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.

RETINA VESSELS CHANGES IN CHORNOBYL NUCLEAR POWER PLANT EMPLOYEES WHO EXPERIENCED LONG-TERM ABNORMAL RADIATION EXPOSURE AT THE WORKPLACE AS A RESULT OF THE OCCUPATION OF CHORNOBYL NUCLEAR POWER PLANT IN 2022. / ZMINY SUDYN SITKIVKY V SPIVROBITNYKIV ChORNOBYL'S'KOÏ ATOMNOÏ ELEKTROSTANTsIÏ, IaKI ZAZNALY TRYVALOGO NENORMOVANOGO RADIATsIINOGO VPLYVU NA ROBOChOMU MISTsI VNASLIDOK OKUPATsIÏ ChAES U 2022 ROTsI.

During the occupation of the Chornobyl Nuclear Power Plant (ChNPP) in 2022, a group of employees remained in the working town for a long time. These personnel were exposed to long-term radiation and non-radiation factors of the production environment, as well as stress and other factors. These factors could result in negative changes of health.It is known that radiation exposure causes changes in the course and caliber of retinal vessels. OBJECTIVE: to assess the condition of retinal arteries and veins and the level of incorporated 137Cs content in persons who were exposed to prolonged exposure to radiation and non-radiation factors of industrial environment, as they were at the workplace overtime during the occupation of the Chornobyl Nuclear Power Plant in 2022. MATERIALS AND METHODS: A comprehensive ophthalmological examination was carried out. Which included the determination of the diameter of the retinal arteries and veins, the arteriovenous ratio, of 55 people from among the personnel of the ChNPP, who worked under the conditions of the occupation of the ChNPP. All those examined were examined on an expert human radiation counter. The results of the ophthalmological examination were compared with the results of earlier examinations of ChNPP employees of the same age groups. RESULTS: It was established that in the examined group, a decrease in the arterio-venous ratio was observed, mainly due to the expansion of retinal veins. Dilatation of the veins was asymmetric, mainly the branches of the central vein of the retina of the right eye were more dilated. Retinal arteries were narrowed in all examined subjects. When comparing the results with the data of previous examinations, it was established that the arterio-venous ratio in this group was probably lower than in previously examined employees of the ChNPP of the same age groups. At the same time, the maximum registered value of the content of incorporated 137Сs was 713 Bq/organism, none of the examined exceeded the control level of 1,000 Bq/organism. CONCLUSIONS: Violation of blood circulation in the retina was detected - a probable increase in the arteriovenous ratio due to the expansion of the retinal veins in the personnel of the Chornobyl nuclear power plant who worked under the conditions of the occupation of the ChNPP in 2022. Since the examined subjects did not exceed the control level of incorporated 137Сs content (1,000 Bq/organism), the observed effect may be a consequence of the influence of other, both radiation and non-radiation factors.

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.

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.

Reconstruction of individualized doses of subjects from the Ukrainian State Register - of Persons that Affected due to Chornobyl accident and reside in Korosten raion of Zhytomyr oblast. / REKONSTRUKTsIIa INDYVIDUALIZOVANYKh DOZ SUB'IeKTIV DERZhAVNOGO REIeSTRU UKRAÏNY OSIB, IaKI POSTRAZhDALY VNASLIDOK ChORNOBYL'S'KOÏ KATASTROFY, ShchO PROZhYVAIuT' V KOROSTENS'KOMU RAY̆ONI ZhYTOMYRS'KOÏ OBLASTI.

STUDY OBJECTIVE: To elaborate an ecological dosimetric model of reconstruction individualized exposure doses of subjects from the State Register of Ukraine (SRU) - of persons, affected due to Chornobyl accident and reside at the radioactive contaminated territory of Korosten raion of Zhytomyr Oblast, and to calculate exposure doses for those persons. MATERIALS AND METHODS: In the paper, an ecological dosimetric model is presented which is elaborated in order to individualize exposure doses of people who reside in Korosten raion of Zhytomyr Oblast and are registered in SRU. The model is based on the results of radio ecological and dosimetric monitoring held in the period of 1986-2013 at the territory of northern oblasts of Ukraine. Annual dose over each post accidental year consists of the two compo nents: (a) annual effective dose of external gamma exposure (due to radioactive fallout on the ground), and (b) internal exposure of the whole body (due to consumption of meal contaminated by radioactive isotopes). For 1986, the dose of internal exposure is evaluated out of all main radionuclides of radioactive accidental fallout, and after 1987 only for radioisotopes of caesium (134Cs and 137Cs). The parameterization of the model is based on the pre vious experience in working out a complex of ecological dosimetric models for estimation of referent exposure doses of Ukrainian population. RESULTS AND CONCLUSIONS: Individualized doses of external and internal exposure (annual and accumulated) are estimated for the population of various age groups that resides in the settlements of Korosten raion (totally about 100 settlements). Separately the doses are presented for rural settlements of the raion and for the city of Korosten for each year of the post accidental period of 1986-2016. Estimates of doses are given that were accumulated: (a) during 15 years just after the accident, (b) for the period of 2000-2016, and (c) for 30 year period after the acci dent. Mean dose accumulated for 30 years after the Chornobyl accident by residents of rural settlements of Korosten raion is estimated as 19.8 mSv, and for inhabitants of the Korosten city as 20.9 mSv. On condition of permanent res idence in the raion, residents of about 66 % settlements of Korosten raion accumulated the doses in the interval 5 20 mSv during 30 years after the accident. For the residents of about 25 % settlements the accumulated dose is in the interval 20-50 mSv, and for 7 % of settlements it exceeds 50 mSv.

Experimental reconstruction of historical WBC measuring procedure in 1986. / EKSPERYMENTAL'NE VIDNOVLENNIa PROTsEDURY PROVEDENNIa LVL VYMIRIuVAN' 1986 ROKU.

OBJECTIVE: Examination and experimental reconstruction of the historical WBC measuring procedure in 1986 and estimation of the minimum detectable activity (MDA) of those measurements. MATERIALS AND METHODS: The SRP 68 01 gamma spectrometer with attached scintillation detector based on a NaI(Tl) O 30 x 25 mm2 crystal and NC 482 ВМ one channel spectrometer (Bicron Co.) with attached scintillation detector based on a NaI(Tl) O 52 x 52 mm2 crystal were used for the study. Protective chamber of the expert type whole body counter (WBC) and homogenous human body dummy phantoms filled with dry radioactive material were applied. Results of measurements on the WBC «Screener 3M¼ were retrieved from the Radiation Registry of the NRCRM. Dosimetry and mathematical methods were applied too. RESULTS AND CONCLUSIONS: The WBC measurement procedure was reconstructed using the examples tested in 1986 to assay the level of incorporated radioactive cesium in population of contaminated territories. MDA under the WBC measurements in 1986 was found being from 1.3 kBq per human body using the NC 482 ВМ one channel spectrom eter with attached scintillation detector based on a NaI(Tl) O 52 x 52 mm2 crystal up to 7.4 kBq per human body using the SRP 68 01 gamma radiometer radiometer with attached scintillation detector based on a NaI(Tl) O 30 x 25 mm2 crystal in adults under the 60 seconds measurement time. The respective values for adolescents and chil dren were within 0.8-5.6 kBq per body and 0.5-3.8 kBq per body.