Monitoring by excretion analysis: results of interlaboratory comparisons

The measurement of radioactivity concentrations in urine samples is an important tool for the monitoring of possible radionuclide intakes by occupationally exposed workers, especially for those radionuclides emitting alpha or beta radiation. The new German guideline for requirements for measuring laboratories requires measures for standardisation and quality assurance by all laboratories responsible for such measurements. For this purpose the working group 'Incorporation Monitoring (AKI)' of the German-Swiss Radiation Protection Association has already performed, in the period from 1981 to 1997, interlaboratory comparisons of uranium, thorium, americium, lead, strontium and tritium in urine. The results and their implications for internal dosimetry are presented. (author)