irradiate

Irradiate is a verb meaning to expose something to radiant energy or to cause it to receive radiation. The term is commonly used for exposure to ionizing radiation—such as X-rays, gamma rays, beta particles, or high-energy electrons—but can also apply to non-ionizing radiation, including ultraviolet light. The exposure can induce chemical changes, kill microorganisms, or alter materials.

Natural sources of irradiation include cosmic radiation and radionuclides present in the environment. Artificial irradiation arises from medical devices (X-ray machines, CT scanners), industrial processes (sterilization facilities, irradiators), and research settings (particle accelerators, nuclear reactors).

Applications: In medicine, irradiation is used in radiotherapy to damage the DNA of cancer cells; in sterilization to render medical equipment free of viable microbes; in food processing to extend shelf life through irradiation; and in materials science for processes such as polymer cross-linking and semiconductor fabrication. In diagnostic imaging, ionizing irradiation provides information through radiography and computed tomography.

Safety and measurement: Exposure to radiation is quantified as absorbed dose in grays (Gy) and, for risk assessment, as equivalent or effective dose in sieverts (Sv). Biological effects depend on dose, dose rate, radiation type, and tissue sensitivity. Protective measures aim to minimize unnecessary exposure, with regulatory limits and shielding in clinical and industrial contexts.

Etymology: Irradiate derives from Latin irradiāre, to shine upon.