Chromosome analysis of workers occupationally exposed to radiation at the Sellafield nuclear facility

Purpose: To investigate the relationship between stable chromosome aberrati on frequency in peripheral blood lymphocytes and occupational cumulative ra diation exposure. Materials and methods: Cytogenetic analysis using G-banding was performed o n peripheral blood lymphocyte cultures from 104 workers from the British Nu clear Fuels PLC facility at Sellafield, UK. The study group comprised 61 me n with lifetime cumulative doses > 500 mSv, 39 men with minimal exposure (i .e. <50 mSv) who formed a control group and 4 men with intermediate doses. Results: The slope of the dose-response, adjusted for smoking status, for t ranslocations and insertions was 0.55 +/- 0.31 x 10(-2)/cell/Sv. Considerat ion of chromosome breakpoints for all aberrations combined in the radiation workers revealed an excess in the C group chromosomes and a deficit in the F group chromosomes with breakpoints being concentrated in the terminal re gions whereas the distribution in the control group did not deviate from ex pectation. Conclusions: The dose-response was not significantly different from the par allel FISH analysis (Tucker ct al. 1997) and confirms that chronic radiatio n exposure appears to be substantially less effective at inducing stable ch romosome aberrations in comparison with acute exposure.