[en] In the past ten years a series of Publications have been issued by Committee 2 of the International Commission on Radiological Protection (ICRP) giving dose coefficients for intakes of radionuclides by inhalation and ingestion for both members of the public and workers. The biokinetic and dosimetric models used in the calculation of dose coefficients have been based largely on the model structure adopted in ICRP Publication 30 although new, physiologically-based models, involving recycling of radionuclides have been developed for both the alkaline earth and actinide elements. In addition, a new model for the human respiratory tract (HRTM) has been developed. A comprehensive series of dose coefficients have also been published by ICRP on CD-ROM. The series of reports giving dose coefficients for members of the public of various ages is to be completed with the issue of two further reports. The first will give dose coefficients for the embryo, fetus and newborn child following intakes of radionuclides by the mother either before or during pregnancy. Models for infants and children can generally be based on those for adults, with modifications to parameter values, but in the case of the embryo and fetus, fundamentally new models have had to be developed. Models are also being developed for calculating radiation doses to the offspring as a result of the intake of radionuclides in breast milk. The HRTM used for calculating inhalation dose coefficients was developed to allow the use of material specific data. To date, however, it has only been applied using default model parameters. A technical report is being developed that will give guidance on the practical application of the HRTM in circumstances which require the use of data on the deposition and solubility characteristics of specific inhaled materials. The present model used for assessing doses from ingestion of radionuclides was prepared in 1966. An improved model for the human alimentary tract is being developed that will be age-dependent and give a better definition of the anatomical regions needed for dosimetry. It will additionally evaluate information on the transport and absorption of materials in the various regions of the gastrointestinal tract and review information on the location of cells at risk. In the longer term there remains a need to develop a full revision of data used for monitoring the internal exposure for workers. With the progressive move to physiologically-based biokinetic models, the aim now is to develop models that are appropriate for both bioassay interpretation and for dosimetry calculations. Considerable thought is being given as to how the data will need to be presented, given the rapid changes in technology and the need for operational health physicists to be able to apply the more complex models that are now being developed. Other issues are presently being considered that are an important input to further model development. These include: the identification of target cells in the skeleton in relation to the calculation of doses from bone seeking radionuclides; the dosimetry of Auger emitters; the calculation of doses from inhaled radon; and the development of more realistic phantoms based on medical imaging data. (author)