FISH-based analysis of stable translocations in a Techa River population

Purpose: Measurements of symmetrical translocations by fluorescence in situ hybridization (FISH) were performed for retrospective biodosimetry in a Techa River population exposed to external (gamma -rays) and internal (90Sr, 137Cs) irradiation. Materials and methods: Chromosome analyses were carried out on peripheral lymphocytes from 73 radiation-exposed residents from settlements along the Techa River (Southern Urals, Russia) located 7-148 km downstream from the site of release of liquid radioactive waste from the plutonium production facility Mayak. Thirty-nine unexposed persons from non-contaminated areas were used as controls. Whole-chromosome painting probes for chromosomes 1, 4 and 12 were used simultaneously with a pancentromeric probe. Results: A significantly elevated mean translocation frequency compared with controls was found for the total study group and for either of two subgroups of inhabitants residing in villages of the upper regions of the Techa River (7-60 km) during 1950 to 1951, or in...