Chromosome aberrations in workers with exposure to alpha-particle radiation from internal deposits of plutonium: expectations from in vitro studies and comparisons with workers with predominantly external gamma-radiation exposure

摘要

mFISH analysis of chromosome aberration profiles of 47 and 144 h lymphocyte cultures following exposure to 193 mGy alpha-particle radiation confirmed that the frequency of stable aberrant cells and stable cells carrying translocations remains constant through repeated cell divisions. Age-specific rates and in vitro dose-response curves were used to derive expected translocation yields in nine workers from the Mayak nuclear facility in Russia. Five had external exposure to gamma-radiation, two of whom also had exposure to neutrons, and four had external exposure to gamma-radiation and internal exposure to alpha-particle radiation from incorporated plutonium. Doubts over the appropriateness of the dose response used to estimate translocations from the neutron component made interpretation difficult in two of the workers with external exposure, but the other three had translocation yields broadly in line with expectations. Three of the four plutonium workers had translocation yields in line with expectations, thus supporting the application of the recently derived in vitro alpha-particle dose response for translocations in stable cells. Overall this report demonstrates that with adequate reference in vitro dose-response curves, translocation yield has the potential to be a useful tool in the validation of red bone marrow doses resulting from mixed exposure to external and internal radiation.