The estimates for 2395, adult body burden were not used to derive values of intake and committed effective dose equivalent since they may be have been the result of erroneous urine collection technique and not the result of internal deposition. The potential for contamination also existed for 905, however the impact of contamination on dose assessment was much greater for Pu. . . Questions concerning the 239 : Pu estimates have led to a study of the sam- pling and analysis procedures which indicated that some 2395, in urine may not have been chemically recovered along with the tracer (Ry82). The extent of sam- ple contamination during collection and the fundamental reasons for variation in recovery of 239 Pu from urine samples remain unanswered at this time. vestigations are underway. In August 1981, Several in- fecal and urine samples were obtained from Rongelap and Utirik residents and are to be analyzed after complete dissolution followed by a liquid solvent extraction technique used in con- junction with a photon-electron rejecting liquid scintillation spectrometer developed by McDowell for low-level alpha spectroscopy (Mc72). The question of initial sample contamination will be answered following additional analysis of urine collected in 1980 from former Bikini Atoll residents. 22