Mitchell, C. R., Azizova, T. V., Hande, M. P., Burak, L. E., Tsakok, J. M., Khokhryakov, V. F., Geard, C. R. and Brenner, D. J. Stable Intrachromosomal Biomarkers of Past Exposure to Densely Ionizing Radiation in Several Chromosomes of Exposed Individuals. Radiat. Res. 162, 257–263 (2004).

A multicolor banding (mBAND) fluorescence in situ hybridization technique was used to investigate the presence in human populations of a stable biomarker—intrachromosomal chromosome aberrations—of past exposure to high-LET radiation. Peripheral blood lymphocytes were taken from healthy Russian nuclear workers occupationally exposed from 1949 onward to either plutonium, γ rays or both. Metaphase spreads were produced and chromosomes 1 and 2 were hybridized with mBAND FISH probes and scored for intrachromosomal aberrations. A large yield of intrachromosomal aberrations was observed in both chromosomes of the individuals exposed to high doses of plutonium, whereas there was no significant increase over the (low) background control rate in the population who were exposed to high doses of γ rays. Interchromosome aberration yields were similar in both the high plutonium and the high γ-ray groups. These results for chromosome 1 and 2 confirm and extend data published previously for chromosome 5. Intrachromosomal aberrations thus represent a potential biomarker for past exposure to high-LET radiations such as α particles and neutrons and could possibly be used as a biodosimeter to estimate both the dose and type of radiation exposure in previously exposed populations.