[The results of the cytogenetic examination of children and adolescents living in radionuclide-contaminated regions of Kaluga Province].

After the Chernobyl accident in a period from 1989 to 1992 blood samples were collected and analysed for chromosomal aberrations in lymphocytes from 490 children born and living continuously in two districts of Kaluga Province with radioactive contamination. The results of cytogenetic examinations show the frequency of unstable aberrations in children from Zhizdra District to be higher than that in children from Ulyanovo District and in the control group. No correlation was found between the thyroid absorbed doses ranging from 0 to 5 Gy and the aberration frequencies. No differences in chromosomal aberration yields were observed in children born before or after the Chernobyl accident. Repeat examinations of the same children cohorts revealed no significant changes with time in the level of unstable aberrations.