The purpose of this study was to establish the dose-response curves for biological dosimetry of the Dong Nam Institute of Radiological and Medical Sciences to monitor radiation exposure of local residents in the vicinity of the nuclear power plant. The blood samples of five healthy volunteers were irradiated with gamma ray, and each sample was divided equally for analysis of chromosomal aberrations by Giemsa staining and three-color fluorescence in situ hybridization painting of the triplet (chromosomes #1, #2, and #4). The results of chromosomal aberrations followed the Poisson distribution in all individual and averaged data which include inter-individual variation in radiation susceptibility. Cytogenetics Dose Estimate Software version 5.2 was used to fit the dose-response curve and to determine the coefficients of linear-quadratic equations. The goodness of fit of the curves and statistical significance of fitted α and β-coefficients were confirmed in both Giemsa-based dicentric analysis and FISH-based translocation analysis. The coefficients calculated from the five-donor average data were almost identical in both of the analyses. We also present the results that the dose-response curve for dicentric chromosomes plus fragments could be more effective for dose estimation following low-dose radiation accidents.
Keywords: Dose–response curves; biological dosimetry; dicentric chromosome; gamma ray; nuclear power plant; translocation.