Persistence of translocations after accidental exposure to ionizing radiation

Purpose: To assess the validity of translocations for retrospective biodosimetry using FISH chromosome painting of peripheral lymphocytes in repeated samples of people accidentally exposed to radiation. Materials and methods : Blood samples from five people exposed to mainly whole-body irradiation of gamma -rays from a radiation accident in Estonia in 1994 were taken at 2-4 month intervals. A total of eight samplings were carried out, including one directly after the accident. Fluorescence in situ hybridization with probes for chromosomes 1, 2 and 4 was performed on metaphase preparations from 48h whole blood cultures; 1500 cells were scored from each individual per time point. Results: Translocations remained relatively stable during 2 years after exposure in all subjects. A noticeable decrease in complete translocation yields and a significant decrease in incomplete translocations were observed in one person. In addition to wholebody exposure, he had also been exposed to partial-body irradiation. Due to...