Esposito G, Antonelli F, Belli M, Campa A, Dini V, Furusawa Y, Simone G, Sorrentino E, Tabocchini M A
Laboratorio di Fisica, Technology and Health Department, Istituto Superiore di Sanita, Rome, Italy.
Adv Space Res. 2005;35(2):243-8. doi: 10.1016/j.asr.2004.11.021.
This paper reports on DNA DSB induction in human fibroblasts by iron ions of different energies, namely 5, 1 GeV/u, 414 and 115 MeV/u, in absence or presence of different shields (PMMA, Al and Pb). Measure of DNA DSB was performed by calibrated Pulsed Field Gel Electrophoresis using the fragment counting method. The RBE-LET relationships for unshielded and shielded beams were obtained both in terms of dose average LET and of track average LET. Weak dependence on these parameters was observed for DSB induction. The shielding efficiency, evaluated by the ratio between the cross sections for unshielded and shielded beams, depends not only on the shield type and thickness, but also on the beam energy. Protection is only observed at high iron ions energy, especially at 5 GeV/u, where PMMA shield gives higher protection compared to Al or Pb shields of the same thickness expressed in g/cm2.
