Application of specific gravity method for normalization of urinary excretion rates of radionuclides

In vitro bioassay monitoring is based on the determination of activity concentration in biological samples excreted from the body and is most suitable for alpha and beta emitters. For occupational workers handling actinides in reprocessing facilities possibility of internal exposure exists and urine assay is preferred method for monitoring such exposure. Urine samples collected for 24 h duration, is the true representative of bioassay sample and hence in the case of insufficient collection time, specific gravity applied method of normalization of urine sample is used. The present study reports the data of specific gravity generated for controlled group of Indian population by the use of densitometer and its application in urinary sample activity normalization. The average specific gravity value obtained for the controlled group was 1.008±0.005 gm/ml. (author)