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