Today there exist two main approaches to developing computational phantoms for bone dosimetry. The first approach is based on a detailed description of the microarchitecture of the spongiosa filling the phantoms. This microarchitecture includes trabeculae and bone marrow separately, i.e., the source tissue and the detector tissue are separated. The second approach involves generating a homogeneous bone where the target and source tissues are combined. In both cases the simulation results are conversion factors that allow converting the specific activity of incorporated radionuclides into the absorbed dose in the bone marrow. For dosimetry of the Techa River population exposed due to incorporated 89,90Sr, the skeletal phantoms were created for people of different sex and age, starting with a newborn. These phantoms included a detailed description of the trabecular bone microstructure, i.e., they belong to the first approach. Also, phantoms of the skeleton of the fetus and pregnant woman at various gestation stages have been developed, which involves modeling the bone as a homogeneous medium. These phantoms are designed for dosimetry of external and internal exposure, including ^89,90Sr dosimetry. The usage of two fundamentally different approaches to bone dosimetry for the pre- and postnatal period raises the issue of compatibility of these approaches and possibility of their combining within a single dosimetric system. Objective: to evaluate the effect of detailing the trabecular structure of bone phantoms on the evaluation of conversion factors of bone marrow exposure due to ^89,90Sr. Computational phantoms of eight regions of a newborn’s skeleton filled in with trabecular bone were generated. For each bone region two phantoms were generated: one phantom with a detailed description of the spongiosa microstructure and one phantom with spongiosa modeled as a homogeneous media. For all phantoms, the radiation transport from ^89,90Sr incorporated in the source tissue was simulated using the MCNP 6.2 code, and the values of conversion factors were calculated. As a result, 16 conversion factors were obtained for all phantoms. On the average the conversion factors obtained for phantoms with homogeneous spongiosa exceed those for phantoms with a detailed description of the spongiosa microstructure by 2.4 times. Such significant difference between the results makes it possible to conclude that the detailing description of trabecular structure of bone phantoms has a significant impact on the assessment of the bone marrow dose due to incorporated ^89,90Sr.

Epidemiological studies of late effects of preconceptional (prior to conception) radiation exposure are necessary in order to understand the risks of tumor and non-tumor pathology in next generations. Research of possible relation between parental preconceptional exposure and development of endocrine and metabolic disorders in the offspring is one of the topical issues of radiation hygiene. The objective of the study: comparative analysis of endocrine and metabolic pathology in children of the individuals exposed to long term preconceptional external gamma-radiation at the Mayak Production Association – at the first atomic industry facility on Russia. Materials and methods: A retrospective research was performed based on the Ozyorsk Children’s Health Registry. Ozyorsk – the city where Mayak Production Association is the enterprise forming the city. Analysis of endocrine and metabolic disorders was performed for 13880 children of 1949-1973 years of birth who were born and resided in Ozyorsk; parents of 9321 children of this number had accumulated doses of prolonged external gamma-radiation exposure at the production facility prior to conception. A comparative analysis of the structure and incidence of “Endocrine, nutritional and metabolic diseases” and nosological forms of this class of pathology was performed. Characteristic features of parental preconceptional exposure were analyzed in relation to thyroid pathology in children. Relative risk of endocrine and metabolic disorders among the children of exposed and unexposed parents was calculated for the whole disease class and for certain nosologies. Results: A significant predominance of thyroid diseases, particularly, iodine deficiencies, was detected at an earlier age among the offspring of Mayak Production Association workers compared to the control group; these cases were mostly related to low dose parental preconceptional exposure. Thyroid cancer was further detected in 0.16% (15/9321) of the studied cohort of the offspring of exposed parents with average manifestation age of 42.6. Relative risk of thyroid diseases was significantly higher among the exposed parents’ offspring compared to the controls: 2.0 among boys (95% confidence interval 1.38-2.9), 1.59 among girls (1.25-2.02) and in the group as a whole – 1.64 (1.34- 2.01). Relative risk of thyroid diseases related to iodine deficiency among the offspring of Mayak Production Association personnel was almost twice higher than the in the control group: 1.92 (1.3-2.84) among boys, 1.68 (1.29-2.2) among girls, 1.7 (1.36-2.12) in the whole group. Discussion and conclusion: A statistically significant overweight of non-tumor thyroid pathology in the offspring of Mayak Production Association personnel cannot be explained through external reasons taking into account similar climate and geographic conditions, possible technogenic exposure and the same unified medical survey of the followed children. We cannot exclude increased sensibility if thyroid tissue to iodine deficiency and its predisposition to hypertrophy and hyperplasia among the offspring of individuals exposed to long term occupational contact with ionizing radiation sources; that should be taken into account in the course of medical monitoring of these patients. Further research of transgenerational effects in the offspring of personnel of radiation hazardous production facilities are needed for complete understanding of the role of parental occupational exposure in health risks for further generations.

The development of nuclear medicine technologies in the Russian Federation contributes to the implementation of new diagnostic radiopharmaceuticals in practice. Theranostic pairs such as antibodies and peptides labeled diagnostic and therapeutic radionuclides are beginning to be commonly used. The use of radionuclides with a longer half-life in radionuclide diagnostics causes the updating of the approaches to management of liquid waste generated as a result of the patient’s metabolic activity during the time spent in the radionuclide diagnostics department. Management of liquid radioactive waste in radionuclide diagnostic department is regulated by guidelines MU 2.6.1.1892-04. The guidelines are not the regulatory document. These were developed about 20 years ago, and do not considering features of the modern methods in radionuclide diagnostics, promising radionuclides with half-life of several days, and new criteria for classifying as a radionuclide waste in accordance with Resolution of the Government of the Russian Federation No. 1069. The aim of the study was the assessment of the radionuclide activities excreted from patient after radiopharmaceutical injection in radionuclide diagnostics departments in order to define the waste management pathways. In a result, all diagnostic and therapeutic radiopharmaceuticals were divided into the categories: radiopharmaceuticals with ultrashort-lived radionuclides, which can be discharged into the hospital sewerage without any restrictions; radiopharmaceuticals with ¹³¹I, which need the special sewerage; the other radiopharmaceuticals, which need to assess the volume of discharged radionuclide activities during the projection of the nuclear medicine department. The method of assessment of the radionuclide activities entering the hospital sewerage is presented. 

The purpose of the study was to analyze the regularities of ¹³⁷Cs concentrations in grain, potatoes and vegetables in the areas affected the Chernobyl accident. The data describing the countermeasures in the south-western districts of the Bryansk region are given. The system of radiological monitoring of plant products is described and the relevant data are presented. Dynamics of concentrations both in grain and in potatoes and vegetables had a pronounced heterogeneous character. Reduction of ¹³⁷Cs concentration in crop production (grain, potato, and vegetables) was determined by the dynamics of agrochemical countermeasures in the contaminated areas, sorption of ¹³⁷Cs in soil and radioactive decay. It has been revealed that effective halflives of ¹³⁷Cs in the above products during intensive implementation of rehabilitation measures (1987-1990) varied within the range from 0,7 up to 1,3 years. Subsequently, in 1991-2011, the decrease of contamination of products slowed down, and in some areas with intensive application of protective measures a certain increase of ¹³⁷Cs content in products was noted. Effective half-lives during that period ranged 10.5-29 years depending on the peculiarities of application of countermeasures and soil characteristics. The pattern of the ¹³⁷Cs concentrations in the grain produced in different districts from 2011 to 2021 also differed depending on the history of the countermeasures’ application in those districts in the previous periods. The estimation of the effective half-life, equal to 18.2 years, for predicting the reduction of plant product contamination in the long term after the Chernobyl accident has been suggested. 

The article presents results of experimental determination of the characteristics of neutron fields behind the biological shielding of reactor facilities in the physical hall of pressurized water research reactors of the pool type. In the work, measurements of the energy distribution of the neutron radiation flux density, determination of anisotropy and correction factors for individual dosimeters were carried out. The energy distribution of the neutron radiation flux density was obtained using an MKS-AT1117M multi-sphere dosimeterradiometer with a BDKN-06 detection unit and a set of polyethylene moderator spheres. Based on the results of determining the energy distribution of the neutron radiation flux density, the average values of the neutron energy were established, which are in the energy range: 0.06–0.35 MeV. The difference between neutron fields at the surveyed personnel workplaces and neutron fields in which individual dosimeters are calibrated leads to an additional error in estimating such dosimetric quantities as ambient dose equivalent, individual dose equivalent or effective dose. The performed studies allow to improve the system of individual dosimetric control based on the cycle of improvements: new knowledge – experimental studies – implementation of research results – regulation of activities to reduce the exposure of workers – analysis of the data obtained – new knowledge. The radiation anisotropy was estimated from the results of measurements of the accumulated dose of neutron radiation by individual thermoluminescent dosimeters placed on four vertical planes of a human phantom. Adequate estimates of the effective dose to personnel can be obtained using correction factors for individual dosimeters. For various workplaces and methods, the correction factors range from 0.04 to 0.7. 

The paper presents the values of the conversion coefficients from the operational quantity, HP(10)/ to the protection quantity, effective dose (E). The conversion coefficients were calculated in a number of points located at a depth of 10 mm under the surface of the torso of the computational model MIRD-5 of the body of an adult. The simulated irradiation conditions corresponded to both uniform and sharply non-uniform irradiation of the employee in the fields of photon radiation with the energy from 0.04 to 2 MeV. It was demonstrated that for the uniform radiation and the “typical” location of the individual dosimeter on the employee’s body, the E/HP(10) ratio is less than one in the entire range of radiation energies for the directions of its incidence in front and from the left side, i.e. Hp(10) is a conservative assessment of E. When the radiation falls on the back and for the “typical” location of an individual dosimeter on the employee’s body in the entire range of radiation energies, the ratio E/Hp(10) is significantly larger (for the energies <0.1 MeV) or close to one, i.e. Hp(10) is not a conservative assessment of E. In the spatial non-uniform fields of photon radiation with an increase in the degree of non-uniformity irradiation of the employee’s body, the values of the conversion coefficients decreased. When irradiation in front and from the left side an individual dosimeter placed in a “typical” position will be conservative estimate the value of an effective dose of the employee in the entire considered range of energies. When irradiation on the right side an individual dosimeter placed in a “typical” position will underestimate the value of an effective dose in the entire considered range of energy. It was demonstrated that the optimal location of the individual dosimeter on the surface of the employee’s body allows us to adequately assess according to his indications the value of an effective dose even with significantly changing geometry of its irradiation during a complete cycle of treatment with the source of ionizing radiation. 

In the condition of modern radiation hazardous production, higher levels of personnel internal exposure are mainly due to the intake of radionuclides in situations caused by faulty equipment or wrong actions of personnel which can or do result in the exposure that exceeds established standards. In such cases, to determine the intake and committed effective dose, daily amount of urine and/or feces is collected followed by the preparation of loads and their subsequent measurements. For a total, it takes three to eight days to obtain the result depending on the method of measurement used. In case of acute intake of plutonium, it is important to estimate the levels of the nuclide intake as soon as possible in order to decide on treatment strategy and dose reduction. To achieve the above goal, the Southern Urals Biophysics Institute has developed a technique for measuring the plutonium-239 activity in blood using an inductively coupled plasma mass spectrometer as in the first hours and 24 hours after intake (through inhalation or damaged skin) the radionuclide concentration in blood is at its maximum level. Also a method has been developed to measure plutonium in urine aliquot using mass-spectrometry to perform special individual dosimetry monitoring that requires almost no sample preparation which allows to estimate the intake within a few hours. It is shown that, depending on the route of intake and chemical form of plutonium compounds entered, the measurement of plutonium activity in blood and urine aliquot performed by the inductively coupled plasma mass spectrometer method allows to determine from 0.1 to 47% of intake limit within the first 24 hours after an accident. The analysis of a blood sample takes one to one-and-a-half workdays against a week required to analyze a urine sample using alpha-spectrometry. The application of the developed methodology, apart from the goal of individual dosimetry monitoring, will provide new information on the effects of chelation therapy on the plutonium behavior in the human body. 

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The paper presents the results of research of the levels of tritium volume activity in lake Kyzyltash, a water storage reservoir for liquid radioactive waste from Mayak Production Association. Insufficient knowledge of the ways of migration of tritium from the reservoir and their quantitative assessment in modern conditions does not allow to fully objectively assess and predict the impact of the object of “nuclear heritage” on the population of Ozersk and the environment. The research was aimed at obtaining scientific results, which will be the starting point for the formation of a tritium monitoring program for industrial reservoirs by Mayak Production Association. The purpose of the study was assessement of the dynamics of tritium volume activity in the lake Kyzyltash, assessment of water balance parameters and the level of tritium intake into the air from its surface during the ice-free period. A total of 33 water samples were collected. The average tritium volume activity in 2021 made 1,57Е+04 Bq/l, SD – 1,1Е+03 Bq/l that more than 2 times exceeds the intervention level. A trend of decrease in the average monthly tritium volume activity in the reservoir during the observation period was revealed. In the course of calculations, it was stated that in the course of evaporation during the ice-free period the 196 TBq of tritium entered the air from lake Kyzyltash surface that is comparable with releases from all the Russia facilities (179 TBq) except Mayak Production Association. The obtained values of evaporated tritium make 13% from atmospheric tritium releases of Mayak Production Association in 2020. A total of ~12,2 million m3 had evaporated from the water reservoir surface in the study period. The model of dependence of tritium volume activity from time in lake Kyzyltash in 2021 and using of exponentially decreasing function allowed defining water balance of lake Kyzyltash in the ice-free period with 6,3 million m3 deficiency. Research of the model parameters allow prediction of sanitary and hygienic characteristics of the water reservoir from the point of view of radiation safety and calculation of water balance of the reservoir in certain periods of time. 

The article presents results of a study of tritium incorporation by vegetable crops with short-term aerial exposure to tritium oxide in laboratory and field conditions. Plants are a key link in the process of tritium migration both in the ecosystem as a whole and in the trophic structure in particular. As a result of photosynthesis, much of tritium is incorporated into the organic matter of plants. In this aspect, the study of tritium incorporation processes and its possible contribution to human radiation exposure from ingested crop products is a relevant task. The aim of the study was to assess tritium incorporation by vegetable crops quantitatively at aerial entry of the radionuclide in the form of tritium oxide. To achieve this goal, laboratory (in the chamber) and field (in the territory of the former Semipalatinsk Test Site) experiments were conducted with commonly cultivated pepper (Capsicum annuum) and eggplant (Solanum melongena) that were affected by short-term exposure to tritium oxide vapors. Air was sampled with a tritium collector “OS 1700”. Plant samples for measuring organically bound tritium were prepared using a “Sample Oxidizer” unit. Tritium activity in samples was measured with “QUANTULUS 1220”. It was found that tissue free water tritium activity in leaves of Capsicum annuum and Solanum melongena was 1-2 orders of magnitude higher than in stems and fruits. The distribution of tissue free water tritium in both crops with a short-term aerial exposure is described by a decreasing series: “leaves < stems < fruits”. The difference between the tissue free water tritium and organically bound tritium concentration in plants for all exposure variants was also 1-2 orders of magnitude. For organically bound tritium, no distinct regularity in the distribution of plant parts was established, which is most likely due to the short period of exposure. By the time the fruits were fully ripe, a significant decrease in the activity of tissue free water tritium (the main source of the formation of organically bound tritium in the post-exposure period) in all plant parts was observed. For organically bound tritium, both an increase and a decrease in the concentration were noted in leaves and stems, and in ripe fruits it remained almost at the same level as at the end of the exposure. The conversion rate of tritium in field conditions was 15-30 times than in the chamber. Organically bound tritium translocation into edible parts of vegetable crops in field conditions was 2-4 times higher than in the chamber, regardless of the tritium oxide concentration in air and leaves. According to a conservative assessment, the possible contribution to the dose of internal exposure from ingested tritium per 1 kg of vegetables contaminated as a result of short–term exposure, based on the absolute activity of radionuclide forms in Capsicum annuum and Solanum melongena fruits will be: for tissue free water tritium – 0.7 and 5.6 nSv; for organically bound tritium – 1.7 and 2.4 nSv, respectively. Since the levels of tritium oxide in the emissions of nuclear fuel cycle enterprises are much lower compared to experimental ones, the possible contribution of tritium to the dose of public internal exposure from the ingestion with crop products after a short-term tritium oxide exposure will be negligible.

The article presents analysis of exposure doses to the population of observation zones and personnel of radiation facilities of the Russian Federation in 2021. For the analysis, we used data received by the Federal Data Bank on Personnel Exposure Doses, which operates as part of the Unified System of Individual Dose Control of the Russian Federation citizens. Data received from 20 359 radiation facilities were used. Among them, there are 19 743 radiation hazardous facilities supervised by Rospotrebnadzor and 616 supervised by the FMBA of Russia. 15 883 (78%) radiation hazardous facilities are medical institutions. In total, in 2021, the Federal Data Bank on Personnel Exposure Doses received the results of measuring the annual individual effective doses of technogenic industrial exposure of 239 743 persons of group A personnel and 22 490 persons of group B personnel. 12 095 people of group A personnel who worked part-time at several radiation facilities were identified The average annual effective dose of technogenic occupational exposure of group A personnel in 2021 was 1.12 mSv, and for group B personnel, whose exposure doses were obtained according to instrumental control data – 0.61 mSv. The maximum values of the average annual effective dose of technogenic occupational exposure for group A personnel in 2021 took place in the Zabaykalsky Krai (2.81 mSv), Perm Krai (2.60 mSv), the Ulyanovsk region (2.03 mSv), the Yamalo-Nenets Autonomous Okrug (1.93 mSv) and the Republic of Buryatia (1.91 mSv). The average individual annual effective dose of technogenic occupational exposure for part-time workers in 2021 was 1.92 mSv/year. It’s in 1.7 times higher compared to personnel A group. In 2021, two cases of exceeding the annual individual dose of 20 mSv and one case of exceeding the annual individual dose of 50 mSv for group A personnel and 12 cases of exceeding the annual individual dose of 5 mSv for group B personnel were identified. The annual individual dose of technogenic occupational exposure of 51.0 mSv (exceeding the dose limit for group A personnel) was registered in the Production association “Sevmash” in the Arkhangelsk region. In 2021, 1.54 million people lived in the radiation control areas of category I of potential hazard radiation facilities. The average annual effective dose of technogenic exposure to this category of the population due to the operation of radiation facilities was 0.018 mSv, which is only 1.8 times higher than the annual effective dose of 0.01 mSv, corresponding to a negligible radiation risk and 55 times less than the average annual dose limit for the population, equal to 1.0 mSv. In general, the radiation situation at the radiation facilities of the Russian Federation is quite stable and complies with safety requirements. Technogenic exposure of the population and personnel due to the normal operation of technogenic sources of ionizing radiation is the least significant radiation factor, both for individual exposure doses and for the collective exposure dose to the population of the Russian Federation. In 2021, only less than 24 thousand persons of group A personnel received annual effective dose of technogenic occupational exposure exceeding 2.0 mSv, which is comparable to the average annual effective dose of natural exposure (3.36 mSv) received by the entire population of Russia. The collective annual effective dose to the population of the Russian Federation due to the operation of radiation facilities in 2021 was less than 0.1% of the dose from all sources.

This study is focused on the description of management of data on the exposure of the Russian population for the State report on the evaluation of sanitary-epidemiological well-being of public in the Russian Federation, that was presented by the Federal service of surveillance on consumer rights protection and human wellbeing. It is shown that the mains sources of data on the radiation situation and public exposure are system of social-hygienic monitoring, Joint state system of control and accounting of public doses; and radiationhygienic passportization, functioning under the control of Rospotrebnadzor facilities. 

The federal forms of statistical reporting (3-DOZ form, form No. 30 of the Ministry of Health of the Russian Federation and radiation-hygienic passports of the subjects of the Russian Federation for 2015–2020) were analyzed in order to estimate the current status of nuclear medicine and assess the perspective and developing proposals for improving the national system of radiation protection in nuclear medicine. Over the past six years, the number of radionuclide examinations in the Russian Federation has been at the same level: on average 530 thousand per year. In 2020 the number of examinations decreased that was caused by the epidemic of coronavirus infection. The largest number of examinations in 2015-2020 were performed in Moscow (21%) and St. Petersburg (11%). Federal medical centers equipped with high-tech equipment are located in these cities, and patients from different regions are examined in these centers. The examination of bone is the most common examination in Russia: 40% from all of nuclear medicine examination; there is a moderate increase of that examinations. There is a high number of renal examinations (17%). The next most frequent are examinations of myocardium, thyroid, liver and lungs; the number of these examinations are decrease. Due to the development of modern diagnostic technologies, installation of new positron emission tomography departments and replacement of the old equipment with the new one (decrease in the number of renographs and increase the number of positron emission tomographs), the number of “other” examinations are increased with a factor of 3.7 since 2015 but the number of “functional” examinations is decreased. About two thousand studies per year were examined on a scanner (renograph, gamma camera, single-photon emission tomography), and about 0.6 thousand hybrid imaging examinations per year were performed on a single-photon emission tomography combined with computed tomography. The annual collective dose of radionuclide diagnosis in the country has increased from 1.2 to 3.7 thousand man-Sv since 2015. The main contribution to the collective dose in Russia was associated with “other” examinations, which include hybrid imaging and whole body positron emission tomography: 55% (39% in St. Petersburg, 60% in Moscow). Due to the limitations and heterogeneous content of the federal forms of statistical reporting it is difficult to assess the current state of nuclear medicine in the Russian Federation. The authors of the study were updated of the data collection system in the radionuclide diagnosis in 3-DOZ forms; it is under approval. For detailed and reliable assessment of the nuclear medicine in the country, it is necessary to conduct a separate survey to determine the types of nuclear medicine examinations, the gender and age profile of patients and patient doses. That survey should be conducted in St. Petersburg or Moscow, as model subjects of the Russian Federation. 

The aim of this study was to evaluate radiation situation at the “Pirit” peaceful underground nuclear explosion site. The peaceful underground nuclear explosion “Pirit” with the capacity of 37.6 kt оf TNT equivalent was carried out on May 25, 1981 on the territory of the Kumzhinskoye gas condensate field at a depth of 1.5 km. The field is located near the northern coast of the European part of Russia in the delta of the Pechora River (Nenets Autonomous District). The peaceful underground nuclear explosion “Pirit” was carried out with the aim to stop the uncontrolled gas gushing. Radiation situation is assessed according to the main indicators: dose rate values and content of technogenic radionuclides in soil and water. The radiation survey included determining geographic coordinates of specific landscape elements, measurement and sampling points using satellite navigators, measurement of ambient dose equivalent rate, identification of gamma-emitting radionuclides in situ by field gamma spectrometry, sampling of water, photo and video shooting. On the site of the underground nuclear explosion “Pirit” the values of the ambient dose equivalent rate were in the range of 0.050–0.089 μSv/h, which corresponds to the levels of the natural radiation background. No sites of local radioactive contamination of soil by 137Cs were detected. The tritium content (less than 5 Bq/kg) in water bodies does not exceed the levels of fluctuations of this indicator in other regions of the European territory of Russia. The estimated value of the effective dose due to ingestion of tritium in drinking water in local settlements was 0.044 μSv/year. The radiation situation on the territory of the peaceful nuclear explosion “Pirit” meets the requirements of the Russian Sanitary Regulations and Standards 2.6.1.2819-10 “Ensuring the radiation safety of the population living in the regions of nuclear explosions for peaceful purposes (1965–1988)” and currently does not pose a threat to public health. Due to the potential danger of technogenic radionuclides coming from the epicenter of the explosion to the surface for long-term radiation safety, it is necessary to organize radiation monitoring of the territory adjacent to the explosion site, determine the boundaries of the protected zone and set appropriate information signs warning of radiation danger. 

When measuring low levels of ¹³⁷Cs in soil samples using spectrometers with a NaI(Tl) detector, identification of the ¹³⁷mBa peak (the 662 keV gamma line of the daughter radionuclide) is difficult due to the influence of natural radionuclides, the peaks of which fall within the ¹³⁷mBa detection region. To identify and estimate the area under the peak of ¹³⁷mBa, it is necessary to know the contribution of the background component to this area and the contribution of each natural radionuclide. When using such approach, the accuracy of estimating the ¹³⁷mBa photopeak area depends on the accuracy with which the levels of natural radionuclides are determined. The article proposes a method of spectrum decomposition based on the taking into account individual parameters of the spectrometer and a more accurate determination of specific activities of natural radionuclides. The method involves the modeling the spectral regions for each natural radionuclide in the area of ¹³⁷mBa peak and subtracting the simulated regions and the background spectrum from the total spectrum under the peak of ¹³⁷mBa. The use of this approach allows to measure with a 63×63 NaI(Tl) detector the specific activity of ¹³⁷Cs at a level of 0.7–1 Bq/kg with an uncertainty of 30-50% in the Marinelly geometry with a volume of 1 liter and with the measurement time of 6 hours.