Purpose: The present system of radiation protection quantities, based on recent recommendations and reports presented by ICRP and ICRU, is rather complicated and thus not easily implementable in practice strictly in accordance with their definitions. The paper discusses some difficulties in the use of specific quantities for assessing personal exposure with specific emphasis on their use in nuclear medicine and a suggestion as to how the situation may be solved.
Methods: All relevant ICRP and ICRU recommendations related to the definitions of basic radiation protection quantities which have been introduced for setting dose limits, dose constraints and reference levels are critically reviewed and scrutinized. Special attention is paid to some inconsistencies between these quantities and operational or other measurable quantities. There is also a reference made to the latest draft of the ICRP/ICRU report on new operational quantities for external radiation exposure.
Results: Careful analyses of the present system of radiation protection quantities have shown that there is a need to reconsider the current approach based on the frequent modification of such quantities which may negatively affect the implementation of radiation protection requirements in practice. This is especially important in maintaining compliance with specific protection standards based on radiation monitoring.
Conclusions: The present system of the quantification of radiation exposure in nuclear medicine is too sophisticated to be easily applied by radiation workers, who can rely only on the available routine dosimeters or monitors, the response of which cannot be easily interpreted in terms of the current quantities. The present trend in refining the radiation protection system should be continued but should be limited to universities and research institutes. For routine monitoring a simpler system should be developed which can be better understood by radiation personnel and could be more readily implemented in practice, including in nuclear medicine, where there are problems with reliable assessment, especially with skin and eye lens exposure.