Chernobyl Accident Research Articles

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.

Minor Fractions of Phospholipids in Mechanism of the Wild Rodent Adaptation to Increased Radiatiom Phone

The participant of the minor fractions of the liver phospholipids in the mechanism of adaptation for four species of wild rodents caught in the different years in the Chernobyl accident zone at the areas with level of the dose rate of the external γ-irradiation from 0.02 to 200 mR/h in 1987 is studied in dependence on the radioresistance of species. At first year after accident the growth of the lysoforms of phospholipids share and sphingomyelin involved in the apoptosis process and the increase of cardiolipin taking part in the interaction of DNA with membrane is revealed, During 5 years after the accident there is the increase of the sum share of phosphatidylinositol and phosphatidylserine taking part in the calcium ion transport and in regulation of the inner cell processes. Data obtained and analysis of literature allow us to conclude that the change of proportion of the minor fractions of phospholipids in liver of the wild rodents living at areas with the increased radiation level causing the adaptive reorganizations in the cell metabolism are the base for formation of the new subpopulations in these territories having the lipid peroxidation regulatory system different from norm.

ЛЕОНИД АНДРЕЕВИЧ ИЛЬИН (К 95-ЛЕТИЮ СО ДНЯ РОЖДЕНИЯ)

Full member of the Russian Academy of Sciences, Doctor of Medical Sciences, Professor Leonid Andreevich Ilyin is a recognized world authority in the field of radiation medicine, biomedical and hygienic aspects of radiation protection. From 1968 to 2008 for 40 years – director and scientific director of the State Scientific Center of the Order of Lenin of the Institute of Biophysics. Since 2008 – Honorary President of the Federal State Budgetary Institution «State Research Center of the Russian Federation – A.I. Burnazyan Federal Medical Biophysical Center» (after the merger of the Institute of Biophysics and Clinical Hospital No. 6). Thanks to the work of Academician Ilyin, his students and colleagues, highly effective drugs for the prevention and treatment of acute radiation injuries were created, tested and entered into domestic practice. Repeatedly took part as a supervisor in testing the developed drugs in field conditions. He is a veteran of special risk units. L.A. Ilyin is the first scientist in the world who developed and substantiated the forecast of the radiological consequences of the Chernobyl disaster, subsequently confirmed by leading foreign and domestic experts.

JRODOS customization for Pakistan and assessment of the consequences of a hypothetical nuclear accident

Since the Chernobyl disaster in 1986, decision support systems and modelling tools have been utilized in response to nuclear and radiological emergencies. The java-based real-time online decision support system (JRODOS) is a decision support tool that can be utilised in response to an emergency in managing off-site radiological consequences. This article documents the customization and use of JRODOS for Pakistan. JRODOS was tailored to the local Pakistan conditions, and a case study of a theoretical nuclear power plant accident was used to assess JRODOS’s feasibility as a decision support tool. A worst-case probabilistic accident scenario was used to identify zones and areas where urgent protective actions, early protective actions and food restriction and other response actions could be required. The areas and distances identified for the implementation of protective and response actions for such a hypothetical accident were found to be in agreement with the emergency planning zones and distances suggested by the International Atomic Energy Agency (IAEA). Additionally, the implications of meteorological and source term input parameters on predicting the radiation doses to members of the public were investigated. It was identified that the output of such tools strongly depends on the availability and accuracy of the input parameters, such as radioactive release and meteorological data. Limitations and uncertainties associated with these tools need to be considered in deciding on protective and other response actions in response to a nuclear accident. As established by the IAEA, protective and other response actions need to be applied on a graded approach, taking into account the protection strategy and uncertainties and limitations in the available information and criteria, based on the conditions at the facility and off-site.

Uptake of Radionuclides by Bryophytes in the Chornobyl Exclusion Zone

The "Chernobyl nuclear disaster" released huge amounts of radionuclides, which are still detectable in plants and sediments today. Bryophytes (mosses) are primitive land plants lacking roots and protective cuticles and therefore readily accumulate multiple contaminants, including metals and radionuclides. This study quantifies 137Cs and 241Am in moss samples from the cooling pond of the power plant, the surrounding woodland and the city of Prypiat. Activity concentrations of up to 297 Bq/g (137Cs) and 0.43 Bq/g (241Am) were found. 137Cs contents were significantly higher at the cooling pond, where 241Am was not detectable. Distance to the damaged reactor, amount of original fallout, presence of vascular tissue in the stem or taxonomy were of little importance. Mosses seem to absorb radionuclides rather indiscriminately, if available. More than 30 years after the disaster, 137Cs was washed out from the very top layer of the soil, where it is no more accessible for rootless mosses but possibly for higher plants. On the other hand, 137Cs still remains solved and accessible in the cooling pond. However, 241Am remained adsorbed to the topsoil, thus accessible to terrestrial mosses, but precipitated in the sapropel of the cooling pond.

Primary incidence of cervical cancer in the population living in ecologically disadvantaged areas (2000–2020)

Introduction. Thirty six years after the Chernobyl disaster about 5 million people live in the radioactively contaminated territories of Ukraine, Belarus and Russia, and the density of radioactive contamination, determined mainly by long-lived Cesium-137 and Strontium-90, will remain radiologically significant for several decades. Purpose of the study. Based on official statistics for 2000-2020, to analyze the trend in the incidence of cervical cancer in females living in conditions of radioactive, chemical, and combined environmental contamination in the Bryansk region. Materials and methods. Poisson regression, Shapiro-Wilk test, Mann-Whitney U-test, Spearman test. Data sources - Bryansk Regional Oncological Dispensary, Rospotrebnadzor, Rostekhnadzor, Bryanskstat. Results. There were no statistically significant differences in the incidence of the cervical cancer, regardless of the level of radioactive, chemical, and combined environmental contamination. Also, we have found no significant correlations between the frequency of primary morbidity of the cervical cancer with neither the density of 137Cs and 90Sr contamination, nor air pollution with gaseous pollutants (VOCs, SO2, CO and NOx). A statistically significant (p<0.00001) gain in the long-term trend in the incidence of the cervical cancer over 2000-2019 was revealed in all the studied groups, regardless of the environmental conditions of the residence. The forecast for the incidence of the cervical cancer on average in the Bryansk region during 2020 shows a decrease by 20.7% in real values compared to the forecast data. Limitations. Incidence of the cervical cancer without regard to age groups, distribution at the stage of the disease, histological, and immunohistochemical profile. Conclusion. The obtained results indicate to the need for further work to understand the trends in the presence/absence of independent and combined effects of pollutants on the growth of oncogynecological pathology from the standpoint of assessing distant and regional metastasis, the histological, and immunohistichemical profile of a specific cervical cancer with levels of radioactive, chemical, and combined environmental contamination.

Socio-economic prerequisites for sustainable development of radioactively contaminated territories in Ukrainian Polissia

The article provides a comprehensive analysis of retrospective prerequisites for the restoration of radioactively contaminated lands in Ukrainian Polissia on the basis of sustainable development principles. The research methodology is based on a systemic approach, which involves the use of modern and classical scientific methods: general scientific methods (analysis and synthesis of data); retrospective and comparative analysis (identification of cause-and-effect relationships); analytical-synthetic (study of scientific and statistical data, archival materials, legislative and founding documents, etc.); mathematical (mathematical processing of obtained results). The research is based on official statistical data from the main statistical offices in Volyn, Zhytomyr, Kyiv, Rivne, and Chernihiv regions. The aim of the study was to outline the socio-economic prerequisites for sustainable development of radioactive contaminated territories in Ukrainian Polissia. The study analyzed the state of economic development in Ukrainian Polissia, including the agricultural and forestry sectors, as well as the social component as a factor and indicator of sustainable regional development. Additionally, the study analyzed the housing conditions and income level of the population in the radioactive contaminated territories of Ukrainian Polissia. It has been established that the ecological factor has a significant impact on the socio-economic situation in Ukrainian Polissia, particularly when analyzing the impact of the radiological factor. The study shows that despite the leading positions of the agricultural and forestry sectors in the region, they have not been able to fully recover after the Chornobyl disaster and the post-Soviet economic crisis, which has led to negative social consequences. To address existing problems, the state employment policy should be focused primarily on preventing crisis situations and stimulating the return of migrants. Additionally, reform of economic specialization should be envisaged, taking into account regional specificities and introducing innovative technologies and solutions that would enable the attraction of investments.

Results and prospects of optimization of agrochemical indicies of arable soils fertility in Belarus

A critical overview of dynamics of agrochemical indices of arable soils fertility over 50-year period is presented. The low-yield sod-podzol and swampy soils of Belarus were relatively poor in available plant nutrients. As a result of the largescale water engineering, liming and the intensive use of fertilizers over the period of 1965–2020 the productivity of arable land increased from 1.5 to 4.6 tons per hectare in grain equivalent. The significant improvement of soil fertility status was also achieved. Data of soil fertility status are based on the large-scale soil test monitoring conducted by State Agrochemical Service every 4–5 years. The share of strongly and moderately acid soils with pH < 5.0, that are harmful for the main crops, decreased from 66.8 % in 1970 to 4.5% of total area of arable land in 2004. However, the share of acid arable soils increased up to 9.8% in 2020, due to insufficient volume of liming that will be increased in the forthcoming years. The average organic matter (O.M.) content had been strongly increased from 1.77 to 2.28 % during the period of 1970–2000, due to high share of perennial grasses in cropping structure and manure application up to 14–15 t/ha per year. About 1 million ha of drained soils with the high O.M. content was also involved to arable land. The average O.M. content in the last two decades had been in mobile equilibrium of 2.23–2.27 % with a tendency to decline in some districts. The average contents of mobile Phosphorous and Potassium in arable soils increased up to 2.4–3.2 times during the experimental period and they are in the optimal range for cultivated crops. Currently balanced fertilization is the most important, with differentiation of fertilizer rates that would be most suitable to crop requirements and soil tests on each field. Formation and maintenance of optimal soil fertility indices, especially pH and mobile Р2О5 and К2О contents, are strictly controlled as protective measures on the land contaminated with radionuclides 137Cs and 90Sr after Chernobyl accident. Measures to improve the efficiency of capital investment at fertility reproduction and use of arable soils are discussed currently.

Influence of Precipitation on the Spatial Distribution of 210Pb, 7Be, 40K and 137Cs in Moss

Mosses have been widely used as biomonitors of a variety of atmospheric pollutants, including radionuclides. Here we determine the radionuclide activity concentration of 210Pb, 137Cs, 7Be, and 40K in moss tissue (Hylocomium splendens) collected from 24 sites across Ireland and assess the influence of precipitation on radionuclide spatial distribution. Lead-210 was the most abundant radionuclide (range: 226–968 Bq kg–1), followed by 7Be (range: <DL—604 Bq kg–1), 40K (range: <DL—155 Bq kg–1), and 137Cs (range: <DL—41 Bq kg–1). Albeit nearly thirty years since the Chernobyl disaster, 137Cs activity concentration was detected at 67% of the study sites; however, the spatial distribution was not fully consistent with the 1986 Chernobyl deposition pattern. Rather, 137Cs was weakly correlated with rainfall, with higher concentrations along the west coast, suggesting that the 2011 Fukushima Dai-ichi nuclear accident was also a potential source. Average annual rainfall was a significant predictor of 210Pb activity (linear regression, R2 = 0.63, p < 0.001). As such, the highest radionuclide activity was observed for 210Pb (average: 541 Bq kg–1), owing to the high levels of precipitation across the study sites (average: 1585 mm). In contrast, 7Be or 40K were not correlated with precipitation; rather, 40K and 7Be were significantly correlated to each other (rs = 0.7), suggesting that both radionuclides were transferred from the substrate or through soil re-suspension. Precipitation is widely reported as an important factor in the spatial distribution of radionuclides; however, only 210Pb activity concentrations in moss were strongly influenced by precipitation in the current study.

Chernobyl disaster optimizer (CDO): a novel meta-heuristic method for global optimization

Chernobyl disaster optimizer (CDO): a novel meta-heuristic method for global optimization

Long-run exposure to low-dose radiation reduces cognitive performance

This paper examines the effect of long-run exposure to low-dose radiation on cognitive performance. We focus on the fallout from the Chernobyl accident, which increased the level of ground radiation in large parts of Europe. To identify a causal effect, we exploit unexpected rainfall patterns in a critical time window after the disaster as well as the trajectory of the radioactive plume, which determine local fallout but have no plausible direct effect on test scores. Based on geo-coded survey data from Germany, we show that people exposed to higher radiation perform significantly worse in standardized cognitive tests 25 years later. An increase in initial exposure by one standard deviation reduces cognitive test scores by around 5% of a standard deviation.

TRACES OF 14C EMISSIONS FOR THE OPERATION PERIOD OF TWO UKRAINIAN NPPS: RIVNE AND CHORNOBYL

ABSTRACTThe aim of this study was a comparative retrospective assessment of radiocarbon (14C) as a tracer, caused by operational emissions of Rivne and Chornobyl nuclear power plants (NPPs), which are equipped with different types of nuclear reactors. For this purpose, 14C was studied in annual tree rings of pine taken at a distance of 1.5 km southwest of the Rivne NPP and at a distance of 3.5 km west-northwest of the Chornobyl NPP, near the Yaniv railway station. As a background, we use the 14C in air data (Hua et al. 2013), which we continue for time interval 2009–2020 with our experimental data for pine tree rings. Tree rings were also collected in a rural area 60 km west of Kyiv, where industrial impact, in our opinion, is absent. 14C in wood samples was determined using the conventional method based on liquid scintillation counting. It was found that the 14C excess in the annual tree-ring samples of pine near the Chornobyl NPP during the observed operation period (1984–2000) was 3.0–13.0 pMC, except for the 1986, the year of the Chornobyl accident, when the 14C value rose sharply to 182.7 pMC (14C excess 62 pMC). After 2000, the content of 14C in the air near the Chornobyl nuclear power plant did not exceed the background values within the uncertainty of the measured data. The concentration of 14C in the samples of annual tree rings of pine near the Rivne NPP for the observation period (1986–2019) corresponded to the background levels within the uncertainty of the measured data. The study of environmental traces of 14C emissions from two NPPs equipped with different types of reactors showed significantly lower emissions of Rivne NPP with VVER compared with emissions from Chornobyl NPP with RBMK reactors.

Potassium applications reduced cesium uptake and altered strontium translocation in soybean plants

ABSTRACT After the Tokyo Electric Power Company’s Fukushima Dai-ichi Nuclear Power Plant accident in 2011, radioactive cesium (RCs) was released in greater concentrations than radioactive strontium (RSr) in the surrounding environment. Most of the countermeasures were developed to mitigate the RCs transfer from the soil to plants. However, to avoid what has happened after the Chernobyl and Mayak accidents, preventing the transfer of RSr from soil to plants should be a priority. Although the application of potassium (K) fertilizers is the most effective method for preventing agricultural crops from absorbing RCs in contaminated fields, this implementation increases the cost and labor requirements. Considering the preparedness for nuclear accidents, it remains unclear how this countermeasure will be affected if RCs and RSr are released simultaneously. We aimed to explore the effect of K applications on cesium (Cs) and strontium (Sr) uptake and their interaction with and correlation to other elements in the soybean plants and soil. The field experiments were conducted in Fukushima Prefecture, Japan, using different K applications (i.e., no, normal, and high K applications). The dry weight and mineral concentrations of K, Cs, Sr, calcium (Ca), magnesium (Mg), and nitrogen (N) concentration in plants and exchangeable K (ExK), exchangeable Cs (ExCs), exchangeable Sr (ExSr), exchangeable Ca (ExCa), exchangeable Mg (ExMg), NH4+ (ammonium), and NO3- (nitrate) concentrations in the soils were evaluated. This study revealed that K application reduced Cs, Ca, and Mg uptake but did not affect the ExSr, ExCa, and ExMg concentrations in the soil and did not change the uptake of Sr. On the other hand, K concentration of the plant especially at later growth stage, which indicates re-translocation of Sr was negatively regulated by K concentration.

Data Corroboration of The Catastrophic Chernobyl Tragedy Using Arc-Length Estimate Conjecture

Nuclear power is perhaps one of the biggest keys to empowerment for any country. In fact, nuclear power has been the backbone of the international superpowers like the US and USSR since the 20th Century. Alongside its merits, nuclear power carried some demerits propping on it. One of the biggest amongst all was the Chernobyl nuclear cataclysm that occurred on the 26’th April 1986. Within hours of the explosion, nuclear radiation blanketed the whole city of Pripyat, Ukraine. In this paper, we have developed a notion namely “Arc-Length Estimate Conjecture” to detect anomaly, and fairness in data sets. If an anomaly is found, the Arc Length Estimate Conjecture is capable of dissecting the anomality in magnitudical terms. Further we have analyzed the Radiation that emerged from the Chernobyl Catastrophe by looking at the concentration of radioactive elements that were measured from different parts of the world. We have considered the elements I131 and Cs134 as elements of utmost importance and have tried to verify the data put forward by USSR regarding the radiation emission level of these radio actives. social-circles, and non-religious students. The results of this study and related studies to follow will be used to inform improvements to mental health counseling and outreach to at- risk individuals at universities across the United States.

Dynamics of 137Cs concentrations in agricultural products after the Chernobyl accident: cereals, potato, and vegetables

The purpose of the study was to analyze the regularities of 137 Cs 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 137 Cs concentration in crop production ( grain , potato , and vegetables ) was determined by the dynamics of agrochemical countermeasures in the contaminated areas , sorption of 137 Cs in soil and radioactive decay . It has been revealed that effective halflives of 137 Cs 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 137 Cs 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 137 Cs 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 .

Sediment and Particulate 137Cs Budget Studies in Upa River Basin: History, Results, and Prospects

The intensive pollution of vast areas after the Chernobyl accident, especially in the territories of Ukraine, Russia, and Belarus, has not only become a serious environmental issue, but also presents wide methodological opportunities for studying the functioning of natural systems. The proposed work is a generalization of the results of studies on the migration of 137Cs in the runoff of river sediments, which were carried out in the basin of the Upa River for over 30 years after the accident. This basin is one of the most radioactively contaminated and studied in Central Russia. Over the past three decades, under the conditions of the decreasing snowmelt runoff in the spring and reduced share of cultivated land over the post-Soviet period, the intensity of the 137Cs transfer has decreased. The 137Cs deposit losses associated with erosion activities do not exceed a few percent. Most of the mobilized sediments and sediment-associated radionuclides accumulate in dry valleys or artificial reservoirs. With a general reduction in the durations of floods, rivers have become the predominant channels for the transfer of sediment yield and particulate pollutants. The exploration of the vertical distribution of the 137Cs in the accumulative strata makes it possible to identify the changes in the sediment budgets of the rivers and their radioecological consequences.

A STUDY REGARDING CORRELATION BETWEEN CONTENTS IN SOIL AND CONTENTS IN PARSLEY ROOTS OF CADMIUM, LEAD, ZINC AND COPPER IN SAMPLES COLLECTED FROM PRIVATE GARDENS IN COPSA MICA

Food security is a high-priority issue for sustainable global development both quantitatively and qualitatively. The increasing contamination of heavy metals in vegetables is attributed to multiple pathways, such as industrial emissions, sewage sludge discharge, agrochemicals and fertilizers abuse, and it has become a serious issue worldwide, especially in developing countries. CopşaMicăhad the reputation of being the most polluted city in Europe until the Chernobyl nuclear accident. This was due to emissions from two factories Carbosin, which produced carbon black and Sometra, the other source of pollution, less visible, but much more serious from the point of view of the impact on the human health.For this study, were collected soil and parsley (Petroselinum crispum) samples from 36 households located in CopşaMică area. The obtained data were used to estimate the accumulation of cadmium, lead, zinc and copper in parsley roots. by correlation factor between contents in soil and contents in parsley roots. For cadmium and lead, the value of linear correlation coefficient is r = 0.571 for cadmium and r = 0.381 for lead and it is indicating a good correlation between the cadmium and lead content in parsley roots and the cadmium and lead content in soil. For zinc and copper, the value of the linear correlation coefficient is r = 0.139 for zinc and r = 0.035 for copper is not significantly different from zero, indicating that the estimation of zinc and copper accumulation in parsley roots cannot be described by simple power-type regressions.

Exposure to ionizing radiation and liver histopathology in the tree frogs of Chornobyl (Ukraine)

Ionizing radiation has the potential to damage organic molecules and decrease the health and survival of wildlife. The accident at the Chornobyl Nuclear Plant (Ukraine, 1986) led to the largest release of radioactive material to the environment. Among the different organs of a vertebrate, the liver plays a crucial role in detoxification processes, and has been used as a biomarker to investigate cellular damage in ecotoxicological research. Here, we examined the impact of the exposure to the current levels of ionizing radiation present in the Chornobyl Exclusion Zone on the liver of Eastern tree frogs (Hyla orientalis). We quantified the area of melanomacrophage cells and morphological variables of hepatocytes, two cell types often used to estimate damage caused by pollutants in vertebrates. First, we investigated whether these hepatic parameters were indicative of frog (individual) condition. Then, we analyzed the effect of individual absorbed dose rates and ambient radiation levels on frog livers. Most of the studied parameters were correlated with individual body condition (a good predictor of amphibian fitness and survival). We did not detect marked morphological lesions in the liver of frogs captured in medium-high radiation environments. The area occupied by melanomacrophages and the morphology of hepatocytes did not change across a gradient of radiocontamination covering two orders of magnitude. Once accounting for body condition and sampling locality, the area of melanomacrophages was lower in areas with high radiation levels. Finally, the area occupied by melanomacrophages was not linked to dorsal skin coloration. Our results indicate that current levels of radiation experienced by tree frogs in Chornobyl do not cause histopathological damage in their liver. These results agree with previous physiological work in the species in the Chornobyl area, and encourage further molecular and physiological research to fully disentangle the current impact of the Chornobyl accident on wildlife.

THYROID CANCER INCIDENCE IN THE POPULATION OF UKRAINE AND ITS EPIDEMIOLOGICAL DETERMINANTS: IONIZING RADIATION AND ENDOCRINE DISRUPTORS.

to estimate the risk of thyroid cancer incidence in the population of Ukraine in connection with its exposure to radioactive iodine fallout of Chornobyl origin and the use of pesticides in agricultural production in the country. Incidence rates of thyroid cancer in the population of Ukraine in 2001-2019, average regional radiation doses absorbed by the thyroid because of the Chornobyl accident, the volume of use of various groups of pesticides in the regions of Ukraine. statistical, mathematical and cartographic. The study covering the period of 2001-2019, revealed significant temporal and regional differences in the thyroid cancer incidence in the population of the Ukraine regions in 2001-2019. The existence of a significant correlation between the thyroid cancer incidence and the amount of radiation exposure to the thyroid associated with the Chornobyl accident was established. The existence of a significant correlation between the thyroid cancer incidence and the degree of pesticide use intensity in agriculture in the Ukraine regions was established. A significant value of multiple correlation r = 0.5866 (p < 0.05) was found between the thyroid cancer incidence in Ukraine andthe average regional radiation doses and the pesticide use intensity in agricultural production in the country. A reliable value of the multiple correlation between the value of the average regional radiation exposure doses to the thyroid associated with the Chornobyl accident and the degree of pesticide use intensity in the national economy of Ukraine and the thyroid cancer incidence in the population was determined.

Методологический подход к оценке риска производства продукции, не соответствующей нормативным требованиям по содержанию Cs-137 и Sr-90

Radioactive contamination of agricultural lands necessitates the need for developing robust methods, tools and techniques that could, on the one hand, minimize the levels of radionuclides in food products, and on the other hand, facilitate in making informed decisions on economic efficiency of farmland use for the production of different types of foods. Following the Chernobyl nuclear accident, significant farmland areas of the Republic of Belarus were affected by radionuclide contamination of technogenic origin. The main soil contaminants nowadays, after the decay of short-lived nuclides, are Cs-137 и Sr-90. Given that a food product from a contaminated farmland may contain both radionuclides, Cs-137 and Sr-90, the risk of its non-compliance with the established maximum permitted levels of contamination should be assessed not only with regard to each individual radionuclide but also for the both of them simultaneously. Using the risk matrix, significance level criteria and rank assignment, the author proposes a new methodological approach for assessing the risk of non-compliance of the produced agricultural foods to the regulatory requirements, accounting not for either but for both radionuclides (Cs-137 and Sr-90) simultaneously. The use of the risk assessment methodological approach for the agricultural produce non-compliances with the food safety standards regulating the contents of Cs-137 and Sr-90 enables one to make substantiated and scientifically justified decisions on the efficiency of landuse for the particular foodstuff production and/or identify the farmlands where radiation-associated food production restrictions could be lifted.