Intake Of 137Cs Research Articles

Changes in radioactive contamination of living ground cover plants in black alder stands since the Chornobyl accident in the forests of Zhytomyr Polissia

The results of research conducted over the past 30 years in the forest ecosystems of Zhytomyr Polissia, in the areas affected by radioactive contamination as a result of the Chornobyl accident. In the course of the research carried out at the Poliskyi Branch of the Ukrainian Research Institute of Forestry and Forest Melioration named after G. M. Vysotsky, methods of forest radioecology, botany, and forestry were used, and the results were processed using statistical analysis. The peculiarities of radioactive contamination of the most common herbaceous and dwarf-shrub plants in the stands of black alder in damp fairly fertile site types were studied. As indicators characterizing these features, we used 137Cs specific activity in the aboveground part of plants and the transfer factor of radionuclide to plant phytomass from the soil. It was found that the highest values of the transfer factor of 137Cs from the soil to the aerial part of the plant phytomass in 1999 are characteristic of ferns: for Dryopteris cristata (L.) A. Gray (276.9 m2∙kg-1∙10-3), Dryopteris carthusiana (Vill.) H. P. Fuchs (236.5 m2∙kg-1∙10-3), Thelypteris palustris Schott (171.2 m2∙kg-1∙10-3), and Athyrium filix-femina (L.) Roth (164.0 m2∙kg-1∙10-3). It was found that among the higher plants, the highest values of this indicator are for the Agrostis stolonifera L. (263.5 m2∙kg-1∙10-3), Galium uliginosum L. (155.8 m2∙kg-1∙10-3) and Maianthemum bifolium (L.) F. W. Schmidt (155.4 m2∙kg-1∙10-3). It was found out that the previously noted trends and interspecific differences in radionuclide accumulation persist after 22 years. It is shown, using the example of three plant species (Lysimachia vulgaris L., Galium uliginosum, and Maianthemum bifolium), that during the observation period (1991-2021) there is a gradual decrease in radioactive contamination of living ground cover plants and the intensity of 137Cs intake into them. This is explained by the decay of the radioactive element, its entry into various perennial components of forest ecosystems, some fixation in the soil, and, possibly, its removal beyond their borders. The established decrease in 137Cs specific activity in the aboveground part of plants is described by linear equations: for Lysimachia vulgaris – Am = –605.34a + 3745.6; R² = 0.98; Galium uliginosum – Am = –5107.5a + 30698; R² = 0.99; Maianthemum bifolium – Am = –4661.6 a + 28280; R² = 0.98. The identified peculiarities of radioactive contamination of various plant species, changes in 137Cs specific activity in them, and transfer factors of the radionuclide from the soil in stands of black alder in damp fairly fertile site types can be used in scientific works to predict possible changes in its redistribution within the ecosystem, as well as in the practice of harvesting medicinal plants in areas contaminated with radionuclides.

Поступление 137Cs в почву из луговых растений при аэральном загрязнении и формирование первичных градиентов концентраций этого поллютанта в почве на агрегатном уровне

In model experiments under field conditions in the Aleksandrovsky district of the Vladimir region, the intake of 137Cs from various meadow plants into soddy-podzolic heavy loamy soil was studied. The radionuclide in the form of an aqueous solution of cesium nitrate was applied to the leaf surface of the middle tier, which prevented 137Cs from entering the soil. Representatives of different families were used as experimental plants: common cuff (Alchemilla vulgaris L.), rosaceae family; forest angelica (Angelica sylvestris L.), celery family; caustic buttercup (Ranunculus acer L.), ranunculaceae family; common tansy (Tanacetum vulgare L.), aster family and meadow timothy (Phleum pratense L.), bluegrass family. The experimental results showed that 2.7 to 6.9% of the applied radiocesium can enter the soil through root secretions, and the largest amount of the pollutant was found in the soil of varieties with forest angelica, the smallest – with common tansy. 137Cs entering the soil accumulated mainly in the uppermost 0 to 4 cm horizon; in the underlying layers of 4 to 12 cm radiocesium was found 1.2 to 6.7 times less. At the aggregate level, 137Cs concentrated mainly on the surface of the smallest soil particles, which were <0.5 and 0.5 to 1 mm in size.

Effectiveness of new agromeliorations under barley cultivation in radionuclide soil contamination

Based on the results of three-year production tests, the effectiveness of new agromeliorants (PhosAgro NPK complex fertilizer and Gumiton organo-mineral complex) was evaluated when growing barley on radioactively contaminated sandy loam soddy-podzolic soils of Novozybkovsky district of Bryansk region. It is shown that non-root treatment of barley crops in the earing phase with Gumiton (1 l/ha) without the use of fertilizer contributed to an increase in grain yield by 17-29% relative to the control, depending on the year. The introduction of PhosAgro NPK fertilizer (0.3 t/ha) gave an increase in yield of 22-39%. The combined use of fertilizer and the drug increased the yield by 18-72%. The multiplicity of the decrease in the intake of 137Cs in grain during the treatment of crops with Gumiton was up to 2.3 times, with the combined use of the drug and fertilizer - up to 4.7 times compared with the control. The use of Gumiton and PhosAgro NPK guaranteed the production of grain with a content of 137Cs corresponding to the standards of Sanitary Rules and Regulations 2.3.2. 2650-10. The conditional net income per 1 ruble of costs for processing barley crops with Gumiton amounted to 3.75-17.6 rubles, depending on the year. Both the introduction of PhosAgro NPK and the treatment of barley crops with Gumiton did not significantly affect the grain quality indicators: the content of protein, ash, fat, fiber. Thus, it is shown that the organo-mineral complex Gumiton and complex fertilizer PhosAgro NPK are effective agromeliorants in barley cultivation technologies in conditions of radioactive contamination of soils.

Influence of daily feeding ration of cattle on the transfer of 137Cs and 90Sr to animal organisms and manure in the agroecosystems of Central Forest-Steppe

The ration of feeding for large cattle was investigated and analyzed in terms of the transfer of 137Cs and 90Sr to muscle tissue, bones, milk, and manure biomass. The specific activity of radionuclides 137Cs and 90Sr was determined in the daily feeding ration of animals. It was found that the soil contamination density of 137Cs at the «Nadiya» farm ranged from 104.2 to 396.5 Bq/m2, while for 90Sr, it ranged from 9.4 to 36.2 Bq/m2. The fields at the «Ivanivske» farm had soil contamination densities of 137Cs ranging from 37.5 to 283.6 Bq/m2 and 90Sr ranging from 7.4 to 32.1 Bq/m2. The soil contamination density of 137Cs at the NNDC BNAU ranged from 4.18 to 8.66 Bq/m2, while for 90Sr, it ranged from 0.44 to 0.88 Bq/m2. The results of the ration assessment indicate that the average daily intake of 137Cs from feed into the animal’s body at the «Nadiya» farm was 375.3±84.2 Bq/kg, and for 90Sr, it was 345.1±98.2 Bq/kg. Significantly lower amounts of radionuclides from the ration entered the animals’ bodies at the «Ivanivske» farm, with an average daily intake of 137Cs at 174.9 Bq/kg and 90Sr at 236.0 Bq/kg. The lowest transfer coefficients of 137Cs and 90Sr from the daily ration to the body were observed at the NNDC BNAU, with 8.56 Bq for 137Cs and 9.69 Bq for 90Sr. It was determined that, overall, the muscle tissue of animals received 6.37% of 137Cs and 0.06% of 90Sr from the ration at the «Nadiya» farm; 2.0% of 137Cs and 0.02% of 90Sr at the «Ivanivske» farm, and 2.22% of 137Cs at the NNDC BNAU. In the case of bones, it was 6.47% of 90Sr at the «Nadiya» farm; 5.47% of 90Sr at the «Ivanivske» farm, and 0.41% of 90Sr at the NNDC BNAU. The obtained results confirmed that 137Cs is capable of evenly accumulating in all organs of the animal, while 90Sr selectively or predominantly accumulates in specific organs. It was established that under conditions of prolonged intake of radionuclides through the ration into the body of large cattle, 85–90% is excreted with the manure biomass.

Dynamics of <sup>137</sup>Cs Transfer Factors to Agricultural Products after the Chernobyl Accident: Grain, Potatoes, and Vegetables

The results of the analysis of the 137Cs aggregated transfer factors (Tag) to crops (cereals, potatoes, and vegetables) produced in the districts of the Bryansk region affected after the Chernobyl accident are presented. The aggregated transfer factors in the year of the deposition as well as the dynamics of Tag in the subsequent years depended considerably on the fertility of soils subjected to contamination. The transfer factors of 137Cs to crops in the areas with higher fertility were 3–8 times lower (depending on the plant species) than in the areas with low fertility, and the most significant differences were observed for cereals. Decrease in Tag values was of irregular nature. The half-lives of 137Cs aggregated transfer factors for the period from 1986 to 2021 were calculated. It is shown that the first half-life values calculated for the period of intensive application of countermeasures (1987–1991) were from 0.7 to 1.4 years. The second half-lives varied from 7.3 to 17.3 years. In some areas, after a strong reduction in 137Cs concentrations in crops after 1994, there was a slow increase in 137Cs aggregated transfer factors, which can be explained by insufficient compensation for this decrease of geochemical binding of 137Cs in the soil. Later the dynamics of crop contamination was determined by multidirectional processes: i.e., increase in 137Cs transfer to plants and natural decrease of radionuclides bioavai-lability in soils under the influence of geochemical processes. In areas with intensive application of countermeasures, the reduction of Tag to crops was determined to a greater extent by the influence of agrochemical countermeasures. In the areas with limited application of countermeasures, the natural biogeochemical processes determining radionuclide binding by the soil-absorbing complex made the predominant contribution to the Tag reduction. Limitations of the approach based on the estimation of half-lives and the necessity of using the history of countermeasures implemented, as well as the soil fertility for prediction of the 137Cs intake by plants is noted.

Comprehensive Assessment of the Impact of Various Types of Agrochemicals on the Intake of 137Cs in Pea Plants

Comprehensive Assessment of the Impact of Various Types of Agrochemicals on the Intake of 137Cs in Pea Plants

COMPLEX RADIATION AND HYGIENIC MONITORING OF POPULATION ON RADIOLOGICALLY CONTAMINATED TERRITORIES OF ZHYTOMYR OBLAST IN 2021.

the key factors identification in radiation dose formation in population of radiologically contaminatedareas of Zhytomyr oblast in the current period of accident through complex radiation and hygienic monitoring in reference settlements in 2021. For complex radiationhygienic monitoring in Zhytomyr oblast, 10 settlements were chosen - Narodychi, Selets, Bazar, Rudnya Bazarska, Khrystynivka - zone 2, Motiyki, Zalissya, Davydky, Radcha, Nova Radcha - zone 3 of Narodychi district, in which the highest radiation doses were recorded after the accident at the Chornobyl Nuclear Power Plant. The research was carried out in June 2021. In order to determine the doses of internal radiation, 645 measurements were performed on whole body counters (WBC) (478 adults and 167 children). The 44 samples of milk, 45 samples of potatoes and vegetables, and 38 samples of wild products were collected in local farms and measured for the 137Cs and 90Sr content. Residents of the studied settlements (n = 220, 175 adults, and 45 children) were interviewed about the levels of consumption of staple foodstuffs. External radiation doses were evaluated in all the studied settlements. Mathematical, dosimetry, and radiochemical methods were applied. Annual effective radiation doses of Zhytomyr oblast population in 2021 were formedmainly due to internal radiation ones that not exceeded 1.8 mSv * year-1 in adults and 0.5 mSv * year-1 in children against the radiologically contaminated territories (RCT) criterion of 1 mSv * year-1. Intake of 137Cs with milk and wild mushrooms, which traditionally occupy a significant part of diet in Zhytomyr oblast area and have consistently high levels of radioactive cesium contamination, remains a key factor of internal radiation dose forming in residents of the surveyed settlements of Zhytomyr oblast.

The Simulation of the dynamics of 137Cs accumulation by freshwater fish

The study aimed to simulate the dynamics of 137Cs accumulation by freshwater fish under conditions of hypothetical radioactive contamination of water reservoirs in different seasons. The subject of research is the regularities of 137Cs accumulation by non-predatory fish species in eutrophic and oligotrophic water bodies. The dynamics of the 137Cs content in freshwater fish was calculated according to the content of radionuclides in water masses. The results of modeling the volumetric activity of 137Cs in water masses were used as an input parameter for the radionuclide accumulation in fish model. The fish organism was represented in the form of 3 independent related only by the balance equation; seasonal changes in the fish feeding intensity were taken into account in the modeling. The parameter that takes into account the contribution of the feeding intensity to the process of 137Cs intake into the fish organism has been determined. The features of the dynamics of 137Cs accumulation in eutrophic and oligotrophic water bodies fish are analyzed for cases of a hypothetical accidental input of 137Cs into ecosystems at the beginning of different periods of the annual life cycle of fish: 1st - from 1 to 31 March; 2nd - from 1 to 30 April; 3rd - from May 1 to September 19; 4th - from September 20 to October 19; 5th - from October 20 to November 30; 6th (freeze-up period) - from December 1 to February 28. The study has found that for a eutrophic water body the highest levels of 137Cs content in peaceful fish will be formed in the case of 137Cs entering ecosystems in spring (options 1–3). The maximum levels of 137Cs content in fish will be observed in the contamination period mentioned in option 3. Under hypothetical pollution in the autumn-winter period (options 4–6), the levels of 137Cs in peaceful fish will be approximately 2 times lower than in the case of pollution of the reservoir in spring. It has been found that the maximum value of the specific activity of 137Cs in fish from an oligotrophic water reservoir is not related to the season of pollution. However, the levels of fish pollution in the oligotrophic reservoir will be 1.5–2 times higher than those of the eutrophic one in options 1–3 and 3–4 times higher in options 4–6 . In the event of an emergency density of 137Cs fallout at the level of 4 kBq /m2 on the surface of different types of closed water reservoirs, its specific activity in peaceful fish will exceed the currently established permissible levels of fish products contamination. If the fallout density is twice as low (2kBq/ m2), the accumulation levels 137Cs by fishes of eutrophic water bodies will exceed the permissible standards in case of emergency inflows in spring. For oligotrophic water reservoirs, the guaranteed non-excess of the established standards in fish products is possible if the 137Cs fallout density is under 0.5 kBq /m2. Key words: fish, modeling, 137Cs, specific activity, hypothetical pollution, reservoirs of different trophic status.

Вплив додаткового «чистого» годування на вміст 90Sr і 137Cs в карасях сріблястих (Carassius Gibelio) у Чорнобильській зоні відчуження

Under natural conditions, in one of the most radioactively contaminated water bodies of the Chornobyl exclusion zone, lake Glyboke in 2020, experimental studies were carried out to assess the effectiveness of the use of additional "clean" feeding to reduce the levels of radioactive contamination of 90Sr and 137Cs in fish. The radiological efficiency of decreasing the 137Cs intake into the muscle tissue of fish with the use of additional "clean" feeding, mainly due to biological dilution, was 2.9 ± 0.4 times. The biological half-life of 137Cs in the muscle tissue of radioactively contaminated fish was 115 ± 25 days with the consumption of natural and additional "clean" food, which is approximately 2 times longer compared to the case when the fish consumes only clean food. In contrast to 137Cs, using additional "clean" feeding led to an increase of 90Sr content in the fish organism as compared to the control (up to 5 times) in proportion to the relative increase in the mass of fishbone tissue, which contains the bulk of strontium.

No increased cancer risk in male hunters in Northern Sweden after radiation exposure from the Chernobyl Nuclear Power Plant accident

BACKGROUND AND AIM: Male hunters have slightly higher total cancer incidence versus male non-hunters in 9 Swedish counties after the Chernobyl Nuclear Power Plant (NPP) accident in 1986. The aim of this study was to investigate whether the contribution of absorbed dose from the Chernobyl fallout could have influenced the elevated cancer incidence, given that hunters have a higher internal radiation exposure due to consumption of game contaminated with ¹³⁷Cs. METHODS: An algorithm was developed to calculate the total absorbed colon dose as a sum of external and internal absorbed colon dose. The time-integrated total absorbed colon dose was calculated individually for hunters (n=40 874) 1986-2015. Allowing for a 5-year latency period, the age-adjusted Incidence Rate Ratios (IRR) per milliGray (mGy) with 95% Confidence Intervals (CI) were calculated using Poisson regression for the follow-up period 1991-2015. A total of 8 964 cancer cases occurred in the hunter cohort to 31 December 2015. Pre-Chernobyl total cancer incidence in each of the counties was investigated as a potential confounding factor. RESULTS:The mean colon dose was 2.39 mGy with more than half of the absorbed colon dose from internal ¹³⁴Cs and ¹³⁷Cs taken together. No specific cancer site showed a significant increased IRR per mGy. For total cancer the IRR per mGy was 0.995 (95% CI 0.988-1.003). The IRR did not change after adjustment for the pre-Chernobyl total cancer incidence. CONCLUSIONS:Using the total colon dose as proxy for the whole body dose, no dose-dependent increased risk for cancer was observed in hunters, hence the elevated cancer incidence in hunters versus non-hunters could probably not be attributed to intake of ¹³⁷Cs contaminated game after the Chernobyl NPP accident. Future analyses will calculate individual organ absorbed dose and investigate dose-response relationship for those cancer sites. KEYWORDS: incidence, ionizing radiation, environmental epidemiology, exposure assessment, cancer and cancer precursors

Absence of Detectable Radionuclides in Breast Milk in Sendai, Japan in 2012 Even by High-Sensitivity Determination: Estimated Dose among Infants after the Fukushima Nuclear Disaster.

The aim of this study was to estimate radionuclide levels in breast milk and the transferred dose to their infants in Sendai (100 km from Fukushima), Japan after the 2011 Fukushima nuclear disaster. Radionuclide concentrations were analyzed in 101 specimens of breast milk collected in 2012. Median values for minimum detectable activities were 0.39, 0.34, 1.1, 1.89, and 17.1 Bq/kg for 137Cs, 134Cs, 131I, 110mAg, and 40K, respectively. Only radionuclides from 40K were detected. To estimate potential exposure and radiocesium dose, we assumed that the samples contained each minimum detectable activity level. The mean minimum detectable activity concentrations (standard deviation) of 137Cs and 134Cs were 0.42 (0.15) and 0.37 (0.14) Bq/kg, respectively. Means of estimated dietary intakes of 137Cs and 134Cs among infants were 0.35 (0.12) and 0.31 (0.11) Bq/day, respectively. The committed effective doses of radiocesium in infants aged 3 and 12 months via breastmilk were estimated at 5.6 (2.1) and 3.3 (1.2) μSv/year, respectively. Dietary intakes of 137Cs and 134Cs in breastfeeding mothers were back-calculated at 1.9 (0.71) and 1.7 (0.65) Bq/day, respectively. The study verified no discernible exposure to radionuclides among infants. The most conservative estimates were below the Japanese internal exposure limit of 1 mSv/year.

Yield and quality of carrots when using the Gumiton organo-mineral complex in conditions of radioactive contamination

The aim of this work is to assess the impact of Gumiton peat-based organo-mineral complex on the productivity and quality of carrots and the transition of 137Cs from soil to root crops under conditions of radioactive contamination. According to the results of field experiments on gray forest and soddy-podzolic soils of the Kaluga region of Russia, it is shown that leaf treatment with Gumiton of carrot plantings in different phases of crop development increases the yield of root crops by 20-40%, depending on the variety, soil type and agricultural background. Analysis of studies in the growing experiment on soddy-podzolic soil showed that Gumiton treatment increases the yield of carrots by 30%. The rate of decrease of 137Cs content is 1,2-1,25 times. Gumiton is a highly effective preparation for carrots, which increases the productivity and quality of the crop and helps to reduce the intake of 137Cs in root crops in radioactively contaminated areas.

Yield and quality of carrots when using the Gumiton organo-mineral complex in conditions of radioactive contamination

The aim of this work is to assess the impact of Gumiton peat-based organo-mineral complex on the productivity and quality of carrots and the transition of 137Cs from soil to root crops under conditions of radioactive contamination. According to the results of field experiments on gray forest and soddy-podzolic soils of the Kaluga region of Russia, it is shown that leaf treatment with Gumiton of carrot plantings in different phases of crop development increases the yield of root crops by 20-40%, depending on the variety, soil type and agricultural background. Analysis of studies in the growing experiment on soddy-podzolic soil showed that Gumiton treatment increases the yield of carrots by 30%. The rate of decrease of 137Cs content is 1,2-1,25 times. Gumiton is a highly effective preparation for carrots, which increases the productivity and quality of the crop and helps to reduce the intake of 137Cs in root crops in radioactively contaminated areas.

ROLE OF GENETIC PREDISPOSITION, GENE POLYMORPHISM OF GLUTATHIONE-S-TRANSFERASE (GSTT1, GSTM1, GSTP1) AND SOME ADVERSE FACTORS IN DEVELOPMENT OF BRONCHIAL ASTHMA IN CHILDREN - RESIDENTS OF RADIOACTIVELY CONTAMINATED AREAS.

to determine the influence of hereditary predisposition, polymorphism of GSTT1, GSTM1, GSTP1 genes andenvironmental factors on the development of bronchial asthma in children - residents of radioactively contaminat-ed areas. School-age children-residents of radioactively contaminated areas with bronchial asthma,and those without clinical signs of respiratory pathology were examined. Genetic, medical, biological and social riskfactors were determined based on the study of anamnestic data and medical records. Ventilation lung capacity wasassessed by the method of computer spirometry. Molecular genetic studies were carried out using polymerase chainreaction (PCR) and restriction fragment length polymorphism (RFLP) for further analysis. Molecular genetic studies of the distribution of genotypes and frequencies of polymorphic variants of thegenes GSTT1, GSTM1, GSTP1 were performed in children living under long-term intake of 137Cs by food chains. It wasfound that in children with BA the tendency to frequency of the deletion variant of the GSTT1 and GSTM1 genes incomparison with children without bronchial and pulmonary pathology was increased. The study of distributing theGSTP1 A313G gene polymorphic variants revealed in children with BA a significant increase in the frequency of AG-genotype, compared with the data of reference group. Adverse factors that increase the risk of developing bron-choobstructive disorders and the probability of their implementation in the form of bronchial asthma in children -residents of RCA have been identified. It is established that among them the leading role is played by hereditarypredisposition to this disease. On the part of the child, such negative factors were unfavorable conditions of fetaldevelopment, the presence of signs of exudative-catarrhal diathesis, manifestations of allergies and frequent respi-ratory diseases from the first months of life. It was found that the risk of developing BA was significantly increasedin children with the GSTT1 and GSTM1 gene deletion genotypes; an increased risk of developing BA in children witha combination of the GSTP1 A313G gene polymorphism with deletion polymorphism of the GSTT1 or GSTM1 gene wasdetermined. Сonclusion. Оne of the leading mechanisms, due to which there is a realization of hereditary predisposition tobronchial asthma in children living under constant intake of radionuclides with a long half-life, is the polymorphismof certain glutathione-S-transferase genes, namely, GSTT1, GSTM1 and A313G gene deletion polymorphism and GSTP1gene polymorphism.

Радиоэкологическая оценка кормовых сельскохозяйственных угодий юго-западных районов Брянской области на основе комплекса статистических моделей

This paper presents a radioecological assessment of forage agricultural land in the southwestern districts of the Bryansk region based on data characterizing the variability of the radionuclides content in the soil. Concentration of 137Cs in forage was calculated taking into account the proba-bility distributions of 137Cs soil contamination density and the soil to plant transfer factor. The pro-cessing data of the radioecological survey has shown the soil contamination density with 137Cs of agricultural lands in the southwestern areas of the Bryansk region obeys a lognormal law. The authors have used statistical models and software modules for the radioecological assessment of forage lands. Risks of exceeding the 137Cs content standards in forage obtained on soils with different texture have been calculated. The limiting levels of contamination of pastures and hay-fields with 137Cs, ensuring compliance with the specified risks for forage, have been estimated. The lowest limiting soil contamination density is characteristic of organic soils, which can be con-sidered “critical” from the point of view of 137Cs intake into forage. The authors have predicted the time of remediation of forage lands in the southwestern districts of the Bryansk region in the ab-sence of protective measures based on a probabilistic approach. The time period during which the risk of forage contamination for sandy, sandy loam and clay loam soils will decrease to 10% varies for the areas under consideration in a wide range, not exceeding 64 years. It is concluded that it is advisable to substantiate the value of the acceptable risk of forage contamination, taking into account radiological and socio-economic aspects.

Some aspects of obtaining the radiologically safe vegetable products in the conditions of Ukrainian Polissia

Considering the urgent need for rehabilitation ofthe Chоrnobyl-affected agricultural lands of Ukrainian Polissia and maximization of the restoration of agricultural production in this area, the issue of reorganization of vegetable growing as one of the most radioecologically problematic in the region deserves to be specially highlighted. The study aimed to determine the influence of species and varietal characteristics, as well as soil, fertilizers, and irrigation on the accumulation of 137Cs by vegetable crops in the remote period after the Chornobyl accident. The research was conducted during 2008–2012 in the II, III, and former IV radioactive contamination zones on the territory of Chernihiv, Kyiv, and Zhytomyr regions. The soil cover of the studied area is represented by sod-podzolic sandy and peat-swamp soils. The most common for the region and recognized species and varieties of vegetables were studied, the list of which was determined by a questionnaire: cucumber; zucchini; pumpkin; scallop; red beet; garden carrot; red cabbage; Savoy cabbage; white cabbage, potatoes of different maturity groups, parsley. Soil and plant samples were taken during the industrial ripeness and the flowering (for potatoes) phases of vegetables. To study the effect of elevated doses ofmineral fertilizers and moldon the value of the 137Cstransfer factor from soil to potato tubers, a complex of mineral fertilizers was used: ammonium nitrate (34% N), tagged superphosphate (19% P2O5), potassium sulfate (50% K2SO4) and hummus made from hog manure. Acceptable levels of soil contamination with 137Cs were calculated by the formula based on the transfer factors and the effectiveness of agricultural measures conducted. The peculiarities of 137Cs accumulation in vegetable products depending on the species, variety, soil, fertilizer, and irrigation have been analyzed and the corresponding acceptable levels of soil radioactive contamination have been determined. The most severe restrictions to vegetable production in radioactively contaminated areas have been set forleaf vegetables, as well as for growing on peat-swamp soils. It has been confirmed that the greatest reduction in the 137Cs intake by vegetables is achieved by irrigation with fossil groundwater. The research findings make it possible to calculate the maximum acceptable levels of 137Cs soil contamination for growing different recognized varieties of vegetables under different fertilizer combinations and irrigation for a certain soil type. Guidelines for vegetable production on radioactively contaminated soils have been proposed, taking into account the varietal characteristics of the crop, fertilizer, and irrigation.

The transfer of 241Am and 137Cs to the tissues of broilers' organs.

Data on the transfer of artificial radionuclides from the environment to the food supply is necessary for internal dose assessment. There is a necessity for expanding and improving the available information on these factors in order to make better dose models for specific scenarios. This paper describes the results of a field experiment with broiler chickens on the transfer factor (Ff) and concentration ratio (CR) for the long-term intake of 241Am and 137Cs with grass meal and soil. The broilers were divided into two groups, each group had nine subgroups and each subgroup had three broilers. The radionuclide concentrations in the feed and the thigh muscle, thigh bone, and liver of 54 broilers divided between the grass meal and soil groups were evaluated by gamma spectrometry for 241Am and 137Cs. The duration of feeding with “contaminated” sources ranged between 1–70 days. The equilibrium stage of 241Am in muscle and bone occurs on the 1st and 40th day, respectively; for 137Cs in muscle– 30th days of intake and for liver and bone– 7th days. For 241Am, the liver did not reach equilibrium stage during the 70 days of intake. Ff of 137Cs in the “forage-muscle” and “soil-muscle” systems were determined as 1.9±0.3 and 0.18±0.05; Ff of 241Am in the “soil-muscle” system was—7.5×10−5.

137Cs, 40K, and K in raw and stir-fried mushrooms from the Boletaceae family from the Midu region in Yunnan, Southwest China

The parallel batches of the same species and geographical origin mushrooms both raw and stir-fried were investigated to get an insight into the content and intake of 137Cs, 40K, and K from mushroom meals. The Boletaceae family species (Baorangia bicolor, Boletus bainiugan, Butyriboletus roseoflavus, Retiboletus griseus, Rugiboletus extremiorientalis, and Sutorius magnificus) were collected from the Midu County (Dali Bai Autonomous Prefecture) in 2018. The activity concentrations of 137Cs in the caps of dried raw mushrooms were in the range 14 ± 1 Bq kg−1 dry biomass (db) (R. griseus) to 34 ± 2 Bq kg−1 db (R. extremiorientalis), and in stems from 16 ± 1 Bq kg−1 db (B. bicolor and B. bainiugan) to 23 ± 1 Bq kg-1 db (R. extremiorientalis). The mean activity concentration in the whole fruiting bodies in all six species was 18 ± 4 Bq kg-1 db. The activity concentrations of 137Cs were roughly the same in both dehydrated materials, stir-fried, and raw mushrooms, while the contents of 40K and stable K were around 2- to 3-fold smaller in stir-fried than raw product. The raw and stir-fried mushrooms on a whole (wet) weight basis showed activity concentrations of 137Cs in the range from 1.2 to 3.2 Bq kg−1 ww (mean 1.9 ± 0.6 Bq kg−1 ww) and 6.0 to 9.4 Bq kg−1 ww (mean 7.0 ± 1.2 Bq kg−1 ww), respectively. Evidently, when expressed on a whole (wet) weight basis, the cooked mushrooms showed on average around 3.5-fold greater activity concentration of 137Cs when compared with raw mushrooms. The 137Cs, 40K, and total K enrichment in stir-frying (in a whole (wet) weight basis for the meal), confronted with the results for dehydrated raw and fried mushrooms, show the direct correlation with loss of mass (largely moisture) during the cooking procedure but not much of 137Cs and 40K. Edible wild mushrooms from Yunnan were little contaminated with radiocaesium. As assessed, the mean radioactivity dose from natural 40K in around 9.3-fold exceeded the dose obtained for artificial 137Cs from stir-fried mushroom meals, which both were very low doses.

Динаміка радіоактивного забруднення зелених мохів в умовах свіжого бору у лісах Житомирського Полісся

Досліджено зміну вмісту радіонуклідів у фітомасі зелених (брієвих) мохів в умовах свіжого бору Українського Полісся впродовж 2016–2018 рр. Середня щільність радіоактивного забруднення ґрунту на пробній площі становила 199±52 кБк/м2. З'ясовано, що величини питомої активності та інтенсивності надходження радіонуклідів до фітомаси аналізованих видів мали значні коливання. Вміст радіонукліду у фітомасі дикрану багатоніжкового за період спостережень зменшився в 1,3 раза, а для плевроцію Шребера подібне зменшення становило 1,2 раза. Виявлено, що дикран багатоніжковий характеризується більшими величинами концентрації 137Cs порівняно з плевроцієм Шребера, в середньому – в 1,5 раза за досліджуваний період. Відзначено загальну закономірність щодо розподілу вмісту 137Cs за фракціями зелених мохів. За величиною радіоактивного забруднення фракції моху можна розмістити у вигляді такого ряду: очос > жива фракція > мертва фракція. Упродовж трьох років спостережень середній вміст 137Cs в очосі верхоплідного та бокоплідного мохів зменшився в 1,4 та 1,2 раза відповідно, а для живої та мертвої фракцій таке зменшення становило 1,3 раза. Інтенсивність надходження радіонуклідів до фітомаси плевроцію Шребера в 1,4 раза менша порівняно з дикраном багатоніжковим. Виявлено тенденцію до зниження значень коефіцієнта переходу 137Cs, як до фітомаси загалом, так і до окремих фракцій обох досліджуваних видів моху.

Investigation of accumulation of radionuclides in different tissues of Whiting fish (Merlangius merlangus euxinus Nordmann, 1840) caught on the coasts of Rize in the eastern Black Sea region of Turkey

In this study, the levels of radioactivity in the muscle, liver, gonad, and gill tissues of the Whiting fish caught from Rize coast of the Black Sea during the winter season in 2017 were determined using gamma spectrometry. Data obtained from the fish showed that the mean activity concentrations in all tissues for males were found to be 4.57 Bq kg−1 for 226Ra, 2.79 Bq kg−1 for 232Th, 308.56 Bq kg−1 for 40K, and 3.38 Bq kg−1 for 137Cs, respectively. The mean activity concentrations in all tissues for females were found to be 2.56 Bq kg−1 for 226Ra, 2.28 Bq kg−1 for 232Th, 277.90 Bq kg−1 for 40K, and 2.87 Bq kg−1 for 137Cs, respectively. Differences in 226Ra, 232Th, 40K, and 137Cs concentrations for all tissues were not statistically significant between males and females (p > 0.05). Furthermore, radiological indices such as a daily intake dose of per capita radioactivity, annual committed effective dose, and lifetime cancer risk values due to the intake of 226Ra, 232Th, 40K, and 137Cs resulting from the consumption of Whiting muscle were calculated and compared with international data. Based on the recommended annual effective dose values, the annual effective dose values for 226Ra, 232Th, and 40K radionuclides are within the limit value given by UNSCEAR. The lifetime cancer risk values calculated from the consumption of muscle tissue of both the female and male Whiting samples were found to be below the acceptable limit value less than 10−3.