226 Health Physics Table 6. Comparison of estimates of average acute intake (MBq) of '*'I among exposed Marshallese and American groupsfollowing deposition of Bravo fallout. All values are rounded to two significant digits. Group and source of estimates Gender(adults) Rongelap Island group Harris (**'") Male-female Lessard etal. Male-female (1985) Simonet al. Male-female (2010b)* Sifo, Ailinginae group Harris (**") Male-female Lessard etal. Male-female (1985) Simonet al. Male-female (2010b)* American military on Rongerik Harris (**") Goetz et al. (1987) Simonet al. (2010b) Male Male Male S81 (MBq) average average 2.8 3.4 average 3.5 average average 1.3 0.69° average 1.2 0.78 (1.7)* 0.56 (1.2)° 1.7 “Intake estimates here use the Simonet al. (2010b) model assumptions and the Table 3 bioassay data (Harris 1954, footnote *) from 3/16/54 and 3/17/54 for Rongelap, while intake estimates for Rongelap in Simonetal. (2010b) used a weighted value of intake per unit deposition from Rongelap and Ailinginae. > Theintake estimate by Lessardet. al. (1985) at Sifo is not solely based on urinary '*'I measurementbut is weighted by fallout particle sizes, external exposure rate measurements, and considers meal times, and time-of-arrival. “ Intake estimates here use the Simonet al. (2010b) model assumptions and the Table 3 bioassay data for Ailinginae while intake estimates for Ailinginae in Simonet al. (2010b) used a weighted value of intake per unit deposition from Rongelap and Ailinginae. 4500 mL urine volume (same as for Marshallese) was used in this calculation; use of 1,100 mL urine volume for LA319A (see Table 2) would have given 1.7 MBq. * 500 mL urine volume (same as for Marshallese) was used; use of 1,100 mL urine volume for LA319A (see Table 2) would have given 1.2 MBq. MBgfor the adults exposed on Rongelap, from 0.7 to 1.3 MBgfor the Rongelap adults exposed on Ailinginae, and from 0.6 to 1.7 MBq for the American military weather observers exposed on Rongerik (Table 6). In this context, “average” refers to the mean value for the group of adults sampled and that contributed to the pooled urine sample. Those data can be reasonably assumed to be applicable to other adults on the atoll who were not sampled on that day. An average of male and female intake estimates is presented in Table 6 for comparison with estimates from other investigators. The estimated intake of ''I among adults on Rongelap was 2.8 MBq by Harris, 3.4 MBq by Lessard et al. (1985), and 3.5 MBq by Simon etal. (2010b). The primary differences can be attributed to the assumed volume of urine excreted in 24 h and the fractional excretion on the day of sampling (eqn 1). A comparison of the estimated intakes of '*'l among the military weather observers on Rongerik by Harris, Goetz et al. (1987), and Simonetal. (2010b) showedsignificant August 2010, Volume 99, Number 2 differences but can be primarily attributed to the volume of urine assumed to have been excreted in 24 h. The actual average urine volume for American military weather observers was 1,072 mL (Table 4). Harris in 1954** and Goetz et al. (1987) both used 500 mL, while Simonet al. (2010b) used the actual mean value. Quality of assays of radionuclides other than ''I Table Al of the Appendix summarizes some information about the assay methods for other radionuclides as implemented by LASL, Walter Reed, and the NRDL. Little detail on these methods could be found. We have attempted to evaluate the reliability of those measurements from sparse documentation with the following conclusions (adapted from Ibrahim 2007°"): 1. Walter Reed data on '*’Cs and the Harris data on '*'1 are good due to the specific measurements employed. Both data sets are likely to have modest-sized measurement uncertainties; 2. Sr data, analyzed only at Walter Reed, are also good due to the specific radiochemical separation used; 3. Sr measured by NRDL and LASLissatisfactory within a modest range of uncertainty; 4. 'Ba measured by LASL wasnotsatisfactory due to interference from '“°La ingrowth; 5. '°Ru measured by LASL during the initial phase of the work was notsatisfactory, but improved somewhat afterwards. Even at best, the associated uncer- tainty with '°’Ru measurements was high; and 6. Plutonium measurements conducted in 1954 were not reliable and were recognized as such in 1954.5 Various counting results from these assays can be found in some of the historical documents previously noted. Tables A2 through A6 present these data, though we do not attempt use or interpret these data since many of those data were either already described or, in some cases, found to be unreliable. This documentation is primarily for historical purposes. CONCLUSION For the first time in the refereed literature, the bioassay measurement data on '*'I and volumesof urine samples collected are presented for samples collected in 1954 following exposure of Marshallese and American military weather observersto radioactive fallout from the Bravo nuclear test. The data reported here include individual and group-average urine volumes, count rates "YT Tbrahim SA. Summary of urine bioassay conducted at the Marshall Islands in the 1950’s and evaluation of reliability and quality of measurements techniques. Report to the National CancerInstitute. 10 October 2007.