What are destructive changes in body molecules directly by radiation termed?

Destructive changes in body molecules directly caused by radiation are termed the direct effect. This concept refers to the mechanism where radiation interacts directly with DNA or other critical biomolecules, causing ionization that leads to structural damage. When radiation passes through biological tissues, it can ionize atoms, disrupting chemical bonds within the molecules. This can result in the impairment of cellular function, which is crucial in the context of both radiation therapy and radiobiology.

The direct effect is significant because it highlights how certain types of radiation, particularly high-energy radiation, can have immediate biological consequences. Understanding this mechanism is essential for evaluating the risks associated with exposure to ionizing radiation in medical and occupational settings.