224 Health Physics August 2010, Volume 99, Number 2 model, the decay correction need only to account for the elapsed time between sampling and counting. This was 1000 the method used by Lessard et al. (1985), Goetz et al. (1987), and Simonet al. (2010b). Urine volumes The distributions of individual urine volumes in the three groups of samples collected by LASL from Rongelapese on March 16 (n = 35), March 17 (n = 31), and April 15 (2 = 21) in 1954 are presented in Table 4 and Fig. 2.***5** The mean urine volumes from the LASL collections in mid-March 1954 were similar; the average values were 427 mL (March 16, Rongelap), 448 mL (March 17, Rongelap), and 385 mL (March 19, Sifo). The distributions and mean urine volumes of the HASL samples (Fig. 3) from March were similar in magnitude to the LASL samples, but slightly higher, 596 mL (March 24, Rongelap), 523 mL (March 25, Rongelap), TT goo /------ an veeeeeed: vetee beeches _— ponoong ee a foveed: ve eeeeees a _| Daily Urine Volume (mL) RESULTS AND DISCUSSION ! BOO boeiecpeee secede beeebecbeeeeebeeee hb cccbeebeecebeeceedienne [ : * ; ' 4 ‘ Oo : ‘ : | 400 [veered debe gfe | o— caster | PoP ob tae —ae— LA317R|: aee aeee 5 10 2030 50 7080 9095 99 99.9 99.99 Cumulative Percent Fig. 2. Empirical cumulative probability distributions of urine volumes obtained from two Los Alamos Scientific Laboratory (LASL) samplings of Rongelapese greater than 16 y old at time of exposure (see Table 4 for a summary of the data). 756 mL (March 24, Sifo), 603 mL (March 25, Sifo), and 573 mL (April 15, Rongelap) (Cronkite et al. 1956).** Individual urine volumes from two groups of the American military weather observers resident on Rongerik at the time of Bravo whoprovided samples in 1954 on March 19 (n = 9 for beta activity measurements and n = 10 for Pu activity measurements) are shown in Fig. 4 and are also summarized in Table 4.***SS The urine volumes collected from the Marshallese were, on average, small compared to the usual range of 800 to 2,000 mL d' reported for populations with a typical fluid intake of about 2 L d| (MedlinePlus 2002). Not all Marshallese sampled, however, excreted these extremely small samples. For example, of those sampled on March 16, the volume for one urine sample was greater than 800 mL, of those sampled on March 17, three (12%) were greater than 800 mL, and of those sampled on June 15, six (30%) were greater than 800 mL. Lowerthan average urine volumesare, in general, a result of either reduced fluid intake and subsequent dehydration or high water losses through feces or, more commonly, through the skin. Hence, one possible explanation for low urine volumes among the Marshallese was a well documented drought that had been underway in the northern Marshall Islands for a number of months prior to the Bravo test. Sharp and Chapman (1957) reported that “for many weeks prior to 1 March, the natives had been rationed to one pint cup per individual per day.” The shortage of fresh water would have also affected those on Ailinginae and Utrik. The average urinary excretion for the American weathermen on Rongerik was significantly greater compared to the Marshallese (Table 4) and averaged about 1,100 to 1,200 mL per day.***’°* However, Rongerik, where the Amer- ican military weather observers were located, had a water distillation unit and drinking water was available in 5-gallon cans at the time of evacuation (Sharp and Chapman 1957). Anotherplausible explanation for the small average values of urine is the reduction of daily urine volumein Table 4. Summary statistics of sampled urine volumes (see Table | for references). All values are nominally mL per 24 h (na = not available). No. of samples Minimum Maximum Mean Median Std Error LA316R LA317R 35 90 31 140 9 730 10 760 850 1,345 1,525 990 427 360 42 448 415 37 LA319A 1,072 1,130 71 LA319AP* 1,197 1,250 86 Group ID LA319S NY324R 15 na na 385 na na 40 70 980 596 653 47 “LASL sample on March 19 from American (A) military for plutonium (P) analysis. NY325R NY324S NY325S NY416R 43 95 980 523 480 44 12 320 965 756 805 57 15 90 985 603 750 76 21 47 980 573 540 59