Internal contamination results when radioactive material is taken into the body via inhalation or ingestion or open wounds.
Internal deposition of radioisotopes in organs results in local exposure at that location.
Internal contamination continues until the radioactive material decays, is flushed from the body by natural processes, or is removed by medical countermeasures.
How to diagnose
If after external decontamination, an appropriate radiation survey meter continues to identify significant residual radioactivity, suspect internal contamination.