In order to reach stability, these atoms give off, or emit, the excess energy or mass. These emissions are called radiation. Gamma radiation and X-rays are examples of electromagnetic radiation. Beta and alpha radiation are examples of particulate radiation. Ionizing radiation can also be produced by devices such as X-ray machines.
Radiation exposure occurs by diagnostic X-ray.
Irradiation by machine-generated radiation occurs only when the machine is turned on. There is also natural background radiation exposure. It comes from cosmic rays and from naturally occurring radioactive materials contained in the earth and in living things. Irradiation Irradiation is exposure to penetrating radiation. Irradiation occurs when all or part of the body is exposed to radiation from an unshielded source.