Background: Exposure ionizing of radiation in radiation workers has the potential to cause DNA damage in the form of double strand break as the beginning of genomic instability. DNA damage can be observed with γ-H2AX as the biomarker of DNA double strand breaks (DSBs). The formation of γ-H2AX in the nucleus can occur after radiation exposure of 1 mGy. This study aims to determine the radiation effects in radiation work environments as a study of adaptive responses of peripheral blood mononuclear cell (PBMCs) after radiation by observing γ-H2AX foci expression..  Methods: Blood samples from nine radiation workers and nine non-radiation workers were irradiated with doses 0 Gy, 1 Gy, 1.5 Gy, and 2 Gy. Detection of γ-H2AX foci was done by immunofluorescence assay. The mean of γ-H2AX foci was counted in 50 PBMCs per sample. The comparison mean of γ-H2AX foci was analyzed using tindependent test.  Result: Based on the result study, there were no significant differences in the number of γ-H2AX foci without treatment (p = 0.807). The results of study showed that the formation of 2-3 foci per cell after exposure of 2 Gy increases along with the increasing irradiation doses.  Conclusion: The mean of index of γ-H2AX foci in PBMCs within normal limits between non-radiation workers and radiation workers and level of risk DSBs damage is relatively similar after exposure at doses 1 Gy, 1.5 Gy, and 2 Gy.

No abstract

Background: Gamma irradiation can cause DNA damage in single and double-strand breaks (SSBs & DSBs), especially in peripheral blood lymphocytes. Radiotherapy medical radiation workers can be exposed to gamma radiation related to their daily work. The comet assay is a sensitive method for analyzing DNA damage, especially SSBs. This study explores DNA damage in medical radiation workers’ peripheral blood lymphocytes as an adaptive response using the comet assay.Methods: Blood samples were obtained from four radiotherapy medical radiation workers as a case study (MRW) and two non-medical radiation workers as controls, and then irradiated with various doses of 0, 1, 1.5, and 2 Gy. Lymphocytes were isolated by histopaque and processed by comet assay on the slide under alkaline conditions. The imaging results were analyzed using the Casplab_1.2.3b2 software. The comet assay parameters observed were Tail Length (TL), % Tail DNA (T.DNA), Tail Moment (TM), and Olive Tail Moment (OTM). The one-way ANOVA method was used to analyze statistically between treatment groups. Results: Based on the study results, an increase in TL, T.DNA, TM, and OTM values in all samples was directly proportional to the increase in radiation dose. However, there was no significant difference (P > 0.05) between the MRW group and the control group on each parameter of the comet assay.Conclusions: From this study, it can be concluded that the level of DNA damage of lymphocyte cells as part of the adaptive response in the MRW and control groups was relatively similar after exposure at doses of 0, 1, 1.5, and 2 Gy.