مقایسه دزیمتری بیولوژیک با دزیمتری فیزیکی در پرتوکاران شهر بابل

Background and purpose : Ït is clearly shown that ionising radiations induce various kinds of DNÂ damages majority of which as sub-lethal damages, are repaired but still some of them are left urepaired and lead to chromosomal aberrations. These chromosomal aberrations in radiation workers, who are occupationally exposed to radiation,could be assayed with cytogenetic evaluation methods.These cytogenetic assessments are good indicators for evaluating the health of radiation workers as well as radiation protection quality in medical radiation centers. The aim of the present study was to determine the frequency of the chromosomal aberrations using analysis of metaphase method in radiation workers of radiology departments in Babol. Materials and methods :. Heparinized venous blood samples were prepared from 62 radiology workers and 29 individuals as control population whose duties did not expose them to radiation sources. Lymphocytes were cultured in culture medium consisting of RPMÏ-1640 supplemented with L-glutamine, 15% fetal calf serum (FÇS) and antibiotics. PHÂ at a concentration of 5 µg/ml was used to stimulate division of lymphocytes in culture. Blood cultures were incubated at 37oÇ for 48 hours and 2 hours prior to harvesting colcemid was added to cultures at a final concentration of 0.1 µg/ml to arrest the dividing lymphocytes in mitosis. Ât hour 50 the cells were collected, washed and fixed on the slides followed by staining. Ône hundred mitoses were analyzed for each sample and chromosomal aberrations were scored and statistically analyzed. Results : Results showed that the mean frequencies of the total chromosomal aberrations in radiation workers is significantly higher than controls (p=0.014). Ït was also shown that there is no significant correlation between the frequency of chromosomal aberration and age, sex and smoking of individuals in both groups. Âlso no significant correlation was noted between the frequency of chromosomal aberrations in radiation workers and the years of work as well as history of over dose. Çonclusion : The higher frequency of chromosomal aberration in lymphocytes of radiation workers compared to non exposed controls is in full agreement with other reports and could be due to the accumulative effect of radiation induced initial DNÂ damage in individuals exposed to chronic and low doses of radiation which, finally leads to detectable chromosomal aberrations. Results showed that the frequency of chromosomal aberrations were age, sex and smoking independent and it was not also a function of years of work and unusual exposure. Regarding the controversy over this issue in the literature, further researches are needed to be done.