Implementation of bioassay methods to improve assessment of incorporated radionuclides

Abstract

The present work which was carried out in the framework of an EU project (IDEA: Internal Dosimetry - Enhancements in Application; Contract Number: FIKR CT2001 00164) shall provide commonly acceptable guidelines for optimum performance of ICP-MS measurements with focus on urinary measurements of uranium, thorium and actinides. From the results of this work it is recommended that, whenever feasible, 24 h urine sampling should be conducted to avoid large uncertainties in the quantitation of daily urinary excretion values. For storage, urine samples should be acidified and kept frozen before analysis. Measurement of total uranium in urine by ICP-MS at physiological levels ( 5 × 104 years. In general, ICP-MS measurements are an easy, fast and cost-saving methodology. New improved measuring techniques (HR-SF-ICP-MS) with detection limits in urine of 150 pg·l1 (1.9 μBq·l1) for 238U, 30 pg·;l1 (2.4 μBq·l1) for 235U and 100 pg·;l1 (0.4 μBq·l1) for 232Th, respectively, meet all necessary requirements. This method should therefore become the routine technique for incorporation monitoring of workers and of members of the general public, in particular for uranium contamination.