chapter  7
16 Pages

Effects of Radioactivity on Plants and Animals

WithKathryn A. Higley

The literature on the effects of ionizing radiation on plants and animals spans nearly a century. Understanding the effect radiation has on living tissues requires that one first examine the physics and chemistry of the initial interaction. There are two types of ionizing radiation: electromagnetic and particulate. Absorption of ionizing radiation energy occurs through indirect and direct mechanisms. Radiation interactions within cells are typically characterized as direct or indirect in nature. The consequences of ionizing radiation interaction can be seen at all levels of biological organization. Radiobiological studies have shown that, in general, cells most sensitive to the effects of ionizing radiation are those that are undifferentiated, well oxygenated, are highly metabolically active, and rapidly reproduce. When radiation effects at the level of the organism are examined, it becomes apparent that radiosensitivity generally increases with increasing organism complexity.