Cytogenetic Investigation of Industrial Workers Occupationally Exposed to Gamma Rays

The incidence of chromosome aberrations has been studied in blood cells of 16 technicians occupationally exposed to gamma irradiation, 8 of whom had been irradiated with doses higher than allowed and the other 8 with smaller than allowed ones. The blood cell count of all subjects did not present abnormalities at any of the periodical medical check-ups. Although the peripheral blood picture was normal, chromosome aberrations in 48-50-hour cultures of blood were detected. The incidence of chromosome aberrations, mainly fragments, distinctly differed (p < 0.001) from that of an equal number of controls. This incidence was also different (p < 0.001) between those who had received doses higher than permissible and the other ones. It should be emphasized that although the incidence of chromosome aberrations did not increase in step with the total accumulated dose, the aberrations can be found even as a result of small doses even though the usual hematological parameters were not modified.