Anderson, R. M., Tsepenko, V. V., Gasteva, G. N., Molokanov, A. A., Sevan'kaev, A. V. and Goodhead, D. T. mFISH Analysis Reveals Complexity of Chromosome Aberrations in Individuals Occupationally Exposed to Internal Plutonium: A Pilot Study to Assess the Relevance of Complex Aberrations as Biomarkers of Exposure to High-LET α Particles. Radiat. Res. 163, 26–35 (2005).

We recently demonstrated that a significant proportion of apparently stable insertions induced after exposure to a mean of one α particle/cell, detected using three-color FISH, were part of larger unstable complexes when visualized by 24-color FISH. Interestingly, regardless of the long-term persistence capability of the cell, the complexity of each α-particle-induced complex appeared to be specific to the nuclear traversal of a single α particle. To assess whether aberrations of a similar complexity are observed in vivo and also to examine the usefulness of detecting such aberrations as a biomarker of chronic exposure to α particles, we have carried out a limited pilot study of Russian workers with large body burdens of α-particle-emitting plutonium. We found unstable cells containing non-transmissible complex aberrations in all of the plutonium-exposed subjects analyzed by mFISH. In addition, all of the complexes seen were consistent with those previously observed in vitro. Non-transmissible complex aberrations were more common than transmissible-type complexes, consistent with ongoing/chronic exposure, and insertions were dominant features of both types of complex. Accordingly, this preliminary study supports the proposal that aberration complexity and non-transmissibility are the major cytogenetic features of α-particle exposure that could potentially be exploited as a specific indicator of chronic exposures to high-LET α particles.