irradiated

Irradiated describes an object or material that has been exposed to ionizing radiation. Exposure can occur with gamma rays, X-rays, or charged particle beams such as electrons. The effects depend on the radiation type, dose, and exposure conditions, and may include physical, chemical, or biological changes in the irradiated substance.

In medicine and healthcare, irradiation is used for several purposes. Radiation therapy directs high-energy radiation at tumors to damage cancer cells. Sterilization of medical devices and pharmaceuticals commonly uses irradiation to eliminate microorganisms without heat. Diagnostic imaging and certain treatments also involve exposure to ionizing radiation, though the term irradiated is most often used in contexts of therapy, sterilization, or research rather than diagnostic procedures.

Food irradiation preserves food by inactivating bacteria, viruses, molds, and insects, thereby reducing spoilage and extending shelf life. It can also control pests in shipments. Importantly, irradiated foods do not become radioactive, and any residual radioactivity is negligible. Doses are measured in grays (Gy), with higher-dose applications used for sterilization or pest control and lower doses for delaying ripening or extending shelf life. Safety and labeling requirements vary by jurisdiction, but many authorities emphasize that irradiation is a physical process that does not make the treated food radioactive.

In industrial and research settings, irradiation is used to sterilize medical disposables, cross-link polymers to alter material properties, and study radiation effects on materials. Facilities employ shielding and dosimetry to monitor exposure and ensure safety for workers and the surrounding environment.