Novel data set for retrospective biodosimetry using both conventional and FISH chromosome analysis after high accidental overexposure

Blood samples of ten Chernobyl and one non-Chernobyl victims were analysed both by conventional cytogenetics and by fluorescence in situ hybridization (FISH) using a cocktail of chromosomes 2, 3 and 8. The analysed group comp rised men acutely irradiated mainly in 1986 and aged 26-47 years at the tim e of first blood sampling. All of them displayed acute radiation syndrome o f varying severity. Chromosome analysis of the earliest blood samples was c arried out by conventional scoring of unstable aberrations with the number of metaphases analysed per individual ranging from 35 to 300. Estimated ind ividual doses ranged from 0.85 to 9.8 G y. After a 10 year delay, i.e. in 1 996, blood samples were analysed both by conventional scoring of unstable a berrations and by FISH measurements of stable ones. Usually about 500 metap hases per individual were scored. Estimated by the FISH-method individual t ranslocation (tc + ti) frequencies ranged from 2.2 to 116.8 per 100 cells f ull genome equivalent. Based on three different published dicentric dose re sponse, in vitro curves individual doses were calculated from the earliest dicentric frequencies. A dose response curve for truly persisting transloca tions (tc + ti) was estimated over the range 1-10 Gy, (C) 2000 Elsevier Sci ence Ltd. All rights reserved.