Cytogenetic analysis of peripheral blood lymphocytes, many years after exposure of workers to low-dose ionizing radiation

The present study aims to measure chromosomal aberrations and micronuclei in peripheral blood lymphocytes from 25 subjects exposed to 0.10-0.33 Gy external or internal irradiation 32-41 years ago using conventional cytogenetic analysis methods. The frequencies of total chromosome-type aberrations and micronucleus significantly increased in the exposed group compared with that in age-matched control group (p < 0.001); chromatid-type aberrations showed no difference between the two groups (p > 0.05). When exposed subjects were divided into two groups based on exposure dose, higher levels of dicentric plus translocation frequencies were observed in the >= 0.15 Gy dose group compared with those in the <0.15 Gy dose group, though the difference was not significant. Borderline association between exposure dose and dicentric frequency was detected in the exposed group (r = 0.358; p = 0.079). These results suggest that the genotoxic effects of ionizing radiation remain in subjects exposed to low-dose radiation even decades after exposure. (C) 2014 Elsevier B.V. All rights reserved.