Monitoring internal doses from plutonium is most effectively accomplished by an indirect method based on the interpretation of nuclide activity measurements in excreta using biokinetic and dosimetric models. Currently, Russian Federation regulatory documents utilize the models presented by the International Commission on Radiological Protection in Publications 30, 66, and 67, while the International Commission on Radiological Protection has developed new models and approaches presented in Publications 130, 134, 137, and 141.The aim of this study was to demonstrate the actual dynamics of plutonium excretion in urine and feces in comparison with calculated data upon the intake of plutonium as part of an industrial compound of complex isotopic composition.Materials and Methods: The initial data for the study were the results of determining the activity of plutonium in daily amounts of urine and feces of three workers with acute inhalation intake of industrial plutonium compounds as a result of an emergency.Results and Discussion: For each case, the most suitable scenario (model and set of physicochemical properties of the compound) was selected using the Akaike criterion, depending on the initial data used for the calculation. The calculations were performed based on the results of plutonium activity measurements in urine, the results of plutonium activity measurements in feces, and the results of plutonium activity measurements in urine and feces simultaneously. The statistical analysis performed showed that the choice of the most suitable model and set of physicochemical properties of the compound was determined by the choice of initial data. In one case, none of the models adequately explained the observed levels of plutonium in urine and feces.Conclusion: There is undoubtedly a current lack of knowledge regarding the metabolism of industrial plutonium compounds, including those present at new fuel production sites. This requires extensive research into both the biokinetics and physicochemical properties of industrial plutonium compounds.
The prolonged discharge of tritium-containing water from the Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean leads to the gradual transport of tritium into Russian fishing zones and its accumulation in marine products. Tritium is incorporated into organic compounds, including seafood. Upon consumption of these seafood products, dose coefficients for organically bound tritium forms exceed those for tritiated water forms. Monitoring of organically bound tritium constitutes a critical component of radiological surveillance and the assessment of internal exposure doses. The purpose of this communication is to summarize current approaches to determining organically bound tritium in environmental media and biological tissues. Based on an analysis of scientific publications, this communication provides brief information on established and currently used methods for preparing counting samples to measure the content of organic tritium compounds in environmental media and biological tissues. Conclusion: Modern methods for determining organically bound tritium provide reliable data but are complex and require standardization. Promising directions for determining organically bound tritium content include improving sample preparation, enhancing the efficiency of converting organically bound tritium into a measurable form, implementing more sensitive analytical methods, and developing a metrological assurance system.
The aim of the study was to perform phantom dosimetry of organs and tissues to assess effective radiation doses to patients during computed tomography of combined areas of the body and calculated based on the readings on the scanner console.Materials and Methods: The study was performed on СT-scanner Toshiba Aquilion 64 an anthropomorphic tissue-equivalent phantom weighing 73.5 kg using thermoluminescent detectors located in the locations of organs and tissues, under standard computed tomography protocols of two combined body regions: 1 – organs of thorax, abdomen and pelvis; 2 – organs of abdomen and pelvis. The effective radiation dose was calculated using tissue weighting factors according to NRB-99/2009 and ICRP Publication 103 recommendations.Results and Discussion: The largest contribution to the total radiation dose was found for the gonads, red bone marrow, colon, lungs and stomach (71.8-76.2% in total). It was established that the effective radiation doses to patients during computed tomography, calculated based on the results of phantom dosimetry with TLD detectors, are higher than the values obtained from DLP data on the console of a computer scanner using tissue weighting factors according to ICRP Publication 103 for CT-1 by 1.12 times, for CT-2 by 1.13 times, according to NRB-99/2009 for CT-1 by 1.30 times, for CT-2 by 1.38 times.Conclusion: Dosimetry on an anthropomorphic tissue-equivalent phantom demonstrates higher patient radiation doses during computed tomography compared to dose values calculated by DLP on the computed tomography scanner console. This demonstrates the importance of periodically comparing patient doses calculated by DLP on the computed tomography scanner console with doses recorded by direct dosimetry under real computed tomography scanning conditions in radiology departments and centers.
The development strategy for Russia's shipbuilding industry anticipates a multi-fold increase in the capacity of ship repair enterprises servicing nuclear maritime facilities, which underscores the need to enhance radiation safety for personnel.The aim of the study was to determine the conditions and levels of occupational radiation exposure at the workplaces of various personnel categories at a nuclear ship repair enterprise, including under increased production loads.Materials and methods: The study was conducted at a major nuclear ship repair facility. The ambient dose equivalent rate of gamma radiation and beta contamination levels were measured at workplaces of main, auxiliary, and administrative personnel (Group A). Data from the plant's radiation monitoring and five-year statistical reports on individual doses (Form No. 1-DOZ, 2016– 2020) were analyzed. Individual thermoluminescent dosimeters were used to estimate potential maximum doses.Results and discussion: During periods when no radiation-hazardous work was being performed, the ambient dose equivalent rate at most workplaces did not exceed background levels (0,16 μSv/h), except near a tank with liquid radioactive waste (up to 6,75 μSv/h). During potentially hazardous operations (primary circuit maintenance, dismantling of safety mechanisms), the ambient dose equivalent rate reached 4,91– 7,15 μSv/h. The highest five-year average individual effective doses were recorded for flaw detection inspectors (6,89 mSv/year). Calculations for a hypothetical scenario of full workload revealed a potential risk of exceeding dose limits for certain occupations (fitter-installer, flaw detection inspector), especially for the lens of the eye.Conclusion: Radiation exposure conditions for personnel vary significantly depending on profession and type of work. To ensure radiation safety, a differentiated approach to planning repair work is required, taking into account personnel specialty, the nature of operations, and strict adherence to safety protocols, especially during high-load periods and for high-risk groups.
The gamma dose rate in air at any given outdoor location is not constant throughout the year. These fluctuations of the dose rate should be taking into account when assessing external radiation dose to humans. The aim of this study was to determine the seasonal variability of ambient dose equivalent rate on the streets of St. Petersburg. Materials and Methods: A portable gamma spectrometer-dosimeter, carried in a backpack on the operator, was used to measure gamma spectra in situ. Measurements were conducted in summer and winter on the streets located in the central part of the city. For comparison, spectra were measured on paths and lawns of the city parks. Results and Discussion: On average, ambient dose equivalent rates from natural radionuclides on the streets in winter were 6 % lower than those in summer. The difference was statistically significant (Wilcoxon test for the pair samples, p < 0.01). More pronounced differences between winter and summer were found in parks: with a snow cover depth of approximately 20 cm, the ambient dose equivalent rate on lawns and paths decreased by 32 % and 29 %, respectively. The differences between the seasons were statistically significant (p < 0.05). The relatively small decrease in the ambient dose equivalent rate on the city streets in winter is explained not only by snow removal from sidewalks and roadways but also by the fact that in this location some gamma radiation comes from radionuclides in the walls of buildings. Conclusion: The seasonal variations in the ambient dose equivalent rate from natural radionuclides on the city streets are extremely small. A coefficient of 0.95 can be used to estimate the magnitude of the reduction in the corresponding rate of external exposure to humans on the streets in winter compared to summer.
To date, studies of the effects of parental pre-conceptional radiation exposure on the health of offspring have not provided sufficient evidence to confirm the detected harm. This underscores the importance of ongoing research in this area.The objective of the study is to analyze the risk of solid cancer incidence in the Urals Cohort of Exposed Population Offspring for the period from 1956 to 2020.Materials and methods: the number of the analyzed cohort amounted to 24952 people, the average age by the end of the follow-up period was 40 years. During the 65-year period, 569 solid cancers were registered. The dose to the parents' gonads was calculated based on the TRDS2016 dosimetry system developed by the staff of the Southern Urals Federal Research and Clinical Center for Medical Biophysics. The median dose to the ovaries of mothers of the cohort members was 6.1 mGy, to the testes of fathers 4.5 mGy, total parental gonadal dose 31.2 mGy. Regression analysis with Poisson distribution using EPICURE statistical package programs was applied for risk assessment.Results: risk analysis of all solid cancer incidence among the offspring of exposed parents did not reveal a significant dependence on parental gonadal dose. At the same time, a significant dependence of the lung cancer risk on maternal and total parental gonadal doses was found among cohort members. The results are in good agreement with similar mortality data in the same cohort. The point values of lung cancer risk have a wide confidence interval, indicating that uncertainty exists and requires further investigation.
Form №3-DOZ is commonly used to analyze patient doses from radiographic procedures. However, direct comparison of average effective dose data from Form №3-DOZ with results of experimental studies is inappropriate, as Form №3-DOZ presents effective doses averaged over the patient's exposure projections. This leads to significant overor underestimation of the comparison results.The aim of this study was to develop a method for estimating average effective doses per frontal or lateral projection for common radiographic procedures using Form №3-DOZ data.Materials and Methods: The study was based on the data from the regional databanks of Form № 3-DOZ for Saint Petersburg and Leningrad regions; an original method for calculating average effective doses per projection has been developed.Results and Discussion: average effective doses for the most common X-ray procedures performed on digital and analog X-ray units in St. Petersburg and the Leningrad Region in 2023 were determined.Conclusion: It is advisable to integrate this method into software for completing Form №3-DOZ.
Osteogenic and hematopoietic stem cells can be exposed to radiation during cancer radiotherapy with radiopharmaceuticals due to adsorption of radionuclides into bones. Calculation of doses to normal radiosensitive cells is important for assessing the benefit/harm ratio. Therefore, the creation of a dosimetric model of bone and bone marrow, which takes into account the microdistribution of radionuclides and target cells, is an important task. Objective: an analytical review of the current state of knowledge about thehistomorphometric characteristics of the trabecular bone and adjacent areas of the bone marrow in order to create an anatomical and morphological basis for constructing a microdosimetric model for calculating doses to hematopoietic stem cells and osteoblasts. Materials and Methods: A search was conducted for published data on the structure and mineralization of bone tissue in the trabecular bone, the cellular composition of the bone marrow, the morphology and location of cells in its volume relative to the bone surface. Results and Discussion: Currently, the morphophysiological features of bone mineralization and the size of the corresponding structures are well studied. The surface of the trabeculae is covered with a layer of unmineralized bone matrix 1-5 microns thick, which is capable of rapidly adsorbing radionuclides. An adjacent layer of osteoblasts is about 1 micrometer thick. Data on the distribution of stem cells in the bone marrow volume is very limited. It is known that most of the stem cells are located within 200 micrometers from the surface of the trabeculae. The cell size is about 6-7 micrometers. Conclusion: Based on the existing knowledge about the structure of bone and the distribution of osteogenic and hematopoietic stem cells in the bone marrow, it is planned to create a model consisting of the number of layers, including a source layer and target layers, describing osteogenic cells and hematopoietic stem cells at different distances from the bone.
Cancer is one of the major late effects of exposure to ionizing radiation. Low dose effect has been still remains one of the most challenging issues. The objective of the study is to analyze the dose dependence of the risk of upper gastrointestinal cancer mortality in members of the Southern Urals Population Exposed to Radiation Cohort over the period from 1950 to 2020. Materials and Methods: Southern Urals Population Exposed to Radiation Cohort includes people aggrieved as a result of two radiation accidents in the Southern Urals. Follow up period is 71 years, cohort size at the end of the follow up is 62,259 individuals, number of person-years at risk – 1964,136. In total 1,587 upper gastrointestinal cancers have been revealed, 844 of them were found in men, and 743 – in women. Dose to the stomach was used as the reference one. Maximum dose over the whole follow up period made up 1.13 Gy, mean dose – 0.04 Gy. Statistical analysis has been performed with the Epicure software package using the Poisson regression with simple parametric model of the excess relative risk. Maximum likelihood method with 95 % probability was applied to evaluate the statistical significance of the results. Results and Discussion: The analysis of the mortality risk of all the upper gastrointestinal cancers revealed linear dose relationship which started to be observed already with 2-year minimum latency period: ERR 0.76/Gy, р = 0.03. Dose dependence of the mortality from oral cavity cancer was also linear with 2-year minimum latency period, ERR/Gy was 4.95, p = 0.01. The risk of the development of upper gastrointestinal cancers did not exhibit statistically significant dependence on dose to the stomach. The effect of modifying factors per unit of radiogenic risk has also been evaluated. Conclusion: Based on the results of the study, a statistically significant excess relative mortality risk of all cancers of the upper gastrointestinal and oral cavity has been obtained.
A special role among natural radionuclides is occupied by radon and its short-lived daughter decay products, which form from 50 to 90 % of the total radiation dose of the population. A danger to a person is represented by closed poorly ventilated rooms in which radon can accumulate in excess of the established hygienic standard. One of the factors for the accumulation of radon in buildings and structures is its emanation from rocks and subsoil. The method of measuring the radon flux density from the subsoil surface is used to assess the potential radon hazard of the land plot intended for the construction of buildings and structures. The purpose of the study is radiation and environmental assessment of the potential radon hazard of the territory of Tyumen and its surroundings. Materials and Methods: The studies were carried out from May to August 2025; the area covered was 697 km2. The measurement of the radon flux density from the soil surface was performed using the AlphaRad Plus-R radiometer (Russia) at 513 control points. At the same time, meteorological parameters (air temperature and humidity, atmospheric pressure) were measured at the measurement sites; the physical properties of the soil (temperature, density, and field moisture) were also measured. The mapping data was created using the QGIS geoinformation system. Results and Discussion: The radon flux density from the soil surface ranges from 20 to 730 mBq/(s·m2). An increase in temperature and a decrease in air humidity intensify the natural erosion of the upper layers, causing cracks and changes in density, resulting in higher radon flux densities from the soil surface in these areas. Conclusion: The identified boundaries of anomalies with high values of radon flux density from the soil surface can be used: 1) in urban planning during the construction, repair, and reconstruction of buildings and structures in order to ensure radiation safety of the population; 2) in the field of engineering surveys and environmental monitoring by executive authorities and private firms.
The relevance of the study is driven by the active development of the shipbuilding industry in Russia, including enterprises of atomic shipbuilding and ship repair, where radioactive waste is generated. The increase in work volumes with radioactive waste raises the risk of increased radiation doses to personnel, necessitating a comprehensive assessment of the radiation environment and improvement of the radiation control system. The aim of this work is to assess the radiation environment at personnel workplaces during radioactive waste handling and to identify priority directions for improving the radiation control system. Materials and Methods: The assessment of the radiation environment was performed based on the enterprise's production control materials and field study data. Parameter measurements were conducted using certified measurement methodologies. All measuring instruments underwent timely metrological verification. Results and Discussion: Results showed that the main radiation factors affecting personnel working conditions are external gamma radiation and radioactive contamination of work surfaces by beta-emitting radionuclides (both fixed and removable). An uneven distribution of dose load on the body was identified during different stages of radioactive waste handling. At the workplaces involved in processing liquid and solid radioactive waste, gamma radiation levels exceed those at other workplaces. However, the average individual radiation doses of personnel do not exceed dose limits and tend to decrease both within specific personnel categories and across the enterprise as a whole. Conclusion: The conclusion confirms the effectiveness of current radiation safety measures and identifies priority directions for improving the radiation control system at the enterprise.
People and the environment must be protected from radiation risks now and in the future. In this regard, the aim of this work was to summarize the existing data on the tailings of the uranium industry in Tajikistan and to develop scientifically grounded radiation-hygienic approaches to the management of low-level radioactive waste. The objective of the research was to analyze the formation of radioactive tailings in the territory of Tajikistan. Materials and Methods: The information base of the research was the results of previously conducted scientific works. The main characteristics of tailings storage facilities, as well as their radiation impact on the environment, have been examined. Particular attention is given to the issues of categorization and passportization of radioactive waste. Radiation monitoring was carried out using modern measuring instruments and equipment manufactured in the Russian Federation (“Doza”), the Republic of Belarus (“Atomtech”), the USA (“Canberra”), and Germany (“Thermo”). Results and Discussion: Existing radioecological risks in the areas where unsealed tailings pond is located have been identified. The radiation and hygiene requirements for ensuring the radiation safety of industrial waste have been considered. It is noted that the reclamation work carried out at the facilities in the of Istiklol city has significant practical importance, as it ensured the reduction of the radiation background to the normative level (0.3 µSv/h), decreased the anthropogenic load on the environment, and increased the ecological safety of the population. Conclusion: Promising directions include the continuation of reclamation of problematic areas, including the tailings pond of shop No. 3 of the former hydrometallurgical plant, the implementation of the Digmay tailings restoration project with the dismantling of contaminated infrastructure, the adoption of measures to ensure the safety of the Adrasman tailings pond, as well as the introduction of a state program for the safe management of uranium legacy with a long-term radioecological monitoring system. The comprehensive implementation of the aforementioned measures will ensure further reduction of radiation and environmental risks, create a foundation for the safe and sustainable development of the area, and also enable its safe future use.
The relevance of the research of new radioprotectors is due to the need to protect healthy tissues during radiation therapy. Existing drugs have serious side effects, which requires the search for safer and more effective analogues.The aim of the work is a comparative analysis of the radioprotective efficacy of three promising compounds – fumaric acid, 3-hydroxypyridine fumarate and deanol aceglumate in vitro. Tasks: to determine non-toxic concentrations of compounds, to evaluate their protective effect under different types of radiation (gamma quanta, protons, 12C ions), to compare the effect on normal (fibroblasts Fb-hTERT) and tumor (neuroblastoma SK-N-BE(2)) cells.Materials and Methods: the study was conducted on cultures of cells under the influence of ionizing radiation of different quality: gamma quanta (60Co), protons and accelerated 12C ions. Optimal concentrations have been established: fumaric acid – 400 μmol, 3-hydroxypyridine fumarate – 200 μmol, deanol aceglumate – 1000 μmol. Incubation time is 24 hours.Results and Discussion: It was shown that all compounds showed a significant radioprotective effect on gamma radiation (1-12 Gy) for fibroblasts; the protective effect was also observed on tumor cells. There was no radioprotective effect when irradiated with protons and 12C ions. Deanol aceglumate has demonstrated the greatest effectiveness.Conclusion: The study confirmed the prospects of deanol aceglumate and other compounds as radioprotectors under gamma irradiation. Their use can reduce damage to healthy tissues during radiation therapy. However, no protective effect has been detected for protons and heavy ions, which requires further study.
In recent years, several methodological documents have been approved and a number of scientific articles have been published concerning the assessment of radiation risks associated with medical exposure. Risk assessment is performed using various quantitative and qualitative risk indicators; however, the issue of their correct application, taking into account the specifics of a particular exposure scenario for solving applied problems in risk management, often remains unresolved. The aim of this study is to develop a framework and to substantiate a method for selecting and applying radiation risk indicators associated with diagnostic medical X-ray and radiological procedures, depending on the purpose of risk assessment, the type and parameters of the procedure, patient sex and age, and other factors. Materials and Methods: An analysis of radiation risk indicators was carried out based on a literature review, comparative analysis of definitions, and calculation methods. Results and Discussion: The main radiation risk indicators and their scope of application were analyzed; a list of indicators recommended for solving applied problems in medical diagnostic exposure was substantiated; a qualitative risk level scale and a scheme for selecting indicators are proposed. Conclusion: The developed approach allows for the alignment of the choice of risk indicator with the assessment purpose, target audience, dose burden, and availability of initial data.
The paper presents some methodological approaches to the organization of radiation survey and radiation control at oil and gas industry enterprises in order to ensure the radiation safety of workers exposed to natural sources of ionizing radiation. Summary. The paper highlights the issue of the lack of guidelines defining the procedure for organizing and conducting radiation survey and radiation control at enterprises in non-nuclear industries where exposure of workers to natural sources of ionizing radiation in industrial conditions is possible. The analysis of radiation sources affecting workers during the extraction, transportation and processing of oil and gas has shown that the main reason for increased levels of exposure in this industry is the generation of industrial waste with elevated concentration of natural radionuclides. It is noted that the mechanisms of waste generation in the oil industry and the gas industry are of a different nature. Based on practical experience, an approach to setting action levels in terms of removable radioactive alpha and beta contamination of technological equipment, ensuring that the established dose limit of 5 mSv/year is not exceeded given single-factor exposure situation, have been proposed for the first time. Several types of measurements are recommended to assess the doses of exposure to workers in the oil industry (gamma dose rate in the workplaces, radon concentration during certain types of operations, activity concentration of natural radionuclides in dust in the presence of dusting processes) and the gas industry (level of removable radioactive contamination with alpha and beta emitting natural radionuclides of the dismantled equipment, gross beta activity concentration in the air of the working area during equipment cleaning from accumulated sediment). Conclusion. The recommendations presented in the paper will be taken into account when developing guidelines for the organization and conduct of radiation survey and radiation control at enterprises in non-nuclear industries where workers are exposed to natural sources of ionizing radiation in industrial conditions. The applying of the guidelines in practice should become the practical basis for implementation of the requirements for ensuring the radiation safety of workers in the oil and gas industry of the Russian Federation.
Chronic radiation exposure can induce persistent epigenetic changes that affect the mechanisms of cell death and the development of long-term biological effects. The role of methylation of redox system genes in the regulation of apoptosis and necrosis of lymphocytes in chronically exposed individuals remains insufficiently studied. The aim of the study is to assess the association of promoter region methylation and transcriptional activity of redox system genes with the intensity of apoptosis and necrosis of peripheral blood lymphocytes in chronically exposed individuals. Materials and Methods: The study included 171 individuals: 99 persons exposed to chronic low-intensity radiation and 72 individuals from the comparison group who lived under similar social and living conditions. Apoptosis and necrosis of peripheral blood lymphocytes were assessed by flow cytometry. Molecular analysis included assessment of CpG dinucleotide methylation in the promoter regions of redox system genes and determination of their transcriptional activity. Results and Discussion: The level of lymphocyte necrosis was statistically significantly higher in the group of chronically exposed individuals compared with the comparison group (p = 0.033). Necrosis positively correlated with radiation doses to red bone marrow (ρ = 0.24; p = 0.001), thymus and peripheral lymphoid organs (ρ = 0.19; p = 0.013). Analysis of apoptosis revealed statistically significant positive correlations with methylation levels of SOD2 (ρ = 0.18; p = 0.017), GPX1 (ρ = 0.26; p = 0.001), GSTP1 (ρ = 0.22; p = 0.004), MPO (ρ = 0.41; p < 0.0001), and CAT (ρ = 0.21; p = 0.006). According to multiple regression analysis, apoptosis was associated with GSTP1 and MPO methylation. Conclusion: Thus, in chronically exposed individuals in the long-term period after exposure, necrotic lymphocyte death is predominantly associated with radiation dose, whereas apoptosis is associated with hypermethylation of promoter regions of redox system genes.
This article presents results of internal radiation dose assessments for the population based on radiation and hygienic surveys of settlements in the Bryansk region bordering the Republic of Belarus in 2019–2022. The objective of the study was to perform dose assessments with various models and to determine model parameters to updating. Materials and Methods: Calculations were performed for different age groups of the population of the surveyed settlements in the Bryansk region, as well as for critical groups, in accordance with current methodological documents. The results of comprehensive radiation and hygienic survey of settlements and radiation monitoring data were used for dose assessments. Results and Discussion: The greatest deviations from the model for 137Cs intake with food products (covering the majority of local food products and their consumption by the population) were obtained for the model which parameters are the coefficients of radionuclide transfer from soil to food products (milk and mushrooms) for the adult population living in areas with high levels of soil contamination (more than 555 kBq/m2 by 137Cs). At the same time, for the population of other areas (the majority of the surveyed settlements), the convergence of the dose assessment results is satisfactory. Conclusion: The average annual effective doses of internal exposure to the population of the surveyed settlements do not exceed 1 mSv, and the internal doses to the critical groups do not exceed 5 mSv. Food products of wild origin make a greater contribution to the internal radiation dose than local agricultural food products. The methodology for dose assessment to the population of the Chernobyl territories has proven its stability in basic approaches. Modification of several model parameters has allowed to improve calculation results.
The relevance of the work is due to the need to improve the methods of control of professional internal exposure due to incorporated radionuclides with a long biological half-life.The aim of the work was to test a methodical document regulating the organization of internal exposure control due to plutonium based on a risk-based approach to limiting radiation exposure to personnel. The task of the work was a practical application of the method of interpretation of the results of individual dosimetric control in monitoring the annual increment of the lifetime excess risk of death from radiation-induced cancer.Materials and Methods: The control system is based on the principle of limiting the doses of radiation to plutonium storage organs, depending on the age at which the exposure occurred, and the permissible levels of plutonium exposure make it possible not to exceed the acceptable level of the radiation-related risk throughout the work experience. Based on an array of data from individual dosimetric monitoring of 44 employees of the Mayak production association, calculations of annual equivalent doses to critical organs were performed, and the radiation effect on personnel was estimated based on the expected effective dose.Results and Discussion: In most cases, during the control periods, admissions were recorded that led to the formation of internal radiation doses above the registration level. The registered values of the expected effective doses for fifty years, as well as the values of equivalent doses for critical organs, did not exceed the established limits. In seven cases, the equivalent doses to critical organs were higher than 60 mSv, while the annual excess risk for the year of control did not exceed 1 ×10 -3. For all employees of the controlled group, no excess of the acceptable annual risk was recorded in any of the control periods.Conclusion: The completed test operation of the methodological guidelines showed the practical applicability of the methods described in the document, made it possible to identify the shortcomings of the tested approach and formulate proposals for improving the calculation algorithms.
The gold standard for early diagnosis of malignant breast neoplasms is mammography (X-ray examination of the breast) performed using digital and analogue X-ray units. This procedure is routinely conducted for all women aged 40 to 75 years on a regular basis (once every one or two years); mammography of both breasts is performed in two projections (four X-ray images). Doses from mammography, in accordance with the Norms of the Radiation Safety NRB 99/2009, shall not exceed 1 mSv per year. Hence, reliable assessment of patient doses for this procedure is important. The aim of this study was to evaluate the patient doses from mammographic procedures in medical facilities in St. Petersburg and the Leningrad Region. Materials and Methods: Data collection was performed at 99 medical facilities in St. Petersburg and the Leningrad Region for 141 digital mammography units during the period 2023–2025. For each mammography unit, mean glandular dose and effective dose was assessed for various compressed breast thicknesses (2, 4, 6, 8, and 10 cm) and projections (craniocaudal and mediolateral oblique), in accordance with the methodological guidelines MU 2.6.1.2944-11. Results and Discussion: The mean effective doses per single mammographic image in either the craniocaudal or mediolateral oblique projection varied from 0.05 to 0.07 mSv; effective doses per complete mammographic examination (two craniocaudal and two mediolateral oblique images) varied from 0.2 to 0.3 mSv. At the same time, substantial differences in patient dose ranges were observed: the ratio between the minimum and maximum mean glandular dose and effective dose reached up by the factor of 60, respectively. The primary factors determining patient exposure doses were the exposure and the X-ray tube output. No significant correlation was found between patient doses and tube voltage, focal-image distance, or the anode/filter combination. Compressed breast thickness also did not significantly influence the effective dose. Conclusion: Although the mean patient exposure levels during digital mammography are acceptable and comparable with international practice, patient doses for several mammography units are anomalously high. For such units, the implementation of patient radiation protection optimization measures is a priority.
