ABSTRACT
This chapter describes radiation-induced lethality as a ‘deterministic effect’ defined as an effect where its severity does increase with increasing exposure dose. The radiation sensitivity of a uniform population of animals is often identified in terms of the dose of radiation which kills 50% of the population within a given time frame. Thus LD50/30 refers to the dose needed to kill 50% of a population within 30 days. The acute radiation exposure of an organism, such as a small mammal or the organ of an animal, to significant doses of penetrating ionising radiation leads to either death of the mammal or a malfunction of the organ as a result of multi-cell inactivation. In extending the cellular effects model to provide an analytical approach to deterministic effects it is assumed that the majority, if not all, of these effects arise as a consequence of multi-cell inactivation.
