INTERNAL DOSIMETRY MONITORING EQUIPMENT - PRESENT AND FUTURE

Internal dosimetry monitoring equipment used in the successful measure ment and assessment of internal exposures is highly dependent on effec tive capabilities in the measurement of radioactive materials directly and/or indirectly in the body. This capability must be supplemented b y comprehensive field measurements to quantify materials (i.e. surface and airborne contamination) in the workplace which become the source of exposure to the workers. Because of current limitations on minimum detectable activities or amounts for in vivo or in vitro measurements for some radionuclides (i.e. poorly transported alpha emitters), a rou tine bioassay programme which would maintain the potential minimum det ectable dose to a few millisieverts committed effective dose equivalen t (H(E.50)) would be prohibitively expensive to operate and unacceptab le to the worker. Thus the operation of a strong field measurement pro gramme to provide warning of possible intakes is extremely important t o permit timely bioassay measurements to be performed within the limit s of detection. The present and future capabilities of the three measu rement programmes will be discussed together with the need to balance research and development costs for new or improved measurement techniq ues with the costs associated with improving knowledge as to the relat ionship(s) between measurement and the amount present in various organ s.