HEAVY-ION ACTION ON BIOLOGICAL-SYSTEMS

Life is governed by molecular processes, particularly involving the ex pression and conservation of genetic information. Heavy ions deposit l arge amount of energy at very small scale comparable to the essential molecular structures of biological systems. This paper illustrates the special aspects of heavy ion radiobiology from a fundamental point of view, After a short summary of the structure and function of biologic al systems, concentrating on the cell and its constituents, the patter n of energy deposition by heavy ions is discussed, Experimental exampl es an the induction of molecular changes in deoxyribonucleic acid, cel l killing and the formation of mutations. It is shown that a close lin k exists between the physical parameters and the inactivation of biolo gical functions that is not restricted to direct particle traversals b ut may also be brought about by the action of far-reaching secondary e lectrons.