Cellular radiation biology in consolidation and transition.

Cellular radiation biology currently is undergoing changes common to all science in which the understanding in one area is becoming solidified while in another area conclusion of the classical phase is being engendered by the needs of modern thought. Aspects of these changing circumstances are discussed here from the standpoint of the roles played by direct and indirect action in cell death and the position that promulgation of the correct explanations of the radiosensitivities of mammalian cells can be facilitated if use of such classical operational definitions as sublethal and potentially lethal damage is discontinued. The latter consideration will be supported by a summary of the responses of synchronous populations of the L5178Y S/S murine leukaemic lymphoblast to 20Ne, 28Si, 40Ar, 56Fe and 93Nb ions of energies broadly in the region of 500 MeV/u.