Chromosome aberrations in peripheral blood lymphocytes in subjects occupationally exposed to ionizing radiation or chemical clastogens.

To get an insight into genotoxic risk in some occupations, in this study the chromosome aberration analysis of peripheral blood lymphocytes was made in 20 physicians and nurses exposed to a low dose of ionizing radiation in a hospital, 12 individuals working with X-rays in a cement factory and 19 technicians working with some chemical toxic agents in the laboratories of a medical school. The control group consisted of 14 sex- and age-matched unexposed persons living in the same district area. The data showed that the total number of chromosome aberrations in 200 scored metaphases in all examined groups were almost the same and inside the low-permitted values. In hospital workers, however, the percentage of acentric and dicentric fragments (1.63 +/- 0.28 vs 0.31 +/- 0.21 and 0.47 +/- 0.18 vs 0.0, respectively) increased predominantly in contrast to cement-factory employees and laboratory workers, where a higher incidence of minutes (0.58 +/- 0.19 vs 0.31 +/- 0.2) or gaps (2.21 +/- 0.37 vs 1.15 +/- 1.15) was noticed. Moreover, in groups exposed to low doses of ionizing radiation (hospital and factory), a positive correlation was found between the total number of chromosome aberrations and the 6-year absorption dose or working period, suggesting an effect of cumulative dosage. The data emphasize that the continuous chromosomal aberration analysis should be obligatory for individuals exposed to various genotoxic substances, even in occupational conditions where according to dosimetric analysis they are exposed to permitted levels of radiation.