Chromosomal Instability Parameters in the Population Affected by Nuclear Explosions at the Semipalatinsk Nuclear Test Site

A population genetic survey of 149 persons who were born and have permanently lived in the contaminated zones of the Semipalatinsk region has been performed. A cytogenetic study has demonstrated that the frequency of aberrant cells is 1.7–3 times higher than control parameters. The total frequencies of chromosome aberrations are 3.43 ± 0.48, 3.1 ± 0.3, 1.8 ± 0.2, and 1.15 ± 0.17 aberrations per 100 cells in the populations of the extreme radiation risk (ERR), maximum radiation risk (MaxRR), minimum radiation risk (MinRR), and control zones, respectively. The high chromosome aberration rate in all three zones of radiation risk has been detected mainly due to radiation-induced chromosome markers, including paired fragments (1.3 ± 0.2, 0.94 ± 0.13, and 0.43 ± 0.06 per 100 cells, respectively), dicentric and ring chromosomes (0.44 ± 0.04, 0.45 ± 0.07, and 0.11 ± 0.02 per 100 cells, respectively), and stable chromosome aberrations (0.74 ± 0.16, 0.8 ± 0.1, and 0.63 ± 0.13 per 100 cells, respectively). The qualitative spectra of the cytogenetic lesions observed in these groups indicate a mutagenic effect of ionizing radiation on chromosomes in the populations studied.