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.

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.

Main internal dose forming factors for inhabitants of contaminated regions at current phase of the Chernobyl nuclear power plant accident (Kyiv region as an example). / OSNOVNI ChYNNYKY FORMUVANNIa VNUTRIShN'OGO OPROMINENNIa NASELENNIa RADIOAKTYVNO ZABRUDNENYKh TERYTORIY NA POTOChNOMU ETAPI AVARII NA ChAES (NA PRYKLADI KYIVS'KOI OBLASTI).

UNLABELLED: Objective of this work is revealing of main dose forming factors of internal doses for inhabitants of contaminated regions of Kyiv region relying on the results of integral dosimetric monitoring. MATERIALS AND METHODS: Three villages have been chosen for the investigation. They are: Raghivka, Zelena Poliana (Poliske district), Karpylivka (Ivankiv district). Twice a year, in May and in October those villages' residents were inspected for content of incorporated 137Cs. They were measured by direct method at the place of residence with the help of whole body counters (WBC). The principal food samples were collected for detection of 90Sr and 137Сs content. Those villages' inhabitants were interviewed about food consumption levels. Mathematical, dosimetric and radio chemical methods were used in this workResults and conclusions. The estimation of internal doses due to intake of 137Cs by ingestion of milk and potatoes are in the range 0.3-34% of doses estimated on the base of WBC data. The contribution to the dose of internal expo sure from intake of 137Cs with the milk consumption is no more than two times higher than the contribution of pota toes consumption in the case of equal consumption levels of these products. Contributions to the dose of internal exposure from intake of 90Sr with milk and potatoes consumptions are approximately similar. Consumption of mush rooms and other wild nature products by inhabitants from the inspected settlements is the main forming factor of internal dose due to 137Cs intake.

Way to improve the radiation hygenic monitoring on contaminated territories.

STUDY OBJECTIVE: To provide an effective radiation hygienic inspection and population protection from ionizing radiation in the late period after the Chornobyl NPP (ChNPP) accident within reforming of the state sanitary & epidemiological supervision services. MATERIALS AND METHODS: The radiation hygienic monitoring (RHM) is performed in Ukraine within the scope of state sanitary & epidemiologic supervision by 158 radiological subdivisions of the sanitary & epidemiological station (SES). The structure of these subdivisions has been created taking into account the territorial regional bounds, a presence of radiological supervision services and ChNPP accident consequences. Nowadays it consists of regional, district, municipal subdivisions, central SESs of Crimea autonomous republic and transport subdivision. In 2012-2013 the State Sanitary & Epidemiological Service of Ukraine had been reformed and reorganized and then in several cases it wasn't optimal for RHM performance. RESULTS AND CONCLUSIONS: The fulfilled analysis of radiation hygienic supervision and protection of population of contaminated regions and efficiency analysis of that supervision and protection allowed to find out and to propose some methods to improve the actual radiation hygienic supervision monitoring system on contaminated Ukrainian areas after the ChNPP accident. It is essential to restore the radiological subdivision (departments, units, labs or groups) work in the State sanitary & epidemiology service structure and to design coordinated and approved methodical recommendations to implement the RHM on contaminated areas to improve and optimize the RHM performance there.

Peculiarities of internal radiation doses due to ¹³7Cs and 9°Sr intake in population from Zhytomyr oblast in a late period after the Chornobyl NPP accident.

STUDY OBJECTIVE: To reveal the peculiarities of internal radiation doses in the inhabitants of Zhytomyr oblast and to provide a scientific ground for arrangements on internal irradiation dose reducing in population from contaminated regions in long-term period after the ChNPP accident. MATERIALS AND METHODS: Comprehensive radiation monitoring was carried out in 4 settlements in Narodychi region of Zhytomyr oblast. The radiochemical, dosimetric methods (instrumental and numerical) were used in the study. RESULTS AND CONCLUSIONS: Significant (2-3.5 times) seasonal increase of incorporated ¹³7Cs level was revealed through a WBC-monitoring in residents (both for adults and children) of the supervised settlements of Narodytsky region, Zhytomyr oblast. The exceeding of 1.0 mSv x year⁻¹ dose was revealed in up to 5 % of inspected persons. The maximal registered in those settlements ¹³7Cs content of 350 kBq is the source of 10 mSv x year⁻¹ annual dose. ¹³7Cs content in milk samples from those settlements didn't change much during a year. Elevation of ¹³7Cs content exceeding the permissible level of 100 Bq x litre⁻¹ was found in ~30-50 % of milk samples from Narodychi and Selets villages, whereas in Motiyky and Khrystynivka villages the ¹³7Cs content didn't exceed permissible levels. 90Sr content both in potatoes and milk samples was much under the permissible level of 20 Bq x litre⁻¹. ¹³7Cs content in potato samples was under the permissible levels. It was found out that main part of internal irradiation doses in the settlements of concern is due to consumption of locally produced victuals i.e. milk and natural/forest-originated products like berries and mushrooms.