232Th Activity Research Articles

External dose assessment of NORM added consumer products using Geant4 Monte Carlo simulations

Radioactive consumer products (RCP) are widely marketed for everyday use. The study herein was conducted on 21 commercially available RCP, including bio-glass discs, energy cards, scalar energy products, and anti-radiation stickers, all purposefully designed to contain naturally occurring radioactive material (NORM). This study investigates the dose influence of such consumer products which acts as external radiation sources that may be in contact with human body. The goal of this study is to assess the potential risk of using NORM-added consumer products, the presence of such products in the living environment unnecessarily exposing members of the public to radiation. A Pb-shielded high purity Ge (HPGe) spectrometer was used to perform the analysis of samples radioactivity levels. Simulations were performed using Geant4 Monte Carlo (GMC) simulations to estimate the equivalent organ doses and annual effective dose (AED) in the use of such products. The total activity in such radioactive consumer products ranges from 2.0 ± 0.1 to 7413 ± 576 Bq, 1.9 ± 0.8 to 1168 ± 131 Bq, and 21 ± 5–574 ± 103 Bq, for 232Th, 238U, and 4 K, respectively. It was found that RCP contains monazite, giving a relatively high concentration of uranium and thorium. The radiological risk posed by the use of such items as healthcare products is assessed, with the daily external exposure doses of particular concern. Dose assessments of the organ equivalent and average effective doses were performed by measuring the activity of 232Th, 238U, and 4 K using the aforementioned products for various exposure duration scenarios. Accordingly, sample A13 a bio-glass disc offered concentrations with mean percentages of 1.29 ± 0.003% and 0.043 ± 0.0003% for Th and U, respectively, giving rise to estimate the greatest annual effective dose exposure of 2.54 mSv among samples, considerably in excess of the public dose limit of 1 mSv y-1

Dissolved and Particulate Barium Distributions Along the US GEOTRACES North Atlantic and East Pacific Zonal Transects (GA03 and GP16): Global Implications for the Marine Barium Cycle

AbstractProcesses controlling dissolved barium (dBa) were investigated along the GEOTRACES GA03 North Atlantic and GP16 Eastern Tropical Pacific transects, which traversed similar physical and biogeochemical provinces. Dissolved Ba concentrations are lowest in surface waters (∼35–50 nmol kg−1) and increase to 70–80 and 140–150 nmol kg−1 in deep waters of the Atlantic and Pacific transects, respectively. Using water mass mixing models, we estimate conservative mixing that accounts for most of dBa variability in both transects. To examine nonconservative processes, particulate excess Ba (pBaxs) formation and dissolution rates were tracked by normalizing particulate excess 230Th activities. Th‐normalized pBaxs fluxes, with barite as the likely phase, have subsurface maxima in the top 1,000 m (∼100–200 μmol m−2 year−1 average) in both basins. Barite precipitation depletes dBa within oxygen minimum zones from concentrations predicted by water mass mixing, whereas inputs from continental margins, particle dissolution in the water column, and benthic diffusive flux raise dBa above predications. Average pBaxs burial efficiencies along GA03 and GP16 are ∼37% and 17%–100%, respectively, and do not seem to be predicated on barite saturation indices in the overlying water column. Using published values, we reevaluate the global freshwater dBa river input as 6.6 ± 3.9 Gmol year−1. Estuarine mixing processes may add another 3–13 Gmol year−1. Dissolved Ba inputs from broad shallow continental margins, previously unaccounted for in global marine summaries, are substantial (∼17 Gmol year−1), exceeding terrestrial freshwater inputs. Revising river and shelf dBa inputs may help bring the marine Ba isotope budget more into balance.

Radiological characterization of nephrite produced in Xinjiang, Northwest China

The specific activities of 226Ra, 232Th and 40K of seven different color classification of nephrite samples from Xinjiang of China were measured by gamma spectrometry, and their radiological hazard indices such as radium equivalent (Ra eq), external hazard index (Hex ), internal hazard index (H in), alpha index (I α), absorbed dose rate (D) and annual effective dose rate (AED) were investigated and assessed. According to the experimental results, the specific activity level of 226Ra, 232Th, 40K in all nephrite samples was between 13.56 and 116.39 Bq·kg−1 with an average of 44.72 Bq·kg−1, between 2.19 and 10.89 Bq·kg−1 with an average of 4.90 Bq·kg−1, and between 21.06 and 94.32 Bq·kg−1 with an average of 52.24 Bq·kg−1, respectively. The mean values of radiological indicators, such as Ra eq, Hex , H in, I α and AED were 55.75 Bq·kg−1, 0.15, 0.27, 0.22, 0.16 mSv·y-1 (worn) and 0.13 mSv·y−1 (indoor), respectively, are lower than the international recommended value. The values of D range from 10.13 to 54.46 nGy·h−1 with an average of 25.80 nGy·h−1. In the end, it can be concluded that the use of the seven different color categories of nephrites as ornament is considered to be safe and unlikely to cause any significant biological radiation hazard to the public.

Analysis of natural and artificial radioactive emission pattern in Qarasu River catchment in Gorgan Bay, northern Iran

Knowledge of distribution and emission pattern of natural and artificial radioactive elements and their radiation level in the environment is very important to assess its effects on human health and living organisms. In this study, the specific activity of natural and artificial radioactive elements for 30 soil and sediment samples collected from upstream and the outlet of Qarasu River to Gorgan Bay as well as sediments in the eastern part of Gorgan Bay were measured using High-Purity Germanium detector and their distribution map with using SURFER and GIS software was drawn. Specific activity of 226Ra, 232Th, 40K and 137Cs was obtained from 8.80 to 31.92, from 11.16 to 43.19, from 183.77 to 562.88 and from 0.83 to 12.72 in Bq/kg respectively. Upstream of the Qarasu River, the average concentration of 226Ra, 232Th, 40K and 137Cs in the soil samples beside the Qarasu River was higher than the sediments of the river, which indicates the washing of sediments and the transport of radioactive elements by water flow and transfer of these elements to lower areas. In Qarasu estuary and Gorgan Bay, 232Th and 40K distribution patterns are almost similar and the highest concentrations of 226Ra, 232Th and 40K elements are related to Qarasu estuary sediments. The concentration of 137Cs in the mouth of Qarasu River has the lowest value and increases with its distance from the mouth to the middle parts of Gorgan Bay, which indicates a high mobility and a tendency to sediment in calmer places for 137Cs. The measured values for radiological parameters and risk indices due to nuclear radiation in this study are within the allowable range and the amount of available nuclear radiation does not threaten the health of the inhabitants of the region‎‎‎.‎

Radiation status of soils from the region of the Eastern Rhodopes (Southern Bulgaria)

Local values of natural radiation background in soils from unexplored regions in the Eastern Rhodopes were established. The impact of anthropogenic activity as a potential risk for increase in radiation background was assessed. Soil samples from areas near the liquidated lead-zinc mines – Madzharovo, gold mine – Ada Tepe, Krumovgrad, lead-zinc complex – Kardzhali, Neochim – Dimitrovgrad, deposits for extraction of gneiss, marble quarries, etc. were analyzed to study possible contamination. Specific activity of natural radionuclides 210Pb, 238U, 226Ra, 235U, 232Th, 40K and technogenic 137Cs in the studied samples was determined by gamma spectrometric analysis with Multichannel analyzer DSA 1000, production of CANBERRA and HPGe-detector.

Risk Assessment of Exposure to Natural Radiation in Soil Using RESRAD-ONSITE and RESRAD-BIOTA in the Cobalt-Nickel Bearing Areas of Lomié in Eastern Cameroon

Nkamouna-Kongo is a cobalt–nickel deposit located in Lomié, Eastern Cameroon. Mining creates radiation exposure pathways that must be considered in risk management scenarios. RESRAD-ONSITE and RESRAD-BIOTA, developed by the US DOE, assess contaminated sites by deriving cleanup criteria and estimating the radiation dose and risk associated with residual radioactive materials using site-specific parameters. This paper evaluated the radiation dose in biota and the health risk from exposure to naturally occurring radionuclides. The activity of 226Ra, 232Th, and 40K was determined by γ-spectrometry. The internal doses were 2.13 × 10−07, 1.42 × 10−06, and 8.38 × 10−05 Gy d−1 for animals and 2.38 × 10−07, 2.04 × 10−06, and 9.07 × 10−05 Gy d−1 for plants. The maximum total dose of 0.7234 mSv yr−1 was obtained at t = 1 year. The external dose contribution obtained at t = 1 year for all nuclides summed and all component pathways was 0.4 mSv yr−1, above the background radiation dose limit of 2.5 × 10−01 mSv yr−1. A maximum cancer risk of 1.36 × 10−03 was observed at t = 1 year. It was also shown in the RESRAD calculations that the total cancer morbidity risks from plant ingestion, radon (independent of water), and external gamma exposure pathways were greater than those from other exposure pathways. The high risk calculated for 226Ra relative to 232Th and 40K makes it the primary human health concern in the study area. The use of a 1 m cover thickness would remediate the contaminated site to a dose on the order of 10−5 mSv yr−1 for a period of 0 to 100 years. The values of these doses are below the US DOE recommended limits.

Technical note: Quantifying uranium-series disequilibrium in natural samples for dosimetric dating – Part 1: gamma spectrometry

Abstract. Dosimetric dating techniques rely on accurate and precise determination of environmental radioactivity. Gamma spectrometry is the method of choice for determining the activity of 238U, 232Th, and 40K. With the aim to standardize gamma-spectrometric procedures for the purpose of determining accurate parent nuclide activities in natural samples, we outline the basics of gamma spectrometry and practical laboratory procedures here. This includes gamma radiation and instrumentation, sample preparation, finding the suitable measurement geometry and sample size for a given detector, and using the most suitable energy peaks in a gamma spectrum. The issue of correct efficiency calibration is highlighted. The procedures outlined are required for estimating contemporary parent nuclide activity. For estimating changing activities during burial specific data analyses are required, and these are also highlighted.

Assessment of Natural Radio Activity Level in Some Imported Food Products in the Iraq Markets

The current study includes the evaluation of the levels of natural radioactivity of some nuclei in food samples included of 12 rice, and 8 legumes. Local markets in the Iraqi city of Hilla were sampled and spectral measurements were carried out using the reagent system sodium activated iodide thallium (NaI (Tl)) (3 3). 238U (214Bi), 232Th, and 40K had average values of (16,580.5278, 20,241.0849), and (388.87023.0914, respectively) of Bq/kg in rice samples, according to the study. (214Bi), (232Th), and 40K were all within the range of samples of legumes (7.46), (20.68) (322.57). All these results for the average specific activities of 238U(214B), 232Th and 40k were compared with the limits recommended by UNSCEAR (32)Bq/kg for specific activity of 238U (214B), (45)Bq/kg for specific activity of 232Th, (412)Bq/kg for specific activity of 40K and found to be below those values. Also, it was found that, the internal hazard index were (0.243) Bq/kg in samples of rice and the Extranl hazard index were(0.194 these results for the average value of the internal hazard index were compared with the limits recommended by UNSCEAR (1) for internal hazard index and found to be below those values. Accordingly, most of the food models that examined are considered honest in terms of contamination of nuclear radiation naturally.

Natural radioactivity in building materials, indoor radon measurements, and assessment of the associated risk indicators in some localities of the Centre Region, Cameroon.

The objective of the current study is to investigate the natural radioactivity of some building materials, the resulting long-term external and internal effective dose equivalents (EEDE and IEDE) analysis followed by indoor radon measurements, and the assessment of some radiological risk indicators associated with radon exposure. A total of 37 samples of building materials were analyzed with a sodium iodide detector (NaI (Tl)), and the computer code RESRAD-BUILD was used for the analysis of the EEDE and IEDE of the structural elements of the houses (walls and floor). For indoor radon measurements, 140 houses were selected, and in each of them was placed 01 RADTRAK dosimeter. Inhalation dose, total dose, and some radiological risk indicators were calculated. The specific activities of 226Ra, 232Th, and 40K for the overall sampled building materials were found to vary between 10 ± 2-52 ± 7, 10 ± 1-95 ± 10, and 31 ± 1-673 ± 20 Bq kg-1, respectively. The dwelling types with bare brick walls, cement mortar plastered walls, and concrete floors show EEDE and IEDE values well below the recommended limits. The corresponding dwelling type contributions to the measured average indoor radon concentration (42 ± 12 Bq m-3) are 22%, 13%, and 16%, respectively. Inhalation dose resulting from the measured indoor radon concentrations varies from 0.35 to 3.24 mSv y-1 with a mean value of 0.96 ± 0.55 mSv y-1, which represents about 65% of the total dose simulated (1.49 ± 0.88 mSv y-1) by the RESRAD-BUILD code. The overall analysis of indoor radon-related radiological risk indicators shows low levels of risk relative to permissible limits.

Natural Radionuclide Levels and Radiological Hazards of Khour Abalea Mineralized Pegmatites, Southeastern Desert, Egypt

Arranged from oldest to youngest, the main granitic rock units exposed in Khour Abalea are metagabbros, cataclastic rocks, ophiolitic melange, granitic rocks, pegmatite and lamprophyre dykes. The presence of radioactivity associated with the heavy bearing minerals in construction materials—like granite—increased interest in the extraction process. As it turns out, granitic rocks play an important economic part in the examination of an area’s surroundings. The radionuclide content is measured by using an NaI (Tl)-detector. In the mineralized pegmatites, U (326 to 2667 ppm), Th (562 to 4010 ppm), RaeU (495 to 1544 ppm) and K (1.38 to 9.12%) ranged considerably with an average of 1700 ppm, 2881.86 ppm, 1171.82 ppm and 5.04%, respectively. Relationships among radioelements clarify that radioactive mineralization in the studied pegmatites is magmatic and hydrothermal. A positive equilibrium condition confirms uranium addition to the studied rocks. This study determined 226Ra, 232Th and 40K activity concentrations in pegmatites samples and assessed the radiological risks associated with these rocks. The activity concentrations of 226Ra (13,176 ± 4394 Bq kg−1), 232Th (11,883 ± 5644 Bq kg−1) and 40K (1573 ± 607 Bq kg−1) in pegmatites samples (P) are greater than the global average. The high activity of the mineralized pegmatite is mainly attributed to the presence of uranium mineral (autunite), uranophane, kasolite and carnotite, thorium minerals (thorite, thorianite and uranothorite) as well as accessories minerals—such as zircon and monazite. To assess the dangerous effects of pegmatites in the studied area, various radiological hazard factors (external, internal hazard indices, radium equivalent activity and annual effective dose) are estimated. The investigated samples almost surpassed the recommended allowable thresholds for all of the environmental factors.

Radioactive risk assessment of beach sand along the coastline of Mediterranean Sea at El-Arish area, North Sinai, Egypt

Beach sand includes various levels of natural radioactivity, which can cause health effects. The natural radioactivity was measured in the beach sand along the coastline of the Mediterranean Sea at the east of the El-Arish area, Egypt. Using the HPGe spectrometer, the contribution of radionuclides 226Ra, 232Th and 40K in the gamma emitted radiation illustrated that the 226Ra, 232Th and 40K activity concentrations are 8.8 ± 3.9, 30.8 ± 12.2 and 106.9 ± 46.8 Bq kg−1, respectively, which is lower than the reported worldwide limit 33, 45 and 412 Bq kg−1. The radioactive hazards associated with the beach sand along the coastline of the Mediterranean Sea at the east of the El-Arish area were investigated. The obtained results among the radiological hazard parameters, the radium equivalent content (Raeq), the absorbed dose rate (Dair), annual effective dose (AED), external (Hex) and internal (Hin) hazard indices were estimated. Moreover, the excess lifetime cancer risk (ELCR) and the annual gonadal dose equivalent (AGDE) were also computed and illustrated their values less than the recommended levels. Multivariate statistical approaches like Pearson correlation, the principal component analysis (PCA) and the hierarchical cluster analysis (HCA) were applied to investigate the correlation between the radionuclides and the corresponding radiological hazard variables. Based on the statistical analysis, the 226Ra and 232Th mainly contribute to the radioactive risk of beach sand. Finally, no significant risk of the public associated with utilizing beach sand in building materials.

Feasibility study of using the artificial neural network modeling for estimation the radiological levels for the environmental samples

An artificial neural network (ANN) code is carried out to estimate the radiological concentration of environmental samples, clay, and sand. The ANN modeling has been calibrated and validated with the measuring data acquired from an HPGe detector. Radioactivity was determined using a gamma spectrometric detector (HPGe) for the collection of clay and sand samples from Al-Tod, Luxor, Egypt. The radiological levels of the natural radioactive series of 226Ra, 232Th, and 40K-isotope have been estimated for the sand and clay samples. The average specific activity of 226Ra, 232Th, and 40K for clay-samples were 14.43 ± 0.5 Bq/kg, 15.8 ± 0.6 Bq/kg, and 273.2 ± 6.1 Bq/kg, respectively, where it for sand-samples were 12.4 ± 0.46 Bq/kg, 13.4 ± 0.5 Bq/kg, and 215.4 ± 15.11 Bq/kg, respectively. The feasibility of the ANN model has been studied by comparing its outcome data with the measured one. However, a robust correlation is observed for the radiological levels achieved by the ANN model and for the measured one in an error of around 5 percent. Therefore, besides measurement techniques, the ANN model could be a promising candidate for estimating and predicting the radiological levels from environmental samples. However, the use of the ANN model will reduce the measurement time and cost over many samples.

Radiological risk assessment in sediment of Namal Lake, Mianwali, Pakistan.

This study is concentrated on the radiological risk assessment of sixteen surface sediment samples recovered from Namal Lake, District Mianwali, Punjab, Pakistan. The activity of 137Cs, 40K, 226Ra, 228Ra, and 232Th was carried out with the help of a high purity germanium detector (HPGe) in the sediment, varied in the ranges of > 0.02-3.73 ± 1.31, 98.32 ± 21.45-341.02 ± 58.67, 18.34 ± 2.16-34.23 ± 4.34, 1.62 ± .30-2.34 ± .52, and 0.14 ± 0.10-2.34 ± 0.59Bqkg-1 with average values 0.74 ± 0.29, 237.26 ± 37.97, 25.06 ± 4.74, 1.97 ± 0.39, and 1.73 ± 0.33Bqkg-1, respectively. The measured concentrations in the current study have been compared with other earlier studies in the world. The data was also used for determining the other useful parameters like radium equivalent activity, absorbed dose rate, annual effective dose rate, and external and internal hazards index to assess the radiological risk assessment for the environment around the study area. The ERICA Tool software was also applied for radiological risk assessment for lake fish due to the radioactivity present in the lake sediments. It was concluded from the results of ERICA tool that the risk quotient in this study is less than one indicating that no toxic effects of radioactivity for Namal Lake fish.

Natural Radioactivity Evaluation and Radiological Peril in some soil specimens of Al-Taimeem Area in Al-Anbar Province, Iraq

In the present work, the radioactivity of ten soil specimens has been measured, which were gathered from various sites from AL-Taimeem area in Al-Anbar province, The qualitative activity of natural radionuclides 238U, 232Th and 40K for soil specimens were evaluated by utilizing gamma-ray spectroscopy with NaI(Tl) detector of (3"×3") dimension. The results revealed that, the qualitative activity, for 238U was varied from (14.730 Bq/kg) to (28.070 Bq/kg), for 232Th was varied from (16.510 Bq/kg) to (29.480 Bq/kg), for 40K was varied from (143.820 Bq/kg) to (231.550 Bq/kg) ,with an average values of (21.152±2.98 Bq/kg) , (24.219±3.93 Bq/kg), (190.720±22.20 Bq/kg), successively. To survey the radiological peril in soil, radium effective activity, absorbed gamma dose in air, annual effective dose equivalent (inner and outer), gamma concentration level index and both (interior and exterior) radiation peril index have been computed, and all the existed results were less than recommended by the International Committee for the Radiation Protection (ICRP).

Natural radioactivity and metal concentration in the Thyspunt area, Eastern Cape Province, South Africa

Naturally occurring radionuclides and metals have adverse human health impacts when they occur at higher activity and concentration above the threshold value, respectively, in the water supply system. This study aimed to establish the baseline radionuclide and metal content in rocks, soils, and water in the Thyspunt area of the Eastern Cape Province, South Africa, which is selected as a potential site for the development of a nuclear power plant. Extensive sampling of rocks, soils, groundwater, and surface water was conducted in the area. The employed methods of sample analyses include ICP-MS, gamma-ray spectrometery (RS 230), and accelerator mass spectrometry. The results indicate that the Ceres Subgroup shale and the Skurwerburg formation quartzite of the Table Mountain Group (TMG) contain the highest activity of most radionuclides, including 238U, 235U, 234U, 226Ra, 232Th, and 210Pb; these are linked to the natural geochemistry of the rocks that have been facilitated by the low-grade metamorphism to which the local geology was subjected. The metamorphism-related radionuclide enrichment is also apparent in the soils and groundwater associated with these rocks. The activity of the radiotoxic and carcinogenic uranium (238U and 235U) and radium (226Ra and 224Ra) isotopes in water was found to be well above the WHO guideline of 0.03 and 1Bq/L, respectively. The exposure dose rate was the highest in the Ceres Subgroup shales (185.7 nS/h), and this is linked to the elevated natural radioactivity in the rocks. The estimate of the ingestion-related effective dose indicates high doses associated with the uranium and radium isotopes, thus signifying the potential adverse impact on human health associated with the ingestion of the widely used groundwater in the area.

Radiation level, radionuclide distribution and mineralogy of soils in Belagavi region of Karnataka, India

ABSTRACT The paper presents the results of systematic investigations on the gamma dose rates in air, natural radioactivity in soil and the dependence of radioactivity on the mineralogy of soils in the environs of the Belagavi, Karnataka, India. The gamma dose rates were measured using a portable survey metre and the activity in soils were measured using NaI(Tl) based gamma ray spectrometer and the mineral composition was studied using FTIR spectroscopy. The activity of 40K varies from 72.52 to 324.76 Bq kg−1 with an average of 153.17 Bq kg−1. The 226Ra activity varies from 16.53 to 70.53 Bq kg−1 with an average value of 23.88 Bq kg−1 and the activity of 232Th varies from 10.95 to 59.07 Bq kg−1 with an average value of 25.75 Bq kg−1. Elevated levels of 226Ra, 232Th and 40K in soils were observed in some part of Belagavi, which was traced to the mineralogy of the region. The higher activity of natural radionuclides poses radiological implications to the population of the region. The activity utilisation index was found to be is above the normal levels in some locations. The pattern of distribution of radionuclides in the region was studied using SPSS statistical software. The soil with clay minerals Haematite, Calcite, Kalonite, Albite and Feldspar showed higher radionuclide content.

ГЕОХИМИЧЕСКИЕ ЩЕЛОЧНЫЕ БАРЬЕРЫ, ОПРЕДЕЛЯЮЩИЕ РАДИОЭКОЛОГИЧЕСКИЕ УСЛОВИЯ В ДОЛИНЕ РЕКИ СОЧИ ЧЕРНОМОРСКОГО ПОБЕРЕЖЬЯ РОССИИ

Radioecological features of natural environments of the Sochi River valley, one of the largest rivers of the Main Caucasian Range and the Black Sea coast of Russia were studied. Alluvial soils, mosses, and river waters were the subject of investigations. Peculiarities of Th and U behavior (their contents were determined by quantitative ICP method) in conditions of existence of alkaline geochemical barriers — calcium barrier formed at the junction of neutral argillites and alkaline marl, and sodium barrier in the river mouth at the contact of river water with sea water were established. The calcium barrier results in lower Th and U concentrations in river waters and higher concentrations of radioactive elements in soils and mosses. Alkaline sodium barrier causes increase of Th and U concentration in river waters, decrease of Th and U concentration in soils and active sorption of elements by mosses. On the whole, the radioecological state of the Sochi River valley is favorable. The level of gamma-radiation exposure dose rate near the surface is lower than the natural level of this parameter for the open mountain territories of the middle belt of Russia. Bottom sediments of the river are notable for low values of specific activity of natural radionuclides 226Ra, 228Ra, 224Ra, 232Th and 40K.

Risk Assessment of Natural Radionuclides in Surface and Ground Water of Oil and Gas Producing Communities, Rivers State, Nigeria

The natural radioactivity and radiological health risk associated with the use of water from hand-dug wells, tap/boreholes and river/creeks in three communities with history of oil spillage, gas flaring, oil bunkering and operation of illegal artisanal oil refining activities in Rivers State, Nigeria was here assessed and measured with gamma ray spectroscopy. The results showed that the mean activity concentration of water samples for hand-dug well water ranged from 11.94±1.12 to 12.77± 1.12Bq/l for 238U, 7.88±1.05 to 9.20±1.82Bq/l for 232Th and 13.50±0.62 to 20.13±3.88Bq/l for 40K. The mean activity concentration for the tap/borehole water ranged from 2.42±0.45Bq/l to 5.31±0.80Bq/l for 238U, 1.02±1.01 to 2.24±0.90Bq/l for 232Th and 9.71±5.04 to 11.73±3.77Bq/l for 40K. The 238U, 232Th and 40K activity concentrations in the river/creek waters ranged respectively from 6.81±0.80 to 8.82±1.20Bq/l, 4.25±0.65 to 9.52±1.16Bq/l and 25.01±3.23 to 30.03±1.96Bq/l. These values are higher than the mean activity concentrations of the 3 radionuclides in the control samples and some are higher than the international permissible standards. Results further revealed that there was statistically significant difference at p

Оценка «нулевого» радиационного фона территорий населенных пунктов Туркестанской области, расположенных вблизи площадки для строительства АЭС Республики Узбекистан

The construction of a nuclear power plant in the Republic of Uzbekistan actualizes measures for the radiation safety of the population and territories of Kazakhstan. The aim of the study was to assess the radiation situation in the settlements of the Turkestan region located near the impact zone of the nuclear power plant. The investigation includes measurements of ambient equivalent dose rates of gamma radiation, equivalent to the equilibrium volumetric activity of radon and thoron in residential buildings, establishing the total alpha and beta activities, and measuring the specific activity of radionuclides in water soil and food samples. In soil samples taken from the villages of Zhetysay and Zhyly-su, the specific activity of 232Th is 2 times higher than the national average. The total alpha activity of drinking water samples from the village of Zhyly-su is 1,5 times higher than the maximum permissible concentration. The concentration of artificial (137Cs, 90Sr) and natural radionuclides (226Ra, 232Th) in food is within the normal range. Obtaining preliminary results of the research will make it possible to assess the predicted radiation doses for various age groups of the population, and to develop preventive measures during the operation of a nuclear power plant.

Assessment of effective dose and radiological risk from natural radioactivity in rock samples of Davanagere locality, Karnataka, India

ABSTRACT This paper presents the results of a systematic investigation of the natural radioactivity in rock samples of Davanagere locality, Karnataka, India. The radioactivity in rocks was measured using the NaI(TI) gamma-ray spectrometer. An effort was made to identify the minerals present in rock samples by FTIR spectroscopy. The activity of 232Th, 226Ra and 40K radionuclides in rocks vary from 27.96 ± 1.00 to 103.85 ± 1.90, 50.89 ± 1.98 to 135.28 ± 3.15 and 512.46 ± 4.86 to 974.31 ± 7.05 Bq kg−1with a mean value of 59.79 ± 1.45, 85.79 ± 2.54 and 787.03 ± 6.19 Bq kg−1, respectively. Radiological hazard parameters such as radium equivalent activity, external and internal hazard indices absorbed dose rate, ELCR for indoor exposure and annual effective doses for different body organs were estimated. The activity of natural radionuclides were found to be high compared to the national and world average values. However, the hazard indices were found to be within the recommended limits. The Quartz, Calcite and Kaolinite extinction coefficients in rocks ranged from 87.37 to 121.73, 31.43 to 119.14, and 33.10 to 63.97, respectively. The radionuclide activity concentration was found to depend on the kaolinite and calcite minerals.