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.
External irradiation does not make a person radioactive. Radioactive Contamination Contamination occurs when material that contains radioactive atoms is deposited on skin, clothing, or any place where is it not desired. A person is externally contaminated if radioactive material is on skin or clothing. A person is internally contaminated if radioactive material is breathed in, swallowed, or absorbed through wounds. The environment is contaminated if radioactive material is spread about or uncontained.