Levels Of Natural Radionuclides Research Articles

ОЦІНКА ПОТОЧНОГО СТАНУ РАДІАЦІЙНОГО ЗАБРУДНЕННЯ ТЕРИТОРІЇ МАЙДАНЧИКУ УРАНОВОЇ СПАДЩИНИ КОЛИШНЬОГО ВО «ПХЗ»

The article summarizes the results of long-term radioecological monitoring of the environment radioactive state within the former 'Prydniprovsk chemical plant' and adjacent territories at the preparatory stage life cycle of uranium legacy site. Data analysis have been determined the background activity levels of natural radionuclides (in particular 238U, 226Ra, 230Th, 210Pb, 210Po) in soils, underground and surface waters, air (fall density and volume activity), exhalation of 222Rn from the soil surface and its volume activity. The results of the determined dynamics and trends in the formation of pollution of environmental elements, which form the main factors of exposure of workers and the population, are presented. Areas with elevated dose rate (≥0.5 μSv·h-1) occupy more than 30% of the entire legacy site territory. In the soil activity may be 10 to 1000 times higher than background (30-50 Bq·kg-1) and can exceed 1000 times the exemption level. In aerosols 238U and 226Ra activitis exceeding the background (0.1 µBq·m-2·s-1, 11.5 µBq·m3) by 100-200 times only during periods of earthworks, under normal conditions they are up to 1.5-2.0 times. The monthly average activity 222Rn in the air of open space are 4-5 times higher of the background (median 200±68 Bq∙m-3), in some areas they can exceed by up to 50 times. In the buildings premises on the site 222Rn can exceed the reference level (250 Bq∙m-3) by 1-5 times, and in individual basements by up to 100 times. The data analysis proves that main ways of exposure of workers are external gamma radiation, the inhalation exposure routes from aerosol pollution and the spread of OA 222Rn in the air can be significant only for workers work at the legacy site and do not pose a threat to the city's population. Radiation assessment contamination of underground and surface water showed in present conditions aquatic pathways cannot form any significant contributions to the radiation exposure dose of the public. The obtained results and data analysis of monitoring observations were used to substantiate the measures of the remediation strategy legacy site.

Assessing radioactive contaminants in Kathmandu soils: measurement and risk analysis.

Soil samples from vegetable farmland in densely populated wards of Nepal were analyzed for natural radionuclide levels, employing a NaI(Tl) 3" [Formula: see text] 3" gamma detector. The study aimed to evaluate the causes of radiation risk, attributing it to soil contamination resulting from the rapid urbanization and concretization that followed the earthquake in 2015. The activity concentration of radium-226, thorium-232, and potassium-40 and the ranges observed are 2.080±0.084-33.675±1.356 Bq kg[Formula: see text], 17.222±0.198-119.949±1.379 Bq kg[Formula: see text], and 11.203 ± 0.325-748.828±21.716 Bq kg[Formula: see text], respectively. The average values obtained for hazard indices are as follows: radium equivalent activity (82.779 Bq kg[Formula: see text]), absorbed dose rate (36.394 nGy h[Formula: see text]), annual effective dose equivalent (0.045 mSv yearr[Formula: see text]), gamma index (0.291), external hazard index (0.224), internal hazard index (0.253), excess lifetime cancer risk (0.159), annual gonadal dose equivalent (243.278 mSv year[Formula: see text]), alpha index (0.054), and activity utilization index (0.716). However, in most places, thorium-232 concentration is greater than those of the world average and recommended values. In specific locations such as Ward 4 in Baluwatar, the soil was found to have concentrations of Ra[Formula: see text] and K[Formula: see text] exceeding recommended limits. Despite this localized concern, the overall analysis of hazard indices across the studied areas revealed that most values were within permissible limits. This suggests that, on a broader scale, radiation exposure may not be a significant concern in the investigated regions. Nonetheless, the study recommends regular monitoring in additional locations to ensure a comprehensive and ongoing assessment of radiation levels.

Natural radioactivity in Turkish foodstuff consumed in Iraq

Different levels of natural radionuclides were found in food items, and these variations were attributed to factors such as background radiation levels, climate, and agricultural practices. These radionuclides are recognized as the primary contributors to the internal radiation exposure experienced by humans. Among the natural radionuclides, the ones of most significant concern for radiation protection are those belonging to the decay series of 238U and 232Th, as well as 40K. The concentration of natural radioactivity in several Turkish food products accessible on the Iraqi market was measured using a NaI (Tl) gamma-ray spectroscopy detector. The measured concentrations in unit Bq kg−1 of 238U, 232Th, and 40K ranged from 3.2 to 19, 1.2 to 24.1, and 22.5 to 690.9, respectively. The study also calculated the annual effective dose for individuals who consume such foods. The annual internal dose from ingesting studied radionuclides found in foodstuff was calculated to be 0.274 ± 0.05 mSv/y. Notably, this calculated dose falls below the worldwide value of 0.32 mSv/y established for the general public.

Oral and dermal exposure to natural radionuclides and heavy metals in water and sediments of Nile River, Qena, southern Egypt

This study assessed the levels of natural radionuclides (226Ra, 232Th, and 40K) and heavy metals (Hg, Fe, Cr, As, Zn, Cu, Cd, and Pb) in surface water and sediment samples from the Nile River in Qena Governorate, southern Egypt, using a gamma-ray spectrometer, 3ʺ NaI (Tl) scintillation detector coupled with 1024 multi-channel analyzer, and an atomic absorption spectrometer. In surface water and sediments, the average activity concentrations of natural radionuclides were 40K (4.73 Bq L−1; 395.76 Bq kg−1) > 226Ra (0.41 Bq L−1; 18.14 Bq kg−1) > 232Th (0.30 Bq L−1; 17.98 Bq kg−1). The average heavy metal concentrations in surface water in µg L−1 were Fe (121.0) > Zn (33.80) > Cr (28.0) > Cu (8.62) > Pb (8.35) > As (1.19) > Hg (0.81) > Cd (0.12). In Nile sediments the concentrations in mg kg−1 were Fe (1670.0) > Zn (207.0) > Cr (29.40) > Cu (16.20) > Pb (4.32) > Hg (0.41) > Cd (0.31) > As (0.14). The heavy metal evaluation index (HMEI) calculations for water samples revealed that 31% of the samples were suitable for domestic use, while 69% were not. The geo-accumulation index, enrichment factor, and ecological risk factor for sediments were estimated, showing extreme enrichment for Hg and Zn with high ecological risk for Hg. Health risks for adults were evaluated due to oral and dermal exposure to Nile surface water and sediments from the study area, indicating minimal radiological risks and potential carcinogenic and non-carcinogenic risks from the metals.

Measurements of natural radionuclide levels and hazards in the Lega Dembi gold mine, Oromia, Ethiopia

ABSTRACT This study aimed to evaluate natural radioactivity levels and hazards of radionuclides 232Th, 226Ra and 40K in soil samples taken from 15 locations in the Lega Dembi gold mining, Oromia, Ethiopia, using gamma-ray spectroscopy coupled with an HPGe detector. It was observed that the respective mean specific activities for 226Ra, 232Th and 40K determined in the mining site were 23.87 ± 0.7, 52.5 ± 1.8 and 391.62 ± 11.35 Bq/kg, and 8.89 ± 0.4, 13.83 ± 0.6 and 423.68 ± 9.5 Bq/kg in the living areas. The specific activity of 232Th was above the permissive limit in the mining site, while for 226Ra and 40K were within the limit. The specific activity of 40K in the living area was observed to be above the permissive limit. The calculated value of radiation hazards parameters; radium equivalent activity (Raeq), internal and external hazards indices (Hin) and (Hex), the mean annual effective dose (AED), and gamma representative indices (Iγ) were within permissively limit. The mean absorbed dose rate in the mining site was above the recommended safety limit. The total annual gonadal dose equivalent value was found to be 494.8 ± 8.7 µSv/a in the mining site. This value was also above the permissively.

Spatial autocorrelation and hotspot analysis of natural radionuclides to study sediment transport

Tracking sediment movement is typically done with artificial radionuclides. However, this can be environmentally harmful and does not allow for sediment classification. Naturally occurring radionuclides are consequently offered as an alternative. In this study, a mobile Delta Underwater Gamma System (DUGS) capable of measuring low levels of natural radionuclides in sediment was deployed in an estuary, and a radiometric map of the sediment was constructed. Spatial autocorrelation using the Moran's I statistic was used to investigate the spatial distribution patterns of natural radionuclides in the sediments. Hotspot analysis using Getis-Ord* was used to validate and map areas that had been identified as clustered by the Moran's I statistic. The Moran's I analysis indicated that 40K displayed a positive spatial autocorrelation with a value of 0.4 and a standardized Z score of 16, thus indicating that the clustering was significant. 238U and 232Th displayed a low Moran's I value but a strong positive correlation, hence indicating some spots of clustering in the river channel. Further analysis of hotspots confirmed that the identified clusters were areas with relatively high radionuclide concentrations. This proved that the hotspot areas identified have a high deposition of sediment. In situ radiometric measurements of sediment, as well as spatial analysis, are consequently useful tools to model and study spatial structure and sediment.

Evaluation of current natural and anthropogenic radionuclide activity in coastal area bottom sediments of the Barents Sea (North of the Kola Peninsula)

This article is devoted to the study of the activity of technogenic 137Cs and 90Sr, as well as natural radionuclides 40K, 232Th and 226Ra in bottom sediments of the Kola coast of the Barents Sea, where a significant number of radiation objects are concentrated. In order to characterize and assess the accumulation of radioactivity in the bottom sediments, we studied the particle size distribution and some physicochemical parameters, such as the content of organic matter, carbonates and ash components. The average activities of natural radionuclides 226Ra, 232Th and 40K were 325.0, 25.1 and 466.7 Bq·kg−1, respectively. Levels of natural radionuclides in the coastal zone of the Kola Peninsula are within the range of marine sediments worldwide. Still, they are slightly higher than those observed in the central areas of the Barents Sea, most likely due to the formation of coastal bottom sediments as a result of the destruction of the natural radionuclide-enriched crystalline basement rocks that make up the Kola coast. The average activities of technogenic 90Sr and 137Cs in the bottom sediments of the Kola coast of the Barents Sea are 3.5 and 5.5 Bq·kg−1, respectively. The highest activities of 90Sr and 137Cs were found in the bays of the Kola coast, while they remain below detection limits in the open parts of the Barents Sea. Despite the presence of potential sources of radiation pollution in the coastal zone of the Barents Sea, we did not find any short-lived radionuclides in the bottom sediments, which indicates the absence of a significant influence of local sources on the transformation of the technogenic radiation background. The study of particle size distribution and physicochemical parameters showed that the accumulation of natural radionuclides is largely related to the content of organic matter and carbonates, while the accumulation of technogenic isotopes occurs in the composition of organic matter and the smallest fractions of bottom sediments.

In Situ Determination of Radioactivity Levels and Radiological Doses in and around the Gold Mine Tailing Dams, Gauteng Province, South Africa

The mining and processing of naturally occurring radioactive materials (NORMs) could result in elevated levels of natural radionuclides in the environment. The gold mining in the goldfields of the Witwatersrand Basin of South Africa has resulted in numerous tailing dams that have high concentrations of NORM bearing residue. The aim of this study was to evaluate the radioactivity levels in tailing dams, soils and rocks, and the consequential radiological exposure to the public in the gold mining areas of Gauteng Province, South Africa. The activity concentrations of 238U, 232Th, and 40K were assessed using a gamma ray spectrometer (RS-230), and the activity concentrations ranges in the mine tailings were 209.95–2578.68 Bq/kg, 19.49–108.00 Bq/kg, and 31.30–626.00 Bq/kg, respectively. The radionuclides show significant spatial variability in soils, with high activities recorded in soils located in close proximity to tailings although regionally, the soil radioactivity levels mainly depend on the chemistry of the underlying rocks. The estimated annual effective doses were higher than the recommended regulatory limit of 0.25 mSv/y in particular tailing dams and soil impacted by tailings. Therefore, to ensure the protection of people and the environment, further monitoring and regulatory control measures targeting these areas are required.

Assessment of Radiation Levels and Potential Radiological Hazards in the Soils of Riruwai Mining Area, North-Western Nigeria

This research aimed to assess the levels of natural radionuclides in the soil of the Riruwai mining area and to evaluate the radiological hazards associated with them. A total of sixty soil samples were collected from four sampling sites during the dry and wet seasons. The concentrations of uranium-238 (238U), thorium-232 (232Th), and potassium-40 (40K) were measured using an HPGe gamma-ray spectrometer, and the measured concentrations were used to estimate the internal and external hazards and gamma dose rate. The results of the analysis indicated that the concentrations of 238U and 232Th in all sampling sites and seasons were higher than the world average. The radionuclide levels in the soils showed a significant seasonal variation, with higher concentrations obtained during the dry season. The correlation analysis revealed a very strong positive relationship between all the radionuclides, which indicates a common origin (parent material). The gamma dose rate computations revealed that only active and abandoned mining sites have a mean gamma dose rate greater than the tolerable limit of 59.00 nGy/h. The internal and external radiological hazards assessments showed that only the active mining sites had the potential to be hazardous to human health. The researchers, therefore, recommend that comprehensive monitoring of mining operations and public education about the dangers of radiation exposure in the study area be carried out.

Gamma-ray absorbing characteristic of obsidian rocks as a potential material for radiation protection

In this study, natural radionuclide levels and mass absorption coefficients of obsidian samples were examined to determine their gamma radiation properties. Fourteen obsidian samples were collected from 7 different locations in Rize province, İkizdere region, Turkey. X-ray fluorescence measurements of the samples revealed the silica structure and comparable elemental structure with slight differences in atomic ratios. Radionuclide analysis showed that the 137Cs activity was below the detection limit, and the mean activities of 238U, 232Th and 40K were 93 ± 9, 67 ± 7, 1027 ± 19 Bq.kg−1, respectively. The average experimental mass absorption coefficients at 81.0 keV, 302.9 keV, 356.0 keV and 661.7 keV were found to be 0.216, 0.108, 0.098 and 0.080 cm2 g−1, respectively. In the <100 keV region which the photoelectric effect is dominant, differences among the absorption coefficients were more pronounced, while it was relatively much smaller in the intermediate energy region. Also, it was seen that the absorption coefficients of the samples were higher than many materials, especially in the low energy region. The average half-value thicknesses showed that obsidian between 1.43 cm and 3.84 cm depending on the photon energy should be used to halve the radiation intensity. In addition, it was determined that the thicknesses in the range of 4.75 cm–12.76 cm were sufficient to reduce the intensity to one tenth. Considering all the analysis results, it can be said that obsidian is a potential material in radiation protection and its absorption properties can be improved by processes such as elemental doping.

Transfer Factors of Natural Radionuclides from Soil to Medicinal Plants used by Local People in Eastern Anatolia, Turkey

Medicinal plants are very useful plants for humans with the various molecules and vitamins they contain. Most of the plants that grow spontaneously in nature were taken into agricultural production practices after their healing properties were discovered. The use of pure active ingredients obtained from plants is quite common. These effective compounds are also used by the pharmaceutical industry in the preparation of modern drug formulations. However, possible high levels of natural radionuclides in medicinal plants, particularly 226Ra, 232Th and 40K, have upraised anxieties regarding radiological risks from plant consumption. In this study, the natural radionuclide activity concentrations of 8 commonly used medicinal plants in the Eastern Anatolia Region of Turkey were determined by gamma spectrometric method using NaI(Tl) detector. Mean transfer factor (TF) values from soil to plant were found to be 0.59, 0.88 and 1.52 for 226Ra, 232Th and 40K, respectively.

Vertical distribution and radiological risk assessment of natural radionuclides in the alluvial soil profile of south-west Punjab, India

Natural radionuclide levels are studied in alluvial sediments upto the depth of 900 cm. Eighteen profiles are selected from agricultural and undisturbed areas and analysed by gamma-ray spectrophotometer. Levels were found to vary significantly with depth and higher concentration is observed in agricultural samples till the depth of 600 cm and values are comparable after this depth, indicating role of anthropogenic activities on radionuclide enrichment in agricultural areas. However, value is higher than global average at both sites, indicating their geogenic presence. Elemental ratio and multi-statistical analysis are utilized to assess the behaviour of radionuclides involved. Radiological hazard risk assesment is also carried out.

Risk survey for the population of Recife and neighboring cities due to the occurrence of radium in groundwater

The Metropolitan Region of Recife and its surroundings are heavily exploited to capture water for public supply through tubular wells. However, a survey of the levels of natural radionuclides from these sources had never been carried out, even though part of this region contains a phosphate deposit that has a high concentration of natural uranium. In this context, this research aimed to identify 228Ra and 226Ra levels in groundwater in the coastal region of Pernambuco, Brazil. About 110 points (wells) of drinking water for public supply were identified and studies were carried out to estimate the level of ingestion and subsequent risk due to the presence of this radionuclide. The average concentration of combined radium was 104 mBq.L−1. For 228Ra an effective dose of 0.46, 0.11, 0.12 and 0.0276 mSv.y−1 for infants, children aged 1 and 10 and adults, respectively, were obtained. Although doses above those recommended by WHO were found, the equivalent dose and the induction of bone sarcoma did not indicate a risk to the population. Groundwater with higher dose values is influenced by local geology.

The &amp;lt;i&amp;gt;μ&amp;lt;/i&amp;gt;Dose system: determination of environmental dose rates by combined alpha and beta counting – performance tests and practical experiences

Abstract. The μDose system is a recently developed analytical instrument applying a combined α- and β-sensitive scintillation technique for determining the radioactivity arising from the decay chains of 235U, 238U and 232Th as well as from the decay of 40K. The device was designed to meet the particular requirements of trapped charge dating methods and allows the assessment of environmental (i.e. low) levels of natural radionuclides. The μDose system was developed as a piece of low-cost laboratory equipment, but a systematic test of its performance is still pending. For the first time, we present results from a comprehensive performance test based on an inter-laboratory comparison. We compare the results obtained with μDose measurements with those from thick source alpha counting (TSAC), inductively coupled plasma optical emission spectrometry (ICP-OES) and low-level high-resolution gamma spectrometry (HRGS) applied in five participating laboratories. In addition, the reproducibility and accuracy of μDose measurements were tested on certified reference materials distributed by the International Atomic Energy Agency (IAEA; RGU-1, RGTh-1 and RGK-1) and on two loess standards (Nussy and Volkegem) frequently used in trapped charge dating studies. We compare μDose-based results for a total of 47 sediment samples with results previously obtained for these materials by well-established methods of dose rate determination. The investigated natural samples cover a great variety of environments, including fluvial, aeolian, littoral, colluvial and (geo-)archaeological sites originating from high and low mountain regions as well as from lowlands in tropical areas, drylands and mid-latitude zones of Europe, Africa, Australia, Central Asia and the Americas. Our results suggest the μDose system's capability of assessing low-level radionuclide contents with very good accuracy and precision comparable to well-established dosimetry methods. Based on the results of our comparative study and with respect to the practical experiences gained so far, the μDose system appears to be a promising tool for trapped charge dating studies.

Natural radionuclides in soil profiles and sediment cores from Jundiaí reservoir, state of Sao Paulo.

The activity concentration of natural radionuclides in soils and sediments is dependent on many factors, such as the rock parental material, pedogenic and weathering processes, physical and chemical properties of the environment, anthropogenic sources, among other aspects. There are few studies about the levels of natural radionuclides in reservoirs in both, international and national, literature. The objective of this paper was to evaluate the activity concentrations of 238U and 232Th by Instrumental Neutron Activation Analysis and 226Ra, 210Pb, 228Ra, 228Th and 40K by gamma spectrometry in two soil profiles and three sediment cores collected in the catchment area of Jundiai reservoir, located in the state of São Paulo, Brazil. Principal component analysis was applied to verify the correlation of the activity concentrations of the natural radionuclides with physical and chemical properties of soil and sediment samples. The mean activity concentrations of the radionuclides in the soil profiles 1 and 2 were, respectively: 238U – 37(1) and 32(1) Bq.kg-1; 232Th – 91(1) and 60(1) Bq.kg-1; 226Ra – 66(1) and 51(1) Bq.kg-1; 210Pb – 35(1) and 37(1) Bq.kg-1; 228Ra – 34(1) and 27(1) Bq.kg-1; 228Th – 78(1) and 58(1) Bq.kg-1; 40K – 96(2) and 171(7) Bq.kg-1. For the three sediment cores analyzed, the average activities concentrations of the radionuclides were, respectively: 238U – 64(0.5), 47(0.1) and 44(0.2) Bq.kg-1; 232Th – 122(2), 100(1) and 64(1) Bq.kg-1; 226Ra – 74(2), 71(1) and 45(1) Bq.kg-1; 210Pb – 70(3), 56(2) and 55(2) Bq.kg-1; 228Ra – 53(1), 41(1) and 33(1) Bq.kg-1; 228Th – 100(2), 92(1) and 63(2); 40K – 316(5), 237(1) and 136(2) Bq.kg-1.

Soil-to-plant transfer factors of 238U and 232Th in rice from Ezillo paddy fields, Ebonyi State, Nigeria

The uptake of radionuclides by plants and their subsequent relocation to the human body through ingestion is one major pathway of human internal exposure. Thus, the present study was conducted to examine the levels of natural radionuclides, 238U and 232Th, in soil of Ezillo paddy fields (field 1 and field 2) at depths 0–4 cm and 4-8 cm, their transfer and accumulation in rice grains. The mean concentrations of both radionuclides in the soil were clearly greater than the UNSCEAR estimated worldwide average while that of the rice with values of 11.7 ± 4.3 and 3.0 ± 1.3 Bq/kg in field 1 and 8.5 ± 4.2 and 4.3 ± 1.6 Bq/kg in field 2 for 238U and 232Th respectively, were well below the worldwide average. The radionuclide transfer factors (TFs) across both depths ranged from 0.03 to 0.67 and 0.01 to 1.20 for 238U and 232Th respectively. The overall geometric means and geometric standard deviations of the TF estimated in field 1 were respectively 0.22 and 1.52 for 238U and 0.18 and 4.21 for 232Th (soil,0-4cm); 0.43 and 1.80 for 238U and 0.18 and 3.79 for 232Th (soil,4-8cm) whereas in field 2 the values were respectively 0.12 and 2.62 for 238U and 0.06 and 4.15 for 232Th (soil,0–4cm); 0.11 and 1.85 for 238U and 0.12 and 4.15 for 232Th (soil,4-8cm). The nuclide concentrations in the rice and the present TFs are within the ranges of values in the literature.

Assessment of Natural Radioactivity and Radiological Risks in River Sediments from Calabria (Southern Italy)

This study was developed to carry out a comprehensive radiological assessment of natural radioactivity for river sediment samples from Calabria, southern Italy, and to define a baseline background for the area on a radiation map. In the studied area, elevated levels of natural radionuclides are expected, due to the outcropping acidic intrusive and metamorphic rocks from which the radioactive elements derive. To identify and quantify the natural radioisotopes, ninety river sediment samples from nine selected coastal sampling points (ten samples for each point) were collected as representative of the Ionian and the Tyrrhenian coastline of Calabria. The samples were analyzed using a gamma ray spectrometer equipped with a high-purity germanium (HPGe) detector. The values of mean activity concentrations of 226Ra, 232Th and 40K measured for the studied samples are (21.3 ± 6.3) Bq kg−1, (30.3 ± 4.5) Bq kg−1 and (849 ± 79) Bq kg−1, respectively. The calculated radiological hazard indices showed average values of 63 nGy h−1 (absorbed dose rate), 0.078 mSv y−1 (effective dose outdoors), 0.111 mSv y−1 (effective dose indoors), 63 Bq kg−1 (radium equivalent), 0.35 (Hex), 0.41 (Hin), 0.50 (activity concentration index) and 458 µSv y−1 (Annual Gonadal Equivalent Dose, AGED). In order to delineate the spatial distribution of natural radionuclides on the radiological map and to identify the areas with low, medium and high radioactivity values, the Surfer 10 software was employed. Finally, the multivariate statistical analysis was performed to deduce the interdependency and any existing relationships between the radiological indices and the concentrations of the radionuclides. The results of this study, also compared with values of other locations of the Italian Peninsula characterized by similar local geological conditions, can be used as a baseline for future investigations about radioactivity background in the investigated area.

The outcomes of functioning of the Unified System of Individual Dose Control of the Russian Federation citizens based on the 2019 data

The article presents results of the analysis of information on the doses of technogenic exposure of personnel and the population due to the normal operation of radiation facilities, exposure of the population due to natural sources and technogenically altered radiation environment, and medical exposure of patients. The data were obtained using the Unified System of Individual Dose Control of the RF citizens for 2019. The analysis was carried out on the basis of the data contained in the forms of state statistical observation No. 1-DOZ (personnel individual doses), No. 2-DOZ (emergency doses), No. 3-DOZ (patients’ exposure doses) and No. 4-DOZ (population exposure doses from natural and technogenically impacted background) for 2019 submitted by the organizations and territories, the state sanitary and epidemiological supervision of which was carried out by Rospotrebnadzor and FMBA of Russia. The article used data obtained within the framework of Radiation-Hygiene passportization. In 2019, 18430 organizations dealing with technogenic sources of ionizing radiation submitted forms No. 1-DOZ with the information on the doses to personnel with a total number of 247934 people, of which 227723 people belonged to the personnel group A and 20211 person to the personnel group B. For these groups, the doses were assessed based on results of individual dosimetric control. In 2019, according to the Unified System of Individual Dose Control data, the average individual annual effective dose of technogenic exposure to the personnel group A was 1.19 mSv, and for the personnel group B it was 0.64 mSv. The total number of X-ray and radiological diagnostic procedures performed in the Russian Federation in 2019 exceeded 306.5 million, or 2.09 procedures per a citizen. The average annual effective dose of medical radiation exposure per one resident of Russia in 2019 was 0.62 mSv, and per procedure — 0.31 mSv. The submittedforms No. 4-DOZ of the constituent entities of the Russian Federation for 2019 contained results of the measurements of dose rate of gamma radiation in 9179 wooden houses, 11,307measurements in low-rise stone houses, 121323 measurements in multi-storey stone houses and 229342 measurements in open areas. These also contained results of 3930 measurements of radon levels in wooden houses, 5071 measurements in low-rise stone houses and 46896 measurements in multi-storey stone houses, as well as the results of 19444 analyses of the levels of natural radionuclides in drinking water. The average annual effective dose of radiation to residents of the Russian Federation from natural sources, according to all measurements for the period from 2001 to 2019, was 3.36 mSv. The article provides Appendices with the final forms of Unified System of Individual Dose Controlfor the Russian Federation for 2019. Data for the forms have been obtained on the basis of summarizing the information contained in the forms of state statistical observation No. 1-DOZ, 3-DOZ and 4-DOZ of the constituent entities of the Russian Federation.

226Ra, 210Po and lead isotopes in a pit lake water profile in Sweden

A pit lake arises as a consequence of anthropogenic activities in opencast mining areas. These water bodies may be enriched in hazardous stable contaminants and/or in naturally occurring radionuclides depending on the local geological conditions. Mining legacy in Sweden produced hundreds of these pit lakes and most of them are used for recreational purposes in the southern part of the country. In this paper, one pit lake was selected for having enhanced levels of natural radionuclides. Physico-chemical parameters (temperature, pH, oxidation-reduction potential, dissolved oxygen and depth), elemental composition (via Inductive Coupled Plasma Mass Spectrometry) and radiometric characterization (via alpha spectrometry of 226Ra, 210Po and 210Pb) were carried along the depth of a 60 m depth pit lake, with the main aim to describe how natural radionuclides and elements behaves with depth in a non-uraniferous pit lake.Based on observed changes in physico-chemical parameters, a thermocline and a chemocline region were identified at around 10 and 30 m depth respectively. Concerning radionuclides, 226Ra ranged from 75 ± 3 up to 360 ± 12 mBq/kg while 210Po ranged from 11 ± 1 up to 71 ± 3 mBq/kg. 210Pb distribution with depth was also determined via secular equilibrium with 210Po after 2 years and also stable Pb was measured. Disequilibrium 226Ra-210Pb was found and the residence time of 210Pb in the water column was assessed. Additionally, different vertical distributions between 210Pb and Pb were found which points out different sources for different lead isotopes in the water body.

Assessment of current natural and anthropogenic radionuclide activity concentrations in the bottom sediments from the Barents Sea

The article is devoted to the study of the activity values of natural radionuclides 40K, 232Th and 226Ra and technogenic radionuclide 137Cs in the bottom sediments of the Barents Sea, which is distinguished from the rest of the Arctic seas by the fact that the largest number of radiation objects are concentrated here. The activity levels of natural radionuclides were within the range of activity values corresponding to marine sediments around the world. The highest radionuclide activities were found within the deepwater shelf of the Barents Sea. The current level of activity of the technogenic radionuclide 137Cs is low and does not exceed 6.5 Bq·kg−1. However, due to global climatic changes, the secondary source of radiation pollution of the sea may be the Novaya Zemlya ice sheet, in which huge quantities of technogenic radionuclides were deposited during atmospheric tests of the 1950s and 1960s.