Protocol for Urine Bioassay Sample Collections Marshall Island's Radiological Safucy Program A. Purpose Radiochemical analyses of urine are used to determine the excretion rates of radionuclides from individuals living in areas affected by the Pacific Testing Programs. The results of these analyses will be used to: (1) (2) estimate body burdens of 99sr, 239,240pu, and other radionuclides which cannot be determined with in vivo counting techniques, provide independent estimates of body burdens of gamma emitzrers (such as 137¢5) which can be determined by in vivo councing, (3) B, and provide an indication of the extent to which restrictions on certain local food items are being followed. Sample Types Three types of urine samples will be used in the bioassay program. They ara (1) single void "grab samples", (2) 24-hour urine samples, and (3) large-volume samples comprised of several 24-hour samples. Each of these is discussed below. (1) Single-void "grab sample" This is the least desirable type, but it is also the easiesc type to collect. Grab samples are useful for estimates of Sr and Cs excretion rates, but 24-hour samples are definitely preferred. Laboratory limits of detecrion are, in part, a function of sample volume (total activity per sample). A practical minimum sample volume is 200 ml. Attempts should be made to collect more than one voiding, if possible. (2) 24-hour urine sample This is the preferred type of sample for routine urine dioassay (except for alpha-emitters). The sample volume (500 to 1500 ml) should be adequate for Sr and Cs radio-assay, and analytical results can be directly compared with published excretion rate data for estimation of body burdens. (3) Large-volume sample Because of the limitations of radiochemical and counting procedures, large-volume samples (>5000 ml) musc be collected for bioassay of transuranic nuclides. Typically, these samples will consist of five or more days of aggregate 24-hour urine collections. Special precaucions muse be followed to minimize the possibility of sample contamination with extraneous material (primarily "local" dust and dirt). C. Sample Collection Procedure (1) 24-hour urine samoles and sinele-void samples

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