Radiosensitivities in acute and late effects on human cells

The risk of cancer in various organs and mutation or malformation in the offspring, increases in organisms exposed to radiation, as an effect other than acute death. Another important effect of radiation is a nonspecific shortening of life span in organisms, although this postulation remains controversial. Others studied the survival rate of mice exposed to X rays (100-500 R) and noted only a small number of acute deaths. However, the survival time of the exposed mice showed a dose-dependent decrease;that is, a shorter life span was associated with a greater exposure to radiation. Other studies of American radiologists suggested that shortening of the life span with radiation exposure probably also applied to humans. Many later studies of radiologists did not demonstrate a nonspecific shortening of life span by radiation. Another extensive study on human concerns follow-up of the atomic bomb survivors of Hiroshima and Nagasaki. These investigations to date revealed no nonspecific shortening of life span in the atomic bomb survivors. This chapter is concerned with the effects of radiation on the proliferating ability of human-derived fibroblasts