Chromosomal Aberrations in Blood Lymphocytes of the Residents of 30-km Chornobyl NPP Exclusion Zone

A comparative сytogenetic examination of 33 self-settlers in the 30 km ChNPP Exclusion Zone and 31 residents in villages of Yahotyn district, Kyiv region was carried out in 1998-99. The levels of soil contamination of their residential areas with Cs, Sr and Pu were 74–477 kBq/m, 33–288 kBq/mand 1.5-10.0 kBq/m, respectively for the former, and 1.9–5.8 kBq/m, 0.6–2.8 kBq/m and 0.01-0.05 kBq/m, respectively for the latter. Using various data about the radiation situation in the Exclusion Zone, the effective doses on whole-body of the self-settlers were estimated to be 30–333 mSv for the whole residing period after the accident. The mean frequencies of aberrant cells and chromosomal aberrations for the Zone self-settlers were significantly higher than those for the residents in Yahotyn district, while the values of the latter group were found to be above the spontaneous levels reported in literatures. The individual variability in the distribution of the same indices was significantly larger for the self-settlers than for the Yahotyn residents. The compared groups also differ in the distribution of aberrations in cells. A repeated examination of 20 Zone selfsettlers was conducted in 2001. A significant decrease in chromosome type aberration frequency was found at the expense of fragments frequency decrease. However, the total frequency of chromosomal aberrations didn’t differ in 1998-99 and in 200