agbara Industrial Area, Ogun State, Nigeria

This study assessed the naturally occurring radioactivity of 40K, 238U, and 232Th, which pose a significant threat to human health, particularly when their concentrations exceed the threshold. Background radiation levels were measured at two specific locations, Access Bank and Market areas, across a total of forty (40) sample points. The measurements were taken using a calibrated RS125 Gamma Spectrometer (a portable NaI [Tl] detector) designed in Canada, in conjunction with a global positioning system (GPS) to accurately record the research coordinates within the Agbara industrial area, Ogun State, Nigeria. The mean activity concentrations of the primordial radionuclides were 177.87 Bqkg-1, 20.01 Bqkg-1, and 52.90 Bqkg-1 for 40K, 238U, and 232Th, respectively. More so, the in-situ measured dose rate (DR) ranges between 12.18 nGyh-1 (Access Bank area) and 97.95 nGyh-1 (Market area), with an average value of 47.22 nGyh-1. The average measured and estimated absorbed dose rates were within the safe limit of 57 nGyh-1 provided by UNSCEAR. However, the measured dose rates exceeded the recommended limit in ten locations, while measured activity for thorium exceeded the world average value for over half of the study locations. Although all estimated radiological parameters were within recommended threshold values, suggesting the low risk of exposure to higher levels of ionising radiation in most locations in the Agbara industrial area, there is a potential cancer risk for individuals who have resided in the area for 70 years or more due to long-term exposure to ionising radiation.

Verification on Molybdenum-99 (99Mo) Breakthrough from Non-Fission 99Mo/99mTc Generator to Produce Technetium-99m (99mTc) Medical Radionuclide

Abstract The medical radionuclide 99mTc is the most widely used type of radionuclide in the field of nuclear medicine. 99mTc is the decay product of 99Mo. One of the quality control parameters of 99mTc is the 99Mo breakthrough limit. It is important to know the 99Mo breakthrough so that the quality of 99mTc produced can be optimal for diagnosis in nuclear medicine. This study aims to verify the 99Mo breakthrough activity from a non-fission 99Mo/99mTc generator whether they meet the established international limit standard. This research used a non-fission 99Mo/99mTc generator produced in multipurpose reactor G.A. Siwabessy, Indonesia. Gamma Spectrometer measurement of 99Mo and two 5 mL liquid standard sources of mix 133Ba and 152Eu used the same geometry. First standard as a calibration and efficiency identification function while the second standard is used to verify the measurement each at 3, 5, 7, 9 and 11 cm source to detector distance respectively. The 99Mo breakthrough activity (µCi) then devided to the activity of 99mTc (mCi) for the six eluted product from each days elution process of the generator. The results obtained showed that the 99Mo elution in the first elution had the highest breakthrough of 0.233 uCi 99Mo /mCi 99mTc, which exceeded the set limit of 0.15 uCi 99Mo /mCi 99mTc. While in the second, third, fourth, and fifth elution still have the 99Mo breakthrough, but these breakthrough did not exceed the limit and met one of the requirements of the 99mTc medical radionuclide parameter.

Calculation of radiological risks for selected soil samples from the north of Kufa district in Najaf, Iraq.

To evaluate radioactivity levels in soil samples and their physical impact on the population. The experimental radiation study was conducted in northern Kufa, Al Najaf Governorate, Iraq, in March 2020 by researchers from the Kufa University, Iraq and comprised soil samples. A gamma spectrometer equipped with a sodium iodide detector activated with a trace amount of thallium was used to calculate the concentration of radium, thorium and potassium. Data was analysed using SPSS 20. There were 30 samples. The average concentration of Radium, Thorium and Potassium was (0.824± 0.392)ppm, (1.536± 0.645)ppm and( 0.597± 0.195)%, respectively, and the radiation hazards were lower than the permissible levels. The reported value of excess lifetime cancer risk was (1.2819 ±0.156)×10-3, and the annual gonadal equivalent dose (AGED) was 116.496± 41.255 (mSv. y-1), which was lower than the recommended limit. There was a positive, strong and significant relationship of radium with all the variables (p<0.05) studied except with potassium (p>0.05). Thorium was positively and significantly associated with all the variables (p<0.05). The study area was found to be safe and there was no relationship between the radiation levels of the studied nuclides and the risk of cancer.

Assessment of Radioactivity Levels in Bottled Drinking Water Consumed by Different Age Groups of People in Kampala City, Uganda

The activity concentrations of natural radionuclides in drinking water may be enhanced depending on the geological strata from which it is extracted. The demand and consumption of bottled drinking water is increasing every year in Uganda mainly in Kampala city. Therefore, the study was purposed to assess the levels of natural radioactivity using a gamma spectrometer in commonly bottled drinking water in Kampala City. The mean specific activities for Ra-226, Th-232, and K-40 in bottled drinking water were 4.45±0.20, 1.32±0.27, and 46.33±0.24 Bq/l respectively which exceeded the specific World Health Organization recommended guidance level of 1.0 Bq/l except for K-40. The mean activity concentrations were however comparable to the mean concentration of tap water used in Kampala City, that is 4.00±0.16, 1.4±0.19, and 47.05±0.21 Bq/l for Ra-226, Th-232, and K-40 respectively. The annual effective dose contributed by two radionuclides of Ra-226 and Th-232 in the bottled water exceeded the maximum dose limit of 0.1 mSv/y recommended by the World Health Organization (WHO). The mean estimated excess lifetime cancer risk due to Ra-226 (0.00177) exceeded the recommended limit of 0.001 while that due to Th-232 (0.0001) was below the recommended limit. Therefore, the main contributor to the total annual ingestion dose was Ra-226. Due to the high solubility and toxicity of Ra-226, there is a significant concern warranting further investigation. Finally, the results from the study revealed that there was not any trace of contamination from artificial radionuclides in the bottled drinking water manufactured and consumed within Kampala City. With the growing populational demand for bottled drinking water, it's recommended that radioactivity levels comply with the WHO recommended radioactivity levels. Therefore, this study contributes to the revision of standards and development of regulations for radiological protection of the public and the environment from risks of radiation exposure associated with bottled drinking water.