Table 2 Pstinwation of Gans eee? Goong abesig recat aa Na Cunne RCC mC tr Vd +4 006 he aramap I. Kangelap Appros, Gane of in aod Cableoat Instrument readings Tie of CVn UD Wd die (16 pacagiicy Best estianate used in duse of total goinma 373 ak;he, M4 7 days 75 calculations dose in air (RK) The 55 ber (bu people) PE. Nils anagsnceer in fla duet her Ube ‘Kir 100 mR he, 1049 dave “ EEL. Rosipenik Hy }h4 ede 11+ Jo he CH ress) Jbink be, bad chavs 74H Whe 2s dor Siarted at db 55 fie Wak he, 4h dave 14 IN). Utisik 147 Ibe bb ber (2thaneny Gonpietod at bbe 7s bie sud the fillowt duration as ~ D2 bie, wath mast off the dase delivered carly in that period, Vhe tines when people were evacuated from tie islands ace shownin Fable 2. 2. Gamme (Whole-Body} Dos The fallout (where seen) resembled snow of mist and was deposited relatively homogencously so that the individuals on cach islind were con- sidered to have received about the same estinuuted dose of gamma radiation. The children may have hala squnewliat higher dose than that calculated for the adults because, being sinatler, they were chaser te the ground and received Larger midline dases, This possibility is supported by the higher incidence of carly nausea aad voaiting and the ureatcr depression of blood clement, in the voung children. Vhe tlimsy houses atlorded lithe attenu: anon of the raciagion. Vhe whole-body doses were calcubuted from iwasurements with radiation field survey tastrugents held8 above the grounel, tnade within a week after the detonation, dw ex- Intpolanon tothe tine of exposure with the energy spectrum and decay taken tote consideration, Vable 2 shows the calculated gamma doses far the ditfcrent populations exposed, The degree of hema: tological depression that developed later is cou- stent with the doses calculated. Lo view of the i geometryof espasure, the middioe doses to indie viduals were higher than those obtained with the sual bikweral exposure of s-radiation.* 3. Skin Dose ‘The dose to the shin surface was much greater thin the whole-body wacnmia douse because of the large amount of beta radiation absaibed by the skin. The actual skin doses, although impossible to clleulate, probably amounted to thouxinads of rads, and cheir range of values, duc tu ditferent amount of fallout sticking to different arcas, accounted for the spotty nature and varying intensityof lesions, The extensiveness of the beta burns in eachisland group correlated roughly with the amount of fall- oul visible on their island (see Table 6}. Most of the skin dose was due to fallout deposited directly on the skin, but sume was due tu beta radiation from fallout on the ground (estimated at Rongelap to be 2000 rads at the level of the dorsum of the feet, GOO rads at hip level, and 300 rads at the head, on the basis of continuous exposure and no shielding).? lt was fortunate that the beta radiation had an average energy insuflicient to penetrate deeply date the skin and therefore resubled for the most part in superticial ber burns. The average bers pardecle probably did not penctrate much bevond the basil Laver of the skin (= 100 y). However, since epilation occurred ia inany people, the region of the hair (olhcles must have received a dase equivalent atleast to the minimal epilating dase of 400 rads of ZOO-KN ps rays. 4, Internal Dose Calculations Internal absorption of radioisotopes was due te inhalation as the radivactive cloud passed over and tojngestion of food and water contaminated with fallout, water probably being a niajor source. Drinking water is obtained by collecting rainfall from the rools into catchments, and a slight cain was reported on Roagelap the might of the Gillout Since the cisterns were nearly empty, the dilution cHeet was iinmimal Water was being rationed at that time, and at ewas drunk in spite of warnings fran the health aide, Ou Ronverik food and water were bever protected fromfallout depositiaa. latcrnal levels of radioisotopes absarbed (rom the fallout were assessed by ousmnerous radiochenu- a Ps