Internal exposure due to inhalation or ingestion of NORM   


Ingestion or inhalation of radionuclides may occur while

  • working at open plant and equipment

  • handling surface contaminated objects

  • handling waste materials

  • cleaning of contaminated equipment


Risk of Ingestion is typically low



Risk of inhalation can be high, particularly if

  • dry abrasive techniques are used and
  • no effective personal protective equipment (including respiratory protection) is used

  • Internal dose from inhalation depends on

    • Diameter of inhaled aerosols (AMAD)

    • Solubility of inhaled material (lung absorption class)


Example: Committed dose per unit intake for inhalation of radionuclides in particles of NORM (5 µm AMAD, absorption type S)


  • 38 µSv per Bq Ra-226
  • 4.5 µSv per Bq Pb-210
  • 2.8 µSv per Bq Po-210
  • 12 µSv per Bq Ra-228
  • 32 µSv per Bq Th-228

















Prof. Dr.-Ing. Hans Richard Doerfel

IDEA System GmbH, Am Burgweg 4, D-76227 Karlsruhe, Germany.