Keywords: cosmic environment, survivor cells, cell death, heavy ions, radiation exposure, Chinese hamster ovary cells, manned space missions, low radiation
An evaluation of the fraction of survivor cells and cell death after exposure to accelerated heavy ions
The cosmic environment is considered to include a mixture of high-energy photons and radiation particles, such as iron ions. The total radiation exposure during manned space missions contribute to heavy ions. The possibility that high Linear Energy Transfer (LET) radiation provides no ionisation within the cell target (survivor cells) and the cells with multihit events is higher due to their uniform distribution in comparison to low LET ionisation. It was explored by evaluating the fraction of survivor cells (20%) and the cells undergoing cell death (70%) in Chinese hamster ovary cells exposed to heavy ions. About 10% of the residue cells suffered from division delay and showed lethal sectoring. The Relative Biological Effectiveness (RBE) in two kinds of cell death for reproductive death and interphase death showed a similar LET dependence with a maximum of around 200 keV/µm. In this LET region, the quantity of nonsurvivor cells with reproductive death was higher than interphase death.