A manufacturing plant uses high-energy gamma radiation from a sealed Cobalt-60 source to cross-link polymer insulation on electrical cables. In a different area of the plant, a pipeline inspector accidentally inhales radon gas containing alpha-emitting decay products that deposit inside their lungs.
State two key differences between irradiation (experienced by the polymer cables) and radioactive contamination (experienced by the pipeline inspector) regarding the location of the radioactive source and whether the affected object/person becomes a source of radiation.