[Diagnosis of radionuclide uptake using samples and excretion measurements]

Diagnosis of internal contamination with radionuclides can be achieved by body or organ counting and by analysis of samples of intake or excretion. Sample counting from air, drinking water, food etc. is preferred in environmental contamination and may be used to estimate average body burden and internal dose. For complete monitoring of intake numerous samples have to be measured. Unknown internal contamination with alpha and low energy beta emitters is detected by excretion analysis. For determination of body or organ burden, based on standard man models, time and frequency of intake, physical, chemical and biological behaviour of radionuclides have to be taken into account. Sample sources are mainly urine, feces, exhaled air and in special cases sweat, blood and hair. The collection of excreta needs the cooperation of the contaminated individuals. The results of analysis is usually delayed because of time consuming radiochemical procedures. Repetition of measurement is necessary to increase precision of dose estimate and for detection of single, recurrent or continuous uptake.