For the estimation of radiation exposure on genetic processes in Mayak PA population we studied the distribution of a number of genetic markers in offsprings of Mayak PA workers depending on radiation (preconceptive and antenatal chronic exteral gamma-radiation) and non-radiation (age-sex characteristics of children and age characteristics of parents to the moment of conception) factors. Relatively unfavorable changes in distribution of genotypes and genes of haptoglobin genetic system in offsprings, whose parents (one or both) were exposed to external gamma-radiation in preconceptive cumulative dose of more than 200 cGy were detected. The most obvious reason of such changes may consist in directed gametic selection (Hp2 allele versus Hp1 allele) which turns out in abnormalities of segregation of Hp2-1 heterozygote that have both alleles. Effect of antenatal exposure on distribution of studied genetic markers in offspring of exposed population in studied dose range were not found. Homotypic changes in distribution of ABO bood groups and alleles in offspring of exposed and unexposed individuals depending on age characteristics of parents (middle age and age differences of both parents) for the moment of conception were also detected.
A multicolor banding (mBAND) fluorescence in situ hybridization technique was used to investigate the presence inhuman 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, gamma rays or both. Metaphase spreads were produced and chromosomes 1 and 2 were hybridized with mBAND FISH probes and scored for intra-chromosomal 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 gamma rays. Interchromosome aberration yields were similar in both the high plutonium and the high gamma-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 alpha 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.