Use of the alkaline comet assay to monitor DNA damage in technicians exposed to low-dose radiation.

The exposure of human beings to ionizing radiation is still of great concern in occupational and environmental medicine, and the widespread use of radiotherapy in the treatment of cancer has led to anxiety about the possible hazards to staff who are at risk of such occupational exposure. In this study, DNA damage in the peripheral lymphocytes of 30 technicians employed in radiation oncology departments for at least 1 year were examined by the alkaline single-cell gel electrophoresis "comet" technique. The results were compared with those of 30 controls with comparable age, sex, and smoking habits who were not working in radiation oncology or chemotherapy services. The DNA damage observed in the lymphocytes of the technicians was significantly higher than that in the controls (P < 0.001). Cigarette smoking was also related to increases in DNA damage, and a significant association was found between the duration of occupational exposure to low-dose ionizing radiation and the DNA damage.