218 Health Physics lying at more southern latitudes, e.g., Kwajalein, Majuro and others (Breslin and Cassidy 1955; Becket al. 2010). Prior to the Bravo test, there was little experience with assessing internal contamination from exposure to fallout or predicting the related health consequences. One central reason that investigators from the Los Alamos Scientific Laboratory (LASL) conducted the urine sam- pling was to correlate data collected during Operation Greenhouse (Enewetak 1951) and in the UK on deter- mining the relative hazards of external and internal exposure to radioactive debris from atomic weapons.* The data obtained from bioassay were also believed to be potentially useful for radiation safety purposes in the future, particularly since the weapons testing program was envisioned to continue for years to come. Soon after the exposures took place from the deposition of Bravo fallout, investigators at LASL realized that urinary excretion of radionuclides by the Marshallese could be used as an index of internal contamination,° and plans were madeto obtain 24-h urine samples from the islanders and the military weather observers stationed on Rongerik.* On the 15th dayafter fallout, the first urine collection was conducted by LASL.Otherinstitutions, in particular, the Naval Radiological Defense Laboratory (NRDL), and later Brookhaven National Laboratory (BNL), also collected urine samples in 1954; however, their purposes were primarily to documentthe effects and responses to, at that time, levels of environmental exposure without precedent (Bond et al. 1955; Conard et al. 1956). The earliest report on radioactivity assays in urine samples collected from Marshallese was from one of us in the form of a laboratory memo referred to here as Harris (1954)**. In that document, summary results of assays (countrates and activity concentrations) of '*'I in urine from the exposed adult population on Rongelap Island and on nearby Sifo Island on Ailinginae were reported and simple estimates of thyroid doses from '*'1 estimated. As will be discussed, the LASL urine samples, while obtained from individual adults, were mixed to form “pooled” samples from which aliquots were assayed for '*'I activity and other radionuclides. At a later date, a modest change in detector efficiency for * Telex communication (memorandum). Los Alamos Scientific Laboratory to USAEC, Washington, DC. 10 March 1954. Availableat: http://www.hss.energy.gov/healthsafety/ihs/marshall/collection/data/ ihp1d/400045e.pdf. ** Harris PS. A summary of the results of urine analysis on Rongelap natives Americans and Japanese fishermen to date. Memo to AEC. Los Alamos, NM: Los Alamos Scientific Laboratory; 1954. August 2010, Volume 99, Number 2 'S!T measurements was determined.’’ Neither the mod- ifications, nor the original data, however, were ever published. In addition to collections by LASL, urine samples were also collected by the Atomic Energy Commission (AEC) New York Operations Office’s (NYOO) Health and Safety Laboratory (HASL) (Bouville and Beck 2000) and the NRDL (Cronkite et al. 1956; Woodward et al. 1959). There does not appear, however, to be any single source of information on all urine samples obtained by the different laboratories. From the sparse historical record, it appears that some of the sampling efforts were partially coordinated. For example, urine samples collected by Navy personnel on 24 and 25 March 1954, under the NRDLauspices, were distributed to HASL, LASL, and NRDL.** In 1958, the Walter Reed Army Institute of Research (Department of Nuclear Medicine), in conjunction with the Department of Pathology of BNL reported on the determination of internally deposited radioisotopes from urine samples collected in 1954. Those data appear to be counting data from which the radionuclide excretions (in terms of activity per day) were reported in 1959 by Walter Reed Army Institute of Research. Possibly because of the poor documentation available on the various urine samplings conducted by different laboratories, James (1964), for an estimation of doses to Rongelap children, mistakenly assumed and reported that the pooled urine samples collected by LASL were 20.1% urine (by volume) from ages 5-16 y and 4.8% from ages <5 y. Those volumes described the Walter Reed samples reported by Woodwardet al. (1959). The LASL samples, in fact, only included urine from adults. In later years, dose assessments for the Marshallese on Rongelap, Ailinginae and Utrik (Lessard et al. 1985) and the American military on Rongerik (Goetz et al. 1987) were conducted, though none were published in peer-reviewed journals. Lessard et al. (1985) estimated external and internal thyroid doses to the Marshallese on Ailinginae, Rongelap, and Utrik from the Bravo test using data of Harris** and other kinds of information. Other authors later cited Lessard et al. (1985) as that analysis was easily the most thorough and best docu- mented analysis at that time. However, all of the above reports incorrectly reported that the pooled urine sample collected by LASL included urine from children. It is unusual, given the significance of the primary bioassay data, that after 55 years, it is so poorly documented in the open literature. However, one of us ** Harris PS. Bravo fallout. Written circa 1980, unpublished manuscript. ** Memorandum from E.P. Cronkite (NRDL) to Merril Eisenbud (NYOO), 4 April 1954.