CHARACTERISTICS AND PROGNOSIS OF THE INTERNAL EXPOSURE DOSES OF THE UKRAINIAN POLISSYA RURAL POPULATION IN THE REMOTE PERIOD AFTER THE ACCIDENT AT THE CHERNOBYL NUCLEAR POWER PLANT (MONITORING STUDY).

Objective: Estimation of the forest ecosystem influence on the formation of annual effective internal exposuredoses (137Cs) of the Ukrainian Polissya population in the remote period after the Chernobyl accident and predictivemodeling of the internal exposure doses of the region residents.

Materials And Methods: Dosimetric control of the population (adults and children of school age, for 80 people inthe group on average in the settlement) of the Kyiv region was conducted during 2003-2011 with the Scriner-3Mspectrometer according to «Methodical recommendations for conducting measurements using whole body countersfor dosimetric certification of settlements» [9]. Gamma-spectrometric analysis of the samples was conducted by thespectrometric method (DSTU 3743-98) with SEG-005, the BEDG-63 detector. Experimental data were analyzed usingMicrosoft Excel 2016 and OriginPro 9. Computer modeling was carried out in the mathematical software MAPLE 10.

Results: Annual effective internal exposure doses of Ukrainian Polissya inhabitants determine by the contamina-tion level of certain ecosystems, first of all so-called critical ones. For the region under study these are primarily for-est ecosystems and natural forage areas which can cause significant body burdens of the population due to the con-sumption of milk and forest food products like wild-breed mushrooms, forest berries, game, etc. The approximationof experimental data by seasons, obtained on the WBC-measurements results, confirmed the hypothesis of the expo-nential distribution for spring and the lognormal one for autumn. The exponential distribution is typical for statis-tical ensembles, formation factors of which are little variable or permanent. Thereby, neither of dos-forming factors,for instance, any food product, is determinative in spring.

Conclusions: The probability of receiving annual effective internal exposure doses by the population increases sig-nificantly in autumn versus spring as a result of forest food products consumption like mushrooms, berries, gamemeat, etc.