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.
Meta. Vyznachennia osnovnykh faktoriv formuvannia oprominennia meshkantsiv obstezhenykh naselenykh punktivradioaktyvno zabrudnenykh terytoriĭ Rivnens'koï oblasti ta otsinka doz oprominennia naselennia na potochnomuetapi avariï.Material i metody. Provedeno kompleksnyĭ radiatsiĭno-gigiienichnyĭ monitoryng u semy naselenykh punktakh Ro-kytnivs'kogo raĭonu Rivnens'koï oblasti – ss. Stare Selo, Vezhytsia, Perekhodychi, Drozdyn', Berezove, Zabolottia,Grabun'. Dvichi na rik, u travni ta zhovtni, u meshkantsiv tsykh naselenykh punktiv bulo provedeno vyznachennia vmistuinkorporovanogo 137Cs shliakhom priamogo vymiriuvannia na lichyl'nykakh vyprominiuvannia liudyny (LVL), zibranoproby osnovnykh produktiv kharchuvannia dlia vyznachennia vmistu v nykh radionuklidiv 90Sr ta 137Ss, opytano mesh-kantsiv shchodo rivniv spozhyvannia tsykh produktiv ta provedeno roboty z otsinky doz zovnishn'ogo oprominennia.V roboti vykorystano matematychni, dozymetrychni, radiokhimichni metody.Rezul'taty ta vysnovky. Richni efektyvni dozy oprominennia naselennia v obstezhuvanykh naselenykh punktakhRivnens'koï oblasti v potochnomu rotsi formuiut'sia za rakhunok doz vnutrishn'ogo oprominennia, iaki variiuiut'sia vmezhakh vid 0,13 mZv · rik-1 do 0,32 mZv · rik-1, shcho nyzhche kryteriiu radioaktyvno zabrudnenykh terytoriĭ. Vstanov-leno, shcho osnovnym faktorom, iakyĭ formuie dozu vnutrishn'ogo oprominennia, ie nadkhodzhennia 137Cs v organizm mesh-kantsiv z takymy osnovnymy produktamy kharchuvannia, iak moloko ta lisovi produkty, nasampered, gryby, iaki vPolis'komu regioni tradytsiĭno zaĭmaiut' suttievu chastynu kharchovogo ratsionu. Vmist 137Cs u perevazhniĭ chastyniprob moloka i grybiv znachno perevyshchuie dopustymi rivni (DR). Maksymal'nyĭ zareiestrovanyĭ vmist 137Cs u zibra-nykh probakh moloka stanovyt' 384,7 Bk · l-1, shcho u 4 razy vyshche DR, u sushenykh grybakh – 36,9 kBk · kg-1 – u 15 razivvyshche DR.Vysnovky. Isnuiucha radiatsiĭno-ekologichna sytuatsiia v mistsevostiakh, iaki piddalysia radioaktyvnomu zabrudnenniuvnaslidok Chornobyl's'koï katastrofy, potrebuie prodovzhennia monitoryngu za rivniamy radioaktyvnogo zabrud-nennia produktiv kharchuvannia, osoblyvo zibranykh u lisakh, ta doz oprominennia naselennia.
Keywords: 137Cs and 90Sr content; comprehensive radiation and hygienic monitoring; external irradiation; foodstuffs; internal irradiation; radiation dose; whole-body counter.
V. V. Vasylenko, S. Yu. Nechaev , M. Ya. Tsigankov, V. O. Pikta, G. M. Zadorozhna, M. S. Kuriata, L. O. Lytvynetz, L. P. Mischenko, T. F. Babenko.