Acute and chromic mtakesof fallout radionuclides @ SL Simow er av urme volume from each sampling of Marshallese appear much smaller than the daily water mtakes associated with normal conditions Water mtake per day for adults m most familiar situations (temperate climates where fresh water1s easily accessible) 1s usually 2 L or more and an uninformed view of urmary excretion is that urmary water losses should approxrmately equal water mtake However, that 1s often untrue m temperate climates and appears, according to much hterature, as almost always untrue in tropical climates The volume of urme excreted daily vanes with a number of factors that suggest a reasonable central estimate for the 73 kg adult reference male 1s 1,600 mL a (ICRP 2002), however, that generalization 1s based on Western Europeans and North Americans (1 e , 1mplying temperate climatesituations with contmual access to potable water) ICRP (2002) further notes that “durmg prolonged periodsof high waterloss or low water mtake, urme output may decrease to as hittle as 6-7 mL kg”! 195 observations of 490 to 3,600 mL d7' (Dosios et al 1974) In studies of 18 young men m the Royal Arr Force transferred from the UK to Bahrain (Persian Gulf), the average daily urme volume decreased from 1,070 mL d7' im the UK (before transfer to Bahram) to 570 mL d7' after transfer to Bahram The reductions m daily urme volume were attributed to persptration losses (Leithead and Palhister 1960) After transfer to a tropical environ- ment, 48% had 24-h urme specimens smaller than 500 mL and 10% were less than 300 mL While the daily populaton-mean values of urme from the samplings of Marshallese im 1954 appear small and atfirst consideration, cast doubt on therr validity to representtrue 24-h volumes, there 1s not only supporting evidence that ure volumes are often small im tropical chmates, there was substantial consistency among the urme volume distributions from eight different samplings, with a shght mcrease after 3 wk after exposure (Table 4, Harris et al 2010) (sweating or perspiration, plus sensible losses) would Several other pomts are important with respect to understandimg the volumes of collected urme At the trme of Bravo (1 March 1954), a lengthy drought was in progress m the northern Marshall Islands (Sharp and Chapman 1957, Lessard et al 1985) According to those sources, Marshallese living on Rongelapat the time had been limited to about one pmt of water (~500 mL) per day from commumity cisterns Further evidence regardimg the drought1s from the small amounts of water m the catchmentsat the time of evacuation as noted by Sharp and Chapman (1957) Simce | cup of water per day 1s not sufficient fluid mtake for adults or children m tropical sex-averaged average value of more than | L water lost daily through pathwaysother than urme and feces (also see draft report of WHO 2004) These estimates oftotal persprration plus msensible water losses agree with needed per person per day was obtamed from the juice from young “drmking” coconuts Drinkmg coconutsare plentiful on every atoll and 1sland in the Marshall Islands One medium drinking coconutcan provide about 350 mL d-™ and cites Johnson (1998) Such extreme conditions would lead to urme volumes as small as 500 mL d7' Johnson explams im more detail that 500 mL d~' 1s about the mmimum waterloss through urme to achieve proper glomerular filtration The description of reference man also indicates typical perspiration losses to be 500 and 375 mL d™' and isensible losses (gaseus water losses via skim and Jungs) to be 690 and 515 mL d7', for adult male and females, respectively (see Table 2 30, ICRP 2002) Accordmg to those estimates, total daily water losses wia the skin be 1,190 mL and 890 mL, for males and females, or a numerous other literature sources (see NAP 1986, 1993) It 1s not clear from the available data whether imsensible water losses result m loss of 1odine from the body, but such losses do help explam the small urme volumes observed by Harms (1954) Tropical, Inghhumidity settmgs tend to favor sweatmg (Wright 1956, Kuno 1956, Dosios et al 1974) over msensible losses (Comroe 1965) and sweating 1s known to be a loss pathway for 1odme (Mao et al 1990, 2001) All these data descriptions and data support our mterpretation that the small urme volumes obtamed m the Marshall Islands were a consequence of perspiration and sensible water losses Other hterature has confirmed stmilar losses of water through perspiration, particularly m tropical settmgs For example, studies of more than 70 adult patients im Greece mdicated mean evaporative water losses (via the skin) of about 1,500 to 1,750 mL da witha range of chmates, 1t must be assumed that the additional water of hquid (FAO 1983) It has been reported that at the tme of fallout, the residents of Rongelap were advised by the Marshallese medical practitioner on the island, a man named Jabwe (Sharp and Chapman 1957, personal notes of PS Har- vis), not to drmk the water im their open catchments because of the unknownnatureofthe fallout Sharp and Chapman (1957) speculated that the native residents probably resorted to drmkmg more water from the catchments than advised by ther medical practitioner and supplemented their fluid mtake with hquid from drinkmg coconuts The residents of Rongelap and those visitmg Ailmginae Atoll were evacuated to Kwayalem around H+50h simce ther exposure to unexpected highlevels offallout had been recogmzed by U S authorities Harris was told by Jabwe that he advised the Rongelap people not to