ON THE METHODOLOGY OF PASSPORT DOSES CALCULATION FOR UKRAINIAN SETTLEMENTS RADIOACTIVELY CONTAMINATED DUE TO THE CHORNOBYL NPP ACCIDENT. / ЩОДО МЕТОДИКИ РОЗРАХУНКУ ПАСПОРТНИХ ДОЗ НАСЕЛЕНИХ ПУНКТІВ УКРАЇНИ, ЯКІ ЗАЗНАЛИ РАДІОАКТИВНОГО ЗАБРУДНЕННЯ В РЕЗУЛЬТАТІ АВАРІЇ НА ЧАЕС.

OBJECTIVE: scientific substantiation of the new methodology for estimation of passport doses of the settlementswhich belong to Zone of Unconditional (obligatory) Resettlement, or 2nd zone and Zone of Granted VoluntaryResettlement, or 3rd zone in the framework of dosimetric passportization in accordance with the legislation ofUkraine. MATERIALS AND METHODS: 37 years after the accident, radioactive contamination of the environment has significantly decreased. However, it is still necessary to carry out ecological and dosimetric monitoring and apply countermeasures in certain territories of Ukraine affected by the accident at the Chornobyl Nuclear Power Plant: restriction of the consumption of locally produced milk, forest products, etc. The methodology, which was since 1996 used to estimate the passport doses of Ukrainian settlements, no longer corresponds to the current level of scientific knowledge about radioactive contamination of environment. The new methods of passport doses calculating presented in the work involves the use of a model whose parameters are determined by the types, quality and completeness of radio-ecological and dosimetric monitoring carried out on the radioactively contaminated territories in 1986-2013. The methodology takes into account the specific of radioactive contamination of each settlement. The passport dose of external exposure is reconstructed only from 137Cs radionuclide, because the contributions of other Chornobyl radionuclides influence the radiation dose only in the first years after the accident. The passport dose of internal exposure is formed as a result of the consumption of 137Cs contaminated food products. It is calculated depending on the availability in the settlement in the current year of the results of measurements of the 137Cs radionuclide activity incorporated in the human body using a whole body counter (WBC) and the activity of 137Cs in the private milk. At the same time, priority is given precisely to the results of WBC measurements of 137Cs. RESULTS AND CONCLUSIONS: A new methodology (Methodology-2023) for passport doses calculation of Ukrainian settlements was substantiated. A comparison of passport doses based on the results of radioecological and dosimetric monitoring in 2011 calculated by Methodology-2023 and passport doses calculated by Methodology-96 was made.Passport doses calculated by Methodology-2023 increased by 40 % on average compared to doses calculated by Methodology-96. At the same time, passport doses of internal radiation calculated by the new methodologyincreased by 1.5 times, and passport doses of external radiation increased by 1.7 times. The passport dose of 2011, calculated by Methodology-2023, exceeds the legally established limit of 1 mSv in 71 settlements, most of which are located in Korostenkyi raion of Zhytomyr Oblast.

COMPLEX RADIATION AND HYGIENIC MONITORING OF POPULATION ON RADIOLOGICALLY CONTAMINATED TERRITORIES OF ZHYTOMYR OBLAST IN 2021. / KOMPLEKSNYI RADIATsIINO-GIGIIeNIChNYI MONITORYNG MEShKANTsIV RADIOAKTYVNO ZABRUDNENYKh TERYTORII ZhYTOMYRS'KOÏ OBLASTI U 2021 ROTsI.

OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS AND CONCLUSIONS: 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.

COMPREHENSIVE RADIATION AND HYGIENIC MONITORING IN POPULATION OF THE RIVNE OBLAST RADIOLOGICALLY CONTAMINATED TERRITORIES. / KOMPLEKSNYI RADIATsIINO/GIGIIeNIChNYI MONITORYNG MEShKANTsIV RADIOAKTYVNO ZABRUDNENYKh TERYTORII RIVNENS'KOÏ OBLASTI U 2020 r.

OBJECTIVE: The key factors identification in radiation dose formation in population of radiologically contaminatedareas of Rivne oblast in the current period of accident through comprehensive radiation and hygienic monitoring inreference settlements in 2020 and estimation of their impact on dose formation were the study objectives. MATERIALS AND METHODS: Comprehensive radiation and hygienic monitoring of settlements in Rivne oblast(province) was provided in Stare Selo, Vezhytsia, Perekhodychi, and Drozdyn villages of Rokytne district, where thehighest radiation doses were registered after the ChNPP accident. Studies were conducted in September 2020.Measurements (n=696, 318 adults, and 378 children) were performed using the whole body counters (WBC) to deter-mine the internal radiation doses. The 48 samples of milk, 45 samples of potatoes and vegetables, and 35 samplesof wild products were collected in local farms and measured for the 137Cs and 90Sr content. Residents of the studiedsettlements (n=229, 140 adults, and 89 children) were interviewed about the levels of consumption of staple food-stuffs. External radiation doses were evaluated in all the studied settlements. Mathematical, dosimetric, and radio-chemical methods were applied. RESULTS AND CONCLUSIONS: Annual effective radiation doses of the Rivne oblast population in 2020 were formedmainly due to internal radiation ones that not exceeded 1.24 mSv · year-1 in adults and 0.65 mSv · year-1 in childrenagainst the RCT criterion of 1 mSv · year-1. Further 1.2-1.9-fold decrease in the annual internal radiation doses vs.the results of WBC-monitoring in autumn of 2017 was registered in the surveyed settlements. The latter confirmeda time pattern of radiation levels gradual reduction at the current stage of Chornobyl accident since 2011. Intakeof 137Cs with milk and wild mushrooms, which traditionally occupy a significant part of diet in the Rivne Polissya areaand have consistently high levels of radioactive cesium contamination, remains a key factor of internal radiationdose forming in residents of the surveyed settlements of Rivne oblast.

RECONSTRUCTION, VERIFICATION AND ANALYSIS OF RESULTS OF WBC MEASUREMENTS DATED 1986 THAT WERE INPUTTED TO ELECTRONIC DATABASE IN 2019-2021. / VIDNOVLENNIa, VERYFIKATsIIa TA ANALIZ REZUL'TATIV LVL/VYMIRIuVAN' 1986 R., ShchO VNESENI DO ELEKTRONNOÏ BAZY U 2019­2021 rr.

Objective of research is to improve the electronic database of WBC measurements dated 1986 by inputting of newinformation from paper carriers, reconstruction of information gaps, verification and analysis of new entered data,revision of internal exposure doses that are based on results of WBC measurements dated 1986. MATERIALS AND METHODS: In 2013-2015 during a revision of databases (DB) of WBC measurements results dated1986-2014, it was discovered a great amount of paper carriers with information about WBC measurements, includ-ing the ones dated 1986, that were not inputted to the electronic DB. The paper carriers were systematized andordered by the following indicators: place of residence of a person and place of WBC measurement, institution andoperator that made the measurement, measurement device and date of measurement. For a comfortable inputtingof the information to the electronic DB, it was additionally created a form which exists as an option in existing program complex Silbody (Version 19.0.9). In the revised DB of WBC measurements dated 1986 internal exposure dosesfrom radio-cesium of Chornobyl origin were computed based on an ecological and dosimetric model for radio-cesiummigration in environment and a model for radio-cesium metabolism in human body. In the work, mathematical andstatistical methods of research were used. RESULTS: In 2019-2021 additionally 35,319 notes were inputted to the electronic DB of WBC measurement dated1986, and as a result its volume increased in 2.2 times. Mostly those are data on results concerning residents of Kyiv,Zhytomyr, Donetsk, Cherkasy, Odessa, Ivano-Frankivsk, and Rivne Oblasts. It was established the information onmeasurement devices and respectively on the minimal detected activity (MDA) for 27,119 notes (76.7 % of all newentered). Information is reconstructed about the body mass of all persons under investigation. Evaluation is madefor values of intake of incorporated radionuclides 137Cs and 134Cs for all new entered to DB. Quality of reconstructedinformation was analyzed. To group 1, «qualitative¼, it was classified 18,598 notes (53 % of all new entered), measurements in 1986 (including new entered). Dose not exceeding 1 mSv was obtained by 80 % of adults (older than20), as well as 73 % of persons younger than 20. CONCLUSION: To DB of WBC measurements, it was additionally inputted 35,319 notes on results of measurementsdated 1986. New entered information is verified and distributed by the quality groups. Individual exposure dosesevaluated based on those data can be used for further scientific research.

RESULTS OF WBC-MONITORING OF FIREFIGHTERS PARTICIPATING IN RESPONSE TO CHORNOBYL FOREST FIRES IN APRIL-MAY 2020. / REZUL'TATY LVL-MONITORYNGU POZhEZhNYKh, ShchO BULY ZADIIaNI U GASINNI LISOVOÏ POZhEZhI V ZONI VIDChUZhENNIa ChAES U KVITNI­TRAVNI 2020 ROKU.

OBJECTIVE: of this study was to determine the levels of radionuclides in the rescuers' bodies of the SES during firefighting in the exclusion zone of the Chornobyl nuclear power plant and to assess the dose of internal radiation dueto this receipt. MATERIALS AND METHODS: From 06.04.2020 to 19.05.2020 in the State Institution «National Research Center forRadiation Medicine of the National Academy of Medical Sciences of Ukraine¼ (NRCRM) measurements of the contentof incorporated gamma radionuclides on whole body counters (WBC) operational class «Screener-3M¼ (Minimumdetected activity (MDA) is 300-500 Bq for 5 minutes of measurement at 137Cs) and expert high-sensitivity WBC (MDAis 20 Bq for 10 minutes of measurement at 137Cs). 470 people (523 measurements) in three groups of personnel ofthe SES of Ukraine who took part in the forest fire liquidation in the exclusion zone in the period from April 4 toMay 5, 2020 were examined. Mathematical and spectrometric methods are used in the work. RESULTS AND CONCLUSIONS: In the vast majority (95 %) of the personnel of the SES of Ukraine, examined at the WBCoperational class «Screener-3M¼ (more than 500 measurements), the assessment of the values of the individualeffective dose of internal radiation due to 137Cs in the body during firefighting, assuming that it receipt occurredduring operation in the exclusion zone, did not exceed the minimum dose detected by MDD (5-14 µSv). The average value of the effective dose of internal radiation in the group of personnel of the State Emergency Service ofUkraine in Kyiv, which participated in the elimination of forest fires in the exclusion zone from April 4 to May 5, 2020(26 people) studied at the expert WBC, is 2.5 ± 1.1 µSv, in the group of personnel of the SES of Ukraine in Cherkasyregion, which participated in the fire on April 19-24, 2020 (9 people) - 2.2 ± 0.6 µSv, in the group of personnel ofthe SES of Ukraine in the Kyiv region, which took part in the elimination of the forest fire in the exclusion zone onApril 4 - May 5, 2020 (42 people) - 4.4 ± 2.4 µSv. Maximum values of 5.1 µSv, 3.5 µSv, 11.8 µSv in the groups ofKyiv city, Cherkasy and Kyiv regions, respectively, which is much lower than the basic dose limit for the populationfrom man-made sources of 1000 µSv · year-1 according to the Law of Ukraine about protection of the person againstinfluence of ionizing radiation.

COMPREHENSIVE RADIOLOGICAL AND HYGIENIC MONITORING OF PARTICULAR SETTLEMENTS OF KYIV REGION IN 2019. / KOMPLEKSNYI RADIATsIINO/GIGIIeNIChNYI MONITORYNG OKREMYKh NASELENYKh PUNKTIV KYÏVS'KOÏ OBLASTI U 2019 ROTsI.

OBJECTIVE: to identificate the main factors and assess their impact on the formation of radiation doses to the population of radioactively contaminated areas of Kyiv region at the current stage of the accident based on complexradiation and hygienic monitoring in the reference settlements in 2019. MATERIALS AND METHODS: Comprehensive radiological and hygienic monitoring was carried out in eight settlementsof Kyiv region - villages of Ragivka, Lygovyky, Mar'yanivka, Zelena Poliana of Polis'kyi district and villages ofHornostaipil, Dytiatky , Pisky, Karpylivka of Ivankiv district. The content of incorporated 137Cs was determined withdirect measurement on whole body counters (WBC) samples of basic foodstuffs were collected to determine the content of radionuclides 90Sr and 137Cs, residents were interviewed about the levels of consumption of these products,and work was performed to estimate external radiation doses. Mathematical, dosimetric, radiochemical methods areused in the work. RESULTS: There was a further decrease in annual doses of internal radiation in the surveyed settlements in 1.3 times, bothin Polis'kyi district (0.041 mSv · year-1 in 2016, 0.030 mSv · year-1 in 2019) and in Ivankiv district (0.023 mSv · year-1in 2016, 0.018 mSv · year-1 in 2019). It is possible to state a slowdown in the reduction of radiation doses comparedto previous years: from 2010 to 2013, the annual doses of internal radiation in the surveyed settlements decreasedby 1.8-2.4 times, from 2013 to 2016 - by 2.3-3.6 times. The content of 137Cs and 90Sr in milk and potatoes in theinspected settlements is lower than the permissible level of the Hygienic Standard HS 6.6.1.1-130-2006 and the useof these foods can not significantly affect the formation of the internal radiation dose. The content of 90Sr in milksamples in the settlements of Ivankiv district is in the range of 2.1-9.9 Bq · kg-1 (in 2016: 1.3-7.4 Bq · kg-1), whichdoes not exceed the permissible level of 20 Bq · kg-1, but due to the dynamics needs further monitoring. The content of 137Cs in samples of dried mushrooms collected from residents of Kyiv region in 2019, as in previous years, issignificantly (up to 100 times) higher than permissible level, and has a high uncertainty - from 1.4 kBq · kg-1 to223.7 kBq · kg-1. CONCLUSIONS: It is established that the annual effective radiation doses of the population in the surveyed settlements in the current year are formed due to internal radiation doses that do not exceed 0.46 mSv · year-1 in Ivankivdistrict and 0.51 mSv · year-1 in Polis'kyi district, which below the RCT criterion 1 mSv · year-1. The main factor that forms the dose of internal radiation of the residents of the surveyed state of emergency of Kyiv region is the intake of 137Cs in the body with forest products, primarily mushrooms.

EVALUATION OF MAIN FOODSTUFFS CONSUMPTION BY RESIDENTS OF PARTICULAR SETTLEMENTS ON RADIOLOGICALLY CONTAMINATED TERRITORIES OF UKRAINE. / OTsINKA SPOZhYVANNIa OSNOVNYKh KhARChOVYKh PRODUKTIV MEShKANTsIaMY OKREMYKh NASELENYKh PUNKTIV RADIOAKTYVNO ZABRUDNENYKh TERYTORIY̆ UKRAÏNY.

OBJECTIVE: evaluation of main foodstuffs consumption levels of residents in particular settlements on radiological- ly contaminated territories of Kyiv, Rivne and Zhytomyr regions and determination of the proportion of local house- holds products to goods purchased in the trade network in the daily ration. MATERIALS AND METHODS: The research was conducted in 22 settlements of Kyiv, Rivne, Zhytomyr regions. For the study, the questionnaires were written for adults and children, which included 47 questions in 5 content blocks regarding the questionnaire data of the interviewed person; peculiarities of household management; levels of food consumption grown in local households and separately purchased in the trade network; levels of local wildlife products consumption; and the fifth - regarding the possession of information on radiation, received an individual dose of radiation from the «Chornobyl component¼, protective preventive measures. In total 539 people were inter- viewed, including 359 adults and 180 children aged 1 to 18 years. Information about children under 14 years of age was provided by their parents. Mathematical, statistical methods were used. RESULTS: According to the results of the survey, it can be stated that the main foodstuffs of residents of the sur- veyed settlements are milk and dairy products, potatoes and root crops of local cultivation, bread and bakery products purchased in the trade network. The analysis of the structure and dynamics of the diet of the popula- tion of the surveyed settlements showed a significant decrease in the consumption levels of basic food products, primarily purchased through the trade network, due to a decline in purchasing power of the population in recent years. CONCLUSIONS: The diet of the residents of the surveyed settlements consists mainly of products produced in private or local households. Fewer people use wildlife products - wildfowl, fish from local water bodies, fresh and canned wild berries, and fresh and dried mushrooms, but due to their significant 137Cs contamination, even small amounts of these products can result in a significant dose of radiation.

RESULTS OF WBC MEASUREMENTS WERE MADE AT RADIOACTIVELY CONTAMINATED TERRITORIES OF UKRAINE IN 1986-2014 (REVISION AND ANALYSIS). / REZUL'TATY LVL6VYMIRIuVAN', PROVEDENYKh NA RADIOAKTYVNO ZABRUDNENYKh TERYTORIIaKh UKRAÏNY U 1986-2014 rr. (REVIZIIa TA ANALIZ).

OBJECTIVE: revision, analysis, and significant improvement of quality of the database of WBC measurements made in1986-2014 at radioactively contaminated territories of Ukraine by the use of renewal of informational gaps andimprovement of the model for assessment of internal exposure doses. MATERIALS AND METHODS: Inthe periodfrom 1986 to 2014 experts of the Whole Body Counters Laboratory of NRCRMaccumulated about 1.5 million results of WBC measurementsof radio-cesium incorporated in the body of personsresiding at the territories which are radioactively contaminated due to Chornobyl accident. Most of measurements(~64 %) were made during the first 15 years after the accident. The most of measurements were made in Kyiv (~23 %),Zhytomyr (~36 %), Rivne (~20 %) and Chernihiv (~5 %) Oblasts. Works on revision of database of WBC measurementsincluded: transformation of data saved in paper format into electronic form, checking for correctness and correspon-dence of information, renewal of lacking information at the fields of database, improvement of the model for eval-uation of internal exposure doses by the data of WBC measurements. In the model for evaluation of revised doses,it is assumed uniform content of radio-cesium during a year. Reference values are used of metabolism parametersand anthropometric human parameters recommended in publications of ICRP. RESULTS: Revised doses have been reconstructed for 1,386,585 records of data base of WBC measurements that fitspecially elaborated criterions for estimation of quality of results. Among them 604,215 records are WBC measure-ments of children and adolescents younger than 18, and 782,370 records correspond to adult inhabitants of Ukraine,most of which reside in Zhytomyr, Kyiv, Rivne and Chenihiv Oblasts. CONCLUSIONS: Obtained results serve as a ground for further works on improvement of models for evaluation of pass-port doses and individualized exposure doses of subjects registered in Ukrainian State Register - of persons thataffected due to Chornobyl accident. Evaluated doses can be used for epidemiological, clinical and other research.

RESULTS OF COMPREHENSIVE RADIOLOGICAL - HYGIENIC MONITORING IN SOME SETTLEMENTS OF RADIOLOGICALLY CONTAMINATED AREAS IN RIVNE REGION IN 2017. / REZUL'TATY KOMPLEKSNOGO RADIATsIINO/GIGIIeNIChNOGO MONITORYNGU OKREMYKh NASELENYKh PUNKTIV RADIOAKTYVNO ZABRUDNENYKh TERYTORII RIVNENS'KOÏ OBLASTI U 2017 r.

OBJECTIVE: Identification of the main factors of radiation exposure formation in the residents of surveyed settle-ments of radiologically contaminated territories in Rivne region and estimation of radiation doses in population ata current stage of the accident. MATERIALS AND METHODS: Comprehensive radiological and hygienic monitoring was conducted within 7 settlementsof the Rokytnivsky district of Rivne region, namely in the Stare Selo, Vezhytsya, Perehodychi, Drozdyn', Berezove,Zabolottya, and Hrabun' villages. Assay of the incorporated 137Cs was held using a whole-body counter in residentsof the villages twice a year, i.e. in May and October. Basic foodstuffs were sampled for the assay of 90Sr and 137Cs alongwith interview of residents about the foodstuff consumption. External radiation doses were estimated. Mathe-matical, dosimetric, and radiochemical methods were applied. RESULTS AND CONCLUSIONS: The annual effective exposure doses of population in the surveyed settlements of Rivneregion in the year of study were formed at the expense of internal exposure doses ranging from 0.13 mSv · year-1 to0.32 mSv · year-1, which is below the criterion for radiologically contaminated territories. It has been establishedthat the incorporation of 137Cs by the inhabitants is a principal factor of the internal radiation dose formation. The 137Cs incorporation occurs through the consumption of such basic foodstuffs as milk and forest products, primarilymushrooms, which traditionally occupy a significant part of the diet in the Polissya area. The 137Cs content in thevast majority of milk and mushroom samples significantly exceeded the permissible levels (PL). The maximum con-tent of 137Cs in the collected milk samples was 384.7 Bq · L-1, which is 4 times higher than PL, and 36.9 kBq · kg-1 indried mushrooms being 15 times higher than PL. CONCLUSIONS: The existing radiation and ecological situation in the areas that were exposed to radioactive contam-ination as a result of the Chornobyl disaster requires the continuation of monitoring of levels of radioactive con-tamination of foodstuffs, especially collected in forests, and doses of radiation exposure of the population.