[Cytogenetic effect in peripheral blood lymphocytes of children living in villages in the Ovruch District, Zhitomir Region of the Ukraine contaminated by radionuclides].

For the purpose of genetic indication of low level of chronic radiation exposure the cytogenetic monitoring of some critical children groups living in two contaminated Ukrainian villages was carried out. In all the groups the mean frequency of aberrant cells and chromosome type aberrations (including dicentrics, centric rings, chromosome translocations as well as polyploid cells) significantly exceeded control level. During the repeated examination of children from Vistupovichi (in 13 months after the first one) the striking increase of cytogenetic effect was revealed. Dicentrics and rings were registered in 79% of persons with the individual rate 0.5-1.5 and mean group frequency 0.57 per 100 cells. The authors tried to evaluate the average cumulative doses of radiation for examined groups using G. Littlefield equation for dicentric outcome under the low dose rate Cs-137 source and taking into account the assumption about the reducing of 50% dicentrics per year. According to this rough calculation, the revealed cytogenetic effect can correspond to the mean total dose of 33 cSv for Vistupovichi children.