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Irradiation is the process by which an object is exposed to radiation. An irradiator is a device used to expose an object to radiation, notably gamma radiation , for a variety of purposes. [ 1 ]
The level of health risk is dependent on duration and the type and strength of irradiation. Penetrating radiation such as gamma rays, X-rays, neutrons or beta particles pose the greatest risk from an external source. Low penetrating radiation such as alpha particles have a low external risk due to the shielding effect of the top layers of skin.
However, important differences between the two conditions exist. The patient that develops neutropenia after radiation is susceptible to irradiation damage to other tissues, such as the gastrointestinal tract, lungs and the central nervous system.
Exposure can be from a source of radiation external to the human body or due to internal irradiation caused by the ingestion of radioactive contamination. Ionizing radiation is widely used in industry and medicine, and can present a significant health hazard by causing microscopic damage to living tissue.
Radiation is a moving form of energy, classified into ionizing and non-ionizing type. [4] Ionizing radiation is further categorized into electromagnetic radiation (without matter) and particulate radiation (with matter). [4] Electromagnetic radiation consists of photons, which can be thought of as energy packets, traveling in the form of a wave ...
Radiation is often categorized as either ionizing or non-ionizing depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volts (eV), which is enough to ionize atoms and molecules and break chemical bonds. This is an important distinction due to the large difference in harmfulness to living organisms.
Radiant exposure: H e: joule per square metre J/m 2: M⋅T −2: Radiant energy received by a surface per unit area, or equivalently irradiance of a surface integrated over time of irradiation. This is sometimes also called "radiant fluence". Spectral exposure: H e,ν [nb 3] joule per square metre per hertz J⋅m −2 ⋅Hz −1: M⋅T −1
Exposing skin to infrared radiation near visible light (IR-A) leads to increased production of free radicals. [41] Short-term exposure can be beneficial (activating protective responses), while prolonged exposure can lead to photoaging. [42] Another important factor is the distance between the worker and the source of radiation.