LABORATORI NAZIONALI DI LEGNARO
Estimating cancer risk to astronauts from exposures to high energy protons and high charge and energy (HZE) nuclei in space is a difficult challenge. The study of chromosomal aberrations by protons and HZE nuclei has been used as a biodosimeter of space radiation exposure, and as a surrogate endpoint for understanding cancer risks. We review studies from heavy ion accelerators of chromosomal changes using fluorescent in-situ hybridization (FISH) techniques including data on biological effectiveness factors for specific aberration types and studies that have identified unique damage types at low fluences of HZE nuclei not identified in gamma-ray exposures. NASA uses biodosimetry for astronauts on long-term space missions on the International Space Station for estimating mission doses. We compare results from physical dosimetry and transport codes estimates of effective doses to biodosimetry results from spaceflight. Our results suggest that accelerator data can be used to make accurate prediction of stable aberrations in spaceflight, however confounding factors such as clonal aberrations and the decay of aberrations after long times are potential confounders of such results for risk analysis.

DATA: 21-06-2005