Distinguish contamination from irradiation.

Contamination and irradiation are two distinct concepts in nuclear physics. Radioactive contamination refers to the unwanted presence of radioactive materials on or within an object or person, which can lead to the emission of radiation from that object. In contrast, irradiation is the process of being exposed to ionising radiation from a radioactive source without the source itself being present on the object or person. While contamination can cause ongoing radiation emission, irradiation does not make the exposed object radioactive. Understanding this distinction is crucial for safety in environments where radioactive materials are present.