Characteristic Lesions in Mouse Retina Irradiated with Accelerated Iron Particles

Abstract

During the Apollo flights to the moon the astronauts reported light flash sensations after dark adaption. The cause of these “flashes” is due to the passage of heavy energetic cosmic-ray particles (HZE) through the retina. The rate of energy transfer of the HZE particle in tissue along the path of the particle is proportional to the square of the atomic number and approximately inversely proportional to the kinetic energy. Thus, a single iron particle (Z=26) transfers 676 times more energy than a proton of the same velocity. A critical question concerning the potential hazards of HZE particles is whether or not an individual particle can inflict serious damage to a series of ceils.A program is underway to determine the radiation hazards of HZE particles using the Bevalac, a heavy-ion accelerator at LBL. Our earlier work with helium, carbon, neon, and argon particles, and exposure of rats to HZE particles in space flight demonstrated some deleterious biological effects.