I 

NVO-140 

VOLUME 

ENEWETAK 

RADIOLOGICAL SURVEY 

OCTOBER 1973 

UNITED STATES ATOMIC ENERGY COMMISSION 

NEVADA OPERATIONS OFFICE 

LAS VEGAS, NEVADA 

Contents 

\[‘s;l‘;>.ci . . . . . . . . . , . . . . . iii 

\-i 

I. Introduciio:: (If.. Uervik, Lan-rence Livermore Laboratory) . . . 1 

Il. ~nen~c:tak (R. Ray, Nevada Operations Office, US_qEC; J. Koranda and 

I;. x;trsh, Ian-rence Livermore Laboratory-; and ~7. Nelson, t-niversity of 

\\.ashingtonj . . . . . . . . . . . . . . 3 

1:. 5urvey EsezLltion . . . . . . . . . . . . . 4’; 

Survey Plan W. Nervik, Lawrence Livermore Laboratory) . . . 47 

-Aerial Radiological and Photographic Survey (T. P. Stuart and 

R. 1Ieibaum, EG&G, Inc. ) . . . . . . . . . 49 

Terrestrial Soil Survey (0. D. T. Lynch Jr., Nevada Operations 

Office, USAEC, and P. H. Gudiksen, ian.rence Livermore 

Laboratory) . . . . . . . . . . . . . 81 

External Dose Estimate (H. L. Beck and J. E. McLaughlin, Health and 

Safety- Laboratory, USAEC; P. II. Guciiksen and D. E. Jones, 

Lawrence Livermore Laboratory; 0. D. T. Lynch, Jr., Nevada 

Operations Office, USAEC; and T. P. Stuart, EG&G, Inc. ) . . 117 

Marine Program (V. Nelson, Laboratory of Radiation Ecology, 

University of Washington, and TI’. E. Xoshkin, Lawrence Livermore 

Laboratory) . . . . . . . . . . 131 

Terrestrial Biota Survey (J. J. Koranda, J. R. Martin, S. E. 

Thompson, Jr., M. L. Stuart, and D. R. McIntyre, Lawrence 

Livermore Laboratory; G. Potter, Environmental Protection 

Agency) . . . . . . . . . . . . . . 225 

Air-Sampling Program (B. Clegg and D, 15’ilson, Lawrence Livermore 

Laboratory) . . . . . . . . . . . . . 349 

Engineering Survey - Radiological Aspects (0. D. T. Lynch, Jr., 

Nevada Operations Office, USAEC) . . . . . . . . 372 

-4nalytical Program (R. W. Hoff, J. W. IIeadows, H. D. Wilson, 

A. L. Prindle, R. Gunnink, and K. 0. Hamby, Lawrence Livermore 

Laboratory) . . . . . . . . . . . . . 426 

Enewetak Survey Radiological Controls (0. D. T. Lynch, Jr., Nevada 

Operations Office, USAEC) . . . . . . . . . 486 

Dose Assessment and Evaluation . . . . . . . . . 491 

Dietary and Living Patterns (W. L. Robison, Lawrence Livermore 

Laboratory) . . . . . . . . . . . . 492 

External Dose Determination (H. L. Beck and J. E. McLaughlin, 

Health and Safety Laboratory, USAEC; P. H. Gudiksen and 

D. E. <Jones, Lawrence Livermore Laboratory) . . . . 498 

Evaluation of the Inhalation Pathway (D. W. Wilson, Lawrence 

Livermore Laboratory) . . . . . . . . 507 

Appendix A - Relationship Between desus’pended Plutonium 

in Air and Plutonium in Soil (L. R. Anspaugh, Lawrence 

Livermore Laboratory) . . . . . . . . . . 515 

-i-
Contents (conrlnued) 

Dose Estimates for the Marine Food Chain (1.1.. L. Robison. 

Lawrence Livermore Laboratory) . . . . . 

Evaluation of the Dosage from Terrestrial Foods (1.. C. Xg, 

B. J. Berger, D. J. Pederson, Y. E. nicker, and S. E. 

Thompson, Jr., Lawrence Livermore Laboratory) . 

Summary of Dose _4ssessment (\Y, L. Robison, I-z>:.-rence 

Livermore Laboratory) . . . . . . . 

. 

. 

. 

. 

. 

. 

326 

542 

612 

IV. Summary of Findings (W. Nervik, Lawrence Livermore Laboratory . 626 

_Xppendix 

Atoll 

I - Planning 

Precleanup 

and Operations Directive 

Radiological Survey . 

(NVO-121) 

. . 

- 1972 

. . 

Enewetak 

. . . 696 

Appendix II - Survey Results by Island . . . . . . . . 1’01s. II-III 

-ii_ 
Abstract 

The AEC has conducted a survey of 

the total radiological environment of Ene-

..vetak Atoll in order to prol:ide data for 

judgments as to lvhether or not all or any 

part of the Atoll can be safely reinhabited. 

Xlore than 3300 samples from all parts of 

the marine, terrestrial, and atmospheric 

components of the Xtoll environment were 

analyzed by instrumental and radiochemical methods. In addition, an aerial survey for gamma-radiation levels was conducted over all land areas. 

“Sr, 137Cs, 6oCo, and 3-3gPu are the 

predominant radioactive isotopes now 

present, but their distribution is far from 

uniform. Islands on the southern half of 

the Atoll from ALVIN to KEITH have levels oi contamination comparable to or 

less than those due to lvorld-wide fallout 

in the l-nited States. On the northern 

half, islands ALICE to IRENE are most 

heavily contaminated, KATE to 1sIILMA 

are least contaminated, and JANET is at 

an intermediate levei. 

These radiological data have been combined with the best information currently 

available on the expected diet of the Enewetak people to estimate potential wholebody and bone doses to the population for 

six living patterns at 5-, lo-, 30-, and 

‘70-yr intervals after return. Thirtyyear integral dose estimates for unmodified (i.e., current) conditions are shown 

in Table A. 

Table A. The 30-yr integral dose for six living patterns, assuming unmodified conditions. 

30-year integral dose, rem 

Unmodified conditions 

External 

Living Inhalation Bone, Terrestrial Marine Total 

pattern Bone Lung Liver W.B. W.B. Bone W. B. Bone W. B. ‘Bone 

I 7(-41 9(-4) 4(-41 0.83 0.14 2.1 0.053 0.84 1.0 3.8 

II 0.029 0.036 0.016 1.6 2.7 33 0.053 0.84 4.4 35 

III 0.10 0.13 0.056 4.0 6.1 75 0.053 0.84 11 80 

IV 0.47 0.59 0.24 10 21 210 0.053 0.84 31 220 

V 0.11 0.13 0.058 2.9 2.7 33 0.053 0.84 5.7 37 

VI 0.090 0.11 0.049 4.4 9.8 130 0.053 0.84 14 135 

Living 

pattern Village island Agriculture Visitation 

I FRED/ELMER/DAVID ALVIN through KEITH Southern islands 

II FRED/ELMER/DAVID KATE through WILMA Northern islands 

plus LEROY 

III JANET JANET Northern islands 

IV BELLE BELLE Northern islands 

V JANET KATE through WILMA 

plus LEROY Northern islands 

VI JANET ALICE through IRENE Northern islands 

-iii_ 
/-1ose comes ri-iroi:gh :he tcrrc.+rr:ai food 

Fathway, follo\x:ed in decreasi122 order 0T‘ 

Significance :,>- The external gamma dose, 

.marine, and inhalation path\va>-z. In the 

terrestrial iaod pathway, Ihe --sin contrlbutlon to both x-hole-body an5 !,one 

dose 1s due T,J :,andanus and hreadfrult. 

Percentag,re cqntributlons to the X0-yr 

integral dose for each of the terrestrial 

food itfrns for a population engaged in 

a~~~~cul:ure ‘):I .T_LSET are .sl~~~.~:r. In 

Table li. 

CorrectiT:e actions to reduce popula-

:lon doses w:ll be most heneficlal if they 

are directed at the primary contributors, 

i.e., pandanus and breadfruit in the diet 

and external gamma dose in the residence 

areas. Since neither pandanus nor breadfruit are nov: growing on the Atoll in sufficient amounts to provide a significant 

dietary component, control of the location 

and manner in which they are reestablished will have a direct influence on the 

population doses from these fruits. If 

their growth were limited to the southern 

islands, for example, and the population 

living on .JASET were to import them 

Table B. Percentage of total 30-yr terrestrial food dose to a population engaged in agriculture on 

JANET. 

00 Sr dose 137Cs dose 

to bone, to whole body, 

Food ‘6 mo 

IIomestlc mear !7 76 

Pandanus fruit 10 35 

IY readfru it 31 29 

Wild birds 0.005 0.003 

Bard eggs 0.05 0.002 

Arrowroot 2 0.3 

Coconut meat 6 9 

Coconut mtlk 0.9 1 

:Tather :!:a:i croa tk~:?l iocai!>-, the es-

;,ecred .; 0 -:;r bone r:->~r’ Ir:oxld be reduced 

I‘rem s,i) 10 :35 rem and the l:;hole-body 

(Jose from l! to ii.5 rem. Similar results 

?vould be obtained I? uncontaminated soil 

\vere Imported to .JXSET for the establishmenr of these piants. Attempts to 

obtain The same results by removal of 

“Sr- and 13’Cs-contaminated soil from 

JANET Ivould require denuding of the 

entire island because of the relatively 

urnform distribution of these isotopes 

over the land surface. 

Significant reduction of the external 

gamma dose may be achieved by placing 

a Z-in. layer of clean gravel in the village areas and by plowing the agricultural 

areas. On JANET, for example, use of 

these procedures reduces the expected 

30-yr external dose from 4.0 to 1.7 rem. 

Thus, from Table A it is clear that a 

very broad range of population doses may 

be expected, depending on village island, 

agricultural island, and living pattern. It 

is equally clear that substantial reductions of the higher doses can be achieved 

through relatively simple modification of 

the agricultural practices and of the soil. 

Table C summarizes the reduction that 

could be expected from these actions for 

a population living on JANET. 

The island of YVONNE presents a 

unique hazard on Enewetak Atoll. Pure 

plutonium particles are present on or 

close to the ground surface, randomly 

scattered in “hot spots” over most of the 

area from the tower to CACTUS crater. 

Examination of these “hot spots” has 

revealed the presence of occasional 

milligram-size pieces of plutonium metal 

as well as smaller pieces which are physically indistinguishable in size from the 
-. 

lY 

1, 

It 

d 

If 

1. 

r 

le 

tal, 

YSt? 

surround:ng coral matri:r, Cis-en these entire isiand an exclusion area-off limcurrent condit:ons, it must be assumed its to ail people, or (2) conduct a cleanup 

that pure ~!utonlllm particles Of respira- campaign which will eliminate the “hotble Size 21-e no:.? also present on. the sur- spot” plutonium problem and remove 

face or may be present in the future as whatever amount of soil is necessary to 

weathering effects oxidize and break reduce the soil plutonium concentration 

down the iarger particles. Lung dose to a level comparable to other northern 

assessn:ents for this area, therefore, islands. As an indication of the volumes 

must be ‘based r;n inhalation of pure piu- of soil involved, removal of a lo-cm 

tonium nzrtlcles rather than those hav- thick layer of topsoil in the area in which 

ing the :i-.-erage plutonium content of the “hot spots” have been detected involves 

sn11. approximately 17,000 m3 of material. 

The p,:eniial health hazard via the Further removal of soil to reduce the 

inhalation ;,ath.way is sufficientiy great to maximum plutonium contamination levels 

dictate t:::c b:isic alternativcs for reme- to 50 pCi/g or less involves an additional 

dial action for this island: (11 Make the 25,000 m3 of material. 

Table C. SO-yr integral doses from all pathways compared to U.S. external background dose. 

30-yr integral dose, rema 

Unmodified soil case Modified soil case b 

Location W. B. Bone W. B. Bone 

Enewetak Atoll living 

pattern III (JANETcurrent conditions) 11 80 8.9 78 

Enewetak Atoll living 

pattern III (JANETpandanus and breadfruit imported 1 6.5 25 4.2 23 

Enewetak Atoll living 

pattern III (JANETall agriculture confined to southern 

islands) 4.2 7.0 1.9 4.7 

Enewetak Atoll living 

pattern I (southern 

islands 1 1.0 3.8 1.0 3.8 

U. S. background onlyC 3.0 3.0 3.0 3.0 

aSum of all pathways for the Enewetak living patterns (i.e., external, inhalation., 

marine, and terrestrial). 

bSoil modified by placing 2 in. of clean gravel in the village area and plowing the 

agricultural area. 

‘Based upon background of 100 mrem/yr at sea level. 

-v-
Acknowledgments 

Successful completion of the Enewetak Radiological Survey was the result of the 

effort and cooperation of many organizations. However, organizations are composed 

of individuals, and it really has been the attitudes and abilities of these people upon 

which so much has depended. We wish to acknowledge most heartily the efforts of all 

participants - those who worked in the field, those who worked in the laboratories at 

home, and those who provided support services so important to an efficient operation. 

The list is long, but that is indicative only of the size and complexity of the operation. X’ery likely, in spite of our most diligent efforts, the names of some who participated have been omitted. To them we extend our apologies and our appreciation. 

All of the foilowing organizations and individuals have made significant contributions to the success of the AEC Enewetak Radiological Survey. To them, collectively 

and individually, we express deepest thanks for a difficult job done well. This report 

is long, and it contains an enormous amount of information, but it does not come close 

to telling the whole story of what happened to all the individuals concerned from September 1972 to October 1973. That is the stuff of which reminiscences are made. 

For simplicity, and to avoid even the appearance of a pecking order, organizations -and individuals within each organization -are listed in alphabetical order. 

Walter E. Nervik 

Lawrence Livermore Laboratory 

Technical Director 

Roger Ray 

AEC -Nevada Operations Office 

Program Manager 

-vi-
AEC Headquarters 

N. Barr E. Held 

F. Camm R. ?.Iaxwell 

J. Deal T. 3IcC raw 

W. Gay F. iVolff 

Scvada Operations Office 

F. Cluff .J. Pate 

M. Gates B. Rostankowski 

R. Lease .J. Stewart 

0. Lynch L. Perrin 

P. Mudra 

Pacific Area Support Office 

1. Hetkowski 

W. Hills 

R. Marchand 

W. Streenan 

F. Van Rensselaer 

Brookhaven National Laboratory (BNL) 

R. Conard 

l)efense Nuclear Agency (DNA) 

G. Brown 

C. Dunn 

A. Futral 

R. Leachman 

W. Ogle 

Eberline Instrument Corporation, Santa Fe, N. Mex. 

R. Aguilar G. Phillips 

E. Geiger J. Price 

C. Gonzales J. Rodriquez 

K. Gustafson L. Romero 

M. Morgan E. Sanchez 

M. Ortiz K. Tyler 

W. Parker G. Young 

Ia:G&G, Inc., Las Vegas, Nev. 

J. Cleland M. Knighten 

J. Doyle R. Mazurkewiz 

T. Hendricks R. Meibaum 

J. Hess T. Stuart 

F. Judd 

l#:newetak Marine Biological Laboratory, University of Hawaii 

I’. Helfrich et al. 

-vii-
C‘nx-lronmental Protection Agency, Las \‘egas, Nev. 

W. Bliss L. RIiller 

C. Costa W. Moore 

G. Doran <J. Price 

C. Fitzimmons L. Rozell 

D. James J. Thrall 

T. Lawson J. ‘i7andervort 

J. LIartin 

Environmental Protection Agency, Washington, D. C. 

C. Weaxrer 

Holmes and Narver, Inc. 

J. Abrew H. Kami 0. Sammons 

F. Bertram E. Labogen C. Smith 

.J. Chambers G. Lara E. Tanaka 

E. Gilmore W. iLlorrison D. Testa 

R. Grewe H. Mutchler R. Woltz 

R. Harbert S. Xakamura S. Yamamoto 

.J. Johnson S. Robertson G. Yokono 

LFE Environmental (Analysis Laboratories Division), Richmond, Calif. 

L. Anderson L. Leventhal M. Tallman 

M. Corsi W. Major M. Thorne 

G. Hankins S. Martinez A. Towry 

C. Heitz R. Melgard R. Trenton 

N. Kahler H. Moore R. Wessman 

K. Lee V. Quan 

Lawrence Livermore Laboratory (LLL) 

A. Abbott J. Evans M. Lindner J. Rego 

W. Abernathy E. Fletcher R. Lougheed B. Rich 

R. Anderson J. Fontanilla 0. Lowe W. Robison 

L. Anspaugh V. Fowler J. Lum N. Sawley 

S. Avilla W. Goishi L. Mann J. Schweiger 

G. Barton P. Gudiksen K. Marsh G. Seibel 

B. Berger R. Gunnink J. Martin E. Snyder 

R. Bishop C. Hanson W. Martin R. Stone 

N. Bonner J. Harder L. Maynard M. Stuart 

S. Brajkovich W. Hayes V. McIntosh C. Sundbeck 

J. Breshears H. Hebard D. McIntyre R. Tandy 

J. Brownlee H. Hicks J. McNabb R. Taylor 

M. Buchler T. Hoeger J. Meadows S. Thompson 

J. Bullock R. Hoff B. Mendoza T. Todaschiene 

J. Button G. Holladay F. Milanovich L. Tolman 

R. Carver K. Hulet D. Myers E. Van Sant 

J. Cate W. Hutchin L. Nelson C. Veith 

M. Chew L. Jackson F. Newbold J. Walton 

B. Clegg W. Jenkins R. Newbury F. Warren 

D. Clifton P. Johnson Y. Ng E. Westkamper 

D. Coles D. Jones J. Niday J. Wharton 

A. Conover G. Jones V. Noshkin J. Wild 

E. Crank J. Koranda W. Phillips E. Willes 

J. Dawson K. Lamson G. Potter D. Wilson 

J. Dellis J. Landrum A. Prindle K Wilson 

R. Dupzyk R. Lanier J. Pyper K Wong 

R. Eagle H. Lentzner B. Qualheim R. Yoder 

-viii-
1‘0s Alamos Scientific Laboratory (LASL) 

c. Richmond 

McClellan Central Laborarorp 

R. Aduddell D. Fletcher R. Lantz W. Richey 

C. Anderson R. Forehand L. Lewis J. Riggs 

J. Baca L. Foster R. Lewis D. Roach 

D. Beach R. Gause J. Lucas G. Robinson 

W. Bingston F. Gross0 R. Lyman S. Rober 

M. Bransfield L. Hammond M. Macinnes D. Runyon 

M. Chambers TV. Hanna J. McKethen W. Rush 

J. Cifelli R. Harrison G. Merrill R. San Miguel 

M. Clark T. Hass G. Merrill N. Savage 

D. Cleverige r H. Hawkins W. Myers B. School 

R. Davis E. Henry T. Niberger R. Smith 

W. Delacy N. Hopkins G. Nowark P. Sparman 

D. Dittmer C. Hosier R. Osborne D. Thomas 

R. Draper Ii. Hume W. Partridge J. Thomason 

W. Dunlap R. .Jefferies C. Passini P. Tudor 

S. Ellingson R. Johnson D. Price K. Von Rodenstein 

H. Endebrock W. Kinch J. Rebstock R. Wagoner 

H. Erdman R. Kovach C. Rehault M. Watkins 

J. Eveland J. Kreer J. Renfrow J. Wright 

D. Fischer B. Lane N. Reybrock 

Micronesian Legal Services 

T. Mitchell 

H. Barry 

0 regon State University 

W. Pearson 

Pan American World Airways 

L. Garner 

R. Reed 

F. Tyner 

-.

Reynolds Electrical Engineering Company, Communications Department 

C. Fancher 

L. Miller 

M. Steinback 

REECO-Environmental Science 

G. Calvird 

I. Hensley 

Scripps Institution of Oceanography 

R. Nolan 

The Administration of the Trust Territory of the Pacific Islands 

0. DeBrum 

J. Tobin 

Ujilang Council (S. Gideon, Magistrate) 

-ix-
LT. S. Air Force 

Site Contractor at Enewetak-MATSCo Corp. 

J. Stevenson et al. 

SAMTEC Vandenberg 

D. verble 

R. Wetzel 

U. S. Army 

Kwajalein Missile Range and Site Contractor, Global Associates 

Tripler ?vIedical Facility 

‘~5;. Babaian 

D. Frerichs 

.J. Pierce 

Sixth Ordnance Detachment 

D. Cambell 

C. Felts 

U. S. Ccast Guard Loran Stations, Enewetak and Kwajalein 

U. S. Marines, 462nd Heavy Marine Helicopter, Enewetak Detachment 

T. Schmidt et al. 

U. S. Navy Amphibious Base, Coronado, Calif. 

Chief Alvarez et al. 

Chief J. Broyles et al. 

U. S. Public Health Service, Health and Safety Laboratory 

H. Beck 

J. McLaughlin 

U. S. Public Health Service, Washington, D. C. 

B. Shleien 

University of Washington 

A. Johnson 

R. Lusk 

V. Nelson 

W. Schell 

A. Seymour 

-x-
I. Introduction 

w_ s\;rvik, Lawrence Livermore 

(111 April 18, 1972, Ambassador 

+anklin Haydn LVilliams, U. S. Repre-

;, illati~~e to the LIicronesian Status Talks, 

_.:,(I ‘TTPI fIigh Commissioner EdT.vard E. 

:,,hnston issued at Saipan a joint announcerc,nt which stated that “the United States 

c :,,~c~r-nn~ent is prepared to release legally 

-;lc entire (Enelvetak) Atoll to the Trust 

.rtB[-rltorygovernment at the end of 1973, 

.<ubject to the retention of some minor 

:-esidual rights.” This announcement was 

..:.elcomed by the Enewetak people, who 

for many years have sought to obtain a 

commitment from the U. S. Government 

for return of their ancestral homeland to 

Their own jurisdiction. They had been 

moved from Enewetak in December 1947 

in order that the Atoll could be used for 

:he nuclear weapon testing program and 

ever since have been living on Ujilang, an 

atoll approximately 125 mi southwest of 

!Inewetak. 

The announcement went on to state 

:!1:1i “prior to the actual settlement of the 

-itoll, it mill be necessary to carry out 

the same type of survey, cleanup, and 

rehabilitation procedures that have been 

utilized for Bikini Atoll. As in Bikini, 

the schedule for resettlement will depend 

on the results of the survey and the pace 

of the rehabilitation program.‘! 

In May 1972 a U. S. Atomic Energy 

Commission (AEC) survey team visited 

Enewetak Atoll to conduct a preliminary 

r.adiological reconnaissance. They could 

not visit all islands in the Atoll in the 

time available, but of those they visited, 

Laboratory, Livermore, California 

they found what they considered to be significrint radiological hazards still existing 

on BELLE, JANET, SALLY, URSULA,

.,: 

and YVONKE . Initiai cleanup and rehabilitation cost estimates based on data from 

this survey had, of necessity, to incorporate a wide range oi assumptions, due 

parr!y to the lack of information on the 

extent of the radiological contamination, 

parrly to the lack of a detailed analysis 

of the dose-to-man implications for each 

isotope comprising that contamination, 

and partly to uncertainties as to the manner of disposal of radioactive debris. 

Acceptability of disposal methods and 

plans would require detailed consideration of bioenvironmental impact, of political concerns, and of the desires of the 

Enewetak people. Since estimates based 

on these assumptions indicated that 

cleanup costs could run to tens of 

millions of dollars, it was considered 

essential that much more comprehensive 

i’: 

For the sake of simplicity, U.S. alphabetical designators for all islands will be 

used in this report. A cross-reference to 

all names we understand to be in use for 

each island may be found on p. v of 

Appendix II. An exception to this 

approach applies to the name for the Atoll 

itself. As Dr. Jack Tobin points out, “It 

is called Enewetak by the Atoll people and 

the rest of the Marshallese. The people 

of the Atoll say that it means island (ene) 

toward, or pointed toward, the east orwetak; hence, Enewetak.” Since there is 

a commitment to return the Atoll to TTPE 

jurisdiction in the near future, this seems 

an appropriate time and place to begin 

using the Marshallese spelling. 

-l-
2nd detailed information on the r::,;ological condition of the Atoll be obtainer 

before the start of cleanup and rehabiiitarion operations. 

On September 7, 19’i2, at an Interagency meeting in Washington, the _AEC 

agreed to assume responsibility for conducting this comprehensive radioiogical 

survey; the Department of Defense agreed 

to assume responsibility for conducting 

such cleanup operations as were required; 

and the Department of the Interior agreed 

to assume U. S. Government responsibilitv for rehabilitation and resettlement of 

rhe native population. 

This report describes the radiological 

survey which has been executed by the 

AEC as a consequence of the September 7 

commitment and presents data which have 

been obtained from that survey. Recommendations for cleanup and/or other corrective action based on these data will 

be the subject of separate action by the 

Atomic Energy Commission. 

In Section II a fairly detailed descriplion of the Enewetak Atoll and a history 

of the Enewetak people are presented to 

set the framework within which the Survey has be conducted. 

Section III contains a separate chapter 

for each major component of the Survey, 

including Plans, Aerial Survey, Terrestrial Soil and Radiation Survey, External 

Dose Estimation, Marine Survey, Terrestrial Biota Survey, Air Sampling, Engineering Survey, Analysis Program, 

Radiological Controls, and Dose 

Assessments. 

Section IV contains a Summary of 

Findings. 

The large number of photographs and 

figures needed to present the data are 

contained in the Appendix as Volumes 

and III. 

-2-

II 
II. Enewetak 

R. Ray, Nevada Operations Office, 

Le. S. _ltomlc Energy Commission, Las Vegas, Nevada 

J. Koranda and K. Marsh, 

Lawrence Livermore Laboratory, Livermore, California 

v. Nelson, University of Washington, Seattle, Washington 

l’ortions of this chapter are largely 

:~~.:~\vnfrom a working draft of the manusc:rlpt which is to become the Draft 

l.;ilvl ronmental Impact Statement for 

i.;ne\vetak cleanup. This statement is 

\,cing prepared by Holmes and Narver, 

inc. under contract to the Department Of 

Ijefense. We are indebted to the Defense 

Nuclear Agency for permitting use of the 

statement and to Dr. Stanley Kaplan of 

llolmes and Narver for his assistance 

toward its timely availability. Dr. Jack 

‘robin, a major contributor to the Kaplan 

effort, was also consulted extensively on 

history and anthropology in relation to 

other sections of this report. The last 

s;cbction of this chapter is drawn from 

field trip reports of Kenneth Marsh and 

\‘ictl~t- Nelson. 

I*:NEWETAK ATOLL-HISTORY 

AND STATUS 

Enewetak Atoll Island Names 

Recause the native names of most of 

the islands in the Enewetak Atoll are 

difficult for English-speaking people to 

pronounce and spell, male and female 

first names were assigned to the islands 

(luring the U. S. occupancy. Site names 

w(‘r(’ also given to several points in the 

lagoon and on the reef where scientific 

structures had been erected. Nearly 

all documents and maps made subsequent 

to 1952 include these site names, and in 

some cases the native names are also 

shown in parentheses. 

Table 1 presents a correlation of 

these site names with the native names 

obtained from the Enewetak people during 

the Ujilang field trip in August 1973, 

and from the U.S. Hydrographic Office 

Charts. It is interesting to note the 

influence of the Japanese romanization 

on the names given in the hydrographic 

charts. 

Physical Description of 

Enewetak Area 

Geography 

Enewetak Atoll is the northwesternmost atoll in the Western (Ralik) Chain of 

the Marshall Islands, forming the northern part of Micronesia in the central 

Pacific Ocean (regional map, Fig. 1). 

The location is 11” 21’N, 162” 21’E, 

approximately 550 naut mi southwest of 

Wake Island, 189 naut mi west of Bikini 

Atoll, and 2380 naut mi southwest of 

Honolulu. 

The Atoll consists of 40 islands on an 

elliptical reef approximately 23 by 

17 naut mi, with the long axis running 

northwest to southeast. The total land 

area is 2.75 mi2, with the land height 

generally averaging 10 ft above mean sea 

-3-
Table 1. Comparison of site and nati:-e names. 

Site Satire namesa 

XLIC E 

BELLE 

CLARA 

DAISY 

EDNA 

HELES 

IRENE 

JANET 

KATE 

1, UC f 

PERCT 

LIAR INANCE 

0 LIVE 

PEARL 

RUBY 

SALLY 

TILDA 

URS CLA 

VERA 

WILALA 

YVOXN E 

SAM 

TOM 

URIAH 

VAN 

ALVI?; 

BRUCE 

CLYDE 

DAVID 

ELhlER 

WALT 

FRED 

BOKOLUO 

BOKOXIBAKO 

KIRUNU 

LOIJJ 

BOCIlXiWOTME 

BOKAIDRIK 

UOtiEN 

ENJEBI 

SltJIK-4DREK 

KIDRINEX 

TAIWEL 

BOKENELAB 

ELLE 

AEJ 

LUJOR 

‘ELELEROX 

AOMON 

BIJILE 

LOJWA 

ALERIBEL 

BILLAE 

R UNIT 

BOKO 

.&I;IUNJOR 

INEDRAi 

b -

JINEDROL 

ANANIJ 

JINIMI 

JAPTAPi 

MEDREiX 

BOKANDRETOK 

ENEWETAK 

GLENN 

HENRY 

IRWIN 

JAhlES 

KEITH 

LEROY 

REX 

OSCAR 

MACK 

Boqallua 

Esgombogo 

Ruchl 

b -

h -

Rogalrikk 

Uogon 

!7ngebi 

:\luzinbaar-lkk:i 

tilrlnian 

h -

Bokonaaranou 

‘:-e1 r-l 

.i1tsu 

RuJoru 

Eberiru 

4omon 

Biljiri 

Ko.loa 

.iaraanb! ru 

Pli raal 

Rumt 

b -

h -

b -

b -

Chin:eero 

_imyaanli 

Chinlml 

Japtan 

Parry 

b -

Eniwetok 

Igurin 

Xlui 

Pokon 

Ribaion 

Giriinien 

Rigili 

Jieroru 

b -

b -

Boeaiiua 

Boeom?oo,go 

Eybo:yae 

1_:3:!Sut 

:, -

Boee:r1k 

Ropon 

Engeb1 

1l.;:!nkar!‘kk~: 

B y 1 i* p 

:, -

Ro!:onarppu 

\-Zlrl 

_A!ISU 

RU:lJTrU 

Eberiru 

.\omon 

BllJirl 

Roloa 

.+iramb!ru 

I’!: ral 

R-2nit 

b -

b -

0 -

b -

b -

Tagran 

<‘hlnlrnl 

‘*l.zri 

Parry 

b -

Eniwetok 

tgurin 

Buganegan 

Bogan 

Libiron 

Grinem 

Rigiie 

Bogen 

b -

b -

Native names fror 

Dr. Jack A. Tobi 

IKUREN 

MUT 

BOKEN 

RIBEWOX 

KIDRENEX 

BIKEN 

JEDROL 

I)REKATIMON 

I’NIBOR 

aAs confirmed by the Enewetak people during the Clilan~ field trip of .Tuly 1073. 

b So native naze. 

-4-
level. The vicinity map (Fig. 2) shows Enewetak is a classic example of the 

the Atoll configuration. Darwinian concept of atoll formation in 

The lagoon, which is about 388 mi2 in T.vhich an atoll is born when an oceanic 

area, has three entrances: an east chan- voicano surrounded by a fringe coral reef 

nel approximately 180 ft deep, between begins to slowly subside below the ocean 

DAVID and ELMER; a 6-ml wide channel lel.-el. As the coral and coralline algae 

to the south; and a shallow (approximately (which require shallow, clear, warm, 

4 fathoms maximum depth) channel to the oxygenated marine waters) maintain an 

southwest. Tidal currents vary from up upward growth commensurate with the 

to 2 knots in the deep channel to 1 knot in subsidence, a fringe reef flourishes, 

the south channel. particularly on the ocean side. AS the 

\-olcano continues to subside, the fringe 

Geology reef gives way to a barrier reef, and 

Enewetak Atoll is 15,000 ft above the Then to an atoll. 

ocean floor, while the top of the eroded Since the northeast trade winds vary 

volcano forming the island base is approx- little in their direction, the reefs on the 

imately 4200 ft below the surface. Steep windward and leeward sides of the atoll 

coralline reefs reaching to the surface are distinctly different. A greater volform a flat oval ring of reef and low- ume of ocean water, carrying nutrients 

lying islands, within which is a shallow necessary for coral growth, flows over 

lagoon with a maximum depth of about the windward side due to the fvind200 ft. generated ocean currents. Therefore, 

140° 160° 180” l&I0--

l 9 

c/Y 

300 0 300 600 

Graphic scale in nautical miles Midway * . . 

. 

t . . 

Marianas 

. . 

:. • Wake 

“’ Hawaiian 

Islands 

\. 

0 -2 !O" 

Islands 1. * Johnston 

Guarrp’ *. Enewetak Atoll 

\ 

. 

-Bikini * . Atoll 

. *. , - Truk * . . . 0.. . . : - .* . . ‘S Caroline Islands 

.

, 

, 

* 

, Kwajalein 

* 

*: 

w ’ * Marshall ‘-

. b *&lands . 

8 Gilbert . Canton ’ Christmas 

\(ew Guinea, . 

Solomon Islands 

‘islands 

‘.., . 

: . 

Island ‘Island 

-0O” 

. :. ,. I . . I 

Fig. 1. Regional map - Central Pacific Ocean. 

-j_ 
., 

WiMA -

Fig. 2. Vicinity map -Enewetak Atoll. 

-6-
,,,ore rapid gron-rh occurs on the windward side, which nas a slightly elevated 

ridge at the reef edge, -.r-hile there is 

none on the leeward side. The leeward 

side drops sharply to ocean depths up to 

360 ft, whereas the windward reef slopes 

seaward at about a 45-deg angle. 

Four near-surface geologic regions 

can be distinguished at Enewetak Atoll: 

island, interisland, ocean reef, and 

lagoon. Descriptions of the island and 

ocean reef geology can be given, based on 

core samples from 50 holes drilled during the nuclear testing program (Cooper 

and Pratt, 19681. So records are available of the interisland and lagoon geologics; hence, these can only be inferred. 

The island geologic profile consists of 

unconsolidated coral sands and gravels, 

saturated below the water table and extending from the surface to a maximum 

depth of 150 ft. The water table varies 

with the tide; its amplitude decreases 

rapidly with distance from shore. Typical water depths (elevation of island 

above mean tide) are 5 to 8 ft. At the 

intertidal level, a l- to 5-ft layer of 

beach rock (calcium-carbonate-cemented 

coral sands and gravels) is usually found; 

the exposed portions of the rock form 

most of the shore line. The rock 

strength ranges from hand-crushable to 

high-strength sandstone, decreasing in 

strength as well as thickness from ocean 

to lagoon. Below the unconsolidated 

coral sands and gravels, there is an old 

reef horizon going from the ocean to 

lagoon side at depths of 50 to 150 ft. 

This reef horizon is gradational and 

porous, consisting of large detrital and 

in situ coral fragments, with fine sands 

and muds occupying the voids. 

The ocean reei proiile shon-5 2 Sinlilarlty to the island profile, esce?: that 

the upper surface layer consists oi a 

wave-planeated, dense, algal-ll;nestone 

reef flat composed of detrital and in situ 

coral. The thickness of the upper reef 

horizon l-aries from 0 to 15 ft, :,rogressing outward from the island, and :S composed of a dense algal limestone. Of two 

holes drilled into the S-ALLY reef ?roper, 

one penetrated a 35-ft sand and grax-el 

horizon between the upper and lov:er 

reefs; the other did not. It is inferred, 

based upon limited drilling and general 

atoll physiography, that the ocean reef 

geology is more heterogeneous than the 

island geology, containing numerous 

large coral heads, caverns, etc. 

The interisland geologic profile can be 

presumed to be similar to the island geologic profile, except for the possibility 

that the top 10 to 40 Et of rock and sand 

has been eroded away by the sea. 

The lagoon geologic profile probably 

consists of soft, fine sediments to a 

depth of a few hundred feet, with intermixed and sporadic lagoonal coral heads. 

The depth of the lower reef horizon, if it 

exists, is probably greater than a few 

hundred feet. 

Climatology 

Enewetak’s climate is the tropical 

marine type, with temperatures ranging 

from 7 1 to 94°F and relative humidity in 

the 73 to 80% range. There is much 

cumulus cloud cover, moderate rainfall 

(57 in. mean annual rainfall), and, to a 

lesser extent, constant northeasterly 

trade winds (0 to 30 knots). Most depressions or tropical storms occur during the 

months of September through December, 

-7-
although they are possible at any time of with the salt water, Porous rock, howthe year. A climatological summary ever, interposes an obstacle to this rapid 

of Enewetak Atoll for a 12-yr period, as spread and restricts the mixing of the 

prepared by the U.S. ,4ir Force Environ- light fresh y.vater with the denser salt 

mental Technical Xpplications Center, is water. The fresh water is only about 

shown in Table 2. 40141 as hea\ as salt seawater and 

floats on the salt water, displacing 40 

parts of seawater for each part of fresh 

Hydrology water floating above the normal saltwater 

Enewetak Atoll relies on rainfall for level. That is, fresh water seeping to 

its supply of fresh water. Since the soil basal groundwater level on coral atolls 

is extremely porous, drainage of rainfall and other porous islands has a depth that 

by downward percolation through the is about 40 times the head or elevation of 

ground is rapid. This “groundwater” its lvater table above sea level (Fig. 3). 

makes contact at its lower face with This head or hydraulic gradient of water 

marine water that has infiltrated through tends to seek sea level by lateral flow 

the porous rock from the sea and lagoon. through the restricting rock. This prinFresh water poured on an open body of ciple of freshwater displacement of salt 

salt water will quickly spread over the water in islands and coastal areas is 

surface of the salt, and through currents known as the Ghyben-Herzberg law, after 

and waves will become thoroughly mixed its discoverers. As the head of water 

Table 2. Meteorological observations for Enewetak Atoll over a 12-yr period. 

Parameter 

description Jan Feb Mar Apr May Jun Jul Aug Sep Ott Nov Dee Annual 

Absolute max 

temp, “F 88 88 89 so 91 20 Of! 01 0 3 91 94 88 94 

Mean 

temp. 

max 

“F 85 85 86 86 86 67 a7 87 88 87 86 86 86 

Mean 

temp. 

min 

“F 78 78 78 78 78 7S 79 70 79 79 79 78 79 

Absolute min 

temp, “F 71 73 73 72 73 73 71 72 72 71 72 71 71 

Mean relative 

humidity, “/‘o. 73 73 75 76 78 79 80 80 79 79 78 76 77 

Mean 

in. 

precip., 

1.03 0.85 1.73 2.47 5.65 -1.06 7.12 6.67 6.76 9.76 7.26 3.6 1 57.0 

Mean No. 

days precip. 

2 0.1 in. 3.4 2.5 4.3 5.3 9.2 0.6 13.0 13.1 13.1 14.0 13.0 7.2 108.3 

Mean No. 

days of thunderstorms 0.0 0.0 0.0 0.0 0.2 0.4 1.3 0.9 1.4 1.9 0.5 0.2 6.0 

P freq. wind 

spd 2 17 knots 47.4 56.2 49.4 47.9 36.7 27.6 11.4 9.3 7.0 9.1 34.7 47.5 32.2 

P freq. wind 

spd 2 28 knots 0.2 0.3 0.5 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.7 1.5 0.3 

8-
Wapid 

1 

sh 

ater 

0 

1s 

:hat 

n of 

I). 

ter 

*in3.1t 

fter 

nnual 

1,4 

86 

79 

71 

77 

57.0 

08.3 

6.0 

32.2 

0.3 

Island surface ? * 

Soil saturated 

with salt water 

X-Y is approx 1/40th 

of Y-Z 

Fig. 3. Schematic representation of an 

island freshwater lens. 

moves outward, the depth of the fresh 

water becomes less until at the edge of 

the shore, where the fresh water seeps 

into the sea, it is just about at sea level, 

disregarding the fluctuations of the tide. 

In a roughly round island of uniform 

permeability, the body of fresh water 

floating upon the salt water assumes the 

shape of a lens, the edges of which 

approximate the edges of the island, with 

the upper face of the lens only slightly 

convex compared with the deeply convex 

lower surface at the salt water interface. 

A pictorial representation of an ideal 

ireshwater lens is shown in Fig. 3. It 

should be noted that the water shown in 

Fig. 3 does not lie in a large pool beneath 

the island, but is trapped within the porous media making up the island. Ideally, 

the saltwater/freshwater interface would 

be clearly defined; however, this is the 

exception to the rule because the lens is 

a dynamic system rather than a static 

system. When the interface moves with 

respect to the porous fluid-containing 

medium, the sharpness is diffused, 

creating a transition zone in which the 

quantity of mising is proportional to the 

rate of movement of the interface (Fig. 1). 

Normally, the mterface moves constantly due to tidal acrlon and seasonal 

changes in the amount of recharge (rainfall percolation) which affects the thickness of the lens. This movement of the 

interface up and down alternately brings 

the invasion of salt and the dilution of 

salt water with fresh water. Thus, the 

contact zone is not sharply defined in 

terms of salinity or freshness, but shows 

a transition in salinity. At the center of 

an island of uniform permeability, the 

tidal fluctuation is at a minimum, and the 

depth of fresh water is at a maximum. 

At the shore the tidal range is at a maximum and there is a reverse gradient at 

high tide carrying salt water into the 

island. Therefore, all of the water 

emerging at the shore line is brackish. 

Terrestrial Ecology 

The terrestrial ecology of Enewetak 

Atoll in the northern Marshall Islands 

presents many interesting facets of plant 

and animal adaptation, bicgeography, and 

Fig. 4. Freshwater lens diffusion zone. 

9-
trophic relationships in a retatix-ely discrete ecosystem. The geolom and soils 

of the Atoll are derived from the skeletal 

and structural residues of plant and 

animal organisms that are present as 

coralline and algal limestone and their 

erosional products. On this unique suhstratum, a terrestrial ecosystem has 

evolved -the product of the disseminative agents of the Pacific basin, namely, 

wind, water, and biotic vectors, lncluding man, who has played a prominent 

role in determining the present biota. 

In its greatest expression, the terrestrial ecosystem of Enewetak Atoll is represented by a forest habitat that is comparable to those found on continents. The 

diversity in species composition of that 

forest is admittedly low because of historical, geographic, and climatic factors 

which have influenced the evolution of the 

Atoll biota. Isolation from source regions, oceanic current circulation, and 

the relative aridity of the northern Marshall Islands determine the plant and 

animal species that will arrive at the 

Atoll, and then subsequently determine 

which of those species will survive. 

The indigenous biota of Enewetak Atoll 

therefore are characterized by organisms 

highly adapted to the marine environment; 

they arrived at the Atoll primarily by 

ocean currents in the prehistoric past. 

A second component of the biota is represented by organisms introduced from 

other regions by man, either intentionally 

or by accident. Weedy plants and roof 

rats are examples of this biotic component . The flora of Enewetak Atoll demonstrates the dual origin of the biota very 

well. St. John (1960) (see Table 3) 

describes the Enewetak flora and 

lists 42 species of plants, four of 

which are native to Enewetak -1toll and 

all in the genus Pa.ndanus. Although 

Pandanus was disseminated by both primitive and contemporary man, the endemic 

species are believed to have evolved on 

Enewetak, and their initial colonization 

occurred long ago when seeds or fruits 

reached the Atoll by ocean currents. The 

number of adventive weeds introduced by 

man on Enewetak Atoll is 27 species, and 

the food and ornamental species which 

may not persist number 26. There are 

seven species of plants that are known 

only from their seeds and fruiting structures that were found on Enewetak 

beaches, such as Barringtonia asiatica. 

The entire flora is represented by 95 

species, more than half of which were 

introduced by man. 

The natural climax vegetation of 

Enewetak Atoll, based on the relatively 

undisturbed examples available for study, 

appears to be the Pisonia grandis forest. 

Only a few other tree species are found 

in this almost pure forest type. The 

Pisonia forest is best expressed on the 

larger islands, although single individuals or clumps of trees may be found on 

smaller islands, but mainly those that 

are recovering from disturbance. 

Ochrosia oppositifolia, another large 

broad-leaved evergreen tree, is occasionally found in small clumps in the 

Pisonia forest on DAVID and GLENN 

Islands, but seldom forms a continuous 

stand on these islands. 

The Pisonia forest on Enewetak Atoll 

usually occurs in dense stands where the 

only reproduction within the stand is 

Pisonia. Scattered individuals of the 

coconut palm, Cocos nucifera, occur in 

-lO-
C 

Table 3. The i!ora of Enewetak Atoll (as reported by St. John, 1960). 

d 

Scientific name 

,-

Trees 

Pandanus 

brachypodus 

Pandanus 

enchablensis 

Pandanus 

korrorensis 

P andanus 

odoratissimus 

var. 

novocaledonicus 

Pandanus 

odoratissimus 

var. 

novoguineensls 

P andanus 

pulposus 

Pandanus 

rectangulatus 

Pandanus 

rhombocarpus 

Pandanus 

utiyamai 

Cocos nucifera 

Artocarous 

incisus 

Pisonia 

grandis 

Hernandia 

Sonora 

Aleurites 

moluccana 

Sapindus 

saponaria 

Carica papaya 

Rhizophora 

mangle 

Terminalia 

samoensis 

Ochrosia 

oppositifolia 

Species 

Common Vernacular 

name name 

Pandanus Punmusi 

Maok 

Bop 

Bop 

Bop 

Jilebar 

Anilip 

Papparawa 

Bop 

Coconut palm 

Breadfruit Me 

Kangae 

Bingbing 

Papaya Keinapu 

Kugung 

Kijebar 

Remarks 

Pandanus leaves are used 

for weaving plaited goods 

and thatch. 

Used for food and copra 

production. 

Of aboriginal cultivation. 

Tree 8 m tall observed 

on Japtan, 1944. 

Abundant, forming forests on better habitats. 

Fruits found on beaches, 

1958. 

Found only as seed on 

sea drift. 

Found as seeds on 

beaches. 

Recently introduced fruit 

tree. Observed 1958. 

Introduced tree, restricted to tidal salty 

shores. 

Tissues poisonous. 

-ll-
-- 

Scientific name 

Trees (cont.) 

Cordia 

xrdata 

Messerschmidia 

argentea 

Guettarda 

speciosa 

Morinda 

citrifolia 

Large Shrubs 

Ximenia 

americana 

Suriana 

maritima 

Ricinus 

communis 

Pemphis 

acidula 

Nicotiana 

glanca 

Scaevola 

frutescens 

var. 

frutescens 

Scaevola 

frutescens 

var. 

sericca 

Wedelia biflora 

Small Shrubs 

Phymatodes 

scolopendria 

Cyperus 

A$[i;i.hes 

Sida fallax 

Pluchea indica 

Vines and Creepers 

C;z;;tpcinia 

Table 

SDecies 

Common 

name 

Heliotrope 

Indian 

mulberry 

Tree tobacco 

:3 continued) 

Vernacular 

name 

Kono 

Kirin 

Wut 

Nen 

Kalikelik 

Ngiungi 

Kungi 

Alar kinat 

Mar kinat 

;Llarguegue 

Kino 

Wujoet in ion 

buil 

Berelitchman 

Kio 

Remarks 

E\,ergreen tree to 16 m. 

Small tree. Leaves may 

be eaten. 

-4 tree to 8 m. 

YIedicinal use. 

Sour, edible fruit. 

Introduced ornamental. 

Hard wood. Leaves 

edible. 

Introduced weed. 

The most abundant shrub, 

especially near the shore. 

Leaves used medicinally; 

wood hard. 

Recorded only in 1944. 

Probably of aboriginal 

introduction. 

Native sedge, abundant 

on most habitats. 

Introduced weed. 

Found only as drift seeds 

on the beaches. 

-12-
scientific name 

\-ines and Creepers 

Canavalia 

mic rocarpa 

Dioclea reflexa 

Entada 

phaseoloides 

AIaguna urens 

Phaseolus 

lulgaris 

Vigna marina 

Triumfetta 

Drocumbens 

Ipomoea 

pes-caprae 

Ipomoea 

purpurea 

Ipomoea tuba 

Citrullus 

v-ulgaris 

Cucumis me10 

Cucurbita 

maxima 

Grasses 

C enchrus 

brownii 

Cenchrus 

echinatus 

Chloris inflata 

Cynodon 

dactylon 

Dactyloctenium 

aegyptium 

Digitaria 

pruriens 

Eleusine indica 

E;z;os;s 

Lepturus repens 

var. repens 

Setaria 

verticillata 

Table 

Species 

Common 

name 

(cont.) 

String beans 

Common 

morning glory 

Watermelon 

Cantaloupe 

Sandbur 

Bermuda 

grass 

Crab grass 

Goose grass 

Love grass 

Bristly foxtail 

3 (continued) 

1;ernacular 

name 

Marlap 

hlarkine!ojo 

Adat 

Marginejojo 

Marbele 

Legalek 

Wujoich 

Ujos aitok 

-13-

Remarks 

Known here only as seeds 

in the sea drift. 

Drift seeds on beach of 

Engebi. 

In gardens. 

A trailing r.lne used in 

weaving. 

Cultivated ornamental. 

Once grown in gardens. 

Once grown in gardens. 

Observed in gardens, 

1944. 

Introduced weed. 

Introduced weed, abundant and troublesome in 

disturbed soils. 

Introduced weed. 

Deliberately introduced 

as lawn grass and as 

sand binder. 

Introduced weed. 

Introduced weed. 

Introduced weed. 

Common, but apparently 

an introduced weed. 

The commonest native 

grass. 

Introduced weed, abundant in disturbed soil 

near settlements. 
Table :! (continued) 

Species 

Common Vernacular 

Scientific name name name Remarks 

Grasses (cont.) 

SorEhum bicolor Sorghum Cultivated crop grain. 

var. technicum 

Thuarea involuta Ujos maroro Local, uncommon, found 

on or near the sea 

beaches. 

Tricachne Introduced weed. 

insularis 

Tricholaena An introduced weed. 

repens

-

Zea mays Once cultivated, observed 

1944. 

Herbs 

Sedge Ujoet Introduced weed, wet 

??Ei_lS places. 

Allium cepa Onions Onions reported in gardens in 1944. 

C rinum Spider lily Observed in gardens, 

asiaticum 1944. 

Tacca Arrowroot Mokmok Tubers grated and 

leontopetaloides washed to obtain edible 

starch. 

Fleurya Nenkutkut 

ruderalis 

Achyranthes Kaleklek Introduced weed. 

aspera 

Amaranthus Introduced weed. 

dub ius 

Amaranthus Introduced weed. 

viridis 

Boerhavia Matok aitok Abundant. 

aiffusa 

mffusa 

Boerhavia Rabitchragai 

diffusa var. 

tetrandra 

Mirabilis jalapa Four-o’clock Emen aur Introduced, probably as 

an ornamental. 

Portulaca lutea Kiran 

Portulaca 

oleracea 

Portulaca Bujon 

samo&sis 

Kenen Parasitic entwining herb. 

-14-
Table 2 (continued) 

species 

Common \-ernacular 

Scientific name name name Remarks 

Ilcrbs (cont.) 

Brassica 

oleracea 

Brassica 

pekinensis 

Raphanus 

sativus 

T ribulus 

cistoides 

Euphorbia 

chamissonis 

Euphorb ia 

hirta 

Euphorbia 

thymifolia 

Phyllanthus 

amarus 

Malvastrum 

coromandelianum 

%$%?a 

Solanum 

lycopersicum 

Erigeron 

bonariensis 

Lactuca sativa 

Pluchea 

odorata 

ire rnonia 

cinerea 

Zinnia elegans 

Cabbage 

Radish 

Caltrop 

5nurge 

Spurge 

Spurge 

Berol 

Ground 

cherry 

Tomato 

Lettuce 

Zinnia 

Senailing 

nagailing 

Cultivated vegetable. 

Cultivated vegetable. 

Cultivated l.egetable. 

Introduced weed. 

Introduced weed. 

Weed introduced from 

America. 

Introduced weed. 

Weed introduced from 

North America. 

Cultivated for its edible 

fruit. 

Introduced weed. 

In gardens, 1944. 

Introduced weed. 

Introduced weed. 

In American gardens, 

1944. 

some of the Pisonia forests. The canopy 

is usually complete, creating deep shade 

in the interior of the forest of pale, 

cream-colored compound trunks. Reproduction is both vegetative and by seedlings. The accumulation of organic 

matter is obvious in the Pisonia forest 

and is produced by the leaf fall which 

may occur during the drier portions of 

the year. Acidification of the alkaline soil 

materials eventually occurs after organic 

matter has accumulated, resulting in the 

dissolution of the calcareous soil materials, 

and in the precipitation of phosphates if 

significant quantities of bird excrement 

are present. There is a strong correlation 

between the occurrence of Pisonia forests 

and phosphatized soil materials. 

-15-
-- 

Occasionally a large specimen of 

2lesserschmidia argentla may persist in 

the Pisonia forest stand, usually at the 

outer edge. The other ubiquitous tree 

species, Scaevola frutescens, is seldom 

found in the Pisonia forest. 

Two halophytic tree species are widespread on Enewetak Atoll and are found 

on most land surfaces, creating dense 

scrubby stands on islands recovering 

from test-period activities. The scattered to continuous stands of Messerschmidia argentea and Scaevola frutestens very likely represent a subclimax 

stage of the Atoll vegetation which will 

eventually develop into the Pisonia forest. 

Two other woody species occur occasionally in the vegetation types found on the 

Atoll, either in the MesserschmidiaScaevola stands or at the edges of the 

Pisonia forest. These trees are Morinda 

citrifolia and Guettarda speciosa. Scattered individuals of these species are 

found on most of the islands, even those 

recently disturbed, which seems to indicate an effective means of seed dispersal. 

Another tree, Cordia subcordata. occurs 

on islands with well-developed forest 

types on them, but stands of any great 

extent have not been seen. Four other 

species of woody plants may be found 

occasionally, mixed in with Messerschmidia and Scaevola or at the edges of 

the Pisonia forest. These are Ximenia 

americana, Suriana maritima, Pemphis 

acidula, and Terminalia litoralis. Most 

of the woody plant biomass of the islands 

on Enewetak Atoll is formed by the four 

species, Messerschmidia argentea, 

Scaevola frutescens, Pisonia grandis, 

and Cocos nucifera. 

The following simplified vegetation 

tJQeS are suggested and provide a useful 

framework of habitats upon which the 

rest of the biota depends, either for food 

or shelter and nesting sites: 

• Pisonia grandis forest with coconut 

palms. 

• Messerschmidia-Scaevola scrub forest: scattered to dense stands, with 

young coconut palms. 

• Sedge-grass-morning glory meadows: 

often with the parasite Cassytha, scattered shrubs such as Pluchea and m. 

• Grassy flats and beaches: usually 

near bird rookeries on small, recently 

formed islands. 

Obvious relationships between plant 

species distribution and the low-relief 

topography are not apparent, although the 

general pattern of MesserschmidiaScaevola scrub vegetation surrounding a 

central forested area occurs on most of 

the larger, undisturbed islands. The 

unobservable factor of substratum water 

conditions is very likely a strong determinant in the plant ecological characteristics of a given site. The vascular plants 

depend either upon rainwater held in the 

interstitial space of the coral sand or 

deeper groundwater for their water requirements. The presence of GhybenHerzberg lenses of fresh or brackish 

water at shallow depths in lenses beneath 

the central portions of the larger islands 

undoubtedly affects and promotes the 

lusher growth of these habitats. 

The position of the island on the reef 

and exposure to storm waves may create 

conditions that favor the growth of the 

more halophytic species in the flora. Of 

16-

.I 
I-I 

eful 

food 

Lit 

‘orith 

ows : 

scat-

-. 

t2ntly 

nt 

?f 

h the 

lg a 

of 

iter 

ermi-

,isants 

the 

‘el-

.eath 

mds 

eef 

eate 

e 

Of 

.!!(> tIVo common trees, Scaevola is appar-

,,ntly more salt-tolerant than Messer-

;chmidia. It is often found at the edges 

!,f the beaches with Pemphis acidula and 

Suriana maritima, and is occasionally 

l,)und in this exposed position. However, 

;!.lesserschmidia is the primary woody 

plant inxvader of a newly formed islet or 

sandbar, and is often the only lvoody species on small islands. 

The three woody species described 

above (SIesserschmidia-ScaevolaI’isonia), plus the coconut palm, COCOS 

nucifera, are the most common component of the terrestrial flora on Enewetak 

Atoll. The coconut palm was introduced 

into the Marshall Islands sometime in the 

early 1800’s. Hager (1885) provides the 

first descriptions of the northern il’larshall Islands; very few observations of 

coconut palms were mentioned in his 

account, which placed the population of 

Enewetak Atoll at 40 people. The present 

pantropical distribution of the coconut 

palm is now generally attributed to deliberate dispersal by man. The lifespan of 

the coconut palm has been estimated at 

50 to 60 yr, at which time nut production 

is declining. It is likely that the zenith 

Oi coconut-palm development on Enewetak 

Atoll was before World War II. Most of 

the trees on the Atoll at this time (1973) 

were planted after World War II or during the nuclear test period. 

Within the rather limited framework 

of the vegetation types present on Enewetak Atoll, a small terrestrial fauna 

exists and perpetuates itself in this 

almost closed ecosystem. Mammals are 

represented by rats of two species, all of 

which were introduced to these islands, 

either during man’s recent activities on 

:kg Atoll or In the prehistor:c past. The 

Polynesian rat, Rattus esulars, is found 

c?n most atolls of the llarshail Islands, 

and is quite abundant on some of the 

southern atolls. This rat feeds on seeds 

of native plants and xi11 eat fallen coconuts, although the general opinion is that 

their use of coconuts does not affect crop 

production when it is being harvested for 

copra. This rat is generally found in the 

sedge-grass-morning glory meadows and 

at ?he edges of the MesserschmidiaScaevola thickets_ 

-1 second and larger animal, Rattus 

rattus, the roof rat, was introduced by 

man, earlier on trading vessels and more 

recently from ships carrying men and 

equipment during World War II, and during the nuclear test period. This larger 

rat is usually associated with dwellings 

and even though it competes successfuliy 

with Rattus exulans, it does not seem to 

thrive in the natural environments of the 

Atoll. The roof rat is said to eat green 

coconuts and has been known to seriously 

damage stored copra. 

-1 third small rodent that may be found 

on the Atoll is the house mouse, Mus 

musculus, and is another product of 

man’s activities on the Atoll. These 

-rodents are probably found today only on 

DA1’ID Island, and possibly on ELMER 

and FRED Islands. They are not a significant component of the terrestrial fauna 

and are usually found around dwellings, 

where they scavenge food scraps. 

No birds that are considered strictly 

land birds were seen on Enewetak Atoll 

during the recent survey of the islands. 

It is possible that the New Zealand cuckoo 

(Eudynamis taitensis) could be seen in the 

northern Marshall Islands as a migrant 

-17-
-- 

species. 4Iost bird species observed at 

Enewetak -Atoll are either reef or seabirds. The seablrds range across the 

open sea and some may be considered 

pelagic, coming to rest only occasionally 

on remote atolls. The reef birds typically obtain their marine food source 

within the Xtoll, either on the reefs or in 

the lagoon. X third avian component of 

the biota is represented by migrant species. The migrant birds typically nest in 

the high latitudes of the northern hemisphere and winter in the South Pacific 

area. The golden plover, Pluvialis 

dominica fulva, is a good example of a 

migrant atoll bird species. 

The fairy tern, Gygis alba, and the 

common noddy, Anous minutus, are examples of reef birds frequently seen at 

Enewetak Xtoll. The sooty tern, Sterna 

fuscata, and the red-tailed tropic-bird, 

Phaeton rubricauda, range offshore on 

the open sea. Reef herons, Demigretta 

sacra sacra, are frequently seen at the 

water’s edge on the islands of the Atoll. 

The bristle-thighed curlew, Numenius 

tahitiensis, and the whimbrel, N 

phaeopus, and various species of sandpipers are migratory species in the Atoll 

avifauna. 

Two crustaceans are found in the terrestrial habitats on Enewetak Atoll. The 

coconut crab, Birgus latro, occurs on 

most islands that support producing coconut palm trees. The islands in the southwestern portion of the Atoll have comparatively large populations of coconut crabs, 

and islands such as Igurin (HENRY) may be 

supporting maximum populations of this 

crustacean. The coconut crab excavates 

a shallow burrow in the organic matter 

around the bases of coconut trees, often 

beneath the crown of the tree itself. The 

coconut crab spawns in the lagoon waters, 

and the larvae leave the water and grow 

to maturity on land. 

Another crab, the hermit crab, 

Coenobita perlatus, may be found on 

islands of Enewetak Atoll, scavenging 

IFegetal and animal debris within the forests and along the beaches. Another species of Coenobita occurs on the Atoll, but 

it is primarily an inhabitant of the 

beaches. 

The preliously described Atoll habitats and the animals constitute the major 

features of the Enewetak terrestrial ecosystem. Other species are present and 

may play small roles in the functioning of 

this unique ecosystem, but the ones described here are the most prominent 

biotic features of the Atoll. The uniqueness of the Enewetak environment lies in 

the relative isolation of the Atoll, the 

evolution of the specialized biota, and the 

functioning of the terrestrial ecosystem, 

which is strongly affected by the local 

marine environment. 

Llarine Ecology 

General features of the ecology of the 

Enewetak marine fauna may be described 

as follows: 

On the reef and in the lagoon there 

is an abundance of plant and animal life 

in which the competition between different species for space and food is evident. Masses of reef-building coral are 

competing with the coralline marine 

algae for space, one often overgrowing 

the other. Fleshy patches of algae are 

pressed tightly against the surface of the 

coral and thus hold against the surges of 

the water pushed across the reef by the 

-18-
I 

1e 

‘S 

Put 

d 

~.~ls~lin~ breakers. Sea -I:-chins and 

‘,3,11s grind ntches into :::e hard coral; 

;<,mc, of them feed on tke :o-.-er of bacte-

:.ILil and algal film whici: :S constantl! 

:;t,lng replaced. The clarr.5, the corals, 

-,,m,. small fish, and other corms are 

c,LXasclessly removing :‘rcrr. suspension in 

r~lc, lvater the small, of:er, microscopic, 

piants, animals, and biTs ,:I debris which

make up the plankton. In regions of 

,iuieter water, where sand has been de110s ited, sea cucumbers and spider snails, 

:lmong the larger forms, r.Lrn the sand 

continuously in their glearung for food. 

Large schools of goatfish, mullet, 

surgeonfish, and other plant and plankton feeders are a common sight. Preying 

on unwary or disabled members of these 

schools are the carnivorous fish-the 

groupers, tuna, jacks, and sharks. LItimately the waste products and carcasses 

of these and other carnivores are returned to the lagoon and reef to complete 

the cycle. In the biological cycling of 

materials, there is not only an abundance 

of organisms, but also a wide variety of 

species, some 700 among the fishes 

alone, so that whatever is not utilized by 

one is quickly taken by another. There 

is hcrc a perfect economy of use of substance essential to life. The phytoplankton comprise the foundation of the food 

chain in the sea. By their diurnal vertical migration, plankton carry materials 

from the deeper waters of the lagoons to 

the surface or even up onto the reefs and 

eventually to the islands. Minerals as 

well as organic materials, concentrated 

and incorporated into the algae, are 

passed on in the food chain to the animals 

that feed upon them. 

In\-ertebrates make up the great bulk 

of the animal life of an atoll. Sea cucumbers have been compared with earthworms in their ceaseless turning of the 

gravel and sand as they obtain their nutriment from bacteria and algae. Corals 

and clams remove microorganisms and 

particulate matter from the water and 

are eroded by algae and sponges, which 

bore holes in the skeleton or shell, thus 

contributing to a return of carbonates to 

the \\-ater. Crabs, sipunculid worms, 

and others also attack the skeleton of the 

corals. Some of the land crabs drag fish 

and algae ashore when feeding. ln short, 

within the invertebrates and their symbionts alone, complete biological cycles 

occur from land to sea and back again. 

Historical Background of 

Enewetak Atoll 

The recorded history of Eneivetak 

dates from the sixteenth century and can 

be separated into four distinct periods: 

the discovery era from 1526 to 1885; the 

German Protectorate from 1885 to 1914; 

the Japanese Mandate from 1914 to 1944; 

and the U.S. Trusteeship from 1944 to 

the present time. 

Discovery Era 

The Atoll was first reported sighted 

by Spaniards in 1526, three years before 

a landing was made by Alvaro de Saavedra 

in October 1529. Several other sightings 

were reported by the British from 1792 

through the end of the 18th century. However, it appears that no significant contacts were made before the 19th century, 

although the first official survey and 

charting was made in 1798. 

-19-
German Protectorate 

In 1886, the Germans formally established a protectorate over the Xlarshall 

Islands, following some years of trading. 

The 1,Iarshallese, including the Enewetakese, accepted coconut seedlings from 

German traders and sold the resulting 

copra back to the Germans for trade 

goods and food. This involved the Enewetak people in a move from a subsistence economy to a mixture of a cash and 

a subsistence economy. The Enewetakese were somewhat on their own because 

the Germans did not have a resident 

agent, nor were there other resident 

Europeans, and foreign visitors were 

kept to a minumum. 

Japanese Mandate 

The Japanese Mandate commenced 

with the seizure of Enewetak and all 

other German Micronesian possessions 

in 1914. As in the case of the Germans, 

visits to Enewetak were made by the 

Japanese Navy in 1920, as well as by 

Japanese traders, but no attempts were 

made to establish a full-time administration. Both Enewetak and Ujilang were 

administered from Ponape in the Carolines, and the only foreign residents on 

Enewetak were a Japanese trader and his 

two assistants. Aside from a weather 

station, established in the 1930’s, Japanese contact with the Atoll languished 

until the years 1939- 194 1. During this 

period, the Japanese decided to make 

Enewetak a strategic base in their conquest of the Pacific. The Atoll was elaborately fortified and a large airfield was 

built on JANET, using both Marshallese and 

imported labor. Thousands of Japanese 

military personnel then occupied the Atoll. 

U. S. Trusteeshin 

Enewetak remained as a key bastion of 

the Japanese until it was captured by the 

U.S. forces in February 1944. The 

United States occupied the Atoll until the 

end of the war, using it as an advanced 

base for further operations to the east. 

The Enewetakese were moved to SALLY 

during the occupation. 

At the conclusion of the war, the 

United States was given a trusteeship of 

the hIarshal1 Islands by the United Nations. 

Use as a Test Site-Between 1948 

and 1958, the United States used Enewetak as a nuclear weapon proving ground 

and conducted 43 nuclear tests on the 

,4to11. 

The U. S. Coast Guard has maintained 

a loran station on the island of Enewetak 

for several years; since the early 1950’s, 

the University of Kawaii has operated the 

Eniwetok Marine Biological Laboratory 

under the auspices of the U. S. Atomic 

Energy Commission. 

Relocation of Enewetak People -

During the U.S. occupancy of Enewetak 

Atoll, 141 people were in residence. 

Prior to the 1944 invasion of Enewetak, 

the population of the Atoll was divided 

into two communities; one was located on 

Enewetak Island (FRED) and the other on 

Engebi Island (JANET). After the invasion, both communities were moved to 

Aomon Island (SALLY), which was under 

the authority of the Chief of the Enewetak 

Island Community (Chief Ioanej). Later, 

the Engebi community moved (at their 

own request) to Bijile Island (TILDA) 

because the latter was under the authority of the Chief of the Engebi community. 

-2o-
{lie I<ngebi peopir ix.-ere mo;-ed i‘llUS, 

:~~,~icc prior :o relocs::cn :o Ujilang 

, ~.:~~,~~b, to _Aomon to S;,Ille 1, whereas the 

I.:ilewetak people were mox:ed once (Ene-

.,vctalc tc, &Aomon) pr!cr to relocation to 

I’lilang. In December 1547 > the people 

,vcre transferred 124 ml to the southwest 

ic, then uninhabited i.-Ilang, where they 

Iiave remained. 

.inthropologv-Ene?l:etak People 

VIost anthropolog!sts are of the opinion that the lIarshalls and other islands 

of n,Iicronesia were settled by peoples 

who migrated from the area of Indonesia 

and into the insular Pacific centuries ago. 

Reflecting the ancient migration patterns 

in Oceania, the Marshallese language 

belongs to the large XIalayo-Polynesian 

language family which is spread from 

Madagascar, through the Indonesian area, 

and across 1Iicronesia, Polynesia, and 

some regions of Xlelanesia. With regard 

to physical type, the 1Iarshallese are 

relatively short in stature and of slender 

build. They have brown skin, brown 

eyes, broad flat noses, straight to curly 

black hair, and sparse body hair. 

According to their on-n oral traditions, 

the people of Enewetak had always lived 

on Enewetak Atoll prior to their relocation to Ujilang; in their own words: “We 

were there from the beginning.” Because 

of Enewetak Atoll’s isolated location in 

the northwestern region of the western of 

the two island chains which comprise the 

Marshallese archipelago, the people had 

relatively little contact with others prior 

to the European era. As a consequence, 

the language and culture of the Enewetakese became differentiated from those of 

other Marshall Islanders, and the people 

-Iid :?OT icientify themselves with the others. 

Rather, rhey thought cf themselves as a 

-eople \i-ho were separate and unique, “the 

Teople o:‘ Enewetak” as opposed to the 

:slanders to the east and south. 

The past and current accomplishments 

si the Enewetakese reelect intelligence 

and qualities of ingenuity, self-reliance, 

and hardiness which have allowed them to 

meet the challenge of the atoll environment which is quite restrictive in comparlson :n the high \-olcanic islands of 

Oceania. Long before the advent of Europeans, They had de\-eloped a culture which 

represented a sophisticated adaptation to 

their ecological setting. They were 

skilled navigators (an art which has been 

lost with the availability of travel on the 

vessels of foreigners); they remain expert builders of sailing canoes and are 

among the world’s best fishermen. In 

response to traders, missionaries, and 

the successive colonial governments 

which have dominated the islands over 

the past century, they have been quick to 

learn and adjust to the different categories of outsiders. Today, they have 

achieved a good understanding of the behavior and values of Americans, and 

several have distinguished themselves in 

government and mission schools. 

Economic and Cultural Resources 

Throughout the Marshall Islands, the 

traditional forms of settlement pattern 

and exploitation of the natural resources 

are characterized by several general 

features. First, the people of an atoll 

reside on one or more of its largest 

islands. Secondly, the people are quite 

mobile as a nonintensive type of agriculture and various fishing and collecting 

-21-
activities are e::rended to embrace every 

niche of the enT::ronment. Regular expeditions are macr to all islands in an 

atoll to make cc?ra and collect coconuts, 

breadfruit, pandanus, arrowroot, and 

other vegetable foods in season. The 

brush is cleared and crops are planted 

during these ~9~::s. The marine resources are also exploited and a wide 

variety of marire animals are utilized. 

Routine expeditions are made to catch 

fish, collect shellfish, and capture turtles and gather Their eggs. Several species of birds are also captured as a food 

source. The Enewetak people may be 

expected to conflnue this way of life to 

some degree when they return to their 

home atoll, as influenced by their contacts with Western culture. 

Sociopolitical Pattern 

Before their relocation to Lljilang, the 

Enewetakese were divided into two separate and distinct communities (community 

is defined as the maximal group of persons who normally reside together in 

face-to-face association) which were 

located on the two largest islands of the 

Atoll. One was situated on Engebi Island 

on the northern rim, and the other was 

located on Enewetak Island, across the 

lagoon in the southeast quadrant of the 

Atoll. The traditional settlement pattern 

of both communities was dispersed; residences were located on separate land 

parcels and were scattered along the 

length of the lagoon beach. 

Members of the two communities intermarried and cooperated in certain economic activities. Each functioned, however, as a separate sociopolitical unit, 

and its members had their bwn identity. 

In contrast to the identity of “the people 

of Enewetak,” as they defined themselves 

in reference to all other populations, the 

people of the Engebi community were 

identified as driEngebi, “the people of 

Enjebi Island,” and those of the Enewetak 

community were driEnewetak, “the 

people of Enewetak Island.” 

The sociopolitical structure of the two 

communities was identical. Each was 

headed by an hereditary iroij or chief, 

and succession to the office was patrilineal. Chiefs directed the affairs of 

their respective communities, arbitrated 

disputes, and consulted one another with 

regard to concerns of the entire Atoll and 

the total population’s relations with outsiders. Each of the chiefs had authority 

over one of the two domains into which 

the Atoll was divided. The domain of the 

Enewetak chief began with the Islands of 

Kidrenen, Ribewon, Boken, Mut, and 

Ikuren in the Atoll’s southwest quadrant, 

extended counterclockwise around the 

Atoll’s south and western rims up to and 

including Runit Island, and also included 

Aomon on the northeast rim. With the 

exception of Aomon, the Engebi chief’s 

domain began north of Runit with Billae 

Island and extended counterclockwise 

around the Atoll’s northern and western 

rims, up to and including Biken Island. 

Relations between the two communities 

and the traditional dispersed pattern of 

residence were altered with the invasion 

of Enewetak Atoll. Because Enewetak 

and Engebi Islands were devastated by 

warfare, the U.S. Navy resettled all of 

the people in a compact village on Aomon 

Island which, as indicated above, fell 

within the domain of the Enewetak Island 

chief. After several months, the Enjebi 

-22-
I,,,lli,lC, mo\.ed to the nearby and adjacent 

which was within the domaln !:I \llC, Lsland 

:; lhcll r own chief. \Vith these reiocatlons 

,,t,,,th,n I:ne\vetak Atoll, the Engebl and 

!Incwetak peoples were no longer sepa-

..ated by the Atoll’s large lagoon, and 

T7%.n,lertBlaining their dual political struc-

‘:lre, they In fact became a single 

i-i,nlmunity. 

The consolidation of the pOpUlatiOn 

::]tO One community and the new compact 

5cattlement pattern were perpetuated with 

:!lc islanders’ resettlement on I;jilang 

:1to11. It has only one sizable island, 

: 1 ilang Island, and the entire population 

was resettled there. Navy officials established a dividing line at the midpoint 

of the island and allotted the western half 

to the Engebi people and the eastern half 

to the Enewetak people. A compact village was constructed in the middle of the 

tsland, with the Engebi and Enewetak 

peoples occupying houses on their respective sides of the dividing line. Later, 

each group divided the land on its portion 

of the island. At a still later date, other 

islands in the atoll were divided among 

members of the two groups. 

During the initial years on cjilang, 

the traditional political structure remained intact. The chiefs functioned in 

their accustomed roles, and they resisted 

American efforts to introduce democratic 

institutions. (According to American 

designs, each atoll population was to be 

governed by an elected council of elders 

headed by an elected magistrate.) By the 

early 1960’s, however, some change was 

observable. Both chiefs were by then 

aged men, and because they were men 

who had matured in a former era, some 

contemporary problems required that the 

declslon-making process be opened to 

include ?-ounger men v:ho had attended 

schools and ‘or had some other experiences \vlth the American administration. 

LLleetlngs of all males were occasionally 

held, and some decisions about community affairs were decided by a majority 

I-ote. The authority and status of the 

chiefs further declined in the late 1960’s, 

when the old Engebi chief died and was 

succeeded in office by his younger 

brother, :vho was also aged and suffered 

from frequent poor health. 

The combination of the above events 

precipitated a major transformation in 

the political structure. The chiefs 

yielded to younger men who desired and 

had been gaining a greater voice in community affairs. Then, in 1968, a magistrate and a council of 12 men were 

elected; reflecting the traditional division 

of the population, the Engebi people 

elected six councilmen from among their 

ranks, and the Enewetak people elected 

six. The magistrate became the head of 

the entire community, and the council 

became the legislative body governing the 

people’s affairs. In a very recent election, however, the 12 councilmen were 

elected from the population at large and 

not from the two groups. Thus, the 

current council reflects a demise of the 

traditional system and indicates that 

the old division between the Engebi and 

Enewetak peoples has lost much of its 

meaning. The council is now a 

representative body drawn from the 

entire population and reflects a unified 

community with acknowledged common 

goals. The chiefs, however, remain 

important figures as advisors and men 

of influence. 

-23-
I 

Church and Religion 

The church is the focal point for many 

community social activities of the Enewetak people. The prevailing religious 

system is a conservative type of Protestantism in which church services, Bible 

classes, church group meetings, and 

hymn singing have replaced traditional 

intertribal wars, sports, games, and 

dancing. 

The minister is the spiritual leader of 

the community and is supported and 

assisted by the chiefs of the clans. The 

church functions are time-consuming and 

require a considerable effort from the 

membership. Sundays in particular are 

devoted almost entirely to church services and related activities. Thus, it is 

apparent that the church influences the 

life ot the Enewetakese to a great degree. 

Land Ownership 

The Enewetak Atoll soil is poor, and 

thus agriculture is limited. For centuries, subsistence has been marginal 

and precarious for the island inhabitants, 

despite hard work. Nevertheless, the 

residents have always maintained a deep 

emotional attachment to their home 

islands and ancestral land. 

The land parcels, or wato, at Enewetak Atoll were like those found elsewhere 

in the Marshalls. Most commonly, each 

was a strip of land stretching across an 

island from lagoon beach to ocean reef 

and varying in area from about 1 to 

5 acres. The resources of all ecological 

zones were thus available to the individuals who held right to the land. Less 

commonly, a parcel was divided into two 

or more portions with transverse boundaries. This usually occurred when an 

island (e.g., Engebi) was very wide. 

Boundaries were usually marked by 

slashes on the trunks of coconut trees, 

or less commonly, ornamental plants. 

Also, other features of the natural topography (e.g., large boulders on the ocean 

reef and the very configuration of an 

island) were used to fix the position of 

landholdings. The latter type of markers 

were employed by the Bikini people, for 

example, after all other markings had 

been obliterated. 

One facet of Enewetak Atoll culture 

that differed from that of the rest of the 

Marshalls was the system of land tenure 

and inheritance. In contrast to the rest 

of the Marshalls, where matrilineal 

descent groups known as bx or lineage 

constitute landholding corporations, the 

land tenure system at Enewetak was in 

ideal and practice a bilateral one. In 

most cases, a married couple divided 

the land they had each inherited among 

their children, and a child usually received some land from both his father 

and mother. As younger islanders 

matured, they worked the land with their 

parents. As the parental generation died 

and as members of the next generation 

married and produced children, the process was repeated with parents allocating 

land among their offspring. 

The islanders resided on their landholdings on Engebi and Enewetak Islands. 

Households were either extended or 

nuclear family groupings. In most cases, 

households were headed by males and 

were situated on land held by them. 

Ideally, residence was patrilocal; i.e., 

upon marriage, females moved to their 

husbands’ households, although exceptions to the rule did occur. 

-24-
~.;vcry indix.,idual possessed rights to 

s<jlne land on tslands away from the settlc,ments on Enelretak and Engebi. Xl1 

land in the Atoll was held by someone, 

c,.xcept for one parcel on Enewetak Island 

\vhich was donated to the mission. 

PRESENT STATUS OF THE 

l<NI?WETAK PEOPLE ON 

I-.JIl,AT’;G 

Comparison of rjilang 

and Enewetak 

1’Jilang lies 121 mi southwest of 

Enewetak (see Fig. 5). In pre-European 

160” 165”

15” -

Bikini 0 0 

Enewetak 

10” - a 

Ujilang 

&Kusaie 

5” -

160” 165’ 

Fig. 5. 

times, L‘jilang was inhabited by a IZIarshailese population. In the 1800’s a 

typhoon decimated the atoll, and killed 

all but a handful of people who were 

moved to the southern Marshalls. The 

atoll was then developed as a commercial 

copra plantation during the German and 

Japanese colonial eras. During the plantatlon period, a small group of islanders 

from the Eastern Carolines served as 

wage laborers on the atoll. However, it 

was abandoned during World War II and 

was thus uninhabited and available for the 

relocation of the Enewetakese. 

17 '00 

15” 

0 

Taong i 

Bikar 

Rongelap 

tic7 ORongerik _a Jtirik 

Ailinginae Taka 

iiIU\ Mejit

Jem? ( 

10” 

Wotje 

‘Erikub 

Ma I’oelap 

Q 

Lib’ Q OAur 

Namu 

Majuro <3” 

Ail inglapalap Arno 

Jaluit Mili 

c3. 8 

Narik Namorik • Koi,i 

5” 

OEbon 

170” 

Marshall Islands. 

-25-
Raij 

Kilometers 

0 1 2 3 

Statute miles 

Fig. 6. Ujilang AtaH. 

-26-
IS also smaller than Eneiverak, 

~,,~l!~ ,n size of the lagoon and :r, the total 

,!I,\, i:ind area (see Fig. 6). Ai <Jmparlson 

,,I’ 1 iicLs 3r~aa~ of both atolls shop.:-s: 

Area, mi2 

Lagoon Dry land 

! ,ianc 

t ,iilaIlg Atoll 25.47 0.67 

357.99 2.26 

!-ram this comparison, it is apparent 

that the potential for production of food 

I‘!-om the reefs and lagoon is considerably 

less on Ujilang than it is on Enewetak. 

The limited food potential on I-jilang has 

made it necessary to import more commodities than would normally be required 

on Enewetak. This has been reported to 

have presented some difficulty because 

lijilang is located further from the 

sources of the needed commodities than 

Enewetak. 

Living Conditions on Ujilang 

The U. S. Navy constructed a village 

on the main island of Ujilang for the displaced Enewetakese, and a brushclearing program was in progress when 

they arrived on the atoll. Coconut trees 

planted during German and Japanese 

administrations were still standing and 

bearing. Seedlings of breadfruit and 

pandanus were brought ashore and 

planted. After the Enewetak people had 

settled in, the Navy departed. There 

was no U. S. official remaining on the 

atoll, nor was there any radio communication with the outside world. 

The former Enewetak inhabitants 

attempted to adjust to their new location. 

They had, and still have, several formidable problems with which to cope. The 

most obvious, and one which they have 

uppermost in their minds, is the great 

disparity in the sizes oi ‘i-iilang and 

Enewetak, as previousI>- mentioned. The 

traditional 1Iarshallese pattern of habitation is for family units to live on their 

land parceis, not in a l-lllage cluster. 

While it is common for community buildings, church, school, dispensary, and 

warehouse to be centralized for convenience and access to all, dwellings are 

usually dispersed over the length of the 

lagoon beach of an island, This pattern 

is obviously desirable from the point of 

view of environmental sanitation and 

public health. AS described, the traditional settlement pattern of the Enewetakese was disrupted because of their 

relocations. 

Natural Resources 

The people practice a nonintensive 

type of agriculture but utilize the environment to the maximum, using the plants 

that can survive and produce in the atoll 

environment. Coconut is converted to 

copra for cash sale to the visiting Trust 

Territory supply ship. Consumer goods 

are purchased from the ship with the 

proceeds of the copra sales. The interest payments from the trust funds pro-

.vided by the TTPI administration also 

help buy needed commodities. Rice, 

flour, sugar, canned meats, and other 

canned goods are staple items of the diet 

and have been for many years. Fish, 

clams, lobster, turtles (flesh and eggs), 

sea birds (flesh and eggs), chickens, and 

pigs provide protein in the diet. The 

marine resources are extremely important in the diet of these people. 

Coconuts, pandanus, breadfruit, and 

arrowroot are the main lregetable 

-27-
products used. Bananas, papayas, and 

squash are used to a lesser extent, probably due to the relative scarcity of the 

banana and papaya which do not seem to 

grow well on Ujilang. 

The Enewetak population shares the 

upward trend of the rest of the LIarshall 

Islands and Micronesia. Records show 

an increase from 104 in 1925 to 432 in 

1972. This tendency toward increased 

population among the Enewetak people is 

resulting in a further drain on the inadequate resources of Ujilang. A census 

made in early November 1972 produced 

the following data on the location of 

Enewetak people: 

Ujilang Atoll 340 

Majuro Atoll (DUD) 31 

Majuro Atoll, Rongron Is. 18 

Maloelap Atoll, Marshall Is. 3 

Kili Island, Marshall Is. 7 

Ponape, Eastern Caroline Is. 5 

Crew members on Trust 

Territory ships 4 

Residing in the United States 3 

Total Enewetak people 411 

Married to Enewetak people and 

living on Ujilang (integral 

part of the community) 21 

Grand total 432 

Males 226 

Females 204 

Sex not reported 2 

Grand total 432 

(Tobin, 1973 1 

Economic Status 

The TTPI administration has 

attempted to upgrade copra production 

and subsistence agriculture for the past 

several years with some noticeable improvement. However, the Enewetak 

people are not as economically well off 

as they would have been if they had not 

been uprooted from the larger Atoll. 

The unfavorable economic situation 

and the persistent desire to return to 

Enewetak finally stimulated aggressive 

action by the people. They threatened to 

evacuate the atoll in 1967, and in 1968 

the leaders petitioned the United Nations 

for assistance in returning to Enewetak. 

In 1968, they again threatened to evacuate the atoll and come to Majuro. Economic help was given them by the administration, and relief shipments of food 

were sent to the community. An ex

-

gratis payment of $1,020,000 was made to 

them in 1969 and placed in a trust fund; 

the interest from the fund has helped. 

Funds were also allocated for a construction program to improve the housing on 

Ujilang and for the construction of badly 

needed public facilities on the atoll. The 

Ujilang community assumed the responsibility for doing the actual labor 

involved. 

Preferences of the Enewetak 

People for their Future 

Efforts to ameliorate living conditions 

on Ujilang, while welcome, did not 

lessen the desire of the people to return 

to their ancestral homeland. They continued to press for this goal. Discussions and meetings were held with government officials. Finally, on April 18, 

1972, the High Commissioner informed 

the District Administrator that Enewetak 

Atoll would be returned to the jurisdiction 

of the TTPI by the end of 1973. 

It is expected that all of the 432 Enewetakese will return to their Atoll. However, it is not known whether those who 

-28-
3ff 

ot 

)n 

1-e 

d to 

8 

ons 

ak. 

:uOnin1 

ie to 

d: 

rut -

In 

31Y 

The 

mx-is 

-n 

l8, 

, 

ak 

ion 

1w-

,,ave interests elsewhere will remain 

i”‘ or leave after \-isiting their rmanen:lY, 

rc,latives and old land claims. It is 

assumed that these people will eventually 

I.c’~It-e on Enewetak. 

(1 planning council has been formed, 

consisting of Enemetakese, who are empoxvered by the people to make decisions 

\vithin specified limits On matters pertaining to short-term, intermediate, and 

long-range planning. The council will be 

augmented by technical advisors to assist 

them in translating the desires of the 

Enewetak people into workable plans. 

The advisors will work closely with the 

planning group and other Enewetakese in 

their particular fields, e.g., architecture, 

short- and long-range economic development, and agriculture. 

EXPECTED LIVING PATTERNS 

AFTER RESETTLEMENT 

Introduction 

The successful resettlement of the 

people of Enewetak will depend strongly 

on the interaction of their current life 

style with the provisions made for them 

by the U. S. Government. While the 

present life style is a result of over a 

hundred years of first German, then 

Japanese, and finally American influence, 

the greatest impact has occurred since 

the end of World War II. The creation, 

under U.N. charter, of the Trust Territory of the Pacific Islands, and the subsequent military development of strategic 

defense areas in the Marshall Islands, 

has brought the simple food-gathering 

culture of the Marshallese into close 

contact with twentieth-century technology. 

In order to gather some first-hand 

information on the living habits, attitudes, 

and desires of the modern Enewetakese, 

a field team spent the period of July 21-31, 

1973, on I‘jilang. The team was composed of Carlton Hawpe (Holmes and 

Carver architect), Howard Schoss (Peace 

Corps architect), John Stewart (AEC/ 

NVOO), ‘Kenneth Alarsh (LLL), and 

Thomas illakiphie (interpreter from 

Micronesian Legal Ser\Tices). Hawpe and 

Schoss were to meet with the Enewetak 

planning council to determine where and 

how the people intended to 1iL.e on Enewetak, what types of houses they preferred, 

and what they wanted in the way of cooking and sanitary facilities. Stewart and 

Marsh were to collect specific information on the people’s daily activities and 

their diet, with particular regard for the 

implications to radiological doseassessment calculations. 

Victor Nelson, University of Washington marine biologist, was to be a member 

of the team, but transportation difficulties resulted in a two-week delay on Enewetak and, because of other commitments, 

Nelson had to return to Seattle. During 

the two weeks on Entwetak, however, he 

spent considerable time with Smith Gideon, 

a native of Enewetak who was then Magistrate of Ujilang, collecting data on the 

fish preferences of the Marshallese. In 

his report (see p.46 ) Nelson recommends 

that a composite of the Ujilang, Bikini, 

and Rongelap diets be used to estimate the 

average diet of the Enewetakese. 

Originally, the present residents of 

Ujilang lived as two tribes (dri) on separate islands around the Enewetak lagoon, 

the driEngebi on Engebi in the northern 

:I: 

See Chakravarti and Held, J. Food Sci. 

28 (2) (1963). -

-29-
half of the atoll, :he drtEnewetak on 

Enewetak in the sou:hern half. The 

r,iilang Atoll, by contrast, has only one 

island large enougn for permanent habitation; hence, today everyone lives on the 

main island of L-;:lang. This island, 

roughly the same size as Enewetak, is 

about 2.5 mi long by 0.1-0.2 mi wide. 

The “town square” divides the island in 

half and consists of the meeting hall, 

dispensary, church, and school. The 

half of the island east of the town square 

belongs to the EneT.vetak people, while the 

western half belongs to the Engebi people. 

Even though the two tribes have intermarried to such an extent that, as Magistrate Smith Gideon says, “we are one big 

family,” the old division is maintained. 

Almost everyone lives in the village, 

which extends a fe7.v hundred feet to 

either side of the town square. There 

are a few houses scattered over the rest 

of the island, but these are used only a 

few days at a time, mostly by older 

people on food-gathering trips. Houses 

are constructed of plywood and corrugated sheet metal, with the floors usually 

about 0.7 -1 m above ground. The space 

under the houses is used for relaxing in 

the shade, and the pigs generally rest 

there as well. 

An increase in the birthrate has resulted in a very young population. Ninety 

percent of the people are under 40 years 

of age, and almost 50% are under ten. 

During the field team visit, a population 

anomaly existed in that there were no 

children of high school age on the island, 

even though they comprise about 10% of 

the population. This is explained by the 

fact that the high school is located 800 mi 

away at Majuro and, while school had 

been out over a month for summer vacation, no ship had been available to return 

the students to L:jilang. 

There were many opportunities for 

misunderstandings to occur. Makiphie 

spoke Marshallese and English fluently, 

but had no knowledge of radioecology. 

Hawpe and Schoss spoke good Marshallese, 

but also had no knowledge of the radiological aspects of Enewetak. On the other 

hand, neither Stewart nor Marsh, the 

radiological experts, spoke any Marshallese. The tendency of the people to 

want to be polite and to please their visitors by giving what they believed to be the 

desired answer, a problem mentioned by 

other investigators, was evident and probably had some effect, but much of the 

data in this report is based on personal 

observations. These problems do, however, lend weight to Nelson’s suggestion 

that a composite of data would best forecast living habits after resettlement. 

This section was reviewed in draft 

form by Jack Tobin, Trust Territory 

Community Development Advisor, and 

many of his comments have been incorporated into the final version. 

Development of Island 

Communities 

The islands of Medren (ELMER) and 

Engebi (JANET) are preferred for permanent dwellings, with possibly some people 

living on Enewetak (FRED), depending on 

facilities remaining after the rehabilitation. Japtan (DAVID) has been suggested 

as a temporary location for a work force 

during the cleanup, but might develop into 

a semipermanent settlement. If too many 

restrictions remain on and around Engebi 

for comfortable permanent habitation, the 

-3o-
P 

,,,,i,i,il, n,ay divide 1Iedren In half and live people r anew and add :o This covering 

probably as they do now on i-::lang. from r:xe I0 time !,y 5zattering gravel n ::I’!‘<‘, 

.,,/~,,nd-home houses on Engebi wouid still collected from the ocean beach. This 

‘)I’ c!lzsired by some people, and couid be area is kept free 01‘ Prass and trash. 

:kI!it <,ither as part of the rehabilitation Rain?s-ater, collected from the roofs of 

II. by the people themselves at a la:er buildings, will be the prlnclpal source of 

I1mf. If the plan suggested by Carlton fresh lvater. C-,ji!ang 9as several conIIawpe is adopted bg the Enewetakese, crete cisterns, but most people have two 

I!ICrt ~~111 be three to six houses per or three is-gal drums, fed from the 

, iuster on each wato. The houses xi11 be roofs of their homes. One of the conlocated about 100 ft or so inland from the crete cisterns has a 10,000-gal capacity 

;aC()on beach, behind a “green belt” of and uses the roof of the rhurch as a 

..0conut trees. 3 wato is a strip of land catchment. It is used by the general 

cstending from the lagoon side to the community, and probably a similar cisocean side, occupied by a single family tern would be built on Enewetak. The le 

group (lo-40 people). On wide islands, proposed plan for the Enewetak houses . 

such as Engebi, the wato may not include calls for a built-in cistern in each house, bboth beaches, but access to both sides of with a storage capacity sufficient for 

the island will be provided. several weeks. Well water is brackish 

Houses will be constructed with the and not used at all when rainwater is 

iloors about 0.7 m above grade, the inter- plentiful; however, as rainwater stocks 

:rening space filled with concrete and decline, well water will be used first to 

coral aggregate. The floors themselves wash clothes, then for the daily bath, and 

will be either concrete or plywood, and only as a last resort for drinking or cookrhe walls will be either poured concrete ing. It should be noted that Enewetak 

or concrete block. Roofs will be corru- receives somewhat less rainfall than 

gated sheet metal, provided with troughs Ljilang, and therefore well water might 

for collecting and transporting rainwater have to be used to a larger extent. Howto cisterns. A high degree of resistance ever, this same lack of rainfall also is 

to typhoons is desired. responsible for a more brackish well 

There is no furniture in a typical water on Enewetak, making it even less 

Ujilang house, and no decorations on the palatable. Well depths on Vjilang varied 

%- walls. Some food may be stored inside from 2.5 to 6 or 7 m, but several people

and a few possessions like mirrors, who lived on Enewetak remembered the .e 

hand-cranked sewing machines, kerosene wells there as deeper than any on Ujilang 

lanterns, or anything subject to rain or (therefore estimate about 10 m). Medren 

Pig damage are kept there, too. These Island presently has considerable area in 

items are usually on the floor and very the form of concrete slabs and metal 

:o rarely are there any shelves or definite roofing which could be used for catchstorage facilities. ment purposes. The airfield alone on ‘Y 

Areas around the houses will be cov- Enewetak could probably supply the entire Ii 

ered with coral gravel. The Ljilang population with water, given a collection e 

-31-

1 
and distribution system. It should be 

possible to make up in area what is lacking in ramfall, at least for the southern 

islands of the Atoll. 

Routine for Daily Activities”’ 

A few activities are common to all 

members of the household. Families retire for the night between 10 and 11 p.m. 

Everyone sleeps inside the house on a 

woven pandanus-leaf sleeping mat spread 

on the floor. A typical mat is made up of 

a double thickness of leaves, about 75-

100 cm wide by 150-180 cm long, and 

weighs about 1 kg. Double mats are also 

used, with the width and weight increased 

about a factor of two. Almost everyone 

arises between 6:30 and 7~30 a.m. 

Two or three days a year the entire 

family will go on a one- or two-day picnic 

to one of the other islands. However, 

transportation is a real problem, and 

there was one girl, 14, who had never 

been off the main island of Ujilang. 

Married women (essentially all women 

over 16- 17 years of age) spend the whole 

Tobin feels that the presence of the 

survey party had a strong influence on 

the daily habits of the people, especially 

the men. He says the Marshallese are 

naturally curious and tend to stay close 

to visitors. Also, the action and excitement were a welcome change from their 

usual routine. For these reasons, copra 

production and outer-island trips were 

probably curtailed. This points up the 

difficulty of gathering reliable information. The presence of the observers 

tends to affect that which is observed, 

but on the other hand, too much reliance 

on interviews runs the risk of bias from 

“cooperative answers.” Again, the best 

picture is a composite from several 

sources. With regard to the survey 

party’s effect on the people’s routine, 

however, it should be mentioned that for 

at least several years after the resettlement of Enewetak, frequent and numerous 

visitors may be expected. 

day in or around the house attending 

small children, cleaning, washing clothe: 

and cooking. The Marshallese are very 

concerned with personal cleanliness. 

Everyone bathes every day and washing 

clothes is a daily activity. Houses are 

swept several times a day, and the custom is to remove shoes or zories (if any) 

before entering the house. Clothes are 

washed outside, usually by teenage girls 

or older women. Many people have set 

aside a particular area for laundry by 

making a raised bed consisting of a 

framework of coconut logs filled with 

coral gravel. These beds are typically 

2-3 m on a side and 1/2-l m high. 

Clothes are washed in a pan (-50 cm 

diam) with soap powder, if available, by 

a combination of wringing, rubbing on 

flat rocks or plywood, and pounding 

with a stick. They are then rinsed 

and hung on a line to dry. This treatment is a little rough on the fabrics, 

but they are clean. Cooking and food 

preparation will be discussed in another 

s ection. 

Men spend the morning hours in and 

around the houses, cleaning up outside 

the house, smoking, visiting with each 

other, and generally taking it easy. 

Afternoons are spent much the same way, 

although these days considerable time is 

spent in meetings regarding the return to 

Enewetak. If a breadfruit- or coconutgathering trip is made away from the 

village, it will usually be early in the 

morning before the heat of the day. Similarly, a fishing trip near the village 

might be planned to take advantage of 

known fish movements. The only significant deviation from this routine occurs 

on Saturday, when the cooperative fishing 

-32-
i 

-les, 

Y 

lY) 

:S 

Itler 

w 

S 

to 

nfing 

(‘hildren LID :a the age of about 3-

,; x-1‘3rs spend most of their time around 

,hc \-illage close to or l-r-side their houses, 

under. the super-x.-:ston of their mother and 

oIder children. Children from about 

(5 years up to about IO-13 years spend 

their time in school and ?laying around 

Ihe \rillage betlveen the ocean and lagoon. 

.At Ieast half of the children’s free 

ttme is spent pIa>-ing on the lagoon beach 

and in shallon Txater; the remainder is 

about e\renly dli-;ded among the I-illage, 

surrounding forest, and ocean beach. 

Girls from about 12 to i3 perform many 

of the arduous household tasks, such as 

grating coconut or preparing breadfruit. 

Boys of this same age climb the coconut 

and breadfruit trees to harvest green 

“drinking coconuts” or ripe breadfruit. 

School was not in session in July; they 

observe a June-to-September recess. 

Children start first grade at about 

6 years and are required to attend 

through the eighth grade. School hours 

are 8-12 a.m. and l-3 p.m. The school 

Table 4. Time spent in various 

Location Men 

Inside houses 60 

Interior of island -outside 80 

Lagoon beach 10 

Lagoon water (boat) 5 

Other islands 5 

Ocean beach 3 

Open sea 5 

! 5 .: ne-room struciui‘r’. 2nd student.; si; 

i:!2 T : I i_ iloor-. Subiects :aueht arc l:npIlsll, 

!I-.&::-.?rnatlcs-, social studies, science, 

ax~c ?h>-slcal education. 1Iost rlqhth 

grade graduates can read and \vrite AIarshallese. If students wish to attend high 

schooi, they go to the district center at 

AIaiL:ro, and the official language is Engl!Sh. .At about age 15, if they do not 

:;:ienti high school, children begin to 

assu_me more of the duties of adults. 

Table 4 provides a rough estimate of 

:he amount of time spent by men, womcxn, 

and children in various locations. I’or 

do.qe-assessment calculations, hours per 

l:*-ecli is probably the best unit. Hours 

per day would carry a large standard 

deviation (-20-50%), while hours per 

month would be unnecessarily Coarse, 

except for time spent off the main island. 

HOK these estimates would change for 

Enex-etak is very difficult to predict. 

\Vith the much larger and less protected 

lagoon there, transportation will have a 

strong influence. If reliable boats arc 

available, the total time spent by men on 

the lagoon water and other islands would 

probably about double or triple, at the 

areas of the l_.jilang Atoll. 

Time, hr/wk 

Women 

(children Children 

to age -5) (-5 to -15) 

60 60 

95 43 

10 50 

0 7 

1 1 

2 7 

0 0 

-33-
expense of time on the home island, 

Women’s and children’s time distribution 

would probably not change more than 

10-200/0, because their lives are more 

centered around the home and community. 

The table gives the time distribution of 

the residents of Ujilang who have lived 

there 26 years. It is probably typical of 

a completely rehabilitated Cnewetak. 

After the cleanup, if the houses are completed, even the first year would be about 

as described. 

Diet 

At the time of the trip to IJjilang, no 

Trust Territory ship had called there for 

over two months. The people were subsisting on the local products, consisting 

of breadfruit, coconut, and fish. The 

survey party took 350 lb of flour, 150 lb 

of rice, 50 lb of sugar, and assorted 

canned goods to Ujilang; thus it was possible to observe the impact of imported 

food on the native diet, It could only be 

described as profound. There is little 

doubt that, given the opportunity, Marshallese consumption of imported foods 

would constitute at least 80% of their diet. 

The favorite imports, unanimously reported, are rice, flour, sugar, canned 

corned beef, and assorted canned fish, 

usually tuna, salmon, and mackerel. 

Marshallese who live on Majuro and Ebye 

(Kwajalein Atoll) and who, therefore, 

have money and access to “American” 

food, live almost entirely on imports, 

including such accessories as soft (and 

hard) drinks, beer, candy, cigarettes, 

and convenience foods, limited only by 

their ability to afford them. However, 

these people become hungry for the 

native diet (breadfruit, coconut, and fish), 

and a once-a-week Llarshallese meal is 

traditional. However, the Marshallese 

foods are of limited availability due to 

population pressures. Thus an interesting picture emerges of the outer-island 

people desiring unavailable imported 

foods, while those in the population centers desire equally unavailable traditional 

foods. The lack of reliable inter-island 

transportation contributes greatly to this 

problem. Dose calculations based on the 

diet observed at Ujilang should provide 

good upper limits on ingestion of radionuclides at Enewetak, modified, of 

course, by a few factors such as the 

greater availability at Enewetak of some 

food sources (e.g., sea birds). 

Cooking and eating are not big social 

events in Marshallese life. Food is usually cooked in the evening, some eaten 

then, and the rest during the next day. 

Families will sometimes eat together, 

but usually everyone eats whatever is 

available whenever he is hungry. When 

more cooked food is required, it is prepared then; thus cooking and general food 

preparation may take place at almost any 

time of the day, and usually is going on 

somewhere in the village all the time. 

On special occasions large meals will be 

prepared, and everyone, often the whole 

village, will eat together. This is about 

as close as the Marshallese come to the 

“American family dinner.” A typical 

day’s food consumption would be a light 

meal in the morning, usually a handful or 

two of food left over from the previous 

evening meal, perhaps a drinking coconut 

and some copra around the middle of the 

day, and then a larger meal of freshly 

cooked food in the evening. There were 

no plates or flatware in use on Ujilang; 

-34-
I 7i. 

,_.,.i,nt 3~~ ..t.-it!: his fingers iron: lez-.-es ,‘ ‘. I 

of ?:._,, brcD3df-uit or cocontii. In the cEse 

(>f isrg-e risk_ nr :neat, people 1.:.ould BET 

tiLr,2,.;ly fror: :he carcass, often pas5:ng 

II ;y.Tm persrn to person. Eating takes ,. L 

plac_ ,,utsicje the houses, and el’eryone 

.-;,ts ,m the g:-ound. 

_A ;ypical :,Iarshallese !‘ltiitchen” has 

zjide for raw food prepara- :In area set 

a single-burner kerosene stove, an tion, 

underground oven or G (rhymes with 

;I 00 :1: ), a fire pit :vith a grate for broiling 

oI. general cooking if there is no kerosene stove, and sometimes a pit for food 

storage. Again, ever-)-thing is on the 

ground, and the cook sits or squats on 

the ground while cooking. Large pieces 

of coral serve to support pans and food 

baskets. Food is commonly gathered, as 

well as stored, in these baskets woven of 

coconut fronds, The kitchen is usually 

attached to the house by extending two 

walls and sometimes the roof; in other 

cases, the kitchen has its own roof. The 

fourth side is usually at least partially 

closed in, but rarely has a hinged door. 

The proposed houses to be built on Enewetak will have similar areas. 

The urn exists in two styles, shallow 

and deep. A shallow urn is excavated in 

the coral to a depth of lo-20 cm, but is 

often not excavated at all. A fire is built 

on the rocks, and when only glowing coals 

remain, the food is wrapped in breadfruit 

leaves and laid on the coals. Everything 

iS covered with more breadfruit leaves, 

then with sand and gravel, and finally 

with coconut fronds or burlap. Cooking 

time is about an hour. The deep urn is 

excavated to 50-60 cm and is used in the 

same way, mostly for baking bread, 

which requires a higher temperature and 

!OnEP‘:. i-akiln,c rime. ::1i><- 3copll; :,L’C’tt~!‘ 

a Col?xan o\-en set (‘3 a -?rosene SttO\.e, 

but t!:ese are rar‘e. .!‘he :‘Qod storage pit 

is esc;‘:ared to a depth c,< ahout SO-75 cr.1 

(but not o\-er an arm’s length), These 

pits are used mostly to s-ore preserlred 

breadfruit, b:it ma\- be used to store 

cooked lefto\Ters. All foocl to be stored 

is 1%.rapped in breadfruit I?a~-es, and the 

pit is lined \vith either b:-iadfrult or 

pandanus lea[-es. 

Ob\-iousl>- the Marshali~sr kitc!len is 

considerably more par-tabie than thr 

American \-ersion. hIan)- fire pits and 

urns are located outside; :n fact, they 

may be constructed and used at the l’oodgathering site. Kerosene stoves are 

lraluable possessions which are kept 

under cover, although seldom in the 

house itself. There was one four-burner 

model occupying a place of honor in one 

Marshallese house. For broiling in an 

um, a fire is started with dry coconut 

frond; then either Messerschmidia wood, 

coconut shells or husk, or pandanus 

wood is added. Most other woods may 

be used, but coconut shell is prcfcrrc\d 

for the urn because it produces good 

coals. 

The important native foods on I:Jilang, 

and presumably on Enewetak, are fish, 

coconut, breadfruit, and arrowroot. 

Pork and chicken are consumed in varying amounts, and water comsumption is 

highly dependent on the availability of tea 

and coffee. Fish, coconut, and breadfruit are eaten both raw and cooked in a 

variety of ways. Only cooked arrowroot 

is eaten. Table 5 represents an attempt 

to quantify the Marshallese diet on a daily 

basis and is based on information supplied by Dr. L’Iary iLIurai of the Ilniversity 

-35-
- I 

Table 5. Summary of Marshallese daily diet.a 

At time of return, g/day 

Children 10 yr 

(older than post return, 

Food item Men Women 3-4 yr) g/day 

Fish 600 600 400 600 

Domestic meatb 

(pork, chicken) 60 60 35 60 

Pandanus fruit 0 0 0 100 

(200-400 

for 

children) 

Wild birds 100 100 60 10 

Bird eggs 20 20 15 5 

Arrowroot 0 0 0 40 

Coconut 20 20 20 100 

Green coconut milk 20 20 20(?) 300 

(O-1500) 

Ripe coconut milk 20 20 15 100 

Coconut crabs 25 25 15 o-5 

Clams (and other 

shellfish) 10 0 0 25 

Garden vegetables 100 100 80 200 

Breadfruit 0 0 0 200 

ImportsC 400- 1000 200- 1000 150-800 O-1600 

Total -1600 -1600 L1300 -1800 

aEvery entry in this table is subject to qualifications and should not be used without 

reading the accompanying text. 

bRanges from 0 to 250 g/day due to individual possession of swine and fowl. 

‘Flour, rice, sugar, tea, canned meats, and canned fish are by far the favorites. 

These will comprise from 0 to 80% of the diet, depending on availability. 

of California (Berkeley), and on observations gathered during the 10 days on 

Ujilang. It should be emphasized that 

imported foods are highly favored by the 

Marshallese and will constitute anywhere 

from 0 to 80% (perhaps even 100% for 

short periods) of the daily diet. The 

critical factor influencing the quantity of 

imported food consumed is availability, 

which for the Ujilangese means transportation. The breakdown into men, 

women, and children is perhaps more 

misleading than informative, particularly 

for the women and children, because they 

are constantly exposed to food during the 

daily preparation and their intake is 

highly variable. 

Pregnant women eat the regular diet, 

sometimes reducing their intake for 

weight-control purposes. Infants are 

nursed up to about l- lf years of age, 

when they are weaned onto the current 

diet with only a modification in food preparation. Certain foods may be mashed 

36-
P 

rn, 

‘0 

n) 

,),- (.ooked .some!f.har longer to make rhem 

n,ore suitable for :nfants. The meat of 

the green COCOtlUt, I\-hich is naturally soft, 

and arro\vrOOt paste are popular- infant 

foods. 

Pandanus is the lollipop of the Alarshall Islands, much favored by children 

and to a certain extent by adults. Fried 

breadfruit is a favorite snack food, especially of older \vomen who may spend 

many afternoons eating fried breadfruit, 

smoking, visiting, and playing bongo, 

Averaged over a monthly basis, the numbers in Table 5 are probably good to 

k50%, the “lo-year postreturn” column 

is strictly a guess; much depends on what 

becomes of Enewetak. The diet will 

depend greatly on the extent of American 

(or Japanese) influence. 

Because it is very difficult to express 

the Marshallese diet in grams per day, 

the following discussion of the various 

food items and their uses is given. 

Seafood 

Fish is certainly a favorite item in the 

Marshallese diet. Even if imported food 

is available, local fish remains high on 

the list of variety foods. If imported 

food is not available, fish probably SUP-

:‘: 

‘According to Tobin, pandanus is probably more important in the diet than this 

report indicates. The fact that it was out 

of season during the visit may have contributed to the impression that it is not 

widely consumed. Tobin states that it is 

a very nutritious food, and that its consumption should be encouraged by planting it in abundance on Enewetak. Perhaps 

the amounts given in Table 2 should be 

doubled or tripled for the lo-year postreturn consumption. Murai originally 

estimated 200 g/day without regard to 

age or sex. 

DIT t!-!c?r-r.:ire protein I.. ‘7 t 3 k c . Tilt> 1‘3\-or.-

ite !‘lsn 87 Tillane, and those nbserx-eti 

caught a,r,d <Jaten, ap~ror~m~:el~ In order 

of abunzance are: rabbitfish cS\ganus), 

grouper (Epinephelus), con\‘:c: sur.geon 

(Hepatus), goatfish (Jlullotdicthys), pOrtlpano (H::nnis), surgeonfich (l\;aso), bonito 

(Sarda?), squirrelfish (se~~eral ;-arietieF), 

ulua (Caranx), and yello\\~Ein tuna (Xeothunnus I. Bonito, ulua, and tuna must I~(, 

caught by trolling; thewfore thctr importance in the diet dcpcnds stroncl?- upon 

mot.orboat availability. :I11 :!lrcxc art’ 

favorite Fish, particularly for sasllimi 

(raw). 

Almost any fish whirh is caught and 

cooked will also be eaten ra\v. The head 

of the smaller fish is considered a delicacy, and the heart and liver are also 

occasionally consumed. Iq’ish which arc 

to be cooked within a few minutes of 

being caught are seldom tvisceratcd. 

Fish eaten raw, and those which ~111 be 

kept even an hour or so are evlsccratcd. 

Large fish, such as the tuna and lacks, 

are usually cleaned back at the village 

because the heart and liver are practically always cooked and eaten. The 

smaller reef fish are cleaned on the spot, 

often just with fingers and teeth. Fish 

are usually cooked with the skin and 

scales left on; the scales peel off easily 

after cooking, and most of the skin is 

usually discarded. However, whether or 

not the skin is eaten depends on both the 

fish and the diner. Sashimi is always 

skinned first. , 

The Marshallese are opportunists and 

will tend to eat what they catch; however, 

they know where and when their favorite 

fish are likely to be found and plan their 

trips accordingly. Their techniques are 

-37-

I 

3 
also directed toward certain types of fish. 

The two principal factors which discriminate against certain fish in the diet are 

flavor and the occurrence of ciguatera or 

other forms of poison. Sharks are good 

examples of the flavor factor. The meat 

contains large quantities of urea, requiring laborious preparation which, when 

combined with the generally unpleasant 

disposition of these fish, serve to eliminate them from the diet. Moray eels, 

barracuda with three gill rakers, and one 

species of mullet are examples of fish 

which frequently contain ciguatera. The 

puffer fish and such obvious species as 

the stonefish and scorpion fish are also 

excluded from the diet. 

Frying in oil or lard and broiling over 

coals are the principal methods of cooking fish, although boiling and baking in 

the urn (particularly for large fish) are 

sometimes used. Cooked fish may be 

kept for several days by wrapping it in 

breadfruit leaves and covering it with 

coconut or pandanus fronds. It is reported that fish can be stored over longer 

periods by salting it raw and drying it in 

the sun. The Ujilangese make their own 

salt by evaporating ocean-side water in 

kettles over a fire. The preserved fish 

are rinsed in fresh water before they are 

eaten. Since fish are abundant, the daily 

intake depends mostly on personal preference. Many interviews indicated that the 

600 g/day, wet weight, estimated by 

Murai and included in Table 5, is probably accurate to within 10-200/o. 

Tridacna and hippopus clams are about 

the only other seafood eaten in any significant quantity. Clams of edible size are 

not common at Ujilang (or Enewetak, for 

that matter), and most are consumed on 

the spot by the fisherman. The large 

adductor muscle is eaten raw, as well as 

the mantle, but dark parts are discarded. 

It is possible that some clam meat, particularly the mantle, finds its way into 

the diet of the women and children, but 

certainly not much. Sea turtles, spider 

snails, and helmet shell snails are also 

sometimes consumed, but again are only 

a small portion of the diet. Sea cucumber (Holothuria) and small crabs are not 

eaten. A variety of small snail 

(Littorina) is a delicacy, but the quantities consumed are insignificant. 

Coconut 

Until one has lived awhile with the 

Marshallese, it is impossible to realize 

what a useful tree the coconut palm is to 

these people. Essentially every part of 

it is used in at least one way. The leaves 

are used to make baskets, to thatch roofs, 

and for various handicrafts. The trunks 

are used for firewood and as logs for 

general building purposes. Coconut 

husks make good fire-building material, 

while the shells make good charcoal and 

are also used as cups and bowls. The 

sap from the blossom of a tree 4-5 years 

old is gathered and used as a syrup; it 

gives a pleasant coconut sweetness to 

several foods. This same sap may be 

fermented to produce an alcoholic drink; 

however, drinking is against the law for 

the Ujilang people. Small roots of the 

tree (-1-2 mm diam) can be bleached in 

the sun, dyed with the water extract of 

colored crepe paper, and woven into a 

variety of baskets. Hearts of palm are 

rarely eaten. The tree must be 

4-5 years old before the top is cut off 

and the growing core is harvested. This 

-38-
P 

elds 1: : about b-5 kg of material and kills 

i as :he tree. 

jed. The coconut itself iS a dietary mainir- s:ay. X drinking nut, ni

- (pronounced 

, “kneel’), is full grown but totally green, 

it and contains about 250-350 ml (grams) of 

2r 1Iquid. The meat at this stage is only 

50 about 4-5 mm thick and, while firm, is 

nly covered 

.- - .‘ Inside. 

:ot highly 

festive 

with a gelatinous coating on the 

Consumption of drinking nuts is 

variable. They are traditional at 

occasions and make an excellent 

;- “coffee-break” drink. Usually they are 

not used to quench thirst because water 

is preferred, but they are used more as 

the Marshallese version of soda pop. 

However, if water is not available, a 

:e working man might consume up to a dozen 

to nuts or so a day. On Ujilang they are 

If plentiful and there for the taking, which 

ves makes an accurate estimate of the conofs, sumption impossible. The meat of the 

iS drinking nuts, a popular baby food, is 

consumed only in small quantities by 

older children and adults. 

1 

L, Ripe coconuts, similar to those for 

d sale in American stores, are consumed 

in a variety of ways, but mostly raw. 

rS Some of the liquid is used in cooking, and 

the meat, called “copra” by the Marshallese, may be eaten in pieces with 

fish, or grated and added to other foods. 

i; Favorite recipes include a mixture of 

r grated coconut, wheat flour, water, and 

a little sugar which is baked in the urn; a 

similar mixture containing baking powder 

which is deep-fried (“doughnut” in Marshallese); a mixture of breadfruit and 

grated coconut baked in the urn; and 

grated coconut and coconut sap, mixed 

with steamed rice. All of the people 

S interviewed said they ate about half a 

i,ince a~. ax-erage coconut yields about 200 g of copra, the figure 

coconut per day. -

of 100 g/day listed In Table 5 is fairly 

accurate. This also agrees \i,ell with 

Llurai’s estimate. 

Commercial copra is prepared by 

spreading pieces of coconut meat on a 

grate about 2 m above an open fire. Coconut husks and shells are the favorite fuel, 

and complete drying requires about 24 hr. 

After drying, the copra is stored in burlap sacks to await a 

ship. Copra-making 

on L’jilang because, 

often spoiled before 

Trust Territory field 

was not in evidence 

the people said, it 

a ship ..vould arrive. 

However, while the survey party was 

there, Smith Gideon built a copra-drying 

shed which he said would dry several 

hundred pounds at a time.’ 

There is a stage of the coconut between ripe and sprouted when it is not 

consumed. Once sprouted, the layer of 

meat is gone and the inside is filled with 

a pithy, yellowish mass called iu (pro- -

nounced (“you”), which is highly prized 

by the Marshallese. Iu may be eaten raw 

:I: 

‘According to Tobin, most copra is 

dried in the sun rather than over a fire, 

and official Trust Territory figures list 

the copra production of Vjilang as 

51.6 tons ($5000) in fiscal 1971 and 

110 tons ($11,000) in fiscal 1972. If 

these figures are reliable, it would seem 

that much more copra-making goes on 

than was evident during the survey 

party’s visit. It is possible that copra is 

made on other islands, but the people 

generally said they did not make much 

copra. Certainly on the main island 

there did not appear to be an area large 

enough to sun-dry more than 100 tons of 

copra, even in a year. Current copra 

production is of little importance to doseassessment calculations, but if copra is 

to be an important cash crop in the future, 

careful attention should be given to potential radionuclide levels. 

-39-

h 
or used like copra. In what is probably 

the favorite recipe for iu, iL is grated 

together with copra and perhaps a little 

sugar, then slurried with ni to make a 

thick drink, a sort of Marshallese milkshake. On Majuro this mixture is frozen 

on sticks and sold like Popsicles. 

Breadfruit is the third main component 

of the hIarshallese native diet and was in 

season during the visit there. Three 

varieties exist, two of which must be 

cooked, and the third, somewhat less 

plentiful, can be eaten either cooked or 

raw. A typical breadfruit will be about 

15 cm long, 10 cm in diameter, slightly 

ovoid, with a rough, light-green skin and 

orange flesh. The general appearance is 

that of a very large avocado. Average 

weight is 1100 g, with about 10% as peel 

and core. The variety eaten raw is 

smaller, weighs perhaps 700-800 g and 

contains about 100 g of seeds which look 

like small chestnuts. These seeds can be 

roasted and eaten. Breadfruit is cooked 

in several ways, much as we would cook 

potatoes. However, the skin is never 

eaten. The breadfruit may be peeled and 

cored, then cut up and boiled, or it may 

be baked whole with the skin on, either 

over coals or in the urn. A favorite way, 

especially of older women, is to peel and 

core the breadfruit, then slice it perpendicularly to the long axis, salt lightly, 

and deep-fry. This produces a product 

resembling fried pineapple rings, but 

somewhat larger, and is a good snack 

food, a sort of Marshallese equivalent of 

potato chips. Once cooked, breadfruit 

can be covered and kept for several days. 

Another method of preparing breadfruit is to peel and core about a dozen 

fruits and let them soak about 24 hr in a 

coconut-frond basket in the lagoon. They 

are then rinsed in fresh water and 

kneaded together on a rock or board until 

the product resembles orange-colored 

bread dough. This is then divided into 

“loaves” of a kilogram or so apiece, 

wrapped in breadfruit leaves, and stored 

underground in a pit as already described. 

It is said to keep several months 

this way, and may be used like fresh 

breadfruit after another rinse in 

fresh water. This product is usually 

mixed with grated coconut and baked 

in the urn. 

Arrowroot grows all over Ujilang and 

is the principal undergrowth in the coconut forest. In July, the tubers were 

small because the harvest season begins 

around November. The preparation of 

arrowroot has been described by Tobin 

and consists of digging, then washing and 

grating the tubers, and placing the pulp 

in a burlap sack or one woven of coconut 

roots. The sack is immersed in salt 

water, squeezed out by hand, and the 

milky extract, consisting of a fine suspension of starch, is collected. In an 

hour or so the starch coagulates and is 

washed several times by decantation with 

salt water, then fresh water. The starch 

is then spread in the sun to dry, ground 

lightly to break up lumps, and stored 

away where it will keep indefinitely. 

Arrowroot starch is not at all like wheat 

flour and is only used as a thickening 

agent in soups or stews. It resembles 

our familiar cornstarch. When questioned, the Ujilangese all stated a preference for wheat flour over arrowroot 

starch. Flour can be used as a thickener, 

as well as for other purposes. They said 

that given both, they would use up the 

-4o-
I’j(luL. first and then fall back on the arrow 

1:ram starl 10 finish, arrowroor ,‘( lot. 

i,,.~,~~uctLOn is a long, ted:ous process, 

,.(..c;,ilting in a product nhlch has no flavor 

,,ntllimited usefulness. 

]‘3ndanus was lust Coming into season 

dur.,ng the July trip. When questioned, 

Inost adults said that the>- eat hardly any 

pandanus. It is corxumed mostly by the

Tobin reports a method of sun. (\hildren. 

(trying pandanus on coconut fronds; the 

1 ,lilangese acknowledged this, but 

c~laimed that they do not make it often. 

[‘andanus is not abundant on Ujilang and 

probably will not be on Enewetak either. 

About the only other native food consumed in any quantity on cjilang was 

pork and, in even lesser amounts, 

chicken. The quantity of Pork consumed 

varies greatly from family to family, 

because pigs are private property, and 

there is no obligation to share them. 

Some families have many pigs and may 

eat pork two or three times per week, 

replacing fish on a gram-for-gram basis, 

while other people have few or no pigs 

and hence eat little or no pork. Chickens 

are in the same category but are very 

scarce. The reason for this seems to be 

that the cats, originally imported to control the rats, did such a good job that 

they had to move on to the chickens. All 

animals are free-roaming and forage 

anywhere on the island. 

Little need be said for other native 

foods. Coconut crabs and wild birds 

have been essentially wiped out on Ujilang but may be important at Enewetak, 

especially for the first year or two. The 

coconut crabs are highly prized for food. 

I Their legs and claws are broken off and 

cooked immediately; then the crab is 

force-fed until the tail doubles in size, 

when 11 is used for soup. &Almost all of 

the sea birds are eaten escept the golden 

plover, which is believed to contain 

spirits of departed souls. The young 

birds just getting feathers are a favorite 

food item. Again, the Marshallese 

I*ecipe is simple: catch the bird, 

wring its neck: and cook it over an 

open Fire, entrails, feathers, and all. 

The liver and heart are eaten. 13ird 

eggs are eaten but are nr\t a favorite 

food item. 

The only garden vegetables growing on 

Iljilang were two pumpkin vines, neither 

of which had any pumpkins, but one was 

in blossom. The lack of agriculture is 

explained first by the fact that there is 

practically no soil, just rocks, and second, that the pigs are free-roaming and 

fond of anything edible. The latter fact, 

when combined with the cat-chicken situation, provides a real insight into the 

Marshallese philosophy of life, “play it 

where it lies.” 

Methods of cooking imported foods 

have been described as they accompanied 

the native diet. Flour, in addition to the 

products mentioned, is also made into 

bread, baked in the urn. Rice is exclusively boiled with the standard proportions of two parts of water to one of rice. 

Tea is drunk hot and is much preferred 

to coffee. In fact, the order of preference in beverages is tea, coffee, water, 

soft drinks, and ni. Sugar is added to 

several foods, and almost everyone uses 

sugar in tea and coffee. Canned meats 

such as corned beef, tuna, salmon, and 

mackerel are eaten with no more preparation than heating, and they replace fresh 

fish on a gram-for-gram basis. 
bledicines and Remedies 

This was the only area where there 

seemed to be a definite desire for 

secrecy. Apparently the Marshallese 

medicine, like the folk medicine in 

parts of the United States, is a family 

secret and not shared extensively, 

especially with outsiders. Part of 

this reticence may be due to the fact 

that the Marshallese realize the 

sophistication of American medicine 

and are afraid of ridicule. It was 

inferred that many of the Marshallese 

themselves did not have much faith in 

their medicine, but it was worth a try, 

particularly if the American version did 

not work or was unavailable. Held’s 

article (0p.cit.j contains some information 

regarding the local remedies of Rongelap. 

The reported uses of Messerschmidia 

and Scaevola were confirmed on Ujilang. 

The use of Messerschmidia is particularly important with regard to dose 

assessment, because leaves are used as 

a first-aid bandage and as a poultice to 

cover open wounds. 

.A few general remarks regarding 

health care should be made. Ujilang is 

the most remote of the Marshall Islands 

and as such, suffers even more than the 

others from a lack of readily available 

first aid, much less real medical care. 

The dispensary stock consisted of aspirin, 

tetracycline capsules, penicillin, dextrose solution, normal saline solution, 

and miscellaneous odds and ends of patent 

medicines. A Marshallese medical 

attendant was in charge. A kerosene 

refrigerator was operable but out of fuel, 

and there was no other medical equipment or furniture of any kind. In case of 

a medical emergency, the usual procedure is to divert a Trust Territory ship 

and take the victim to Majuro. Usually 

this means a minimum of three days’ 

delay. The people all appeared very 

healthy and vigorous, and there seemed 

to be no evidence of malnutrition or illness. However, it was reported that all 

through the Marshall Islands a baby’s 

first birthday is a big event and a cause 

for celebration. 

Agricultural Considerations 

Just what the level of agriculture will 

be in Enewetak is very difficult to say. 

Certainly the two staples, coconut and 

breadfruit, will be grown, especially on 

the islands of Medren, Japtan, and 

Engebi. Some pandanus and arrowroot 

will also be raised. The fact that no 

agriculture is practiced on Ujilang and 

the reasons why have already been mentioned. Whether things will be different 

at Enewetak remains to be seen. Many 

Ujilangese interviewed remembered that 

the Japanese raised a variety of vegetables as row crops on Engebi and Enewetak. These were irrigated with either 

cistern or well water containing human 

waste. No one knew whether vegetables 

could be grown on any other islands 

(probably Japtan) but, since irrigation is 

necessary, the availability of fresh water 

would be a crucial factor. The implication is that, given some effort and perhaps some fertilizer, a variety of crops 

could be grown. One Ujilangese, Balik 

by name, worked as a Trust Territory 

agriculturalist on Majuro for a year. He 

also lived on Enewetak at the time of the 

Japanese occupation and recalls their 

growing pumpkins, cucumbers, watermelons, potatoes, sweet potatoes, green 

-42-. 
F a 

,,,,I ‘1.5, c-abbage (bok chol), carrots, and crabs and snails from the lagoon beach. 

I,i.L...:YLt soybeans. Thus there is cerra:nl; Presumably the chickens consume a sim-

;, p,:rCIntial for augmenting the standari liar diet. It would seem that on Enewetak 

ij,C.: ,-,f coconut, breadfrult, and fish. It the confining of either the animals or the 

,? :-._,ported by Tobin and confirmed by vegetables would be benefici.al. 

,,thL’!“; that the rjilangese are quite incluS:!.lu~s and will probably grow at ieast Marine Resources at Enewetak 

sc,r.e vegetables, but will 

pl.3ctlce American-style 

Pigs and chickens will 

ti()mestic animals raised 

probably no: During conversations and fishing trips 

truck farming. with Smith Gideon, Ujilang magistrate, 

remain the only in a two-week period at Enewetak Atoll in 

for food; no one July 1973, some information on the food 

,nter~,iewed indicated 

,‘\.(‘r, Tobin says that 

turkeys do well in this 

shalls. As on Ujilang, 

otherwise. How - habits of the ‘Ujilang people was gained 

_YIuscovy ducks and which may be used to help estimate dose 

part of the Mar- rates from food intake. In general, the 

livestock will be data gathered concern the use of fish in 

allowed to forage on their own, although the IYjilang diet and specifically include 

it \vould seem that for at least a few data on meals eaten during fishing trips 

years after return, some sort of food while on Enewetak. 

supplement would 

lang the pigs ate 

ripeness, grass, 

pet morning glory 

breadfruit, family 

Table 6. Average 

be necessary. On Uji- Generally, it can be stated that the 

coconuts at all stages of Ujilang people are opportunists and will 

the leaves of the trum- eat most types of fish which they happen 

(Ipomoea), fallen to catch. However, certain fish are pregarbage, and small ferred and special efforts are made to 

wet weights of tissues from common edible nearshore fish at EneweCommon name 

Goatflsh 

Goatfish 

Goatfish 

Mullet 

Mullet 

Mullet 

fiabbitfish 

Convict Surgeon 

Parrotfish 

tak Atoll. 

Tissue 

Eviscerated 

Viscera 

Muscle 

Muscle 

Eviscerated 

Viscera 

Muscle 

Eviscerated 

Viscera 

Muscle 

Muscle 

whole 

whole 

whole 

No. of 

fish 

61 

61 

32 

32 

32 

9 

47 

47 

17 

Average 

wet weight Wet/dry 

145 3.4 

13 3.5 

45-5oa 4.8a 

57 3 

167 3 

44 2 

200 3.9 

54 3.5 

10 5.3 

15b 4.0b 

144 4.9 

aEstimated 

b 

Estimated. 

from similarity to size and body shape of mullet. 

-43-
capture the preferred species. Also, 

certain fish are avoided either because 

they are known to be poisonous (ciguatera), difficult to prepare, or simply 

because they are not as flavorable as 

other species. 

One apparently favorite fish is the 

goatfish, either “Jo” (1Iulloidichthys) or 

“.Jome” (LI. auriflamma). The whole fish 

is laid on a grill (if available) and roasted 

over a bed of hot coals for about 10 minutes. The skin is then peeled off and the 

flesh eaten. The head of the goatfish is 

considered a delicacy and is often offered 

to a guest as a courtesy. The soft parts 

(brain, eyes) of the head are eaten, but 

the bones and viscera are discarded. All 

organic waste from a meal is placed in 

the fire and burned. This is a garbage 

disposal method and serves to keep the 

fly population down. One goatfish or 

mullet (see Table 6 for average weight of 

fish) is a reasonable intake at one meal; 

however, some people may eat three goatfish. The remainder of the meal usually 

consists of one-third of a copra coconut 

and a drinking coconut. 

Another apparent favorite is the rabbitfish, “bejrok” (Siganus). Rabbitfish of 

other species are also known as “mole” 

or “molle” and are referred to several 

times in Tobin’s 1955 journal as a favorite fish of the Ujilang people. The rabbitfish are cooked in the same manner as 

the goatfish. In fact, it appears that 

most fish are cooked in this manner, except for occasions when the urn is used. 

Only the flesh of the rabbitfish is eaten, 

and one fish is the usual intake for a 

meal. One-fourth of a copra-type coconut (the kind usually sold in the U.S., 

with the meat dry), coconut crab legs 

(100 g, wet), and a drinking coconut 

completed this meal as prepared at 

Enewetak. 

Other fish which were captured on 

fishing trips and which are said to be 

eaten are mullet, convict surgeon, parrotfish, grouper, su rgeonfish, and 

damselfish. These fish, along with the 

goatfish and rabbitfish, probably comprise the most common fish found in the 

nearshore water around the island of 

Enewetak, and hence will probably be the 

most common fish in the diet. Seven or 

eight convict surgeon, some copra, and 

a drinking coconut, or two to three convict surgeon, copra, rice, and a drinking coconut are typical meals. 

There seems to be some conflicting 

opinion as to whether or not the Ujilang 

people eat mullet and parrotfish. Tobin, 

in one conversation, stated that the Ujilang people do not eat either mullet or 

parrotfish. However, Smith Gideon, 

when shown specimens of mullet and parrotfish, indicated that at least three different species of the smaller (~12 in.) 

mullet, both “ikare” (Chelon vaigiensis 

or Neomyxus chaptalii) and “jomou” 

(Mugil sp.), and three species of parrotfish are eaten on occasion. The conflicting opinions may be due to the fact that 

one genus of mullet, “iol” (Crenimugel 

=.I, is considered to be poisonous and 

therefore is not eaten. Furthermore, 

parrotfish from the northern end of the 

Enewetak Atoll are also considered to be 

poisonous and are not eaten. Parrotfish 

from the David to James area of the Atoll 

are eaten. In addition, the fact that other 

species of fish (goatfish and rabbitfish) 

are preferred may have led to the confusion on this point. However, it seems 

-44-

t 
i.lc31- that Tie I lilans p~>o?le, on occa1~~11 ear both mullet and parrotflsz. slon, 

of the fish actuall)- captured and shox::n 

to Smith, i::s preference in descending 

order seemed to be goatfish, rabbitfish, 

mullet, convict surgeon, and parrotfish, 

\vith grouper, surgeon and damselfish 

occupying indefinite intermediate positions bet\%,een rabbitfish and parrotfish. 

These nearshore fish are captured by 

several melhods, including use of thrownets, gillnets, and a surround technique 

by which the fish are driven into shallow 

water where they are hand-captured or 

dip-netted. Additional thrownets and 

gillnets, along with appropriate mending 

materials, might be considered as a part 

of the rehabilitation program for the 

Enewetak people. 

A fish not actually captured but indicated to be very good to eat is the flying 

fish, “jojo” (Exocoetidae). These fish 

are captured at night by building a fire in 

a boat and attracting them to within a 

range where they may be netted. Some 

flying fish also fall into the boat during 

their flight toward the attracting light. 

Small hooks on a line are also used in a 

manner similar to the jigging of herring 

or smelt which bite on the bare hooks 

that simulate the planktonic organisms 

they feed on. 

Other fish which reportedly are eaten 

are barracuda with four gill rakers, 

“nidwa,” tunas, and other similar lagoon 

fish such as jacks, mackerel, and dolphin. Although larger sharks (probably 

gray sharks but not thresher or nurse 

sharks) are eaten, they probably are a 

minor portion of the diet due to the length 

of time required in the preparation of the 

flesh to make it edible. This lengthy 

c 

. ..\ _ I.)- :.enders the fresh fish unpalatable: 

E shark has a big smell.” 

In the preparation oi shark flesh, the 

I1 5 r, is boiled in hot water for about 

15 minutes, after which the skin is rern7.,.ed. The flesh is then boiled for several hours, presumably until the smell 

~2~s a-s::av“. Nest, the boiled meat is 

fr:ed or steamed (urn) and then placed in 

IL? sun until it is dry. This process 

rakes n:ost of a day, but the finished 

?:-oduc: is considered good. 

The capture of large lagoon fish reoulres boats and fairly heavy fishing 

I .-

T-eoaration is due to the urea in the flesh 

L .,,es, feathered jigs, and large hooks. 

Hence, the use of these fish in the diet is 

hlehly dependent on these items and is 

probably less than the utilization of the 

nearshore fish because of the present 

scarcity of adequate fishing gear and beca.Jse r!le nearshore fish are so abundant 

and easily captured at most times. In 

general, at the present time, deepwater 

lagoon fish are probably not as abundant 

in the diet as they would be if more fishing gear were available to the people. 

Other martne organisms which may be 

eaten include porpoise, tridacna clams, 

l” kabwu r” ), shore crabs, and large gastropods (en). Other smaller gastropods are 

also called en, but they are not eaten. 

These include spider snails and smaller 

Strombus species. 

Porpoise are captured by surrounding 

them as they enter the wide pass or deep 

channel and herding them into shallow 

water. Herding is accomplished by banging rocks together underwater and splashing on the surface. 

Three types of Tridacna are distinguished by the Enewetak people: (1) the 
large killer clam, ‘I’ridacnagigas; (2) a 

white-mantle, medium-sized clam; and 

(3) small clams jr-ith colored mantles 

which are embedded in the reef. All 

types are called kabwar. NO information was obtained on how these clams are 

prepared, but it is known that other Marshallese people do not eat the kidney, due 

to its very bitter ilavor, and it may be 

presumed that this is the case for the 

Enewetak people until different information is obtained. 

Another organism which will certainly 

be eaten by the returning Enewetak people, 

unless advised to the contrary, is the 

coconut crab, “baru lip” (Birgus latro). 

The first step in preparing this crab is to 

knock the pincer legs and the largest 

walking legs off with a machete. The legs 

appear to break off near the body at a natural breaking point, which quickly heals 

over. By doing this the crabs can be 

easily contained without causing damage 

to themselves or to their captors. Also, 

crabs can be held alive like this for several weeks. The legs and the bodies of 

crabs not to be saved are then roasted 

over a bed of coals. 

From discussions with Smith Gideon, 

I would conclude that the diet of the Ujilang people is very similar to diets of the 

Bikini people, the Rongelap people, and 

other northern island groups in the Marshall Islands. This is true because the 

basic foods are the same in all these 

areas. Breadfruit, pandanus, arrowroot, 

and coconut are the chief natural terrestrially grown Lregetative foods, with imported rice and flour supplementing this 

portion of the diet to a degree which is 

very dependent upon the length of 

time from the visit of the last fieldtrip ship. 

Fish, clams, and langousta from the 

lagoon and reef; birds and bird eggs from 

bird-nesting islands; domestic pigs and 

chickens raised on the village island; and 

imported meats (corned beef, sardines) 

provide the animal protein in the diet. 

Again, the proportions vary greatly with 

the availability of specific items; however, fish are indicated as being an important part of the diet at Ujilang and 

will probably be more important at Enewetak Atoll where the fish supply is 

greater. 

It should be remembered that a diet 

determined for the Ujilang people over 

one short time period may differ greatly 

from a diet determined over another time 

period in a different season or at a different length of time from the last visit of a 

trade ship. I feel, therefore, that a composite diet, based on all available diet 

information for the Ujilang, Bikini, and 

Rongelap people, is the best information 

to be used in the calculation of dose rates 

from food intake. 

-46-
III. Survey Execution 

Iv!‘. Ser\-ik, Lawrence 1-i:.ermore Laboratory, Li\.ermore, C‘aliiornis 

rot, 

jId 

le 

ra 

n-

:\fter agreeing tie conduct the radiologthe AEC assigned responsi- li~al survey, 

l,Llity for the program coordination to its 

l)lvLsion 0f Military 

hlajor General F. 

ylgr. for Military 

directed the AEC 

Office (NV001 to esecute the program, 

using the following specific instructions: 

“As a result of commitments made by 

Ambassador Williams and initial agreements reached during an interagency 

meeting held on September 7, 197 2, it is 

the overall AEC purpose to gain a sufficient understanding of the total radiological environment of Enewetak Atoll to 

permit 

any part 

habited 

cleanup 

Applications (DMA). 

A. Camm, Asst. Gen. 

Applications, then 

Nevada Operations 

judgements as to whether all or 

of the Atoll can safety be reinand, if so, what steps toward 

should be taken beforehand and 

what postrehabilitation constraints must 

be imposed. It is necessary to thoroughly examine and evaluate radiological 

conditions on all islands of the Atoll and 

in the local marine environment prior to 

commencement of cleanup activities in 

order to obtain sufficient radiological 

intelligence to develop an appropriate 

cleanup program. Specifically, it is 

necessary: 

1. TO locate and identify contaminated 

and activated test debris, 

2. To locate and evaluate any significant 

radiological hazards which may complicate cleanup activities, and 

-47-

:3. To identify sources of direct radiation and food-chain-to-man paths 

having radiological implications. 

You are directed to plan, organize, 

and conduct a radiological field survey to 

develop sufficient data on the total radiological environment of Enewetak Atoll to 

permit the assessments on which the 

judgements described above can be 

made.” 

A number of factors strongly influenced the planning of the survey: 

Although a number of studies of Mewetak had been conducted previously, 

none provided either current or complete information on the radiological 

state of the Atoll. The Survey would 

therefore have to obtain data on all 

islands and all human dose pathways 

in sufficient detail and accuracy to 

permit reliable population dose estimates to be made for the future 

inhabitants. 

In September, 1972, the only field support facilities available at Enewetak 

were those operated by the U. S. Air 

Force, which then had custody of the 

Atoll. The base support resources 

were committed to certain military 

activities, but an open period in those 

activities permitted the scheduling of 

support to the AEC survey from mid 

October thru December 1972. 

Although Ambassador Williams had not 

promised the return of the Enewetak 

people to the Atoll at the end of 1973., 

his speech was widely interpreted to 
mean lust that, land therefore there 

was considerable pressure for the 

XEC radiological survey and dose 

assessment effort to be completed as 

quickly as possible. 

• Given the size of the sampling program, the time constraints imposed 

by limited field support facilities, the 

large amount of radiochemical analytical work required, the complex dose 

assessments that were needed, and the 

growing hopes and expectations of an 

early resettlement, it was clear that 

no single technical organization was 

big enough to conduct this program by 

itself, nor were there many who could 

or would divert sizable numbers of 

highly qualified technical people from 

previous commitments on less than 

one month’s notice. 

With these factors influencing decisions, the Radiological Survey was organized in the following way: 

A Program Manager (Roger Ray) was 

assigned by NV00 to provide overall 

program responsibility, liaison and 

coordination among organizations 

operating in the field, and fiscal controls at the NV00 level. 

The Lawrence Livermore Laboratory 

(LLL) agreed to provide a Technical 

Director (Dr. Walter Nervik) for the 

program and to act as the focal point 

for technical activities associated 

with the program. 

Technical leadership for the various 

components of the program was 

assigned as follows: 

Aerial Photography and Radiation 

Survey (J. Doyle, EGG) 

Terrestrial Soil and Radiation 

Survey (P. Gudiksen, LLL, and 

0. D. T. Lynch, XVOO) 

External Dose Estimates 

(J. McLaughlin, HAS L, 

P. Gudiksen, LLL, and D. Jones, 

LLL) 

Marine Survey (V. Noshkin, LLL, 

and V. Nelson, U. Wash.) 

Terrestrial Biota Survey 

(G. Potter and J. Koranda, LLL) 

Air Sampling (D. Wilson and 

B. Clegg, LLL) 

Radiological Support to the DOD 

Engineering Survey (0. D. T. 

Lynch, NV001 

Analysis Program (R. Hoff, LLL) 

Radiological Controls (0. D. T. 

Lynch, NV00 1 

Dose Assessments (D. Wilson, 

Y. Ng, and W. Robison, LLL) 

• These leaders then completed plans 

for the field sampling, analysis, and 

interpretation portions of their component and identified individuals who 

would be doing the work. Because of 

the scope and unusual nature of this 

program, individuals from an exceptionally large number of organizations 

have been involved, including NVOO, 

LLL, National Environmental Research 

Center (EPA, Las Vegas), Laboratory 

for Radiation Ecology (LRE) (University of Washington), University of 

Hawaii Enewetak Marine Biological 

Laboratory (EMBL), Trust Territory 

of The Pacific Islands (TTPI), 

McClellan Central Laboratory (MCL), 

Laboratory for Environmental Studies 

(LFE), Eberline Instrument Co. (EIC): 

AEC Division of Operational Safety, 

AEC Division of Biomedical and Environmental Research, EG&G, Inc. 

-48-
,l.;GG), _iEC Health and Safety Labora-

:ory (HASL), the Defense Zuciear 

.Agency (3sA), Holmes and Sarver 

iH and 31, the L-‘. S. Savy, C.S. Marine 

Corps, ar,d the r. S. Air Force field

support contractors. 

Given the directive to proceed 011 

1972, the Survey plan was 

completed, reviewed, and approved on 

September 13. (A copy of the final Sur-

\.ey plan appears in Appendix I.) The 

[TieId Survey party departed COSUS in 

two contingents, one on October 13 and 

the second on October 15, and field operations were begun on October 16 with the 

Soil, Marine, Terrestrial Biota, _Air 

Sampling, and Engineering Sut-I-ey Components all conducting their activities 

simultaneously. This put a very definite 

strain on the marine transport equipment 

(four boats), but all operations were 

proceeding smoothly until October 21, 

when the Survey party received its first 

alert warning of the approach of Typhoon 

Olga, predicted to pass directly over 

Enewetak on October 24 with winds of 

125 knots and gusts to 165 knots. Survey 

activities ceased with that alert, all 

equipment was made secure, and everyone on the Atoll was evacuated to Kwajalein on the evening of October 23. Upon 

return to Enewetak on October 25, the 

Power plant was found inoperative, and 

we were advised that the island could not 

support the Survey Party. All Survey 

Personnel were sent home until support 

facilities could be provided once again. 

Operations were resumed on November 8 with the initiation of the aerial 

survey. In the interim period from October 25 to November 8, changes in the 

scheduling of the military programs at 

September 7, 

Enelr-etak provided further relief in the 

form of an extension oi available ileld 

support. The AEC radlologlcal ileld 

survey schedule was thus extended to m:d 

February. The field effort actually terminated on February 13, 1073. In the 

following sections each component of the 

Survey is discussed in detail by those 

who were responsible for the effort. 

AERIAL RADIOLOGIC_\L -4111 

PHOTOGRAPHIC SLiRVE\ 

T. P. Stuart and R. ;IIeibaum 

EG&G, Inc., Las Vegas, Sevada 

Introduction 

An aerial radiological and photographic survey of Enewetak Atoll was 

performed by EG&G during a 16-day 

period between November 8 and 23, 1972. 

This work was done in order to characterize the terrain, including the entire 

reef, and to determine the gammaradiation levels and the spatial distribution of radioactive isotopes which are 

residues from earlier nuclear explosive 

experiments. Much of the fissionproduct and activation residues from the 

nuclear explosives experiments during 

the period 1948 through 1958 have remained to contaminate many of the 

islands and sections of the adjoining reef. 

In addition to fission and activation products, there is plutonium metal scattered 

at some locations as a result of explosive 

experiments which did not achieve a fiss ion yield. Primary contaminants observed from the aerial radiological 

measurements are 6oCo, 137Cs, and 

23gPu. 

The aerial radiological and photographic survey was carried out from a 

-49-
helicopter and covered all 39 islands of 

the Atoll, The photography covered four 

wavelength bands in the visible and nearinfrared spectrum, and served to document the geographical features of the 

Atoll and serve as a basis for navigation 

in carrying out the radiological survey. 

The aerial radiological survey involved 

only gamma-ray measurements and included both gross gamma counts and 

energy spectral information in the 50-keV 

to 3-MeV range. The radiological meas -

urements resulted in a determination of 

the spatial distribution of gammaradiation exposure rate in pR/hr at one 

meter above the ground, as well as isotopic concentration for 6oCo, 137Cs, and 

plutonium-related 241Am. These measurements are presented as isopleth plots 

superimposed on aerial photographs of 

the islands. Correlations with groundbased radiation measurements and soil 

sample analysis are discussed in the 

subsection on Nuclear Lnstrumentation 

Systems and Methods. 

The photographic data, together with 

the radiological survey results for the 

gamma-exposure rates and isotopic concentration for 6oco, 137Cs, and 

plutonium-related 241Am, are presented 

in Appendix II. The next subsection of 

this report gives a description of the 

photographic instrumentation and methods, while the last subsection describes 

the nuclear instrumentation systems and 

methods. 

Photographic Instrumentation 

and Methods 

Multispectral Camera System 

Hasselblad Camera System - The 

aerial photographs of the islands comprising the Enewetak Atoll were taken with a 

four-camera system consisting of 70-mm 

500 EL Hasselblad cameras, equipped 

with 80-mm lenses. The four cameras 

were arranged along parallel optical paths 

and imaged identical ground images on 

the four image planes. The frame size 

was 55 X 55 mm. 

Each of the four cameras recorded a 

different portion of the visible and nearinfrared spectrum. The wavelength 

region recorded was controlled by the 

choice of film sensitivity and optical 

filter combinations. The four film and 

filter combinations used are shown in 

Figs. 7 through 10. The four wavelength 

regions recorded were: 

Normal color 4000 -7000 A 

Infrared color 5000- 9000 i 

Panchromatic / 

red filter 6000-7000 A 

Infrared black 

and white 7000- 9000 i 

Camera Mounting - The four 

Hasselblad cameras were mounted on a 

rigid plate which subsequently was 

mounted to the floor of a CH-53 Sea 

Stallion helicopter, allowing the cameras 

to view the terrain through a large port 

in the floor. Since gyrostabilization or 

shock mounting of the cameras was not 

used, the system optical axis moved in 

concert with the aircraft attitude and 

pitch. The optical axis of the camera 

system was perpendicular to the floor of 

the aircraft, which was maintained 

reasonably level during photographic 

missions. 

Onerational Considerations -

Photographic missions were flown at 

altitudes selected to image a single island 

-5o-
P 

vith a 

iO-mm 

,,,] :: single 

i onsecutive 

frame. On 

o\rerlappine 

Tc? longer islands, 

frames xvere 

rke 

Sea 

nearest 

level) 

conl.enien: 

interval in 

300-m 

order to 

imean 

simplify 

ped :aken to provide a mos;i:: of the individual rhe flight plans and allow the acquisition 

eras 

11 paths 

Island. Flight altitudes -.:ere selected to 31 several 

Once over 

islands on 

the island, 

a single flight 

the cameras 

path. 

were 

; on 

size I 

Speciral 

I I 

sensitivity 

I 

curves 

1 

Triggered simultaneously by an operator 

looking through the floor of the aircraft. 

flight altitudes ranged from 300 to 

ied a 

near -

h 

:he 

3 

2 

Yellow forming layer 

Magenta farming 

Cyan forming \ 

layer 

layer7 

3000 meters. 

In addition to the lndi\-idual island 

photographs, complete co\‘erage of the 

-Atoll was acquired from an altitude of 

Ll 3000 m. For this co\yeragc the pilot 

and xas directed to fly the center of the 

in :.isible portion of the _4toll while the 

length 

Oii 

500 600 

Wavelength - nm 

700 camera system was 

o\-erlapping coverage. 

The islands were 

triggered to 

photographed 

record 

over a 

Oi 3.0 I I I I span of 8 days from November 12 to 20, 

Ofi 

OA .; 

-G

2.5 -

2.0 

1.5 t r 

Spectral 

Ye I low 

dye 

dye density curves 

Neutral 

Magenta 

r dye 

1972, and at diurnal periods between 

0955 and 1624 hours, local time. The 

specific time of day of any photograph 

the set presented in Appendix II is 

available. 

in 

on a 

Quick-Look Photography - The 

first missions flown on the island were 

neras 

3ort 

for the purpose of acquiring photographic 

1 or Wavelength - nm 

not 

ZI in 

d 

ra 

or of 

C 

.t 

island 

i 

CJ 

9 

a, ’ 

? 

0 

z 

._ 

Eul 

s 

c' 

0.1 

1, 

10 -

1001 

300 

Wratten filter 

I 

500 

Wavelength 

No. 2A 

- nm 

700 

Fig. 7. Kodak Aerocolor Negative Film 

2445. This film is a three-layer 

color film with sensitivity in the 

visible portion of the spectrum. 

This film is designed for processing to a color negative and 

does not have an integral color 

mask. In this form, the film is 

suitable for direct visual interpretation or can be readily 

printed to a positive print. The 

three layer sensitivities are to 

blue, green, and red. The film 

is normally used with a Wratten 

2A haze filter, which reduces 

the recording of unwanted atmospheric haze on the film. 

-51-
Spectral sensitivity curves maps for use by the radiation monitoring 

personnel. This was accomplished by 

using the four-camera system equipped 

with a different film and filter combina- ::j 

tion than for the multispectral coverage. 

Kodak Plus-X Aerographic with a Wratter 

12 filter was used to provide a photographic record in black and white that 

closely simulated the tonal relationship kO0 500 600 700 800 900 

Wavelength - nm 

Spectral sensitivity curve 

Spectral dye density curves 

31 

: 2.0 

3 

a 1 .5 

‘3 1.0 200 500 600 700 

v,k 0.5 Wavelength - nm 

0 

400 500 600 700 

Wavelength - nm Wratten filter No. 25 

0.1 

8 Wra tten Wratten 

I filter No. 12 cc 30 blue 

1 1 

10 

0.1 

100 FBI EizEEl

400 600 300 500 700 10 - I 

Wavelength - nm 

Fig. 8. Kodak Aerochrome Infrared 

Film 2443. This film is a false- loo* color reversal film designed for 400 500 600 ; IO use in aerial photography. It 

differs from ordinary color film Wavelength - nm 

in that the three layers are sensitive to green, red, and infrared 

radiation instead of the usual Fig. 9. Kodak Plux-X Aerographic Film 

blue, green, and red. A Wratten 2402. This film is a panchro12 yellow filter is always used matic negative material that has 

with this film to absorb blue extended red sensitivity. When 

light, to which all three layers used with a Wratten 25 filter 

are sensitive. The Wratten which absorbs blue and green 

CC30 blue filter was used to cor- light, only those objects that 

rect the color balance of this have reflections in the red porparticular emulsion batch and is tion of the spectrum will be 

not normally used with this film. recorded. 

-52-
Spectral sensirivity curve 

>-. 

Yen 

!z!zzxI 

400 600 

Wavelength 

800 

- nm 

1000 

Wratten fi I ter No. 89B 

Wavelength -nm 

Fig. 10. Kodak Infrared Xerographic 

Film 2424. This film is a negative material which is sensitive to infrared radiation, as 

well as to the blue light of the 

visible spectrum. When used 

with a Wratten 89B filter, which 

absorbs all visible radiation, 

only the infrared radiation from 

the subject is recorded on the 

film. 

that the human eye sees. The missions 

1 

were flown 

missions. 

similarly to the multispectral 

i 

.n 

Photographic 

Printing 

Processing and 

:S 

1 

I 

The 

look 

On-Island Processing and Printingimagery acquired during the quickphotogranhic missions was processed 

and printed on the island, using the 

Eniwetok Marine Biology Laboratory. 

Conventional black-and-white developing 

and nr:ntinp v:ere accomplished to provide a 40 X 50-cm phorozraphic map of 

each Island. 

Laboratory Processing and 

Printing - Exposed film from the 

multispectral camera system leas processed in Las L-egas, Nevada. The two 

black-and-white films were processed by 

EG&G in a 1-ersamat 5N. Roth colorfilm records were processed commercially in a Kodak Color 1-ersamat. 

Photographic enlargements \vere made 

by EG&G from all records. The degree 

of enlargement varied for each island 

photograph because the island size was 

imaged to fit the print format with some 

water surrounding it. 

Report Reproductions - The color 

lithographs in Appendix II were made from 

the normal color photographic record 

using four-color separation negatives prepared by EG8;G. The color printing was 

done by EG&G on a model 1250 L&W Multilith press. Overprinting of titles and data 

was accomplished on the same press. 

Interpretation and Utility of the 

Photoaradhs 

Multispectral Imagery Interpretation - The imagery acquired of each island 

consists of the four wavelength regions 

previously described, examples of which 

are shown in Figs. 11-14. These are 

film records recorded simultaneously 

over Japtan Island (DAVID). Each figure 

shows imagery from a different portion of 

the spectrum. Figure 11 shows normal 

wavelengths similar to those seen by the 

human eye, covering 4000 to 7000 i. In 

Fig. 12 all of the colors seen are “false” 
with regard to human vision. In this picture, wavelengths between 5000 and 6000 i 

(green wavelengths) are recorded as blue, 

wavelengths between 6000 and 7000 i (red 

wavelengths) are recorded as green, and 

wavelengths between 7000 and 9000 i 

(infraredwavelengths) are recorded as red. 

Figure 13 is the black-and-white record 

on panchromatic film and exposed through 

a it’ratten 25 red filter. On this imagery, 

only wavelengths between 6000 and 7000 _L 

are recorded. Figure 14 is the blackand-white record recorded on infrared 

film with a visible absorbing filter, On 

this imagery only infrared wavelengths 

between 7000 and 9000 Aare recorded. 

While there are many facets to consider when interpreting multispectral 

photographs, a few general guidelines 

may be helpful. It is best to spread the 

four photographs for any one island out 

on a table when examining them so that 

the differences can be easily and quickly 

observed. The normal color record and 

the black-and-white (red filter) record 

both penetrate water depths well and show 

underwater terrain well. However, from 

the normal color record, it is difficult to 

determine where the water’s edge is 

located. This can be easily determined 

by looking at the black-and-white (infrared 

film) record which shows all water areas 

as black. The differences between the 

appearance of the water areas on the normal color and the infrared color record 

are significant. The normal color record 

shows colors on the print as they would 

be seen by the eye. However, on the 

infrared color record, all the colors are 

“false.” On this record the water still 

shows as a blue color, even though the 

film, when used with a yellow filter, has no 

sensitivity to blue wavelengths. The blue 

areas on the print are the direct result 

of green wavelengths reflected to the 

camera. In this “false-color” imagery, 

healthy vegetation and coral areas show 

as red. This indicates high reflectivity 

in the near-infrared region of the spectrum. The black-and-white (red filter) 

record shows green trees very dark and 

generally causes man-made objects such 

as concrete, asphalt, and buildings to 

stand out against the dark background. 

On the black-and-white (infrared film) 

record, green healthy trees which have a 

high reflectance in the infrared region 

appear very light, indicating again a high 

reflectance in the infrared region. 

Other Interpretations of the Photography - A wealth of information is contained in the photographs. Using a 

detailed study of one or of a series of 

photographs and aided by suitable analysis 

techniques, the photographs could be used 

for the following: 

Determine the percentage of tree 

cover for any island. 

Establish vegetation types. 

Determine the waterline at the time 

of the photograph. 

Locate major areas of debris. 

Determine suitable boat landing 

areas. 

Determine relative water depths 

around the islands. 

Additionally, because some islands were 

photographed with overlapping coverage, 

a stereo presentation is possible. This 

results in considerably more information 

about the terrain, surface cover, and manmade structures than is possible with a 

single photograph. 

- 54-
blue 

.l1t 

try, 

LOW 

.ity 

?Car) 

and 

;Uch 

1. 

1) 

ve a 

n 

high 

lysis 

used 

!e 

ime 

rre 

:e, 

.S 

ion 

mana 

Fig. Il. Normal color aerial photograph of DAVID covering 4000 to 7000 i. 

-55-

Fig. 12. False color aerial photograph of DAVID covering 5000 to 9000 

-57-

Fig. 13. Aerial photograph of DAVID covering 6000 to 7000 8.. 

-59-

Y 

Fig. 14. Aerial photograph of DAVID covering 7000 to 9000 1. 

-61-

Fig. 15, Single frame of high-altitude photographic coverage. 

-63-

Fig. 16. Assembled mosaic from JANET to WILMA. 

-65-

-67-

, 

frillf---* -iFig. 18. Data recording system. 

-69-

High-Altitude Mosaic - The entire 

Atoll was photographed with the MultiSystem from an altitude ,prcrral Camera 

(,I 3000 m over a period of several days 

for the purpose of making a mosaic. A 

sing]<‘ frame of the high-altitude coverFrom this alti- age !s shown in Fig. 15. 

rllde the relationship of the islands to one 

as well as the entire reef strut- another, 

ture, can be clearly seen. A portion of 

tl,c assembled mosaic extending from 

.IA>ET to WILIvlA is shown in Fig. 16. 

Qclear Instrumentation Systems 

and hlethods 

@scriptions of Instrument Systems 

Detectors -Gamma rays were detected in two arrays of twenty 12.7-cm 

diam x 5-cm thick NaI crystal spectrometers. Figure 17 shows one of these 

arrays. The output from the crystal 

photomultiplier-preamplifier combinations 

was summed and fed to the recording 

system. 

Inertial Navigation System - Accurate position data are obtained from a 

Litton Inertial Navigation System, LTN51. The actual flight coordinates (latitude 

and longitude) are recorded on magnetic 

tape. Special software, prepared by 

Litton to our specifications, allows these 

data to be recorded with a minimum 

detectable distance increment of 15 ft. 

When these data are processed, the 

flight paths are overlaid on a photographic 

map of the survey area. The end points 

are matched with the known positions of 

the start and finish of each line. The 

Position of the aircraft is then known at 

any point along the flight path with an 

uncertainty related to the flying time of 

~112 sec. For a typical survey, conducted at an altitude of 100 ft above terrain and at a speed of 30 m/set, this 

implies that the location of the aircraft 

is known with an uncertainty of 115 m. 

Recording System - Summed signals 

from the separate detectors were split 

and fed to (1) a 300-channel pulse-height 

analyzer and (2) a maximum of eight 

single-channel analyzers with adjustable 

upper and lower limits. These limits are 

set to monitor regions of the spectrum 

pertinent to isotopes of interest. Accumulation time for single-channel data was a 

minimum of 0.2 set, while accumulation 

time for multichannel data was a minimum 

of 3 sec. Inertial-navigation position data 

and multi- and single-channel counts 

occurring in the above time intervals were 

recorded on magnetic tape. The recording system is shown in Fig. 18. 

Data-Processing System - Magnetic 

tape was processed by a ground-based 

system, key components of which were 

two cipher data tape drives, a NOVA 

computer, and a Cal Comp plotter. 

Helicopter - The NaI spectrometer 

pods and the data-recording system were 

carried inside a Marine CH53 helicopter. 

This arrangement resulted in the radiological measurements being made with 

the terrestrial gamma radiation traveling 

through the floor of the helicopter to reach 

the gamma spectrometers. This attenuation effect was taken into account by performing calibrations in a similar geometry. 

This is discussed in the subsection on 

Isotopic Concentration. 

-71-
Operational Procedures 

Survey NIeasurements - Due to the 

large difference in photopeak energies 

and resolution of the recording system, a 

separate survey was made for plutonium 

60 while data for Co and 137 Cs concentrations were accumulated simultaneously. 

Plutonium was sensed via the 60-keV 

241 

y ray from Am, a decay product of 

241Pu. Electronic gain was adjusted for 

those surveys so that the full-energy scale 

corresponded to a y-ray energy of 300 keV. 

Typical spectra with and without 241Am 

are shown in Fig. 19. Shaded areas in 

this figure define three single channels, 

the outer two of which were set to monitor 

changes in background levels. The central window monitors the 60-keV photopeak. 

Electronic gain was set to cover a full 

scale of 3 MeV for the 6oCo and 137Cs 

surveys. A typical spectrum is shown in 

Fig. 20. Shaded areas in this figure again 

define the single channels set up to 

monitor background and photopeak regions 

of the spectra. Gross counts (those 

between 50 keV and 3 MeV) were also 

recorded during the high-energy surveys. 

A grid of lines spaced 150 ft apart was 

flown over each island at an altitude of 

100 ft and an airspeed of e 70 knots. 

Flight lines were laid out on aerial photographs taken for navigation purposes. An 

on-top marker was recorded on the 

magnetic tape when a landmark near the 

shore was crossed at the start and finish 

of the flight line. Some individual detectors in the array were turned off, and 

flight lines were reflown when count rates 

were high enough to produce spectral 

distortion due to pulse pileup. 

IIII ml III 1 I I 

241 ___ Am plus background 

-Background 

Background windows 

Photopea k window 

Background windows 

il /-

25 50100 200 300 

Energy - keV 

Fig. 19. Gamma spectra with and without the 241Am contribution. 

1.0 

Cs photopeak winda< 

i X0.8 

xs LV1 ._ 

\\ rBackground windows ] 

z!- Zf 0.6 

._ 

;; 0.4 

> 

5 s 0.2 

SF& 

0 

0 0.5 1.0 1.5 2.0 2.5 3.0 

Energy - Mev 

Fig. 20. High-energy gamma spectrum 

showing contributions from 

6oCo and 137Cs. 

Data Processing - The dataprocessing system converts magnetic tap 

records to scalar field plots of aircraft 

position vs count-rate data. Symbols 

denoting the on-top markers are also 

printed on the plot. Lines are contractec 

and expanded in length so that the on-top 

markers coincide with the photographic 

landmarks used to annotate the tape. 
(‘c,rItours are drawn after all flight lines 

I,:,\.~~been properly Positioned on the 

i,i,otograph of the island. 

Computer software has been developed 

to plot weighted sums of any combination 

,)f single-channel data accumulated during 

1 -s~(’ time intervals. Llultichannel data 

“an be processed to give the same type of 

information, but with a minimum of 3-Set 

1ime intervals. 

Instrumentation Calibration and 

Conversion Factors 

This section describes the method used 

to convert aerially measured gamma-ray 

count rates to exposure rates one meter 

above the ground and to isotopic concentrations in the ground. Count rates in 

windows previously defined are used to 

derive isotopic concentrations. The isotopic concentrations can be converted to 

exposure rates one meter above the ground 

using previously derived data.:” 

General Expressions for Isotopic 

Concentration-Count rates in pulseheight windows centered on gamma-ray 

photopeaks of interest are composed of 

unscattered y rays from the isotope of 

interest and background counts from 

(1) cosmic rays and natural activity in 

the aircraft and Atoll material and 

( 2) possible contribution from higherenergy contaminants. Background is 

compensated when the data are processed 

by subtracting weighted combinations of 

count rates in appropriate windows. The 

r: 

H. L. Beck, J. DeCampo, and C. 

Gogolak, In Situ Ge(Li) and NaI(W 

Gamma-Ray Spectroscopy, HASL, 258, 

P. 49, 1972. 

assumption that only unscattered y rays 

remain In the photopeak window after the 

background is subtracted allows simple 

expressions to be derived to relate aerial 

count rates to various source geometries. 

Good definition of the photopeaks lends 

credence to this approach. 

Conversion factors are developed in 

the following paragraphs. Detector 

efficiency is defined in terms of an 

effective detector area at normal incidence. This area is calculated from 

gamma-ray count rates measured in 

helicopter hovers over point radioactive 

sources of known strength. The change 

in effective detector area with angle of 

incidence must be considered for sources 

distributed over the Atoll. Appropriate 

or limiting values for angular responses 

will be assumed according to y-ray 

energy. Conversion factors result from 

eliminating effective detector area between expressions derived for count rates 

over a point calibration source and the 

distributed source of interest. 

Detector efficiency (effective area) is 

determined by signal minus background 

count rates when hovering over 6oco, 

137 Cs, and 241 Am calibration sources of 

known strength. The photopeak window 

count rates, CR when hovering directly P’ over a calibration source can be written 

in terms of an effective detector area: 

CRP=.2 exp [-(< + i,] (1) 

where 

d= distance between point source and 

the detector, 

t= thickness of aircraft skin and 

floor, 

73-
i 

s = source strength, 

xa = ~-ray mean free path in air, 

X, = y-ray mean free path through aircraft structure, 

and 

A = effective detector area at normal 

incidence to the crystal face. 

The derivation of the effective detector 

area includes consideration of the effect 

of photopeak window efficiency, and the 

possibility of subtraction of photopeak 

counts appearing in radiation background 

windows. 

Equation (1) can be combined with an 

assumed detector angular response to 

derive expressions for the diameter of 

the circle that contains ground concentrations that are spatially close enough to 

the aircraft to contribute to the aerially 

measured count rates. The count rate 

when hovering to the side of a point source 

is: 

SA f(e) @z

CR; = exp -

47r(P2 + d2) C( -%--

J (2)

where 

B = lateral distance between source 

and detector, 

and 

f(e) = detector angular response. 

The diameter of the circle of influence is 

defined as twice the lateral distance between the source and detector when the 

signal is equal to half the value measured 

when the detector is directly over the 

source. The following equation defines 

the diameter, Ax, of the circle of 

influence: 

1-= 

2 

w 1 

(3) 

For a detector with isotropic angular 

response, this equation becomes: 

d2 1 

For a detector with a cosine angular 

response, this equation becomes: 

f- 312 

1 d2 -= 

2 1 

The diameters calculated from these 

equations apply to a stationary detector. 

A moving detector, accumulating data 

over discrete time intervals, will not be 

described by a circle of influence, but 

rather by a figure resembling an ellipse 

74-
,~,t ,, ihc major axis along the direction where 

The increase in length along 3 = reciprocal relaxation depth of con- ,,j ,notion. 

‘,,,5 direction is equal to the product of :ributing radionuclide, 

,!:,,a accumulation time and helicopter n = total surface concentration or 

This product is - 100 ft for all integral of volume concentration .S;‘~Wl. 

241Am data. to 30 depth, t,ut ’ Ile 

‘l’lie form of the expression for count h = height above ground, 

r.ate at altitude from a distributed source and 

:lcpends upon the vertical distribution of hm= -: -ray mean free path in the Atoll 

JJ ,lic source in the soil and the angular material. 

(3) ,.csponse of the detector. Due to incoml,lcte knowledge of the form of the source The abo\-e expression can be integrated 

,iistribution, an exponential decrease over the x) half space defining the ground 

\vith depth will be assumed. It will be to give: 

shown that factors for converting aerially 

Ineasured count rates to one-meter-level 

CR = q & 7; r ;) e-nzdz, 

exposure rates are insensitive to relaxa- a S m 

tion depth and, therefore, to form of (7) 

distribution. 

where El is an exponential integral of the me to the geometrical configuration of 

first kind. The following equation results the NaI crystals and the detector array, 

from eliminating A between Eqs. (1) and the highest efficiency occurs for photons 

(4) (7). incident at 0” with respect to the normal 

to the crystal face. The hypothetical 

conditions, then, of isotropic angular 

response and cosine angular response 

(zero efficiency at 90” incidence) bracket 

the true angular response. 

The conversion factor in brackets contains 

The differential count rate from a known geometrical parameters, calibraconcentration at depth z uniformly distion source strengths, and measured 

tributed over a volume Pnrdr dz of atoll 

count rates. 

material is given by: 

The expression corresponding to Eq. (6) 

for a cosine angular response includes an 

ar)e -CYz A dCR = additional factor equal to h/m The 

4n(h2 + r2) 1 integral of this expression is: L 

se 

>r. 

CR = $ ~1 emQz E2($+fi<)dz. (9) exP 

be 

This equation is the same as Eq. (7) with se 

X 2nr dr dz, (6) the order of the exponential integral 

-75-
. , ‘“_ _ -L. ‘a._ _.L-__ _ ._I ._I

changed. The conversion fac:or cor- channel windows as set up for the plutonresponding to Eq. (8) is: therefore: ium survey. Spatial resolution along the 

direction of flight is degraded by use of 

the multichannel data, which have a 3-set 

data accumulation time. Part of the expected 300-ft degradation is removed by 

the manner in which the data are processed. The diameter of the circle of 

Plutonium Concentrations influence is 135 ft, as calculated from 

Plutonium is sensed \-ia the 60-keV Eq. (5). 

241 

y ray from Am, which is a decay Due to the presence of the cadmium 

product of 241Pu. The pulse- height shielding on the sides of the crystals, the 

spectrum from Y rays with energy greater count rate for low-energy photons is 

than - 100 keV is linear in the energy proportional to the cosine of the angle of 

range between 40 and 80 keV. Therefore, incidence with respect to the normal to 

the background count rate in the 20-keV- the crystal faces. The appropriate conwide signal window (50 - 70 keV) is assumed version factor is therefore given by Eq. 

to be equal to the sum of two count rates (10). The conversion factor as calculated 

from lo-keV-wide windows contiguous to from this equation with an assumed relaxaboth sides of the signal window. tion depth of 10 cm is shown in Table 7. 

[Yindow count rates can be taken from 

Cobalt-60 Concentrations 

multichannel data or from single-channel 

60 data. Multichannel data have been used, Background counts in the Co photodue to electronic problems and the pres- peak window (1.095 to 1.395 MeV) are 

ence of excessive count rates in the single- assumed to be proportional to aircraft 

Table 7. Photopeak window conversion factors. 

Conversion factor 

Exposure 

Concentration,? s rate at 1 m 

as calcuRelaxation tsotropic Cosine lated from 

depth in angular angular Average of previous . 

Atoll response response previous column, 1 

Radio- material, of detector of detector two pR set ’ 

nuclide cm array array columns hrcnt : 

24 ‘Am 10 66 x lo-4 

, 

137cs 1 8.5 X ld4 15.2 X ld4 11.8 X 1O-4 74x1o-4 : 

Averagea 20.9 X 1O-4 72X1O-4 t 

10 23.2 X lO-4 36.6 X lO-4 30.0 x 1o-4 70 x ld4 2 

6oco 1 4.6 X ld4 7.2 X lO-4 5.9 x lo-4 155 x 1o-4 

Ave ragea 10.6 X 1O-4 152 X 1O-4 ; 

10 11.2 x 1o-4 19.4 x 1o-4 15.3 x ld4 150 x lo-4 ’ 

-8 

, aAverage value for two relaxation depths. 

-76-
Ton- cosmic rays, and contribu - ~,;,,.‘~$pund, conver::ng the resulting count rate to 

the r,o,lS from natural background emitters, ground concentration for two relaxation 

of :ul ,,, the energy interval between 1.305 depths. Cther experiments have shown 

-set The ratio is determined .IIlti 3.00 3leL-e That the true detector angular response 

ex- i,~ fii~~ts at 100 ft over water, which is such that the average conversion 

bY ._lloul,~ contain negligible amounts of 6O co. factors in the fifth column are accurate to 

3- ,)ata 3re processed to continuously sub- within a few percent. 

1f :i.,?ct this background from the photopeak The diameter of the circle of influence 

n ,\’ jndou’ count rate. lies between 145 and 180 ft, as calculated 

Table 7 compares the factors [ (calcu- from Eqs. (4) and (5). 

n latcd from Eqs. (8) and (IO)] for conthe l.,_rting the resulting count rate t0 ground Exposure Rates - Factors for con-

,.,,,lcentratiOn for two relaxation depths. 50 verting Co and 137 Cs photopeak count 

’ of ~~~l,cconversion factor shown in the fifth rates to l-meter-level dose rates have 

0 c.Olumn 1s the average of \.alues from the been calculated by combining data in the 

In- I\I’O previous columns. This a\.erage fifth column of Table 7 with data from 

9. represents the best value presently avail- H. L. Beck et al. The result of this 

137 

able. Experiments with Cs sources combination is given in the last column of 

:laxa- have shown the average to be accurate to the same table. The average value be7. \vithin a few percent. tween extremes in angular response is 

The diameter of the circle of influence used because experiments show that this 

lies between 145 and 180 ft, as calculated average is good to a few percent, at least 

o- from Eqs. (4) and (5). 137 for Cs sources. The same averaging 

60 

process is used for Co sources, although 

Cesium- 137 Concentrations similar measurements have not been made. 

The background count rate in the 137cs Note that the factor for converting 

photopeak window (0.6 to 0.75 MeV) is aerially measured count rates to dose 

assumed to be composed of two parts. One rate is insensitive to large variations in 

0f tht>se is proportional to aircraft back- relaxation depth. In most cases the two 

ground, cosmic rays, and contributions assumed relaxation depths bracket those 

from natural background emitters in the measured in soil-sample analyses. 

energy interval between 1.395 and 3 MeV. 

The second background component, which Comparison with Ground Data 

60 is Proportional to the CO contribution Aerial data were processed to give 

t0 the 137 CS window, was determined from 200/Oincrements between contour levels 

60 spectral shape when Co was present for the islands of JANET, ALICE, BELLE, 

with negligible amounts of 137cs . Back- and DAISY. The sum of Co and Cs congrounds of both types were subtracted tributions to dose rates (using the conduring data processing by summing version factors listed in the last column 

apProPriately weighted single-channel of Tabie 7) is compared with LiF thermocount rates. Table 7 compares the factors luminescent dosimetry (TLD) measureI(calculated from Eqs. (8) and (lo)] for ments at 37 locations in the chapter on 

-77-
ext e rn al 2ose estimates. Dose rates 

averaged over these locations were 11% 

lower for The aerial measurements than 

for the s;andard TLD measurements. TWO 

special TLD badges, shielded against 

3 rays, gave a 10% lower exposure rate 

than the standard unshielded badges at the 

same location. The aerial measurements 

do not sense $ rays because of the mass 

of air and structure betweenthe source and 

NaI. Therefore, the aerial measurements 

for -f rays only are in excellent agreement 

with the -: - ray contribution to the TLD measurements. The aerial data have not been 

normalized to the unshielded TLD data. 

It should be mentioned that the escellent 

agreement between the aerial data and the 

TLD data is well within the uncertainties 

in the aerial measurements. In particular, 

an error of a few feet in the 50-ft hover 

altitude over the calibration sources would 

introduce a 10% error in the conversion 

factor. Oscillations about the point directly 

over the source effectively increase the 

average slant range. Use of an excessively 

small slant range falsely increases quoted 

concentrations. 

The total mass of aircraft structure 

between the detectors and sources was not 

known. In particular, the mass of reinforcing material between the two outside 

plates of the aircraft floor was not known 

and was excluded in the attenuation calculations. The presence of additional mass 

lowers the distributed source count rate 

relative to the count rate from the point 

calibration source. Neglect of this additional mass has the effect of falsely decreasing quoted concentrations. The two 

types of errors described above occur in 

opposite directions and are expected to be 

partially self-compensating. 

Explanation of Contour Xlaps 

6o Co and 137Cs Separately -

Contour maps were generated for e 

island on the basis of photopeak wir 

count rates for 6oCo and 137Cs sep 

All other types of background were 

tracted so that the only counts rem: 

were due to the separate isotopes. 

were processed so that letter symb 

denoted a range of values for count 

in the photopeak windows. The fiftl 

seventh columns in Table 8 relate t 

contour letter symbols (correspond 

window count rates) to the dose rate 

delivered by each isotope. This re 

ship is established from values in t 

last column of Table 7. Table 8 al: 

lates letter symbols to soil concent 

averaged over the two extremes asr 

for relaxation depths. The two exti 

and the average conversion factor a 

given in the fifth column of Table 7. 

contours are superimposed on gray 

of the islands (the “m” series of fig 

137 in Appendix II); Cs contours are 

imposed on green prints of the islar 

(the “k” series of figures in Append 

These contours were used to tab\ 

an estimated average dose rate ove 

is land. Results are shown in Table 

-4verage Dose Rates From Gr 

Counts - Contours superimposed on 

greenish-gold prints (the “b” series 

figures in Appendix II) were constm 

from counts in the energy interval t 

50 keV and 3 MeV. An average con 

factor must be established to relate 

counts to concentration, since this 1 

60 interval senses both Co and 137C: 

This average conversion factor is a 

-78-
Table 8. Contour map key for use with figures in Appendix II. 

“4 l_Am <‘13n(‘<‘n;ratlon ,- cn 

s~‘.‘c‘raeed for : m c rr - Lsposurr For 1 cm c re- I:sposure exposure Total !‘:c r rap :a~:i: ‘In drpth rate, laxation depth r3:e, rate, ‘\ I’! -

pCllm 

2 LO cm < :rJ (‘II? u f3 ,‘h r c 10 cm uR hr UR ‘hr. !IOl 

I- : I~/ [I ! o-o.:+4 

\- ;,~, .-0.” 0 . :i 4 - 0. G H o-o.01 0-0.39 

“g ) .I L'l-30 - I ‘; - _“,_: ii.6:$- 1. >li 0.04-0.02 0.5’~-1.11 o- 1.11 

ta 

:’ 50-15 ; .: - I!' ,~ -:.I_0 1. ‘(i-2.0 o.o::-0.1” 1. 14-1.; 1.0-1.5 ,) 

(’ 45-66 1‘a_.?;; ,’ -il. ; .!.O-” -. 7 0.1”-0.16 !.YO-2.:: 1.5-2.0 

es !) 66- 100 A::-1” ~1 -i.!) -. 7-5.4 J o.l&o.:i:! ‘.3--1.i; 2.0-A

d loo-145 ;Z-Gl . - :. 1 1.1- I1 0.:+9-0.6-i I.ii-!!.:! 4 -8 

, ! i15-210 5; ] -;,(i ..-,>.A 11-L'? O.iil-1.:; !a.‘-l:: :i - 1 (i 

(; 2 10-300 81- 130 .,.2-l.’ ““-4-i 11.::-2.5 13-36 l(i-:i:i to 

II 300450 1:io-l!‘O : 1 - 1 .-I 4-i -ii:; 2.5-5.0 .:6-T" :;:i-(ici 

I _ - -10 ii::- 170 ,-I0 72-l-10 ii 6 - 1 :i 0 

3n- .I -‘I-! 00 i;o- 41) IO-20 110-11’0 i:;O-260 

I\ ,“I-~“0 :40--700 20-40 2!!0- 5110 ztio-520 

I, 200-100 TOO- l-l00 40-80 >:io-1200 r,“o- 1050 eon 

ed 

es to be half the sum of the separate con- at the 3-ft level at the same location. The 

137 version factors for Cs and 6oC~. The primary contributor in these areas, 

co two separate factors are calculated by cosmic rays, are estimated to produce

nts multiplying photopeak conversion factors -3 pR/hr at the 3 ft level. The product of 

S in the sixth column of Table 7 by the ratio gross counts and conversion factor is

ser- of photopeak counts to gross counts in 0.9 pR/hr. Therefore, the fractional error 

spectra taken at 100 ft over islands that is small for dose rates greater than 

I). contain predominantly one or the other 20 PRlhr and consistent with errors ine isotope. Uncertainty as to whether the herent in the average conversion factor 

ch contaminant is 6oCo or 137 Cs introduces concept. 

errors of SO% in the exposure rates derived from gross counts. 

241 The seventh column of Table 8 relates Am Concentration - The island 

the contour letter symbols to exposure of YVONNE has been contoured for 24 ‘Am 

rates for these figures. concentration. Data were processed so 

j Count rates produced by aircraft back- that contour letter symbols denoted a

een ground and cosmic rays have not been range of counts remaining in the photo-

;ion subtracted before application of the con- peak window after the two contiguous 

se version factor. The contours, therefore, background windows had been subtracted. 

assume that the conversion factor multi- This letter symbol and range of count ‘gY 

Plied by gross count rates over uncontam- rates was related to concentration accordned inated Atoll material equals the dose rate ing to Eq. (10). A lo-cm relaxation depth 

-79-
Table 114. Summary of average exposure rates for islands in Enewetak Atoll. 

Average exposure rate, ;tR /hr at 1 ma 

Total 1 !37Cs Island @%o (O-3 AIeV) Rangeb 

XLIC E 4’ 36 81 ‘l-170 

BELLE 61 50 115 5-200 

CLARA 20 19 42 5-100 

DAISY 6.8 14.4 21.3 5-149 

EDNA 2.3 2.4 6 5-8 

IRENE 14 63 80 3-560 

JANET 13 40 ‘-150 ‘7 5 

KATE 11 7 19 3-22 

LUCY 6 7 14 l-20 

PERCI 2 5 ‘-11 ‘1 

lIARI- 5.5 4 10 ‘-12 

SANC Y 6 5 12 I-50 

OLIVE 6.5 4.5 11 1-15 

PEARL 12 45 70 l-400 

RUBY 2 12 I4 l-42 

SA LLT 3.5 .3 7 3-110 

TILDA 4 ‘7 6 2-11 

URSULA 3 1, H 5 1-7 

VERA 2.8 ‘7 5 1-6 

WILLIA 1 ! 2 1-3 

YVONNE 5.6 ‘2.4 33 l-750 

SAM co.3 (0.20) <‘0.6 CO.! i 10.9 o-1 

TOM CO.3 (0.18) ,-0.6 (0.13 co.9 o-1 

URIAII <0.3 (0.06) CO.6 (0.43 CO.9 o-1 

VAN <0.3 (0.081 /0.6 (0.35 co.9 O-l 

ALVIN N. D. (0.06) -‘0.6 (0.25 CO.9 o-1 

BRUCE 0.4 (0.221 0.8 (0.34) 1.2 o-1 

CLYDE co.3 (0.04 1 ‘-0.6 (0.11) co.9 o-1 

DAVID N. D. (0.21) N. D. (0.10) CO.9 o-5 

REX CO.3 (0.281 CO.6 (0.25) co.9 o-1 

ELMER N. D. (0.19) N. D. (0.12) co.09 o-2 

WALT co.3 (0.08) CO.6 (0.10) co.9 o-1 

FRED N. D. (0.14) N. D. (0.12) co.9 o-1 

GLENN 0.4 (0.33) CO.6 (0.20) co.9 o-1 

HENRY co.3 (0.14) CO.6 (0.20) co.9 o-1 

IRWIN co.3 (0.08) CO.6 (0.46) co.9 o-1 

JAMES co.3 (0.05) 2.8 3.0 o-5 

KEITH co.3 (0.15) CO.6 (0.49) co.9 o-2 

LEROY 2.8 4.8 7.6 3-8 

aAverage dose rates given are derived from aerial survey data. On islands where activity 

levels are at the lower limit of sensitivity of the aerial survey equipment, dose rates derived 

from the soil sample data are given in parentheses. 

bAs measured with the Baird-Atomic instrument. 

,<.a~ ass 

ured in 

mg conI 

fourth c 

column 

t,ols to 

lated wi 

third co 

spondin& 

,,\er the 

Cone f 

!,Btcctab 

I,rcsent 

:,lotting 

I-i*ntratic 

1.1~ min 

trolled b 

hnckgroL 

1:i7 

cs, : 

;~hlc leve 

Island ar 

1K~rticuls 

show con 

:rble fror 

(‘011nt rat 

vogetatic 

GO-keV y 

TI’RRES 

0. I). T. 

Nevada ( 

Las Vegi 

p. II. Gu, 

I.awrenc 

I.ivermc 

Soil Surs 

‘The I 

this set’ 

augh ev: 

Cal cond 

~‘lanning 

-8O-
,vas assumed as an average of those measured in soil sample analyses. The resulting conversion iactor is given in the 

fourth column cf Table 7. The second 

column of Table 8 relates contour symbols t0 241 -Am concentrations as calculated with this conversion factor. The 

third column of Table 8 lists the corresponding voiume concentrations averaged 

Over the top 10 cm. 

Concentrations above our minimum 

241

detectable level in ?im were not 

present in sufficient quantity to justify 

plotting ,exposure rate or material concentration distributions for other islands. 

The minimum detectable level is controlled by statistical variations in the 

background count rate from cosmic rays, 

137Cs, and 6oCo. The minimum detectable level, thus, changes from island to 

island and from point to point within a 

particular island. Soil samples may, 

show concentrations that are not detectable from the air due to high background 

count rates or to the presence of dense 

vegetation, which severely attenuates the 

60-keV y rays from 241Am. 

TERRESTRIAL SOIL SURVEY 

0. D. T. Lynch, Jr. 

Nevada Operations Office, USAEC 

Las Vegas, Nevada 

I’. H. Gudiksen 

Lawrence Livermore Laboratory 

Livermore, California 

Soil Survey Plan 

The Enewetak soil survey, described in 

this section, had as its objective a thorough evaluation of the present radiological conditions of all islands of the Atoll. 

planning of the soil survey was based 

upon extensive investigations of the historical aspects of the weapons-testing 

program, the most recent Information 

gathered during previous radiological 

surveys of Bikini Atoll, and preliminary 

surveys of Enewetak Atoll in July 1971 

and May 1972. 

Laboratories which conducted the experiments provided reports containing 

data on the original nuclear devices. 

Actual test information, fallout patterns, 

radiological safety reports, etc., came 

from AEC sources. Construction drawings and information on modifications to 

the topography were made available by 

the testing support contractor, Holmes 

and Narl-er, Inc. (H&N). Other organizations, including those which conducted 

environmental studies during and after 

the testing program, supplied their findings. In addition, a wealth of information 

was available in old reports, records, 

documents, etc., stored in archives. 

Examination of reports from the Lawrence Livermore Laboratory (LLL) and 

Los Alamos Scientific Laboratory (LASL) 

enabled us to identify radionuclides most 

likely to be present, based upon the composition of the nuclear devices and associated experiments. These radionuclides 

are listed on Table 10. The quantities of 

of “environmental” materials such as 

structural steel, concrete, wiring, pipe, 

etc., were also determined for purposes 

of estimating the types of contaminated 

debris that should have remained after a 

shot. 

The Test Manager’s operations reports contained fallout patterns for nearly 

every event. From these reports, in a 

crude effort to estimate residual conditions, the Atoll’s islands were graded as 

-81-
- I 

Table 10. Radionuclides expected in Enewetak Atoll soil. 

Radio- Radionuclide Source nuclide Source 

241A* T_-nburned weapon fuel Fission product 

340Pu Unburned weapon fuel Fission product 

23gPu Unburned weapon fuel Fission product 

238Pu rnburned weapon fuel Activation product 

238 U Cnburned weapon fuel Fission product 

235U Cnburned weapon fuel Activation product 

207Hi Activation product Activation product 

155Eu Fission product Activation product 

154Eu Fission product Activation product 

152Eu Activation product Activation product and 

15%m Fission product fuel 

a function of the reported fallout contamination corrected to H + 1 hr past detonation. The resulting gradation is shown in 

Table 11. 

Radiological safety reports written 

during and after the test operations indicated several acute radiological problems 

which were subsequently corrected, such 

as serious alpha contamination, radioactive debris, etc. Unfortunately, these 

reports failed to provide sufficient detail 

to determine, in all cases, the eventual 

fate of the radioactivity itself -whether 

it was disposed of in land, lagoon, or sea, 

for instance, and how thoroughly. 

Interviews with test personnel produced additional information, although 

somewhat contradictory at times. However, these interviews did confirm that 

burial and relocation of high-level radioactive contaminated debris was attempted 

frequently in many places. Verification 

of these burial activities by documentation has been very difficult and only partially successful. This information, 

however, indicates that radioactive debris probably is buried only on islands 

that had surface ground zeros. A list, 

shown in Table 12, has been made of suspected or known burial sites, the locations of which are shown in Figs. 21-24. 

Two preliminary radiological surveys, 

conducted in July 1971 and May 1972, 

confirmed suspected conditions on most 

of the islands and provided approximate 

but valuable estimates of the range of 

radioactivity levels to be expected. 

The July 1971 survey was severely 

limited in time and scope. Even though 

visits were only made to six islandsIRENE, JANET, SALLY, TLLDA, 

URSULA, and YVONNE -the following 

information was obtained: 

Many of the islands were still 

radioactively contaminated. 

Much of the Atoll was heavily revegetated and difficult to traverse. 

There were no obvious indicators 

(signs, posts, fences, etc.) of buried 

radioactivity in clear sight. 

-82-

--_ 
t 

t 

t 

t 

t 

t and 

le3s 

it, 

susa24. 

reys, 

ost 

ate 

i 

Y 

10 

-

‘g 

e-

*se. 

rs 

lried 

Ranking of islands in Enewetak y_ible 1 1. 

H 2 1 hr. 

Island code name Local name 

~ToNNE Runit

Eberiru RUBY 

Sanildefenso 1:DNA 

Bogon :RI,:NE 

Bogairikk IIBLENb 

!>EARL Rujoru

Cochiti ;jAISY 

Engebi JANET 

Bogallua :iLICE 

IiI:LLE Bogombogo 

Ruchl 

!,IARY Bokonaarappu 

c‘ LA RA 

Xomon 

I.UCY Kirinian 

KATE 1luzin 

0 LIVE Xitsu 

NANCY Yeiri 

TILDA Biijiri 

I!RSULA Rojoa 

-

5.ALLY 

CORAL HEAD (MACK) 

WILMA Piiraal 

VERA Aaraanbiru 

LEROY Rigili 

KEITH Giriinien 

-JAMES Ribaion 

IRWIN Pokon 

HENRY Mui 

G I (17NN Igurin 

ELMER Parry 

FRED Enewetak 

BRUCE Aniyaanii 

DAVID Japtan (Muti) 

TOM -

SAM -

URIAH -

VAN -

ALVIN Chinieero 

CLYDE Chinimi 

REX Jieroru 

aThis includes the events that produced 

location. 

bPresently part of IRENE. 

Atoll according 

Total R ihr 

62,849 

10,643 

9,533 

6,184 

5,277 

4,329 

3,554 

3,501 

3,383 

3,382 

3,151 

2,785 

1,981 

1,776 

1,753 

1,252 

1.251 

774 

651 

452 

29-1 

270 

235 

31 

23 

10 

13 

11 

2.6 

2.6 

1.5 

1 

0 

0 

0 

0 

0 

0 

0 

contamination by 

-83-

to fallout contamination 

Total eventsa Total 

24 

16 

16 

24 

23 

13 

20 

26 

28 

25 

24 

18 

16 

10 

11 

12 

7 

17 

12 

10 

13 

11 

13 

3 

3 

3 

3 

.3 

5 

4 

4 

3 

1 

1 L 

fallout or surface ground 

at 

SGZ 

8 

2 

0 

1 

0 

1 

0 

3 

0 

0 

0 

0 

3 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

zero 
Table 12. Suspected or known burial sites for radioactive debris. 

. island Contamination Quantity Locatlon Confidence Sour-cc” 

:RESE 

JAXET 

PEARL 

RCBYb 

Soil 

Activated metal 

Activated metal 

Soil/activated metal 

Debris 

Pu debris 

Pu debris 

Pu debris 

Pu debris 

Pu debris 

Activated metal 

Contaminated 

Contaminated 

debris 

debris 

Contaminated sotl 

Large 

Large 

Cnknown 

Unknown 

Unknown 

Unknown 

LTnknown 

Unknown 

Large 

Cnknown 

Unknown 

Unknown 

Unknown 

Unknown 

Unknown/central island 

Around SGZ’s 

Around SGZ 

Old SGZ 

Western SGZ area 

KICKAPOO SGZ 

ivestern SGZ area 

Causeway, SALLY/ 

TILDA 

FIG/QUINCE SGZlagoon side 

Disposal arealocation unknown 

Anywhere -exact 

locations unknown 

West of CACTUS crater 

ERIE SGZ 

North of HARDTACK 

Sta. 1310 

Fair 

Fair 

Suspected 

Positive, 

high 

Suspected 

Absolute 

Absolute 

Absolute 

Absolute 4 

Positive, 

high 

Absolute 

4 

5 

Suspected 

Positive, 

high 

Positive, 

high 

6 

7 

8 

aSources 

1. Interview. 

2. Assumption. 

3. H&N Drawing GS-6270, Apt-11 3, 1957, and FS-6287, April 18, 1957. 

-f. Task Group 7.5 Rad-Safe Support, HARDTACK, Phase I, OTD-58-3, April 1959. 

3. Survey, 1971, 1972. 

6. Completion Report, Operation HARDTACK, PHASE I 

7. H&N Drawing 25-002-G7, January 20, 1958. 

8. H&N Drawings 25-002-C3, 4. 5, January 20, 1958. 

b That portion remaining attached to SALLY by a causeway. 

• There was significant contaminated limited reconnaissance effort during May 

radioactive debris on YVONNE of that year. Of the 43 islands of the 

(Runit Island) at the CACTUS cra- Atoll, 18 were visited in May 1972. 

ter lip and also a plutonium- These, in addition to three other islands 

contaminated soil outcropping on visited in the July 1971 effort, made 

the oceanside beach, mid-island available recent data regarding soil activ-

• There appeared to be a definite ity levels and radiation exposure rates on 

pattern to the exposure rates en- 21 islands, slightly less than half of the 

countered, with the higher rates total number of islands within the Atoll. 

observed on the northern half of The results of this survey also verified 

the Atoll. the Atoll-wide pattern of contamination 

As a result of this survey, the AEC’s suggested by the 197 1 survey and the 

1972 Bikini radiological survey was ex- ranking of islands according to fallout 

tended to cover Enewetak Atoll in a very levels. 

-84-
\ 

Suspectea 

buried debris, 

\/ 1 !K //X/ 

Susbected //v//v 

\ 

Fig. 21. Suspected or known radioactive 

Since a cleanup effort would require 

preliminary cost estimates for the disposal of contaminated soil, the sampling 

plan was designed to provide data that 

c70uld be used to estimate, at least in a 

gross manner, the volume of contaminated soil on those islands where it was 

thought to exist or had a high probability 

for existence. 

The Atoll was stratified into groups of 

islands, individual islands, or specific 

areas of islands, according to what was 

known or suspected about the radiological 

condition of the area and the type of survey information that was desired. Since 

Pu is an isotope whose distribution at 

Enewetak is of particular concern, estimates of its abundance were also used in 

the stratification process. A summary 

-85-

material burial sites, JANET. 

of this stratification, and the reasons for 

each stratification effort are indicated 

below, by phase, group, island, and fraction of island, as appropriate. Figure 25 

shows the location of islands in each 

classification. 

Phase I Islands 

These islands, all of those on roughly 

the southern half of the Atoll, from all 

indications are relatively clean in comparison with the remainder. None of 

these islands included any surface ground 

zeros. All, with the exception of LEROY, 

received little fallout from the nuclear 

tests. LEROY is included because of its 

location and the fact that its fallout dosage was small compared to islands on the 

northern half of the Atoll. 

239 
Reef v \ 

Plutonium contamination 

in concrete slabs 

95 ‘I 

y- k’- SALLY 

Suspected burial site Plutonium contamination 

Fig. 22. Snspected or known radioactive material burial sites, SALLY. 

Fig. 23. QUINCE and FIG decontamination operations RADEX area, established 1958 

YVONNE. 

-86-
Suspected or- known radioactive material burlal sites, Fig. 24. 

-Y Phase III 

urn 

waste 

. 

4

/Air 

strip 

;li 

\ 

ed 195% Fig. 25. Stratification of Enewetak Atoll for soil sampling program. 

-8i-
The average contamination of the 

Phase I islands was about 10 R/hr at 

H + 1 hr (see Table 11). FRED and 

ELAIER were the sites of the main camps 

and airfields, and DAVID was used as a 

rest area. 

The islands of Phase I were divided 

into the following three groups for soilsampling purposes: 

Phase I -Group I 

BRUCE (Aniyaanii) IRWIN (Pokon) 

REX (Jieroru) JAMES (Ribaion) 

GLENN (Igurin) KEITH (Giriinien) 

HENRY (Mui) LEROY (Rigili) 

Phase I -Group II 

DAVID (Japtan) FRED (Enewetak) 

ELMER (Parry) 

Phase I -Group III 

SAhI WALT ALVIN (Chinicero) 

TOM VAN CLYDE (Chinimi) 

URLAH 

Those in Group I are relatively large 

islands with fairly heavy vegetation; those 

in Group 11 are southern islands which 

are very likely to be inhabited continuously by the Enewetak people after they 

return; and those in Group III are sandbars or very small islands with relatively 

little vegetation or likelihood of heavy use. 

Phase II Islands 

The Phase II islands were termed to 

be “lightly contaminated,” based upon the 

historical background, ranking of islands 

by fallout levels, and previous surveys. 

The term “lightly contaminated” is, of 

course, only a relative one. The islands 

were expected to be significantly more 

contaminated than any of the Phase I 

islands. Using the gamma exposure 

rates measured on ALICE through EDNA 

during previous surveys, and the positions of these islands relative to the 

islands with ground zeros, two groups of 

islands were developed: Phase II, 

Group I, those islands which had been 

visited and for which some radiological 

information was available, and Phase II, 

Group II, islands which have not been visited recently (except for limited sampling 

on TILDA and URSULA), but from all 

indications were likely to be similar in 

fallout level and exposure rate to the 

Phase II, Group I islands. These two 

Phase 11 groups consisted of the following 

islands : 

Phase II -Group I 

(visited during previous surveys) 

ALICE (Bogallua) DAISY (Lidilbut) 

BELLE (Bogombogo) EDNA (Sanildefonso) CLARA (Eybbiyae) 

Phase II -Group II 

(not visited during previous surveys) 

KATE (Muzin) TILDA (Biijirija 

MARY (Bokonaarappu) WILMA (Piiraai) 

PEARL (Rujoru) PERCY 

VERA (Aaraanbiru) OLIVE (Aitsu) 

LUCY (Kirinian) URSULA (Rojoala 

NANCY (Yeiri) 

aVisited July 1971. 

Soil samples were available from the 

May 1972 survey for the islands of 

ALICE, BELLE, CLARA, DAISY, and 

EDNA. These samples were very limited in number, and, unfortunately, were 

combined for each island during collection. However, they did indicate that the 

-88-
I 

se I 

iure 

:h EDNA 

posithe 

roups of 

1, 

been 

ogical 

hase II, 

been visiampling 

1 all 

lar in 

the 

3 two 

ollowing 

?ys) 

>idilbut) 

anso) 

veys) 

‘iijiri) a 

‘iiraai) 

itsu) 

(Rojoala 

m the 

and 

limwere 

lleciat the 

,s,ands were contaminated, and there 

,ppeared to be some difference between 

the lagoon and the ocean sides of the 

Plutonium-239 activities in soil Islands-

~,” these islands were relatively high for 

!,,e Atoll, ranging from about 17 pCi/g on 

[<DNA to a maximum of 129 pCi/g on 

BELLE. A crude mean of 50 pCi/g was

assumed for planning purposes for this 

,-hain of islands (ALICE through EDNA). 

As a general rule, the nUmber of 

samples to be collected on a particular 

,siand by this survey was proportional to 

239 the expected mean activity of Pu in 

the soil on that island. The mean value 

of 50 pCi/g, listed above, was assumed 

t0 be applicable to all Phase II islands. 

However, the islands that had not been 

previously visited received an increased 

sample allocation because of the large 

uncertainty in their mean activity values. 

Phase III Islands 

These islands were designated with 

the relative term “moderately contaminated.” Four islands and a tiny new islet 

are included in this phase: IRENE 

(Bogon), JANET (Engebi), RUBY (Eberiru), SALLY (Aomon), and what we 

chose to call SALLY’S CHILD, a small 

islet on the reef apparently formed by the 

deposition of sand and debris from the 

region between SALLY and TILDA. 

All of these islands in Phase III were 

the sites of surface ground zeros. The 

historical search indicated that there had 

been considerable impact to the islands 

from close-in fallout, and some had or 

were expected to have burial grounds for 

Contaminated debris. 

IRENE (Bogon) is a medium-sized 

island whose single nuclear test left a 

sizable crater. Exposure rates of the 

order of 50-100 ,uR/hr were observed in 

the 1971 survey effort. The accumulated 

H + 1 hr fallout level was about 6184 R/hr 

from a total of 24 nuclear tests, sound 

indication of both fallout and probable 

buried contamination over much of the 

island’s area. 

JANET (Engebi) is the second largest 

island on the Atoll and was the site of 

three early nuclear tests. Weapons test 

structures may be found in numerous 

locations. The island was the site of a 

large base camp. It was also a primary 

site of native habitation and would possibly be so again. 

Both SALLY and RUBY were the sites 

of multiple SGZ’s. Buried contamination 

was expected, but not necessarily located 

prior to the survey effort. An additional 

complication, that of Project PACE excavation, affected the utility and the execution of a meaningful soils effort. Large 

areas of SALLY were excavated by PACE, 

some adjacent to SGZ’s and suspected 

burial sites. In addition, the excavated 

material had been deposited on the remaining surface areas of SALLY and 

between SALLY and what remains of 

RUBY. Because of this situation, an 

attempt was made early in the survey to 

delete these islands from the effort, 

since PACE was then active and any 

earth-moving or other land modifications 

conducted by them would negate any soilsurvey results before they could be reported. However, while the survey was 

in progress, PACE ceased all activities 

on the Atoll, at which time it was deemed 

prudent to include the undisturbed portions of these islands in the survey 

efforts. 

89-
Phase IV Island 

Only one island, 1VONNE (Runit) was 

classified in the Phase Il7, “severely 

contaminated” category. This island, at 

the top of the list in accumulated fallout, 

with a total H + 1 hr fallout of 62,849 R/hr 

is the site of eight SGZ’S. The island is 

the most disturbed testing location on the 

Atoll. Record searches produce many 

conflicting reports of the disposal of 

radioactive materials on or near the 

island. These records all show considerable construction and reconstruction 

activity. “Old -timers ” indicate that the 

island was actually plowed in the search 

for experimental packages dispersed during several nuclear tests. The island is 

known to have significant amounts of activated or contaminated scrap and of 

plutonium-contaminated soil. 

Every recent survey effort from July 

197 1 through the several cursory surveys 

conducted late in 1972 and early in 1973 

confirms the indication that the northern 

half of the island is a heterogeneous conglomeration of radioactive debris. On 

the northern half of the island, soil samples collected at one location are not 

necessarily representative of those obtained at other locations within the 

immediate area. 

It was obvious that a random-sampling 

approach to such a situation was inappropriate. Therefore, a sampling pattern 

based upon prior knowledge of known 

surface activity levels, ground-zero locations, construction activities, suspected 

burial areas, etc., was adopted. In 

essence, the plan included sampling the 

area in the vicinity of the QUINCE ground 

’ zero to a depth of 120 cm on an approximate 200-ft grid system, and every 200 ft 

along a line up the center of the island to 

the Cactus crater at the north end. It 

was felt that this approach would be adequate to reveal the extent of seriously 

contaminated areas in sufficient detail to 

enable cleanup estimates to be made. 

The southern portion of the island (the 

area south of the bunker) also has a surface ground zero. However, most of the 

area was subjected to fallout from the 

nearby tests and could be sampled by a 

random approach similar to that used on 

Phase III islands. 

Soil-Sampling Philosophy 

A random-sampling technique was 

chosen as the primary method for determining soil-sample locations. The actual 

number of samples that were collected on 

a particular island was a function of 

parameters such as total accumulated 

fallout, number of ground-zero locations, 

amount of construction activities, and the 

likelihood of habitation. In general, the 

sampling frequency increased with contamination level; it was lowest on the 

Phase I islands and highest on Phase IV. 

Table 13 lists the actual number of sample locations on an island-by-island basis. 

Selection of Sample Locations 

The random selection of sampling locations was performed in the following manner. A map of each island was divided 

into relatively small rectangular areas. 

The grid spacing was generally 50 ft in 

order to get several thousand squares on 

the map of a large island. Each of these 

grid squares was numbered, except for 

those that would be impossible to sample, 

such as concrete pads, coral reef, runways, paved roads, etc. The sample 

-9o-
I 

1 

ld to 

It 

adeY 

.ii to 

(the 

sur-

:‘ the 

e 

. a 

-i on 

:erztual 

bd on 

3ns, 

i the 

the 

nIV. 

.masis. 

.ocanand 

5. 

n 

on 

!se 

r 

)le, 

lTable 13. Xumber qf sample locations on each isiand. 

Approx Assumed X0. of sample locations ‘7 7 cl area, mean -“-Pu Surface, itratl- j -:- Island 10 activity, pCi/g O-15 cm Proilles ;:catlon 

i’hase 1 BRUCE 10 

/ ;:. ,i1p I REX 4 

GLENS 2 8 

HENRY 14 

IRWIN 9 

JAMES 6 

KEITH 11 12 

LEROY 7 8 

DAVID ; :: 5 3 7 

ELiGER i:0 HO 10 

FRED 140 64 :1 

P!?ase I SAM 0.3 

Group II! TOnl O.?i 

L-RIAH 0. i, ? 

WALT 1.7: 

VAN l.?? 

ALVIN O.Fi 

CLYDE 1.01 

Phase II ALICE 10 50 2’ 1 

Group I BELLE 20 50 :i 3 -1 

CLARA 2 50 L’ :i 

DAISY 6 50 15 4 

EDNA 0.3 50 6 2 

Phase II KATE 8 50 22 L’ 

Group 11 LUCY 10.5 50 22 4 

PERCY 1 50 5 1 

MARY 6 50 22 3 

NANCY 9 50 22 4 

OLIVE 14 50 23 4 

PEARL 27 50 45 4 

TILDA 15 50 33 5 

URSULA 12 50 27 4 

VERA 10 50 22 3 

WILMA I 50 22 3 

Phase III IRENE 20 100 20 14 

JANET 120 50 132 12 

SALLY 37 50 (west end) 34 9 

(including 10 (elsewhere) 

SALLY’s CHILD) 

Phase IV YVONNE 18 50 51 9 

(south) 

. YVONNE 25 Highly variable 0 46 

(north) 

-91-
locations were chosen for each island by 

using random-number tables,” with an 

excess of 10% chosen to allow for additional locations which could not be sampled due to unforeseen coral outcroppings, 

concrete pads, beach erosion, etc. These 

locations were then replotted on the work 

maps, drawings, or photographs that 

were used in the field. Both surface and 

profile locations were determined in this 

manner. 

The exact location of the sample collection was to be the center of the area 

chosen by the grid and random-number 

technique. It was realized that the determination of such a point with any great 

precision or accuracy in the field was 

technically difficult in most cases, even 

though large-scale photographs taken 

during the aerial radiological survey 

were used by the field parties. It was 

most important, however, that the individual collecting the sample make every 

reasonable effort to locate the position as 

closely as possible. In particular, the 

sample was to come from within a 10 

X lo-ft area, defined as the center area 

for the grid point. In the field the sampling site was to be chosen by pacing 

from a known reference point or other 

field direction. If there were some obstacle to sampling at this specified location (which had not been eliminated prior 

to the random-selection process), then 

that fact was recorded in the field and no 

samples collected at that point. In this 

way, bias due to a collector choosing the 

easiest location to sample, such as a 

Q 

Handbook of Mathematical Functions, 

USDC. NHS Applied Mathematics Series 

55 (U.-S. Government Printing Office, 

Washington, D. C . , 19651, pp. 991-995. 

clearing rather than within a dense 

thicket, was minimized. This protocol 

was followed rigidly and did, in fact, 

result in some collection groups going to 

great effort cutting through jungle and 

arriving at the designated location, only 

to find it to be on a large pad of concrete 

or outcropping of coral. On JANET each 

sampling point was located accurately by 

an engineering survey team fielded for 

that purpose. This additional effort was 

expended because of the island’s large 

size, dense vegetation cover, and probable rehabitation. 

During November 1972 an aerial radiation survey was made of all islands 

within the Atoll which identified “hot 

spots” on a number of islands. Soil samples were taken in all of these locations 

independently of the random-sampling 

process. 

Execution of Soil-Sampling 

Program 

The soil survey was conducted over 

a period of 8 weeks by roughly 18 people. The islands surveyed ranged from 

small, bare sandbars to large (31-acre), 

densely vegetated islands, often infested 

with wasps and spiders. With the exception of FRED (Enewetak Island), the 

islands of the Atoll were accessible only 

by boat. Only five of the islands had 

usable personnel piers (FRED, ELMER, 

DAVID, YVONNE, and URSULA). All 

other islands had to be reached by using 

a small rubber dinghy or landing craft. 

Depending on the weather, tides, and 

location on the Atoll, these landings had 

to be made in up to Force 4 (11-16 knots) 

trade winds through surf of various conditions onto sandy beaches or coral reefs. 

-92-
\r,cctation on the islands ranged from Special tools were used to assure 

01 ,,,,nc, on small sandbars to sparse on sev- uniformity of samplmg and ease of coliec-

,,:.al islands to very dense on most of the tion. The shallow core (5 cm) was ob-

‘2 to _.iands to be surveyed. The survey par- tained with a “cookie-cutter” type tool. 

ci. L,,,s had to cut into the dense jungle to The sampler was a section of hardened 

:>ly rc>ach sample locations, clear areas to steel pipe exactly 5 cm deep, with an 

rete mak(. COlleCtions, and locate themselves 2 internal cross-sectional area of 30 cm . 

each ,>{,ith sufficient precision to Carry Out the A handle on top assisted in pushing the 

y by :.andom selection aspects of the program. tool down tnto the soil to its depth. The 

3r The samples were taken from a wide surrounding soil was then scraped away 

‘6’as I.3nge of soil conditions. Soil texture and a cutting tool (a flat piece of steel) 

re ,.anged from soft coral sand to rough was inserted beneath the tool, cutting the 

,ob- ,.oral aggregates. These, in turn, were sample free. Excess debris was blown 

,nterlaced with plant roots and scrap or wiped off the cutter surface, and the 

-adi- lnctal junk. The possibility of encounter- sample was bagged and numbered. 

,“g World War II ordnance was a constant The deep core (15 cm) was obtained 

threat on several islands, particularly with a similar device, a hardened steel 

sam- JANET, where a U.S. Army EOD team pipe with l-cm increments marked on the 

ons assisted in the soils collection effort. side to a depth of 15 cm. The pipe, 

:g Soil profiles observed on most of the 30 cm2 in cross section, was driven into 

islets consisted of a surface layer of the soil. The surrounding soil was then 

vegetative litter of varied thickness, fol- removed, the cutter inserted, and the 

lowed by a somewhat thicker layer of sample treated in the same manner as the 

dark coral soil containing some root shallow core. 

er structure, and other organic material. “Profile” samples were obtained using 

20- ‘This layer also varied in thickness; it another special tool designed by Wayne 

*om was thicker on undisturbed islands and Bliss of the Environmental Protection 

:re), thinner or absent on disturbed islands. Agency. This consisted of a drawer-like 

sted This second layer was usually followed sample collector, with the back of the 

:cep- by thfl basic coral sand structure of the drawer absent, which was inserted into 

Island, which prevailed down to the hard the side wall of a trench dug to a total 

only coral limestone bedrock. Buried hori- profile depth. The drawer was 10 

f zons were found at almost any depth. X 10 cm on top and 5 cm deep. After the 

IER, drawer was inserted into the soil, a cutLll Soil-Sampling Techniques ter (large putty knife) was inserted as 

sing Two types of soil samples were taken the back of the drawer, freeing the samift. during the survey-“surface” and “profile.” ple. The sample was then removed, 

d At “surface” sampling locations, two bagged, and numbered. 

had 

2 samPles were taken; one a 30-cm The next sample was taken immediriots)) X l5-cm-deep core, and the second a ately below the previous one, continuing 

con- comPosite of two 30-cm2 x 5-cm-deep down the groove thus formed until the 

reefs. cores. bottom of the profile was reached. 

-93-
1 

The trenches used to collect the profiles were ‘dug by hand on most islands. 

On those islands where deep (greater 

than 120 cm) profiles ‘.vere required, a 

backhoe was landed and used to dig the 

trenches. 

Profile samples were taken at nominal 

depth increments of: 0 to 2, 2 to 5, 5 to 

10, 10 to 15, 15 to 25, and 25 to 35 cm 

and at lo-cm increments to total depth. 

If soil horizons were encountered, an 

attempt was made to choose the interface 

lines as additional increments. 

Each soil sample collected was placed 

in a plastic bag; the bag was numbered 

and placed inside of another plastic bag. 

The double-bagged sample was then 

placed in a field pack with other samples 

and transported to the shore, where all 

samples were placed in large plastic 

bags for transport back to FRED via 

rubber boat and larger craft. 

Upon arrival at FRED, the samples 

were taken to a sample-processing area 

for short-term storage, sample-control 

processes, and bag checks to assure 

rebagging of those samples whose bags 

had been damaged in transport. Each 

sample was then gamma-scanned in the 

field counting laboratory, and placed in 

storage until it could be shipped to the 

continental U. S. laboratory. 

Results and Discussion 

The soil-sampling locations on each 

island are shown in the “f” overlay figures of Appendix II. Each location has 

an identifying number for reference purposes. These locations were chosen 

primarily by a random-selection technique with a few sites chosen to study 

specific areas of interest such as hot 

spots, decontamination areas, surfact 

ground zeros, etc. The average activ 

239Fu, ties of “St-, 137Cs, and 6oC0 , 

exhibited by the core samples collecte, 

to a depth ,2,f 15 cm, are shown in the ’ 

“j,” “1,” and “n” overlays of Appendix 

These activities, expressed in picocur 

per gram of dry soil, are displayed at 

the geographical locations where the rc 

spective samples were collected. For 

those who desire to convert these data 

into activ:ties per unit area, one may t 

an approximate dry soil density of 1.5 l 

3 cm . attempt was made to measurf 

in situ densities. The meaning of the r 

sulting deposition values, however, is 

subject to some interpretation since one 

must realize that an appreciable fractic 

of the total activity may be situated belt 

the sampling depth, as shown in the pro 

file figures for each island. In these 

figures the activities of 23gPu, “Sr, 

137Cs, and 6o Co are plotted as a functic 

of depth for the corresponding profile 

locations. Additionally, the complete 

records of all radionuclides are reproduced on microfiche at the end of Appen, 

dix II. 

In general, the activities shown in the 

figures, when properly grouped, approx 

mate lognormal distributions. This ma: 

be illustrated by grouping the actiky 

levels measured in the 15-cm deep core 

samples collected on JANET into equal 

class intervals and plotting the resulting 

frequency distribution curve shown in 

Fig. 26. Instead of being symmetric 

about the maximum as a normal distribu 

tion, one observes a long “tail” which 

includes a significant proportion of relatively high activity levels. This distribu 

tion can be transformed into the more 

-94-

\” 

(5

Q 

I 

x 

.-

>.-

2 

10 

1 

Cumulative percent of samples 

Fig. 27. Distribution of 23g Pu activities in surface samples collected on JANET. 

-96-

-.---.- __ - __-_--.__ - . r..--n~.wPv-.----

.~ 
This correlation of activity IVith *Atoll. 

,.,getative cover was also observed at 

Bikini. Thus, a particular island may 

show the following distinct areas having 

significantly different radiological conditions : Densely vegetated areas exhibiting 

the highest activities; sparsely vegetated 

areas showing intermedIate activity levels; and beach areas displaying the lowest activities. This pattern is occasionally perturbed in “hot-spot” areas where 

ground-zero locations existed, as well as 

in areas that have been subjected to extensive construction actl:i:ies. 

The 23gP~, ‘*Sr, 137Cs, and 6oCo 

activities shown in the figures in Appendix II were plotted separately on log probability paper on an island-by-island basis. 

Islands situated in the southern part of 

the Atoll were combined into groups because to their radiological similarities 

and low activity levels. T1S.henever appropriate, an island was divided into “dense 

Vegetation,” light Vegetation,” and “beach” 

categories, and if significant radiological 

differences were noted, a mean value and 

the standard deviation were obtained for 

each distinct area on the island. In those 

cases where the differences in the mean 

Values were less than a factor of two, all 

of the measurements for a particular 

radionuclide were combined, and the 

mean and standard deviations were obtained for the entire island, excluding the 

beach areas. In most situations, the 

standard deviations were fairly constant, 

ranging largely between 1.5 and 2.5, indicating that the degree of variability of the 

measurements from one island to the 

next was small. 

The distributions of activity with soil 

depth obta .ined for the profile samples 

sholi many -.-ariations. Ilowever, in 

spite of these l-ariat:ons, some general 

comments ,may be made. Excluding 

beaches anti areas subjected to extensive 

construction activity, the radioactivity 

generally decreases with depth in some 

highly I-artable and nonlinear fashion. 

Frequently, The acti:-lty decreases rapidly within the first fe!V centimeters and 

then more slowly with increasing depth. 

A relaxation length of 3-5 cm (the depth 

at which the activity is e 

-1 or 37% of the 

surface activity) is commonly observed 

within the top 5-8 cm. Below this depth 

the relaxation length frequently increases 

to 10 cm or more. Profile samples co1 -

lected on or near the beaches display a 

different depth distribution. Surface 

activities are usually considerably lower 

than island interior Values, and the distributions are essentially uniform or may 

even increase with depth. 

Radionuclides other than 23gPu, “Sr, 

137Cs , and ” Co appeared in the gammaray spectra. A convenient way to evaluate these actiVity levels is presented in 

Table 14, which gives the median activity 

ratios of 241Am/23gPu, 238Pu/23gPu, 

125Sb/‘37Cs, and 155Eu/137Cs for each 

island situated within the northern portion of the Atoll. Inspection of the data 

indicates that the median activity ratios, 

of 241Am/23gPu, 238Pu/23gPu, and 

125Sb/137Cs are essentially constant, 

with approximate values of 0.40, 0.10, 

and 0.07, respectively. 155Eu/137Cs 

values exhibit a reasonably constant 

value of 0.20, except for DAISY, EDNA, 

and IRENE, where the values rise to a 

maximum of 2.5. 

The following is a description of the 

current radiological conditions of the 

-97 -
Table 14. LIedian actilrity ratios of pertLnent radionuclides measured in soil samples 

-

241 239Pu 23SP,: ‘)x$ua 1 xi;__ 131C _ 1 25Sb,137Cs Island -AmI ,s 

ALICE 0.39 0.10 0.12 0.05 

BELLE 0.33 0.11 0.13 0.07 

CLARA 0.26 0.14 0.15 0.04 

DAISY 0.36 - 0.72 0.09 

EDNA 0.35 0.06 0.81 0.03 

IRENE 0.19 - 2.5 0.15 

<JANET 0.38 - 0.11 0.03 

KATE 0.42 0 .-- 33 0.06 

LU CT 0.43 0.3; 0.07 

PERC\ 0.41 - 0.17 

MARY 0.38 - 0.22 0.06 

NANCY 0.49 - 0.23 0.08 

OLIVE 0.38 - 0.30 0.08 

PEARL 0.25 - 0.48 0.08 

RUBY 0.11 - 2.6 0.31 

SALLY 0.28 0.18 0.07 

TILDA 0.51 - 0.20 0.08 

URSULA 0.41 0.1-l 0.07 

VERA 0.44 - 0.17 0.05 

WILMA 0.40 - 0.11 0.09 

a238Pu activitie s were measured only in a few samples. 

islands within the Atoll. For discussion activities listed in the discussions were 

purposes each island situated within the obtained from the surface samples colnorthern part of the Atoll is treated sep- lected to a depth of 15 cm. 

arately, while those within the southern For ease of comparison, the data for 

part of the Atoll are treated in groups the northern islands are summarized in 

because of their radiological similarities. Table 15 and for the southern islands in 

In addition, the mean values and range of Table 16. 

observed activities listed for the northern islands do not include the activities Northern Portion of Atoll 

(ALICE- YVONNE) of samples collected on the beaches, 

since it was felt that these low values ALICE-This island is densely 

might unduly distort the description of vegetated over its entire surface. The 

the islands’ radiological condition. This mean and range of observed activities 

was not considered to be true of islands exhibited by the surface samples for the 

within the southern part of the Atoll. The following radionuclides are: 

-98-

----L.__ ---- __~_ .- ~ 
imples. Activity, pCi ig The radioact::-ity seems to be fair11 Radio- Mean Range *uclide homogeneously ::str!butc’d -F.YOU~~IOU; the 137 CS !)Op 80 14-130 island, e\en though considerable con137C. 36 5.6-141 struction acti\,lr:es, such as :he building I.05 

“39pu 12 3.9-68 of an airstrip along the centcir of the I.07 

5.9 1.4 -33 6OCo island and large-scale earth grading at I.04 

1.09 Table 15. Enewetak soil data, “northern islands” (pCi g in top 15 cm). 

1.03 goSr 137cs 239pu 6Oco 

I.15 Rlean Range Mean Range 1lean Range lIean Range 

1.03 30 14-430 36 5.6-141 12 3 . 9 - i; ii :i.P 1 .A-33 :I LICE 

I.06 

BELLE Dense 123 14-670 48 14-170 36 7-z 130 10 3.1-30

1.07 Sparse 44 35- 130 8.6 3.3-4-I 11 5.%-2r; t . 6 2.4-9.6 

J. 17 

CLARA 65 13-310 26 5.6-110 ‘2 :3.,7-i::; fi .4 0.91-20

1.06 

I ,AISS Dense 190 loo-380 11 3.4-33 -11 --

73-q,y 11 6.4-26 

1.08 Sparse 32 16-120 3.8 0.86-9.0 15 3.:-33 0 .o0: 1 0.37-7.4 

1.08 -16 30-220 1.2 2.7-6.4 1 8 !%?-I 0.43 0.33-0.63 

1.08 

I-DNA 

30 5.9-570 3.2 0.22-41 11 “.-i-280 5.4 0.12-520 

J.3 1 

IRENE 

.J ANET 44 l-6-630 16 0.57-180 8.5 0.08-170 1.9 0.02-33 

1.07 KATE Dense 67 37-200 24 18-37 17 8.6-50 2.7 1.6-5.8 

J.08 Sparse 11 1.6-49 4.8 1.8-16 2.3 0.17-13 0.46 0.03-3.5 

J.07 LU CY 32 lo-83 11 2.2-25 7.7 2.4-22 I.5 0.26-3.8 

J.05 MARY 29 11-140 9.9 5.6-26 8.0 2.0-35 1.5 0.74-4.8 

1.09 NANCY 36 16-110 12 6.0-28 9.1 2.3-28 1.6 0.56-5.3 

PERCY 13 3.6-73 0.94 0.12-17 3.5 1.5-23 0.47 0.08-2.9 

OLIVE Dense 22 4.6-70 3.5 3.5-28 7.7 2.2-30 1.5 0.65-4.1 

Sparse 4.5 2.0-l 1 0.16 0.07-11 2.8 1.9-4.1 0.11 0.05-0.31 

; were PEARL Hot spot 62 35- 140 19 7.4-55 51 15-530 12 3.6-70 

5 COlRemainder 17 3.2-61 7.6 1.2-34 11 0.85-100 4.1 0.49-49 

RJUBY 12 7.1-63 1.4 0.71-7.2 7.3 3.0-24 0.93 0.29-16 

ita for SALLY 8.4 0.87-140 3.0 0.03-30 4.3 0.21-130 0.54 0.05-69 

zed in TILDA Dense 27 17-54 8.4 3.5-20 7.6 1.4-17 1.2 0.61-1.9 

nds in 

Sparse 8.7 2.2-47 1.0 0.04-5.3 2.5 1.1-34 0.37 0.21-l-7 

URSULA 6.8 2.0-19 1.7 0.13-7.8 1.3 0.26-7.3 0.31 0.05-1.7 

VERA 6.3 1.1-68 2.0 0.03-12 2.5 0.60-25 0.30 0.02-2.2 

WILMA 3.3 0.26-13 1.3 0.31-7.2 1.1 o-1-5.3 0.12 0.01-0.7 

Southern 

.ely YVONNE 1.7 0.09-20 0.40 0.02-3.6 3.2 0.02-50 0.64 0.01-20 

The Northern 

Beaches 6.4 1.2-30 0.30 0.03-9.0 2.7 0.34-18 0.13 0.03-1.6 .ties 

YVONNE - Because of the complex distribution of activities on Northern YVONNE no ‘or the 

single mean value for an isotope can be used for the island as a whole without being misleading. Readers should consult the YVONNE discussion in 

this section and the detailed data in Appendix II for information pertinent to 

their interests. 

-99-
Table 16. Znewetak soil data, southern Islands (pCi g !n top 15 cm). 

137 239Pu 9OSr CS 6oCo 

Mean Range Mean Range LIean Range Mean Range 

Group A 

(DAVID, 

ELMER, 

FRED) 0.41 0.02-4.8 0.2 1 0.01-2.1 0.04 0.004-0.31 0.03 0.01-O. 

Group B 

(All others 

except ^ 

LEROY )” 0.52 0.03-3.9 0.14 0.004-1.8 0.07 0.004-1.1 0.06 0.007-6 

Group C 

(LEROY) 11 1.6-34 3.2 0.5-10 0.63 0.02-2.0 0.58 0.04-5.1 

aSAhl, TOM, URIAH, VAN, ALVIN. BRUCE, CLYDE, REX, WALT, GLENN, 

HENRY, IRWIN, JAMES and KEITH. 

the northeastern end, took place during 

the weapons-testing period. This relative homogeneity is also supported by the 

results of the aerial survey. 

The activities as a function of depth, 

obtained from Locations 24, 26, and 100 

within the island’s interior, follow the 

general rule of a rapid decrease in activity within the first few centimeters of the 

surface (relaxation lengths of 3-5 cm) 

and then level off to become almost 

homogeneous (as demonstrated at Location 100). Profile samples collected at 

Locations 23 and 25, which are on or 

near the beaches, display essentially 

homogeneous activity distributions, 

BELLE -As clearly indicated by 

the photographs, this island is so heavily 

vegetated that it was almost impossible 

to penetrate. The only exception is the 

northeast corner of the island, which is 

relatively open with sparse vegetation. 

Most of the soil samples were collected 

within the densely vegetated areas, with . 

a few obtained within the sparsely vegetated northeast corner. The following 

activities resulted: 

Radio- Activity, Qci/{ 

nuclide Mean Ran 

Areas of dense vegetation 

90Sr 123 14-f 

137cs 48 14-’ 

23gPu 26 ?.2-: 

6oco 10 3.1-: 

Areas of sparse vegetation 

“Sr 44 35-

137cs 8.6 3.3-1 

23gPu 11 5.8-: 

6oco 4.6 2.4-i 

The mean activities exhibited by the 

samples from the northeast corner arc 

roughly a factor of three smaller than 

those from the remainder of the island 

Since only a few samples were collect6 

within the corner area, the factor of 

three may or may not reflect the true 

difference in the mean values. The 

aerial survey results do not reflect thi 

difference. 

-lOO-

-- -- ------w-l- -----a-- -~ 
The depth distributions indicate fairly Radio- Activitl., pCii/g 

nuclide Mean Range rapid decrease Of activity with depth. 

~~~ activities are highest at Locations 35 Areas of dense vegetation

3nd 100 in the interior of the island and g”Sr 190 !OO-380 

,nnslderably lower at Locations 36 and 137cs 11 3.4 -33 

which are situated near the beaches. .)I>”1 I 23gp, -11 22-9s 

6oco 11 6.4-26 

CLARA- This ts a small, narrow Areas of s arse I-egetation 

,sland with reasonably dense vegetation. 32 16-120 

ThLrtecn Iocattons were sampled on the 

3.3 0.86-9.0 

and the results of the analyses Island, 15 3.8-33 

xre: 0.83 0.37-7.4 

Activity, pCi /g 

Mean Hange liadtonuclides 

Thus, one obserl:es large differences 

!‘OSr 65 13-3 10 between the mean values exhibited by 

137Cs 26 5.6-110 samples collected within the densely and 

“:X$u 22 3.5-88 sparsely vegetated areas. The highest 

6Oco 6.4 0.9 l-20 

5 activity levels were measured in samples 

ge obtained slightly toward the northwestern - These activities are somewhat lower (leeward) side of the island, which is in 

than those measured on ALICE and excellent agreement with the exposure 670 

l%ELLE. Since the radiological contam- rate contours produced by aerial survey 170 

ination by the weapons tests to CLARA is measurements. 

130 

essentially the same as that for ALICE The depth distributions measured at 

30 

and BELLE, the Lower restdual activities Locations 16, 17, and 18 dtsplay similar 

are probably due to mcreased weathering slopes. At Location 100, situated m the 

130 processes. midst of the most densely vegetated area, 

14 All of the profile sampling locations the depth distrlbutlon shows a rapid de26 are situated within the interior of the crease in activity within the top 5 cm 

2.6 island, and the results from these Loca- (retaxatton Lengths of 2-4 cm) and then -

tions show properties similar to those assumes a much slower rate of decrease 

observed for samples collected within with depth similar to those at Locations 16, 

the interiors of ALICE and BELLE. 17, and 18. A homogeneous distribution 

was measured at Location 19, as would be 

DA&Y-The southern (Lagoon) and expected because of its close proximity to 

eastern sides of this island consist the beach. 

prtmarily of a very sparsely vegetated 

area, and the northwest portion contains EDNA -This ttny island really conconsiderably denser vegetation. The sists of a sandbar wtth a little vegetation 

mean and range of the observed activities on it. The activities obtained from the 

In the soil from these two areas are: eight sampling locattons are: 

10 l-
Act::-ltv, pCiig 

Radionuclide Mean Range 

noSI- 46 30-220 

239Pu 18 13-24 

137Cs 4.2 2.7 -6.4 

6oco 0.43 0.33 -0.63 

These mean activities are lower than 

those measured on ALICE, BELLE, 

CLARA, or DAISY, even though the 

radiological contamination of EDNA from 

the weapons tests is a factor of three 

greater than those given to the other 

islands in the group. This ts, of course, 

most probably due to the enhanced wind 

and wave action operating on this tiny 

island which has diluted and transported 

the activity. The homogeneous depth 

distribution at Locations 7 and 8 tends to 

bear this out. 

IRENE -This island played a 

central role in the weapons-testing program. Highlights of its role include the 

detonation of the SEMINOLE event, which 

created a large water-filled crater within 

the island’s central region; its proximity 

to the MIKE and KOA thermonuclear 

events, which significantly altered its 

physical characteristics; and extensive 

construction activities which involved the 

erection of test structures and the movement of large amounts of earth. Thus, 

one would expect the radiological situation on this island to be exceedingly complex and this was certainly borne out by 

the survey. The geographical distributions 

of the surface activities are relatively 

heterogeneous. Elevated 23gPu, “Sr, 

and 6o Co activities appear immediately 

east and north of the crater; however, 

137Cs seems to be most abundant within 

the central portions of the present land 

mass. Because of the complex situation, 

no attempt was made to divide the iStand 

into areas of dtstinct radiological conditions. The activities of various radionuclides distributed over the island to a 

depth of 15 cm (including the beaches) are: 

Activity, pCi/g 

Radionuctide Mean Range 

“Sr 30 5.9-570 

239Pu 11 2.4 -280 

6oco 5.4 0.12-520 

137cs 3.2 0.22-41 

Profile samples were collected at 

numerous places throughout the island. 

The resulting depth distributions of 

activity also reveal the complexity of,the 

situation. After a careful review of the 

distributions, one may identify several 

239 areas that show Pu activities of about 

100 pCi/g to depths as much as one meter 

beneath the surface. The approximate 

geographical distribution of these areas 

is shown in Fig. 28. 

JANET- This is the largest island 

within the northern part of the Atoll. 

Three nuclear devices were detonated on 

the island. An enormous amount of construction activity associated with the 

weapons program and World War II 

operations took place, as indicated by the 

significant quantities of radioactive and 

nonradioactive scrap scattered around 

the island (refer to Engineering Survey 

data), the bunkers, test structures, and 

mounds of soil. In addition, an airstrip 

was constructed along the northern side 

-102-
n, 

d 

Ii 

ire: 

I,~,K. 28. The shading denotes 

show elevated levels 

239~~ contamination, 

areas that 

of subsurface 

IRENE. 

,)(‘ the island. -4 major fraction Of the 

is;Landfs surface is covered with dense 

,.egetation; however, other areas, 

especially along the northern side, are 

more sparsely vegetated. Even these 

are covered with some sort of ground 

te 

1t 

er 

Id 

n 

.-

c.over. 

The island was sampled extenstvely 

ciuring this survey, partly because of its 

past history, but principally because it 

IS the most likely site in the northern 

[Iart of the Atoll for habitation by the 

returning native population. Surprisingly, 

iii vtew of man’s past activities on the 

Island, the soil radioactivities measured 

in all of the lj-cm-deep surface samples 

(excluding beach samples) closely follow 

a lognormal distribution (as demonstrated 

In Fig. 27), even though they were 

collected throughout the island from areas 

of widely differing vegetation densities. 

The standard geometric deviations, on the 

other hand, were somewhat greater than 

“sual (2.8-3.0), indicating increased 

variability in the measurements in relation 

to similar measurements made on the 

Other islands. The pertinent activities 

exhibited by these surface samples are: 

Actlvtty, pet g) 

Radionucl!de ilIean Range 

goS, 44 1.6-630 

137Cs 16 0.57-180 

23gpu 8.5 0.08- 170 

6oco 1.0 0.02-33 

. 90 The geographical distrtbutton oi Sr, 

137Cs, and 239 Pu do not show any 

parttcular systematic pattern, but elevated 

60Co levels are observed preferentlall> 

within the northeast corner of the Island. 

The area Ls primarily north of the alrstrlp, 

with a long finger extending south across 

the alrstrlp and halfway across the island. 

The mean activity within this area Ls about 

a factor of 2-3 greater than that shown 

above. These elevated actlvltles are 

probably due to a surface ground zero 

situated within the open area near the 

beach, on the northeast corner of the 

island. 

The depth distributions of activity 

were measured at 12 Locations on the 

island to depths as great as 180 cm. AS 

one would expect, considerable varlabillty 

exists between the individual dlstrlbutlons. 

However, some common features do exist. 

Most of the distributions display a relatively rapid decrease m activity wlthm 

the top few centimeters (relaxation 

lengths typically 3-10 cm) and subsequent 

leveling off in activity with increasing 

depth. Significant deviations from this 

behavior, however, are observed at 

several sites. At Location 147, the distributions reveal a layer of contaminated 

material situated between 50 and 90 cm 

below the surface. A similar feature, on 

a smaller scale, was also noted at 

Location 140. In addition, the depth 

-103-
distrtbution at Location 143 LS essentially 

homogeneous to a depth of 50 cm below 

the surface. 

KATE- This tsland contains relatively open, sparsely vegetated areas 

over a cons!derable portion of its tntertor 

and along the lagoon and north sides. The 

remainder of the tsland is covered with a 

dense Lregetation cover. The activities 

of interest with respect to these areas 

are: 

Radio - Activity, pCi /G 

nuclide Mean Range 

Areas of dense vegetation 

g0St- 67 3.7-200 

137cs 24 18-37 

23gPu 17 8.6-50 

6oco 2.7 1.6-5.8 

Areas of sparse vegetation 

9OSr 11 1.6-49 

137cs 4.8 1.8-16 

23gPl_l 2.3 0.17-14 

6oco 0.46 0.03-3.5 

Aga Ln, considerable differences are 

noted in the mean values corresponding to 

the sparse and dense vegetated areas. 

The depth distributions of activity do not 

show grossly dissimilar characteristics 

from those obtained from more pristine 

areas, but they may not be entirely due to 

environmental factors since earth grading 

and building construction took place on 

this island durtng the weapons-testing 

program. 

LUCY-This island is heavily 

vegetated over most of its surface, with 

somewhat lighter vegetation occurring on 

Its southern end. Since only a few SOit 

samples were obtatned from this ltghtly 

,;egetated area, it was necessary to treat 

thus island as a single enttty. The tsoexposure contours developed from the 

aertal survey measurements, however, 

reitect lower exposure rates over the 

lightly vegetated area. The mean and 

range of activities observed in soil 

samples collected on this island are: 

Activity, pCi/g 

Radionuct ide Mean Range 

9oSr 32 

137Cs 11 2.2-25 

23gpu 7.7 2.4-22 

6oco 1.5 0.26-3.8 

The profile samples generally reflect 

a sharp decrease in activity within the 

top 10 cm (relaxation lengths of about 

5 cm) and a leveling off below this depth. 

MARY- The distribution of radioactivity seems fairly homogeneously 

distributed throughout the island, with no 

significant correlation between activity 

levels and the degree of vegetation in the 

vicinity of the sampling locations. The 

mean and range of activities observed 

over the entire island, excluding the 

beaches, are: 

Activity, pCi/g 

Radionuclide Mean HaW 

“Sr 29 1 l-140 

137cs 9.9 5.6-26 

23gPU 8.0 2.0-35 

6oco 1.5 0.74-4.8 

Relatively minor construction activity 

did take place on this island during the 

- 104-

10-83 
,il 

tlY 

rest 

3-

effects tcstlng perLod. The 

be reflected m the somewhat 

dep~ distributions observed. 

ci mis may 

nomogeneous 

activity ts situated 3-8 cm below the 

surface. This may have resulted from 

weathering processes that have dtluted 

the surface activity levels. 

NANCY This - island is essentially 

rr covered with dense vegetation over its OLIVE - This tsland contatns dense 

entIre surface. The radioact:vity seems vegetation over most of its surface, with 

-

:e 

-

83 

25 

22 

3.8 

to be fairly homogeneously distributed 

throughout the island. The activities of 

the pertinent radionuclides are: 

Activitv, pci/g 

Mean Range i{adlonuclide 

“OSr 36 16-110 

137Cs 12 6.0-28 

‘X$u 9.1 2.3-28 

GO CO 1.6 0.56-5.3 

the exception of a relatively sparsely 

vegetated area toward the south end. The 

sampling locations were divided tnto two 

groups: (1) those within the sparsely 

vegetated area on the south end and several 

locations situated on the edge between the 

vegetated area and the beach, and (2) those 

wlthin the remainder of the island, where 

the vegetative cover is reasonably dense. 

The activities of interest in regard to these 

areas are: 

ct 

h. 

The depth distributions display the 

familiar rapid decrease of activity 

immediately below the surface (relaxation lengths of 3-5 cm) at Locations 23, 

24, and 25 situated within the island’s 

Radionuclide 

Areas 

“Sr 

of dense 

Activity, 

Mean 

vegetation 

22 

pC i/g 

Range 

4.6-70 

)-

no 

interior. The distribution at Location 22 

IS essentially homogeneous, as would be 

expected because of its location on the 

137cs 

23gPu 

6oco 

8.5 

7.7 

1.5 

3.5-28 

2.2-30 

0.65-4.1 

beach. Areas of sparse vegetation 

le 

PERCY - This island is a small 

sandbar with no vegetation on tt. Samples 

obtained from six sampling locations show 

the following activities: 

“Sr 

137cs 

23gPu 

6oco 

4.5 

0.16 

2.8 

0.11 

2.0-11 

0.07-11 

1.9-4.1 

0.05-0.3 1 

Radionuclide 

Activity, 

Mean 

pCi/g 

Range The unusually large difference in the 

10 

i 

i 

8 

9OSr 

137Cs 

239 

Pu 

6oC0 

13 

0.94 

3.5 

0.47 

3.6-73 

0.12-17 

1.5-23 

0.08-2.9 

mean values of the two groups of data 

is probably due to the fact that (1) 

samples collected on or near the edge of 

the sparsely vegetated area to some 

degree reflect the low activities on the 

beach, and that (2) a significant portion 

The depth distribution obtained from a of the samples representing the densely 

*ingle profile indicates that the maximum vegetated interior were collected in an 

- 105-
-- 

area somewhat toward the ocean side. 

According to the aertal survey measurements, the latter area had a slightly 

higher radiatton level than the rest of 

the island. 

The depth distributions obtained within 

the interior of the island, Locations 24, 

25, and 26, are quite stmilar. Relaxation 

lengths of about 5 cm are typical. The 

distribution measured at Location 27 IS 

essentially homogeneous as expected. 

PEARL-Since this island contains 

a surface ground zero, the radiological 

analysks was based entirely upon the 

measured soil activities wtthout regard 

to the degree of vegetation. A review of 

the data reveals a “hot spot” centered 

around Locations 5, 6, 9, 10, and 11. 

This is in reasonable agreement with the 

aerial survey measurements, except for 

the exact geographical location of the hot 

spot. The mean and range of observed 

activities for the hot spot and the remainder of the island are: 

Radionuclide 

Activity, 

Mean 

pCi/g 

Range 

Hot spot 

g”Sr 

l37cs 

62 

19 

35-140 

7.4-55 

23gPu 

6oco 

51 

12 

15-530 

3.6-70 

Remainder of island 

g”Sr 

137c s 

23gPu 

6oco 

17 

7.6 

11 

4.1 

3.2-61 

1.2-34 

0.85- 100 

0.49-49 

The depth distributions measured at 

various locations throughout the island 

- 106-

show relaxation lengths, of the order, 

5 cm, except at iocatlon -IS (near the 

southeast end), where the soil activitl, 

seem to be much more homogeneous H 

depth. 

RUBY -This is a tiny island 

situated tmmediately north of SALLY. 

The activittes obtamed from five samp 

lbcations are: 

Radionucltde 

Activity, 

mean 

pCi/g 

Range 

12 7.1-f 

1.4 0.7 1-T 

7.3 3.0-5 

0.93 0.29-I 

The profile samples collected at 

Location 2 indicate a homogeneous distribution of activity with depth. 

SALLY - This island was the site 

of several surface detonations. In addition, the PACE Project had excavated 

extensive areas throughout the island 

during the past year. Since some of 

these excavations centered around the 

surface ground zeros and possible buriz 

sites, it was difficult to devise a 

meaningful and realistic soil survey. 

Therefore, a decision was made to include only the undisturbed areas in the 

sampling plan. The results of this effol 

should not be regarded as a definitive 

statement of the radiological conditions 

this island, but only as an indication of 

the activity levels that may be encountel 

The pertinent activities obtained from tl 

samples collected within the undisturbec 

areas on SALLY and SALLY’S CHILD 

are: 
of Activity, pCi/g 

1 -Mean Range [{ad ionucl ides 

(es 8.4 0.87- 140 ?OSr 

with 3.0 0.03-30 *%s 

z39pu 4.3 0.21-130 

0.54 0.05-69 6Oco 

The maximum activities, listed above, 

Pie 

Were all obtained from a sample collected 

at Location 30 on the beach at the 

z- northern tip Of SALLY. These activities 

are approximately a hundred times greater 

63 Since these elevated levels thaws expected. 

7.2 ,,,ere not recognized until after the com-

!4 pletion of the field portion of the survey, 

16 no additional samples were collected to 

define the extent of the COntaminatiOn. 

The profile samples collected at 

Locations 34 and 35 indicate increasing 

activities to a depth of 60-150 cm below 

t_he surface, while the distribution at 

Location 200 is essentially homogeneous 

to a depth of 40 cm. These unusual 

distributions may have resulted from 

mechanical mixing of the soils due to 

construction activities during the weaponstesting period or, more likely, due to the 

Project PACE excavations. The depth 

distributions measured at the remaining 

sites throughout SALLY and SALLY’S 

CHILD show the more conventional rapid 

decrease in activity with depth through the 

first lo-20 cm with a gradual Leveling off 

in the rate of decrease below 20 cm. 

TILDA-The activity that is distributed throughout this island resulted 

Primarily from the devices detonated 

On SALLY, the adjacent island to the 

north. This activity seems to be distributed fairly homogeneously throughout 

the island; however, a direct correlation 

-107-

may again be made with the density of 

vegetation present. The tsland is divided 

more or less centrally by an old airstrip. 

Inspection of the aerial photographs of 

the island reveals that the area north of 

the airstrip and on the lagoon (west) side 

of the north-south road is much less 

densely vegetated than the remainder of 

the island situated between the airstrip 

and the road. The following activities 

reflect this difference in vegetation: 

Radionuclide 

Activity, 

Mean 

pCi/g 

Range 

Areas of dense vegetation 

“Sr 27 17-54 

137CS 

23gPU 

6oco 

Areas of sparse 

8.4 

7.6 

1.2 

vegetation 

3.5-20 

1.4-17 

0.61-1.9 

“5, 

137cs 

8.7 

1.0 

2.2-47 

0.04-5.3 

23gPll 

6oco 

2.5 

0.37 

1.1-34 

0.21-1.7 

Thus, the mean values vary by factors 

of nearly three or more between these 

two areas. This variation is also observed 

in the aerial survey measurements. 

The depth distributions of activity seem 

to vary considerably throughout the island. 

The distribution measured at Location 35 

reveals a maximum activity value at 

lo-15 cm below the surface, possibly due 

to road construction. On the other hand, 

the profiles obtained at Locations 34 and 

36 display the usual rapid decrease in 

activity within the first few centimeters 

(relaxation lengths of 3-5 cm), while the 

activity at Location 38 falls off almost 

exponentially with a relaxation length of 

roughly 20 cm. 
URSULA-The activities measured 

on this island were quite low with respect 

to those measured on the more northern 

islands. Posstbly due to these low 

activities, no correlation was observed 

between activity and the degree of vegetation. The mean and range of activities 

measured in the surface samples collected 

over the entire island are: 

Activity, pCi/g 

Radionuclides Mean Range 

9OSr 6.8 2.0-19 

137CS 1.7 0.13-7.8 

239Pu 1.3 0.26-7.3 

6oco 0.3 1 o-05-1.7 

The depth distribution at Location 29, 

an interior site, shows the typical decrease in activity with depth; however, 

the distributions measured at Locations 28 

and 31 reveal higher acttvities beneath 

the surface. This may be due to their 

proximity to the beaches. 

VERA -The radiological contamination of this island from the weapons tests 

is relatively minor. Consequently, the 

activities measured in the surface samples 

collected on this very densely vegetated 

island are correspondingly low. The 

pertinent activities are: 

Activity, pCi/g 

Rad ionucl id es Mean Range 

g”S, 6.3 1.1-68 

137cs 2.0 0.03-12 

23gPu 2.5 0.60-25 

6oco 0.30 0.02-2.2 

The depth distributions at Location 24 

display relaxation lengths of 2-5 cm, 

while those at Locations 23 and 25 are 

more Like lo-15 cm. 

WILMA-Since 

contamination of this 

the radiologtcal 

island was similar 

to that for VERA, one would expect roughl] 

the same activity levels. This was borne 

out by the following data obtained from 

the surface samples collected. 

Radionuclide 

Activity, 

Mean 

pCi 

Ran&F 

"Sr 3.3 0.26-13 

137cs 1.3 0.3 l-7.2 

239Pu 1.1 0.1-5.3 

6oco 0.12 0.01-0.7 

The profile samples collected at 

several sites throughout the island display similar depth distributions, with 

relaxation lengths of 10-l 5 cm being the 

general rule. 

t ) 

1 

t 

Beaches -Since the activities of 

the samples collected on the beaches are 

appreciably lower than those measured 

in samples from the islands’ interiors, 

and since these activities do not vary 

greatly from one island to another, it is 

convenient for discussion purposes to 

combine the beach activities obtained 

’ 

from all of the islands in the northern 

part of the Atoll, except for IRENE, 

EDNA, RUBY, and PERCY. The results 

are: 

i 

Radionuclides 

Activity, 

Mean 

pCi/g 

Range 

-‘OSr 

137cs 

23gPu 

6oco 

6.4 

0.30 

2.7 

0.13 

1.2-30 

0.03-9.0 

0.34-18 

0.03-1.6 

-108-
I 

re 

11 

.ilar 

xghly 

borne 

3m 

-13 

-7.2 

.5.3 

-0.7 

is-

:h 

the 

of 

; are 

.ed 

rs, 

Y 

It is 

0 

j 

n 

‘g 

-

-30 

-9.9 

-18 

-1.6 

-

yVoNNE- Yvonne received the 

,,,O.t severe radiologtcat dose of any ,1 

,<,ai,d within the Atoll. Eight nuclear 

tcsts were conducted on the island, and 

fallout patterns from an the close -in 

intersected various ,&jitlc)flaI 16 events 

parts of the island. This fallout history, 

;,li,s construction and decontamination 

,,tivities conducted during and after the 

have produced a rather testing period, 

i,eterogeneous and unusual radiological 

sltuation on the tsland. 

To facilitate the sot1 survey, the 

!sland was divided into two sections: 

(1) the southern section consisting of the 

area south of the bunker complex 

(approximate center of YVONNE C 

photograph), and (2) the area situated 

north of the bunker (YVONNE A and I3 

photographs). This division was based 

upon a review of historical records, data 

obtained from the aerial survey, and 

data from previous ground surveys. 

Indications were that these two sections 

were quite distinct in their radiological 

characteristics; it was expected that the 

southern section would be only slightly 

contaminated, while the northern section 

would probably reveal elevated activity 

levels with high geographical variability. 

Southern YVONNE-A review of the 

activities measured in the soil samples 

collected on this section of the island 

Indicates that the geographical distribution of activity within the top 15 cm is 

rather uniform; however, somewhat higher 

values appear preferentially within the 

area immediately north of the runway 

(see YVONNE figures in Appendix II). 

The geometric mean and the range of 

activities of selected radionuclides 

measured within the top Is-cm layer are: 

Activity, pCi/g 

Radionuclides h?ean Range 

“Sr 1.7 0.09-20 

137cs 0.40 0.02-3.6 

23gPu 3.2 0.02-50 

6oco 0.64 0.01-20 

The distributions of activity with depth 

at Locations 33 and 34 show some irregular variations with depth but generally 

indicate reasonably homogeneous 

characteristics. The distributions at 

Locations 35 and 37, on the other hand, 

indicate fairly rapid decreases in 

activities with depth. This may be contrasted with those at Location 61, where 

the activities actually increase with depth 

by about a factor of five over those 

measured at the surface. 

Northern YVONNE - The complexity 

of the radiological conditions on this 

section of the island was produced by 

several nuclear events. Most notable of 

these is the QUINCE event (see Fig. 23 

for approximate SGZ location), which 

failed to produce a fission yield, with the 

result that the plutonium within the device 

was merely dispersed by the high explosives. Some effort was expended shortly 

after the event to decontaminate the area 

by soil removal and the placement of 

clean soil over the decontaminated area. 

In spite of this decontamination effort, 

considerable plutonium was still left 

behind. Subsequently, a second nuclear 

device was detonated over the same area. 

Recent radiation surveys reveal that the 

area is heterogeneously contaminated 

-109-
wick 239Pu particles 0i i-arious sizes. 

RadLation surveys were conducted to 

evaluate the frequency and geographical 

distrlbutton of the plutonLum-bearing 

fragments situated on or near the surface 

within the QUINCE area. The surveys 

were executed by traversing the area on 

a lo-ft grid pattern wtth a Fidler 

instrument and carefully searching the 

area for relative “hot spots,” or localized 

high Fidler readings. The Fidler, consistmg of a thin Nat detector connected 

to a rate meter, is a field instrument 

designed to detect low-energy gamma 

241 radiation emitted by the Am associated 

with the plutonium. The surveys uncovered 

roughly 60 “hot spots” scattered throughout the area in a highly random fashion. 

On Fig. B.23.la (YVOIWE B) the area 

in which “hot spots” have been found is 

bounded roughly by a line across the 

island 1 cm from the right-hand border 

of the figure and a line across the island 

2 cm from the left-hand border, the full 

width of the island. One must be quite 

cautious in interpreting the meaning of 

a high Fidler reading since the instrument responds to low-energy scattered 

radiation produced by high-energy gamma 

emitters, as well as gamma rays 

associated with 241Am. In addition, the 

instrument’s response is a function of the 

amount of radioactive material, as well 

as its depth of burial. Thus, the “hot 

spots” found on YVONNE are local concentrations of radioactivity which, because of the history of the area, are 

probably, but not certainly, plutonium. 

Soil samples were taken on a number 

of “hot spot” locations and progressively 

divided into “hot” and “cold” halves on the 

basis of Fidler readings, resulting in the 

isolation of milltgram-sLze pieces of 

plutonium metal. The “cold” fractions 

were not amenable to further physical 

separation of plutonium; they gave Fidler 

readings but appeared to have plutonium 

uniformly dispersed through the soil 

volume. 

In addition to the plutonium contam&_ 

tion, the northern tip of YVONNE was 

the site of several nuclear detonations; 

the most notable were the CACTUS and 

LA CROSSE events, which produced large 

craters now filled with water. The throw. 

out material from these events, according 

to the aerial survey results, presently 

display the highest gamma exposure rates 

on the Atoll [see Fig. B.22.lb (YVONNE 

A)]. 

With this situation in mind, the 

sampling plan illustrated in Figs. B.22.lf 

and B.23.lf was developed. In essence, 

the plan included sampling the QUINCE 

area to a depth of 120 cm on a systematic 

grid pattern, as well as every 200 ft along 

a line running up the center of the island 

to the CACTUS crater. The program also 

included sampling along a cross section 

leading from the crater to the Lagoon side 

of the island. It was realized that this 

program could not address the complete 

distribution of the large plutonium 

fragments within the QUINCE area, but 

would only reveal the general contamination levels in the soil. 

The following discussion of the 

radiological conditions is simplified for 

the sake of brevity and clarity. For a 

detailed analysis of the situation, the 

reader is referred to the original data 

shown in YVONNE figures in Appendix 11. 

Analytical data for each of the profile 

sampling locations is also presented in the 

110-
i 

),voNNE -4 and B secttons of Appendix 11. 

~~ aid in l-lsualizmg the three-

,ilmensional dtstrtbution of plutonium on 

be northern half ‘r 

plutonium profile 

,n Figs. 29-37, 

a section etther 

through a portion 

_4 careful review of the Pu activities 

,,easured tn soil samples collected within 

his area reveals 

tlon of the activity 

ocean side of the 

tlons 104 and 117. 

activities generally 

depths of 30 cm or 

high contamtnation 

of YVONNE, the 

data have been plotted 

each of which represents 

across the island or 

Of its length. 

239 

that a stgnificant fracis situated along the 

island between LocaIvithin 

exceed 

more. 

levels 

this area, the 

100 pCi/g to 

These relatively 

appear to 

lesser exrez: ;Lo~g the iagoon side of the 

island. -Act:-.-.:-es exceeding 100 pCi,g 

were meascre- 70 depths of 20 cm within 

a narrow sir.2 s :ruated along Locations 

111, 116, 170, ar:d 125. _An additional 

area of interes; :ay be noted at depths 

of 60-90 CI= ;eceath the surface within 

the island’s .r.;er:or. _q strtp, estimated 

to be as mccr. 2s :OO-200 ft wide, may be 

deltneated ET L >cations 110 and intersecting Loc;:.:r.s 114 and 115. The 

239 Pu activ!r.?s generally exceed 

10 pCi/g w:-,T..Y. ?.e strip, with an observed 

maximum ci -:Z.;e of 70 pCi,g. 

The 239 ?: k:::-.-Ities measured in the 

samples ccl:?::t: along the ltne runnmg 

up the center 1: r^.e island to the CACTUS 

crater are s.,r.i:cantly lower than those 

measured u‘.x._T. tie QUINCE area. For 

instance, acr::.:.es exceeding 100 pCi/g 

were meas:rf- ;?.ly on the surface at 

Location ! ZL. Z:<cept for minor varia32;

tions, the - S_ zctlvities range from 

- .-_ 

1.8 

-0XI -1 -. ^. 

location number 

.z 107 

Lagoon 

Locations lo&-::;, YVONNE. 

iC 

ng 

so 

ie 

. . 

tie 

penetrate furthest inland along the Location 112-116 cross section, as evidenced 

by activity levels of greater than 

100 pCi/g to depths of 50 cm at Location 

113 and 10 cm 

239PU activities 

Depth -

cm 

Surface 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 

100 110, 

120 

130 

10140' 

150 IU4 

Ocean 

Fig. 

at Location 114. Elevated 

are also observed to a 

IUD 

Profile 

29. Plutonium profile data, 

-ill-
-- 

‘. -

Depth -

cm 

Surface 

10 

450 //i 

100 10 

, _ 

.I83 

10._ 

\ 2b 

100 . 

\ 1An1 

20 

100 30. 

10 40* 

50 

63 

70 

80 

90 

100 

110 

120 

130 

140 - - -

150 I I I 

108 109 110 111 

Ocean LClgoOCl 

Profile locstion number 

Fig. 30. Plutonium profile data, Locations 108-111, YVONNE. 

Depth, 

cm 

. 

isi 

3.8 0 .I%2 

0.95 0.3 

0.75 0 .&I3 

0 16 - 0.01 - / 

‘“” 112 113 114 115 116 

Ocean Profile location number lagoon 

Fig. 31. Plutonium profile data, Locations 112-116, YVONNE. 

5 to 30 pCi/g within the top 30 cm between where activities range typically between 

Locations 132 and 142. Slightly higher 10 and 150 pCi/g. 

activities, however, were measured at With the exception of the CACTUS crater 

Locations 143, 144, and 146, along the area, the activities of ‘O’S,, 137Cs, and . 60 CACTUS crater-to-lagoon cross section, CO seem to be fairly evenly distributed 

-112-
- - - - 

- - 

- - - -

- - - - 140 - I I I I 2 

1506 I 

117 118 119 120 121 

-agoon Ocean 

Profile location number 

Lagoon 

Fig. 32. Plutonium profile data, Locations 117 - 121, YVONNE. 

Depth -

130 -

- - 140 -

I I I I \ 150 ’ 

122 123 124 125 126 

Ocean Protile location number Lagoon 

Fig. 33. Plutonium profile data, Locations 122-126, YVONNE. 

we* ‘hroughout northern YVONNE. Generally, tude and usually range between 0.1 and 

the go Sr activities range between 1 and 2 pCi/g. 

rater 5 PCi/g within the top 50 cm and less than Within the CACTUS crater area, the 

x-d ’ Pci/fZ beneath this depth. The activities mean surface activities of 9oSr, 13’Cs, 

huted of l37 Cs and 6o Co are similar in magni- and ” Co are generally an order of 
- - 

- - - - 

Surfa 

“0 

‘1 

0.03 0.1 

0.03 

‘00 

0.008 

o-663 

1’0 I

OAQ’ - ‘20 

I ‘30 - - 140 I

‘50 I 1 I J 

128 ‘29 ‘30 131 

Ocean Lagoon 

Profile location number 

Fig. 34. Plutonium profile data, Locations 128-131, YVONNE. 

Depth -

Cffl 

; 0x4 0x3 074 o-37 0.07 0 xi69 OXI 0.03 I 

7. 0.04 KG1 0.008 0.4 0.02 

8. 0x1 0.03 0.01 007 02 -

ox.1 0.03 o.J2 0.08 0.02 90 OS 

0x2 0x5 026 0.05 100 OS 

0x8 OX , 50.04 OX4 OX1 038 0.03 l1o 0.008 

120 @??3 032 0-C’ 23 - CI5 o-67 0.011 - - --L - L 

130- - - - - - - _ _ 

140_ - - - - - - - -

150- l I I I I I I I 1 

129 124 119 114 109 105 103 102 101 

Profile location number 

Fig. 35. Plutonium profile data, Locations 101-103, 105, 109, 114, 119, 124, and 

129, YVONNE. 

magnitude greater than those measured similar characteristics. For instance, 

throughout the remainder of Northern if one proceeds outward on the two sample 

YVONNE. Even though the geographical radials leading from Location 142, on the 

distributions of these radionuclides are crater lip, one encounters an approximate 

highly variable, they do show somewhat tenfold increase in activity levels (averaged 

114-
••

- - - - 

Depth -

cm 10 10 10 10 10 

\ 1 \ 

5 10 

i 

1 

b 

‘7 

0.1 

2 9:

3n 

Profile location number 

Fig. 36. Plutonium profile data, Locations 132-142, YVONNE. 

Depth, 

cm 

- 130 -

CACTUS Crclter Profi ie locat ion number Lagoon 

Fig. 37. Plutonium profile 

over 120 cm depth) in the vicinity of 

Pie Locations 141-140 and Locations 143-

he 144. These activities fall off, however, 

ate as one proceeds to Locations 139 

;ed and 145. 

data, Locations 142-146, YVONNE. 

Southern Portion of Atoll (SAM-LEROY) 

For discussion 

within this portion 

divided into three 

includes DAVID, 

purposes, the islands 

of the Atoll have been 

groups. Group A 

ELMER, and FRED 

-115-
because of their :rr?ortance as like11 

sites for habitat.or, oy the returning 

native population. These islands are no 

different, radtoioglcally speaking, from 

the remainder of the tslands in this part 

of the Atoll. Group B cons tsts of all of 

the remaining tslands except LEROY, 

including: SAXI, TOM, URIAH, VAN, 

ALVIN, BRUCE, CLYDE, REX, iVALT, 

GLENN, HEKRY, !RWIN, JAMES, and 

KEITH. LEROY is placed in Group C 

because its radiologtcal conditions are 

slightly different from those of the other 

islands. 

Group A- The scientific and 

military headquarters were s ttuated on 

ELMER and FRED during the weaponstesting period. DAVID was used mostly 

for communications and recreational 

purposes. Relative to the northern 

islands, radiologLca1 contamination of 

these islands was small. Any observed 

elevated levels of contamination probably 

would have resulted from special operations such as equipment decontamination, 

radiochemical processing, etc. Special 

samples were collected in those areas 

suspected of containing contamination 

from these operations; however, no 

elevated levels were noted. The mean 

and range of activities observed on these 

islands are: 

Radionuclide 

“Sr 0.4 1 0.02-4.8 

137CS 0.21 0.01-2.1 

23gPU 0.04 0.004-0.31 

6oco 0.03 0.01-O. 15 

The depth distributions generally displa,,, 

a sllghr decrease in actlvlty immediate\.,. 

below *he surface and then become 

essentially homogeneous with increasine 

depth. 

Group B-Most of the islands in 

this group are small tn area; tn fact, 

SAM, TOAI, URIAH, VAN, -ALVIN, 

CLYDE, and KALT are hardly more 

than small sandbars with some vegetation 

on them. The mean and range of observed activities obtained from the 

15-cm-deep surface samples, including 

those collected on the beaches, are: 

Activity pCi/g 

Radionuclide Mean Range 

goS, 0.52 0.03-3.9 

137Cs 0.14 0.004-1.8 

23gpu 0.07 0.004-1.1 

6oco 0.06 0.007-63 

The distributions of activity with depth 

display .sLm dar characteristics throughout these islands. In areas of dense 

vegetatton, the activtties within the top 

20 cm decrease relatively slowly with 

relaxation lengths of about 8 cm. On the 

other hand, profile samples collected in 

open or sparsely vegetated areas exhibit 

essentially homogeneous distributions. 

Group C- LEROY was situated 

within the fallout patterns from several 

events that took place on the eastern and 

northern sides of the Atoll. This, of 

course, was reflected by the elevated 

activities measured in soil samples fror! 

this island. Furthermore, the island’s 

dense vegetation probably tends to inhibi 

-116-

- -. 
display 

ed lately 

e 

reasing 

ds in 

ict, 

v:, 

ore 

getation 

obe 

luding 

e: 

,03-3.9 

104-1.8 

104-1.1 

07-63 

epth 

-oughs 

se 

3 top 

Jith 

Onth 

ted ir 

xhibi 

)ns. 

ed 

.eral 

n ar 

of 

ed 

Lfr 

Id’E 

nh 

Ci,lutLOn of the activities by envtronmental 

pr0cesses. The activities obtained from

-deep surface samples are: the i5-cm 

Activtty pCi/g 

IxI1tiionuclide Mean Range 

-

90Sr 11 1.6-34 

1j7Cs 3.2 0.5-10 

?39Pu 0.63 0.02-2.0 

6Oco 0.58 0.04-5.0 

These mean activities are roughly ten 

times greater than those observed on the 

other islands in the southern part of the 

Atoll. The depth distributions of activity 

measured at three locations within the 

Interior of the island exhibit very gradual 

decreases in activity with depth. Relaxation lengths of 10 cm or greater are 

typical. 

EXTERNAL DOSE ESTIMATES 

II. L. Beck and J. E. McLaughlin 

Health and Safety Laboratory 

USAEC, New York, New York 

P. H. Gudiksen and D. E. Jones 

Lawrence Livermore Laboratory 

Livermore, California 

0. 0. T. Lynch, Jr. 

Nevada Operations Office 

USAEC, Las Vegas, Nevada 

T. P. Stuart 

EC&G, Inc. 

Las Vegas, Nevada 

Introduction 

Our objective was to quantitatively 

assess the total external dose that the 

returning native population might receive 

as a result of the radiological contaminants distributed in the environs Of the 

Enewetak Atoll. Since the external dose 

is almost entirely due to the gammaemirting radionuc!:des. .:.-lth onl\- minor 

contrtbutions from alpha and beta emitters, 

it was essential to obtain the best possible 

description of the geographical i,ariability 

of the gamma exposure rates in air on 

each island of the _L?toll. These data, in 

conjunction with pertinent population 

statistics and expected life style, will 

enable us to make realistic estimates of 

the external dose to the future inhabitants. 

Several independent techniques were 

used to measure these esposure rates, 

since each technique has its own set of 

1imi:ations (i. e. nonlinear energy response, 

portability of equipment, and estent of 

geographical coverage). \5ie used results 

from the following techniques to satisfy 

the objective: ground measurements made 

with the use of a portable, hand-held 

Baird-Atomic NaI scintillation detector, 

two types of thermoluminescent dosimeters 

(TLD), and a helicopter-borne NaI detector array (aerial survey). The first 

two techniques are discussed below, while 

the details and results of the aerial survey 

are discussed m a separate chapter of 

this report. A comparison of the results 

obtained by these techniques and the use 

of the results in the population dose computation is included in the following 

discussions. 

Measurement Techniques 

Ground Measurements Made With 

Baird-Atomic NaI Detector 

This instrument is a transistorized, 

hand-held portable ratemeter sensitive to 

gamma radiation. It consists of a photomultiplier tube optically coupled with a 

NaI crystal, electronic circuits, meter, 

associated range selector, and two “D” 

117-
batteries in a sealed container. The 

detector assembly is a thallium-activated 

NaI crystal (2.51-cm diam X 3.3-cm long). 

It is contained in a hermetically sealed 

can fitted with a glass window which is 

optically coupled to the photocathode 

window of the photomultiplier tube. The 

radiation level indicating meter is calibrated in microroentgens per hour in three 

ranges corresponding to 0 to 30, 0 to 300, 

and 0 to 3000 pR/hr. Since the instrument 

is completely sealed and desiccated, it 

readily survived the conditions of constant 

exposure to sunlight, rain, salt water, 

and general rough handling encountered 

on the Atoll. 

The instruments were carefully calibrated at the primary calibration range of 

the xational Environmental Research 

Center, Las Vegas. The range, consisting of a horizontal track approximately 

10 m long is situated in an air-conditioned 

concrete block room. Prior to calibration, each instrument was turned on for 

several hours and thoroughly inspected. 

The calibration was performed by attaching the detector to a traveling dolly 

mounted on a horizontal track. This 

allowed positioning of the instrument at 

various distances from a 1-mCi 137Cs 

source inserted in the source holder at 

one end of the track. The instrument’s 

response was then recorded at various 

distances from the source so that all three 

ranges of the instrument were checked. 

The response was then compared with the 

calculated dose rate at the corresponding 

distances from the source, and, if 

necessary, appropriate corrections were 

applied to the instrument. 

While the energy response of this 

instrument is inherently nonlinear, it was 

not a serious limitation in :his case be_ 

cause of the dominance 01’ ls7Cs in the 

radiation background on rhe -4toll. The 

instrument was espected :o overrespond 

if the gamma flux was due ro scattering 

from a buried area source rather than 

from a point source as used in the calihr,. 

t ion. This will be shown to be of minor 

consequence when we compare the resulting data with those obtained by other 

techniques. In addition, the instrument 

does not respond quantitatively to cosmic 

radiation, which is essentially the only 

natural source of radiation on the Atoll. 

Practically all of the measurements 

obtained with this instrument were made 

by the soil-survey teams. The exposure 

rate at 1 m above the ground was measured at each of the soil sample locations 

on every island in the Atoll for possible 

correlation with the soil activities. The 

resulting data, which include a rather 

extensive coverage of islands, are presented in the ‘Id” series of figures in 

Appendix II. Additional measurements 

mere made at each TLD location for 

direct correlation with the TLD measurements. 

Thermoluminescent Dosimeter 

(TLD) Measurements 

We used LiF and CaF2:Dy TLD chips 

for measuring the radiation fields at 

numerous locations on the Atoll. The 

LiF chip was used as the principal detector due to its energy linearity and its 

excellent thermal stability. Its response 

is within approximately 1% of being air 

equivalent for a typical environmental 

radiation field that contains appreciable 

scattered radiation in addition to the primary gamma rays that are present. 

-1 18-
I 

5 

the resul7s deri\ved from the 

i,ik. rrLD~ were chosen as a reference to 

.)C - .i.~,urefore, 

he 

,vt,ic]l measurements obtained by zhe other ‘he 

tccllniques could be compared, The CaF2 and 

,r~,l)s have an enhanced energy response “g 

nt 10~4~energies and were used to detect n 

possible low-energy radiation fields. A libra. 

,.omparison of their signals with those or 

from the LiF TLDs may provide an indiier ,~ntion of the presence of an unsuspected 

concentration of low-energy radiation. :nt 

i.‘or a typical radiation field, the CaF2 tnic 

~~~~,l)swere expected to overestimate the Y 

i)ose rate to air by approsimately 30 to Il. 

10”:~. 

The LiF and CaF2 chips (1 /E-in. de 

square X 0.035-in. and 0.040-in. thick, re 

respectively) were carefully selected by 3-

ns 

le 

he 

thermoluminescent 

re-

;e 

i- Fig. 38. Field placement of TLD’s with 

enlarged view of TLD packet. 

-119-

a process of annealing, followed by 

irradiation to a common total esposure. 

Subsequent readout then allowed the 

extraction of defective chips. The TLDs 

were transported to Enewetak and annealed 

on the Atoll immediately prior to being 

placed on the seven outlying islands that 

were selected for the TLD program. Two 

LLL plastic personnel badges containing 

three LiF and three CaF2 chips were 

placed at each field location. The TLD 

packets were attached by two nails and a 

nylon strap to small tree limbs at a 

height of 1 m above the ground (Fig. 38). 

Each location was marked with copious 

quantities of fluorescent tape and paint 

to facilitate retrieval of the TLDs after 

the 3-l/2-mo exposure period. The 

locations were carefully chosen to obtain 

a representative sampling of the terrain 

(i. e., densely and sparsely vegetated 

areas and areas adjacent to sandy beaches). 

Upon retrieval each TLD packet was 

immediately placed in a lead container 

and handcarried to LLL where it was 

stored in a lead container in an underground, radiation-counting facility. Each 

chip was individually read on the LLL, 

hot-nitrogen, automatic TLD chip reader”’ 

which was interfaced to a PDP-11 computer. In this way a catastrophic reader 

failure would only reduce the precision of 

the answer and would not result in the 

total loss of data from any badge. This 

technique also eliminated undetected 

errors due to drift in reader sensitivity. 

xK. F. Petrock and D. E. Jones “Hot 

Nitrogen Gas for Heating Thermolu’minescent Dosimeters,” in Proceedings of 

the Second International Conference on 

Luminescent Dosimetry (Gatlinburg, 

Tenn., 1968). 
137 

!I number of ancillary cspet-lments 

were performed for calibration purposes 

and to insure that no errors were incorporated into the measurements. _A 

separate set of chips \I:as exposed to a 

Cs point source at convenient times 

during the field exposure period for calibration and signal-fading studies. The 

strength of the calibration source was 

checked before and after field use with 

NBS-calibrated Radocon chambers and is 

known to within 3% at one standard 

deviation. Control TLDs were carried 

to the outer islands and back to measure 

the dose received during transit, All of 

the chips were then stored in the lead 

containers for the balance of the field 

measurement period. In add it ion, anot he r 

set of control TLDs was stored within 

and on the periphery of the lead storage 

containers for environmental background 

studies. 

The background exposure on the control 

TLDs was essentially all contributed by 

cosmic radiation during the 3-l/2-mo 

exposure period on the Atoll and during 

the aircraft flight to LLL. The average 

background exposure for the two types 

of TLDs was subtracted from all field 

measurements SO that the results represent only the terrestrial radiation exposure rates. For verification purposes, 

the magnitude of the total background exposure was also estimated by using successive differences for each type of TLD 

on the three sets of calibration exposures 

and by using the sensitivity in light output 

per milliroentgen (mR 1to estimate exposure 

for the average control light output. All 

estimates fell in the range of 10 to 12 mR, 

which agrees well with our previous experience of measuring cosmic ray exposures. 

The TLD-signal-fading data have h 

carefully analyzed to determine the 

necessity, if any, of applying a fading 

correction. Figure 39 shows the net 1 

sums for identical exposures at specif 

times following the start of the field 

measurement. The TLDs were expos 

at different times during the field mea 

urement, and thus long post-annealing 

times represent later exposures. Not 

that early exposures (day 41, have low 

light sums than those at the end of the 

field measurement (day 11 l), due to 

thermal fading. In the analysis a con 

stant exposure rate was assumed and 

empirical fit of Fig. 39 was assumed: 

LiF 

a 

\ 

AI AlA 

-4----h 

Post-annealing time - days 

Fig. 39. A plot showing TLD fading 

characteristics. The TLD; 

were subjected to equal exposures (137Cs source) at 

various times during the fileld 

measurement period. Anne Laling time was at t=O, exp0St 1res 

were from t=l to t=lll day S, 

and the light readings were 

taken from t=130 to t:134 dlays. 

-120-
I 

,icscribe the fading. These assumptions The LiF measurements for the islands of 

5i10uld be quite good for the nearly con- ALICE, BELLE, CLAR.A. DAISY, IRENE, 

“g 

?t light 

,cified 

1 

srnr,t ambient field conditions and the age 

‘,f the artificial radionuclides present. 

Corrections of less than 1% for LiF and 

.~{l’ior CaFZ were obtained by integration .1 

JANET, AKD PEARL are shown in figure 

overlays at the respective geographical 

locations where the measurements were 

made (see iZppendix II, series h). Table l’i 

osed and applied to the calibration data. These contains a complete listing of the CaF2, 

leas- fading exposures were performed on the LiF, and portable Nal measurements for 

;ng atoll and the TLDs were stored under each TLD location. 

Kate ambient conditions. 

ower The net light outputs from the calibra- Table 17. Listing of exposure rate levels. 

.he 

1 

ontloll exposures are 

c.;iiculated exposures 

if(>,pree polynomial 

plotted against the 

in Fig. 40. Secondexpressions are fitted 

TLD 

location 

TLD 

(LiF) 

Exposure 

TLI) 

(CaF2) 

rates, pli’hr 

Porrlibltt 

Tat 

detector 

Id the IO the data. From these curves, one may Island: ALICE 

‘d to ;lssign exposures to the light outputs from 17 48 59 55 

~11 the TLDs. These exposures were then 

separated by island and divided by the 

number of hours of field exposure to determine the appropriate exposure rates. 

18 

19 

55 

56 

57 

120 

108 

0 

45 

42 

132 

120 

1 

52 

50 

120 

110 

35 

45 

58 109 128 100 

59 127 142 130 

,A’ 

60 

61 

6 

26 

10 

28 

7 

20 

aJ 

u Island : I3ELLE 

/ 

/” 

; 

4 

14 

15 

16 

a4 

131 

121 

97 

151 

132 

21 8 16 

22 129 133 110 

23 118 136 130 

24 154 173 140 

25 139 173 140 

26 138 155 145, l-m height 

YS 

27 

28 

29 

149 

140 

124 

168 

167 

153 

145, 

145, 

145, 

0.33-m 

0.67-m 

1.33-m 

height 

height 

height 

uz 

.Ds 

,XIt 

field 

neal1su I-e 

3ys, 

.7say! 

Fig. 40. 

IO3 104 

Light sum - counts 

Calibration curves for LiF and 

CaF2: Dy TLD’s. The values 

for CaF2 counts have been 

multiplied by 0.05 to enable 

presentation of both sets of 

data in the same figure. 

38 

39 

Island: 

20 

41 

42 

43 

44 

CL-4 RA 

200 

81 

67 

12 

58 

49 

58 

219 

92 

65 

15 

59 

58 

66 

200 

100 

75 

8.5 

50 

50, l-m height 

50, 0.33-m height 

-121-
Table 17 (continued) 

Espos,~;re rates, UK hr Exposure rates. pR,hr ’ 

Portable P~~x-tabl> 

T I,11 TLii NaI TLD TLIJ TLI) NaI ~_ 

(LlF‘l IC3I.‘21 detector location (LiF) (CaF21 detector 

\ . _ 1; 55 61 50, 0.67-m height 88 -13 58 60 

45 52 52 50, 1.33-m height 89 30 42 50 

-1; 54 5a GO 310 3 a 7.5 

51 104 112 105 311 33 41 45 

r 3L .- 118 l-ll : 30 312 110 137 135 

313 79 104 110 

Islard: DAIS\ 

314 37 64 75, l-m height 

-&a 11 13 10 

11 

63 

33 

20 

35 

28 

20 

13 

315 

316 

-16 

55 

61 

70 

75, 1.5-m 

75, 0.5-m 

height 

heigb 

317 66 75 75 

64 17 21 13 

318 43 61 65 

65 18 21 11 

319 54 Gl G5 

66 a 12 a 320 36 16 50 

67 a 11 7, l-m height 321 28 35 22 

68 

69 

9 

I 

12 

11 

7, 

7, 

0.5-m 

1.5-m 

height 

height 

322 2 3, 1 - m hqight 

bunker’ 

id. 

70 7 12 7.5 323 1 2 3.5 

75 a 13 10 324 19 19 16 

76 106 113 90 327 33 60 75, l-m height, 

77 65 72 65 0.02-in-Al 

cover ‘. 

Island: IRENE 328 0 1 3, l-m height, 

7: 92 107 90 

0.02-in.-AI 

cover 

73 194 215 200 Island: PEARL 

74 25 34 45 1 23 3 3 21 

78 72 86 75 2 159 1 a 1 170 

80 26 34 25 3 151 178 170 

Island: .JANET 4 48 70 70 

301 62 71 70 5 52 7 3 60 

302 65 73 80 6 44 56 50 

303 56 73 80 7 31 44 40 

304 70 a5 90 a 19 26 25 

305 30 42 45 9 19 26 14 

306 36 48 55 11 14 19 10 

307 45 58 65 12 19 24 12 

308 36 42 -l5 13 14 17 a 

309 37 44 45 31 68 7-l G5 

81 1 5 5 32 128 13R ti 5 

a2 19 26 18 33 80 SO ii0 

83 8 16 12 34 39 49 50 

84 32 43 27 35 43 56 50 

85 50 65 65 36 67 a2 65 

86 46 58 cn 

“Y 

37 3a 44 40 

87 54 67 65 Contiguous locations. 

-122-
-m height 

.5-m height 

.5-m height 

-1-n height in 

lnker 

-m height, 

.02-in.-Al 

>vei 

-m height, 

02- in.-Al 

)ve r 

tI ,tatistical analysis was performed 

,i, ,),termine the accuracy of the TLD relvithin the range of 30 to 50 pR/hr, <l~iiS. 

!,,(, accuracy of the exposure rates is con-

,G,>r.,,,atively estimated to be 4% for CaF2 

,,!,ti 6”~ for LiF at one standard deviation. 

i ~)I‘ the CaF2 results, this estimate 

does not include the nonrandom error 

due to the nonlinear energy response. 

j..or very low exposure rates the error 

i,t,comes much larger, especially in re-

,,;ird to the LiF data. This is due to the 

,G,li,traction of the relatively large backGround, the increased variability of the 

ii:lta at low exposure rates, and the 

,.mnirical fitting technique that forces the 

i,t:st fit at the higher exposure rates. For 

Instance, at an exposure rate of 4 pR/hr 

the LiF results are considered to be 

;tccurate to approximately 40%; the relative precision is considerably better. 

Aerial Radiological Survey 

The details of this survey, including 

results, are provided in a separate 

chapter of this report. In essence, gamma 

rays were detected by a helicopter-borne 

;Irray of 40 NaI detectors flown over each 

island on a 150-ft grid spacing. An 

Irll’rtial navigation system provided position 

coordinates. The output from the detectors 

was analyzed according to pulse height and 

recorded along with the position data on 

magnetic tape. The tape was processed 

On a ground-based computer to produce a 

“erY detailed mapping of the iso-exposure 

rate ContOUrS at 1 m above the ground for 

(!ach island in the Atoll. 

<3omparison of Results 

Recause the LiF TLD has excellent 

thermal stability and its response is 

essential!\7 air equiva.lent, the LiF measurements are considered to be the most 

accurate measure of the gamma exposure 

rates at the limited number of sites where 

TLDs were placed. and, therefore are 

used as the reference to which all the other 

measurements are compared. How ever, 

when making comparisons between results obtained with various techniques, 

one must be careful to avoid comparing 

measurements that are entirely different 

in nature. For instance, the radiation 

field measured by the TLDs and portable 

NaI detector is very local in nature (the 

order of a few square meters), while that 

measured by the aerial system is of the 

order of hundreds of square meters. Thus, 

local radiation gradients are averaged 

over large areas by the aerial system,and 

the results obtained from specific areas 

may be quite different from those obtained 

by the TLDs and portable survey meters. 

The comparison, shown in Table 18, 

specifically excludes areas exhibiting 

steep radiation gradients so that the TLD 

and portable-survey-meter measurements 

may be considered representative of an 

area of several hundred square meters. 

With this in mind the TLD locations in 

Table 18 were selected from areas of 

uniform exposure rates in the interiors of 

ALICE, BELLE, DAISY, and JANET. 

Inspection of the data in Table 18 reveals 

that the LiF measurements are approximately 17% less than those of CaF2. This 

is reasonable in view of the enhanced 

energy response of CaF2 at low energies. 

This expected relative difference between 

the results of the two types of TLDs also 

gives added credence to the LiF measurements. The table also reveals that the 

aerial survey measurements and the -

1 23-

1 
Table 15. Cornpa:-:son of the gamma-ra?- esposure rates _ (pR hri obtained at selected

:ocatlo:x 

Exposure 

TLD 

Island location 

DAISY 19 

63 

64 

65 

77 

.I AnTET S5 

86 

87 

88 

89 

301 

302 

303 

304 

305 

306 

307 

308 

309 

312 

313 

317 

318 

319 

320 

321 

Average 

ratios 

bv 

rate, 

T L D 

1 L:F) 

the x-arlous techniques. 

piR .‘hr 

T L D TLU (LtF) 

(CaFp) TLD (CaF2) 

59 0.81 

132 0.91 

52 0.87 

128 0.85 

l-12 0.89 

0.97 

0.87 

o.s9 

0.80 

0.91 

0 . 8 :I 

0.94 

0.71 

0.81 

0.86 

0.90 

65 0 .7-i 

5 8 0.79 

67 0.81 

s 8 0.74 

12 0.71 

71 0.87 

72 0.89 

73 0.77 

85 0.82 

42 0.71 

48 0.75 

58 0.78 

42 0.86 

44 0.84 

137 0.80 

104 0.76 

75 0.88 

61 0.70 

61 0.89 

46 0.78 

35 0.80 

0.83 f 0.07 

Exposure rate, UR /hr 

TLD (I_iF) 

Portable Portable 

SaI NaI rlerlal TLD (LiF) 

detector detector su r\rev .&erial SU rvey 

55 0.8-i 56 0.85 

120 1.0 81 1.48 

45 1.0 3s 1.21 

100 1.09 121 0.89 

130 0.98 121 1.04 

110 1.17 101 1.28 

130 0.91 121 ‘0.97 

140 1.10 149 1.04 

l-10 0.99 119 0.93 

‘00 1 ,oo 122 1.64 

100 0 * 8 1 81 1.00 

20 1.65 2 s 1.30 

13 1.54 25 0.79 

13 1.31 17 0.99 

11 1.64 17 1.04 

65 1 .oo 5G l.lG 

65 0.77 1 3 1.17 

GO 0.77 -13 1.07 

65 0.83 43 1.26 

60 0.72 3G 1.21 

50 O.GO 3 8 0.79 

70 0.89 13 1.45 

30 0.81 46 1.41 

80 0.70 54 1.04 

90 0.78 52 1.34 

-15 0.6’i 40 0.75 

55 0.65 55 0.66 

65 0.69 52 0.87 

45 0.80 35 1.04 

45 0.82 28 1.34 

135 0.81 87 1.27 

110 0.76 70 1.13 

75 0.88 43 1.54 

65 0.66 43 1.00 

65 0.88 43 1.26 

50 0.72 40 0.90 

22 1.27 32 0.88 

0.93 zk 0.26 1.10 i 0.28 

-124-
-1 

! 

‘t Eii 

. 

G 

-

detector results agree, on ./ ,..::li)l(X ya1 

,,\ cI-;lge, v.fithin about 10’5 with the LIF . I

.I 

This is within The accu- ::.,,l,i5il wmf=ts. 

:,,i‘,~ of the measurements and the agree-

_,,hi is considered excellent. On the 

i,;i5,:: (,f this comparison and because of 

i,c ,,htensive geographical coverage, we 

;,,?I that the aerial measurements provide 

,, elost complete and accurate description “1,’ 

cl: -he gamma exposure rates throughout 

Zj:e entire _AtOll. Therefore, we feel 

,;:,:lfied in using these data as a basis for 

I,.ermi~~ing the external dose to the re-

‘!: rning population. 

i;sternal Dose Determination 

in addition to the gamma-ray exposure 

rat es, one needs to consider the expected 

living patterns of the future inhabitants in 

order to evaluate the external dose 

Problem. Due to the uncertainties inherent in predicting future living patterns, 

seseral cases were chosen for analysis. 

‘I‘hese are presented in Table 19. The 

selection of these cases was based upon 

:Ile most recent information available 

regarding present population figures, age 

clistributions, and expected life styles 

(see The Enewetak Atoll People, p. 25). 

f+rthcrmore, the cases were chosen in 

such a manner as to bracket the most 

likely range of doses which could be received by any sizable segment of the 

PoPulatlon. This will allow any other 

reasonable pattern to be inferred by proper 

interPolation of the results obtained for 

the cases shown in Table 19. 

The first four cases are based upon 

the assumption that some fraction of the 

Population may choose to reside primarily 

O~JANET (the largest island within the 

mainder residing on FRED, EL;\lER, or 

DAVID in the southern group of islands. 

Each case under consideration allows for 

visits to other islands. Case Ib differs 

from case Ia in that more time is allotted 

to temporary occupation of islands other 

than JANET at the expense of less time 

being spent in the JANET village area. 

These cases, or combinations thereof, 

are considered to represent the most 

likely living patterns. 

Case V. on the other hand, represents 

a “worst credible” type of living pattern. 

The village is situated on BELLE, the 

island with the highest mean gamma-ray 

exposure rates (excluding YVONNE), and 

visits are only allowed to the other 

northern islands. Thus, Case V would 

most probably lead to upper-limit doses 

if some reasonable fraction of the population should decide to reside permanently 

on BELLE. However, such a plan is not 

being considered at this time. No 

attempt was made to subdivide the time 

spent on other islands into specific areas, 

since it was felt that such a breakdown 

would unnecessarily complicate the 

calculations. 

Even though wide variations in gammaray exposure rates were measured 

throughout the northern islands, it was 

necessary, for the purpose of the dose 

calculation, to derive the most reasonable values of the current mean exposure 

rates for each specific geographical area 

under consideration. These values are 

shown in Table 20. The mean exposure 

rates for specific areas of JANET were 

obtained by examination of the 13?Cs and 

60Co iso-exposure-rate contour maps 

provided by the aerial survey. The village -

“orthern part of the Atoll), with the re- area was assumed to lie along the lagoon 

-125-
••••

l‘ill;cse on J.‘IZET. Infan;s 5 0 0 

\.1Slts I:) other northern Children 10 15 3 

islands only. 1Ien 5 15 10 

1!‘omen 10 10 0 

l‘illa,oe on .J.iXET, Infants 70 5 5 0 20 

\.isiis ‘i) other northern a Childrer! 50 3 15 10 20 

islan::j oni\-. 1Ien 40 5 20 10 25 

\\-orn en 30 5 15 5 25 

[-illage on FRED, ELiLIER, Infants Same as Case t,, 

0r r)$T-m. Children 3 \Tisits ;c, liorthern :slands 1Ien 

only 1excl. .J _4SET). 1i omen 

l’illage on .J_lSET, Infant 3 Same as Case I 

visits :o southern b Chi1dre.n a 

islanus only. 1Ien 

1i omen 

lyillage on FRED, ELblER, Infants Same as Case lb 

or DAT-ID, Children 

visits to southernb islands XIen 

only. Women 

Village on BELLE, visits Infants Same as Case Ib 

to other northern islands Children 

only. firen 

11’omen 

aNorthern islands include ALICE, BELLE, CLARA, DAISY, IRENE, <JANET, KATE, 

LUCY, DIARY, NANCY, OLIVE, PEARL. SALLY. TILDA, URSULA, \‘ERA, and 

WILMA. 

bSouthern islands include all islands from TORl through LEROY, proceeding clockwise around the Atoll. 

‘These values represent the percentage of time spent in the various areas. 

side of the island. The mean values gil-en radionuclides in the soil and sea water 

for all of the northern islands were ob- were expected to contribute an additional 

tained by weighting the mean exposure 0.2 clR/hr. 

rates for each individual island with the The relative gamma-ray exposure 

area of each island. Since the minor con- rate contributions from6’Co and 137Cs 

tamination of the southern islands is obtained from the aerial survey agrees 

relatively uniform, the mean 13’Cs and well with values independently inferred 

6CCo exposure rates were chosen by in- from the soil activity-depth profile measspection of the individual aerial-survey urements. Although the soil measurecontour maps. The cosmic-ray contribu- ments indicate trace amounts of other 

tion was estimated to be 3.3 ~R’hr at this gamma emitters, such as 125Sb. 1551S~, 

latitude and the naturally occurring and 241 Am, calculations of exposure 

126-
I 

. 

Olill~, 

1 !Slan+ 

. 

20 

20 

25 

25 

KATE, 

nd 

:iockater 

it tonal 

GCs 

rees 

rred 

measIreicr 

J5 Ku, 

se 

.r:lble 30. E:s?imated mean esnojure rate-: IuR hr) used for dose calculations. a 

/ 

:$I ajar 

L,,,,cr3nhical area Source 

Exposure rate, 

Village Intertor 

yR /hr 

Beach 

. __ 

[ ,a~oon Cosmic and natural 3.5 3.5 3.5 

Area-v:eighted mean exposure rates, pR/hr 

rorthern islands 137Cs 11 

r,.\l.lc~-WILMA, but 6OCo ‘21 

,Sscluding JANET) 

sorthern islands 137Cs 15 

(..11,ICE-WILMA, but 6Oco 16 

excluding BELLE 1 

Southern islands 137cs 0.2 

(TOM-LEROY) 60~0 0.1 

aBased upon the mean values reported in the aerial survey section. 

rates based upon the observed soil described in Table 19. The results were 

activities indicate that these radionuclides then combined by “folding” in the present 

contribute at most an additional 3 to 5% of population distribution shown in Table 21. 

the total exposure rate. The contribution Corrections were made for radioactive 

due to these radionuclides was therefore decay but not for possible weathering and 

neglected. Thus, the mean exposure rates subsequent deeper penetration of the 

shown in Table 20 are felt to be the most radionuclides in the soil. The results of 

reasonable values available for computing these calculations are given in Table 22 

integrated dose values. In fact, these and are labeled “unmodified.” Additional 

mean values may be somewhat high (con- calculations were made to ascertain the 

servative), even though the aerial survey effect of reasonable attempts to reduce 

data agree well with the TLD data, be- the exposure rates on the Atoll. 

cause the latter may have slightly over- The first modification, labeled “village 

estimated the exposure rates due to the graveled” in Table 22, reflects the effect 

minimal beta-ray shielding afforded by of covering the village areas with about 

the TLD badges, 2 in. of coral gravel - a common practice 

throughout Micronesia.:” This action can Integral 5; lo-, 30; and 70-yr gammaraY doses for each age group were calcu- ::: 

J. A. Tobin, private communication, 

lated for each case or living pattern 1973. 

-127-
Age croups 

Infants CO-3 yr1 

XIale 

Female 

Children ‘6- 18 s.r) 

Alale 

Female 

:ldults (19-50 3’r) 

Alale 

Female 

:1tlults 1 over 50) 

Wale 

Female 

Total population 432 

On L.,jilang now 310 

be expected to reduce the gamma esposure 

rates in the village area by approximately 

a factor of two. The second and third 

modifications are based upon the assumption that clearing the islands for agricultural use and housing will result in some 

mixing of the top soil. It appears that it 

would be practical during this period to 

also plow many of the more contaminated 

islands to a depth of 1 ft. ilssuming that 

plowing results in mixing rather than 

burying the topsoil, an average reduction 

in exposure rates of about a factor of 

three may be obtained. This reduction 

factor is based upon the present 3- to 5-

cm relaxation lengths (the depth at which 

the activity is e -1 , or 37%, of the surface 

activity) for activity depth distribution in 

the uppermost soil layers of the more contaminated areas. This value, however, 

is highly variable from site to site. In 

Table 22 modification (2) indicates the 

effect of plowing only ,JANET or BELLE, 

rior,zi el‘fect of plo~.:~lnrr all the northern 

iSlZ.nCIS. Deeper ?lo\r~inp or turning oIrCil’ 

the soil rather than mirlnq 11 oulti, of 

course, result in f:<.-en ,grcater exposure_ 

rare reductions. ,L‘or example, mixing to 

a depth of 2 ft wouid reduce the exposure 

rates by an additional factor of two, whilr. 

covering the Sourco5 v:iTh 3pprosimatelv 

1 ft OC uncontaminated soil would essentially reduce the exposure r3tes to 

negligible i,alues similar to those obser-:ed on the southern Islands. Removing 

the top 6 in. of soil, v:hich often contains 

about Two-thirds of the kjctivity, would 

resulr in a threefold reduction in the exposu re rates. The advantages of plowing 

or removing the topsoil should, however, 

be considered on a case-by-case basis 

because of the highly variable distributions of activity with depth. In fact, 

plowing IRENE could possibly increase the 

exposure rates in specific areas due to 

the elevated activity levels beneath the 

surface. 

A review of Table 22 reveals that extensive modifications may not be required 

in order to reduce the dose levels to 

values comparable to typical U.S. values. 

Keeping in mind that Cases I-IV represent 

approximations to the most likely living 

patterns, one observes that even for 

Cases Ia and Ib, the unmodified 70-yr 

integral doses are comparable to the 

U. S. Values,“’ while Cases II and IV 

lead to considerably lower doses. The 

mean integrated doses to the entire population, shown in Table 22, were derived 

H. L. Beck, W. J. Lowder, B. G. 

Bennett, and W. J. Condon, Further 

Studies of External Environmental Radiation, I-SAEC, Rept. H=2SL-170 (1966). 

-128-
I 

‘he addi-

:orthern 

,ning o\‘er 

13, 0 f 

?SPOSU re_ 

mixing to 

CXpOSUre 

TIVO, while 

simatelv 

! essento 

c? obRemoi.inc 

contains 

WOUld 

the esplowing 

lowever, 

basis 

jtribuct, 

rease the 

due to 

h the 

hat exrequired 

to 

values. 

epresent 

1 iving 

or 

-Yr 

the 

The 

? popurived 

G. 

lr 

Fadia-

;6). 

Table 22. Estimated integral external free air gamma doses (I-ads). 

5 

Time 

10 

interval, yr 

30 70 

I 

.I 

1 ,,modified 

(1) Village graveled 

(2) + JANET plowed

(3) + Northern islands 

plowed 

0.76 

(0.627 

(0.4 1) 

(0.30) 

1.37 

7-iX.z 

(0.75) 

(0.56) 

3.12 

m 

(1.77) 

(1.40) 

5.33 

Km 

(3.27) 

(2.76) 

‘I, 8.83 1.49 3.35 5.65 

(1) Village graveled (0.71) 0 (2.89) (4.96J 

i2) 7 J_&KET plowed (0.49) (0.87) (2.01) (3.62) 

I’nmodified 

(3) + Northern islands (0.33) (0.61) (1.50) (2.90) 

plowed 

II 

I‘nmodified 0.38 0.68 1.59 2.97 

(3) Northern islands (0.227 (0.41) (1.08) (2.26J 

plowed 

III 

[‘nmodified 0.60 1.10 2.60 4.60 

(1) Village graveled (0.48) 0 0 

(2) + JANET plowed (0.25) (0.48) (1.26) E . 

IV 

Unmodified 0.14 0.28 0.83 1.92 

V 

Unmodified 2.72 4.78 10.06 15.50 

(1) Village graveled (1.787 mm 

(2) + BELLE plowed (0.83) (3.26) % 

(3) + Northern islands (0.68) (2.77) (4:76) 

plowed 

Mean population dose 

(average of cases Ib-IV) 

Unmodified 0.49 2.09 3.79 

(1) Village graveled (0.43) mm 

(2) + JANET plowed io132j (1.42) K 

(3) + All northern (0.24) (1.17) (2:4 1) 

islands plowed 

Sea level U. S. A. 0.40 0.80 2.40 5.60 

(80 mrad/yr) Typical 

bY averaging those for Cases Ib’ II, III, southern islands are equally likely for 

and IV. This implies that half of the re- both groups. The unmodified mean popturning population live on JANET and the ulation doses are all quite comparable to 

other half live on FRED, ELMER, or U. S. values. At most, implementation of 

DAVID and that trips to the northern or modifications 1 and 2 should be sufficient 

-129-

IV 
- To;al integrated dose, rad 

Group 5 vr 10 yr 30 J-r 70 vr 

Infants 0.6-1 1.15 2.66 4.53 

Children 0.7O< 1.43 3.24 5.52 

YIen 0.82 1.37 3.32 5.61 

\I:omen 0.70 1.42 3.20 5.42 

to assure mean population exposures well .%s illustrated in Table 23 for Case Ia, th? 

below the I. 5. lel-els. Case 1’ repre- differences in radiation exposure of the 

sents 3 “..:‘orst credible” ‘ype of living i-arious population groups are minor, 

pattern \vhich, of course, leads to particularly for the longer time periods. 

appreciably higher doses. Howec-er, even Similar results were obtained for the othe 

in this situation, the modifications can cases, indicating that the exact breakdown 

bring the levels down to the range of U.S. among age groups is not highly important. 

values. The fact that the doses for Cases Ia and 

Because of the low amount of natural Ib do not differ substantially indicates 

radioactivity normally present in the coral that the exact time breakdown among 

atolls, the external dose levels calculated geographical areas is also not critical. 

for Cases I-III and V are still appreciably Table 24 illustrates the distribution of 

higher than corresponding levels found dose with respect to geographical area fol 

elsewhere in the Marshall Islands (essen- Cases I-IV. The large fraction received 

tially Case IV). The results for Cases II while working in the interior or on other 

and IV indicate that restricting the perma- islands reflects, of course, the higher 

nent villages to “clean” southern islands exposure rates present in these areas. 

at least temporarily would result in lower All of the doses discussed so far are 

exposures. Pu’ote that for Case Ib almost due to free-air gamma plus cosmic-ray 

as much exposure is accumulated in the exposures The effect of shielding by 

first 10 years as in the succeeding 20 years. structures or the body itself on gonadal 

Table 24. Percentage of unmodified exposure received from various locales.a 

Case Village Beach Interior Lagoon Other islands 

Ia 47 2 27 1 23 

Ib 36 1 33 2 28 

II 22 2 8 4 64 

III 58 2 33 1 5 

IV 50 5 17 8 20 

aFor 30-yr intervals averaged over population distribution. Percentages for other 

time periods are similar. 

-130-
70 vr 

4.53 

5.32 

5.61 

5.42 

1st I the a’ 

3 of the 

inor, 

oeriods, 

r the othel 

reakdown 

nportant, 

Ia and 

:ates 

ong 

tical. 

on of 

area for 

?ceived 

1 other 

gher 

‘eas. 

r are 

z-ray 

by 

ladal 

a 

Ids 

or hone doses has been !pnored. To condose 1rads) to gonadal ,,C,r,from free- air 

a body-shielding factor of 

(jose (rem), 

o 8 may be used. 

The free-air dose will be additionally 

(,i,Iianced by the presence Of beta rays, 

9*Sr_g*Y ,;*.iginating primarily from 

in the soil. In radiation fields produced

t,y global fallout, where the g”Sr/137Cs 

activity ratio in the soil 1~ normally about 

0.67, the free-air beta dose at 1 m above 

[be ground is expected to be about four 

137 

,imcs that due to the CS gamma rays. 

,jt Enewetak, however, the g”Sr/137Cs 

activity ratios in the soil samples showed 

;I wide range of values with an average 

ratio of about three. Thus, the free-air 

beta dose rates may average about 

600 prad/hr in the interior of JANET and 

about 200 prad/hr in the village area. The 

resulting beta-ray doses to the skin, eye 

lenses, and gonads will be about 50, 25 

and l%, respectively, of the free-air 

valu es. t Thus, appreciable increases in 

skin and eye-lens doses due to the beta 

contribution could be expected. The 

gonadal dose, on the other hand, would 

be insignificant. 

Very little informatlon is available to 

“erifY these calculated beta-ray air doses, 

but indications are that they may be unrealistically high. This is based upon 

data obtained from two LiF TLD badges 

that were equipped with aluminum shields, 

one of which was situated within the 

Report of the United Natlons Scientific 

Committee on The Effects of Atomic 

Radiation, 27th Session, Vol. 1, Supplement No. 25 (1975). 

t K. O’Brien, Health and Safety Laboratory. USAEC, New York, private 

Communication (1973 ). 

interior of ,J_ANET. These shielded badges 

only showed an approximate lO?o reduction 

in exposure rates from those measured by 

the unshielded badges at the same location, thus leading one to suspect that the 

beta air doses are considerably less than 

the calculated values. 

MARINE PROGRALI 

V. Nelson 

Laboratory of Radiation Ecology 

University of Washington 

Seattle, Washington 

V. E. Noshkin 

Lawrence Livermore Laboratory 

Livermore, California 

Purpose 

The mission of the aquatic survey was 

to collect enough sufficiently representative samples to define and’quantify the 

contributing radioactivities in the lagoon 

and reef areas of the Atoll. The radiological data are needed to assess both the 

exposure pathways to persons utilizing 

the aquatic environment and to determine 

the distribution of selected radionuclides 

in the Enewetak marine environment. 

Fish, invertebrates, plankton, and water 

and marine sediment were collected and 

other marine observations conducted 

during October, November, and December, 

1972. This section of the report describes 

the kinds and quantities of samples obtained, the methods of collecting and processing, and the details pertinent to each 

kind of sample or program. 

General Program Description 

Ships and Capabilities 

A 17-ft Boston Whaler was flown from 

.er LLL to Enewetak for the survey of the

-131-
Lagoon. It was powered by a 65-h? outhoard engine and carried a 7.5-hp outboard for emergency use. It was equipped 

with a depth sounder and davit with a handoperated winch and 500 ft of 3/32-in. steel 

cable, sufficient to reach any depth in the 

lagoon. 

This boat was used chiefly for sampling near the shore: its range was 

limIted because it was necessary to remain within sight of land to fix the station 

locations, which was done with a sighting 

compass. \Ve sampled the lagoon between FRED and PEARL, no more than 

6 km from shore; additional collections 

were made between LEROY and FRED, 

including stations in the Wide Passage. 

Sampling by the Whaler crew included 

water collection, sediment collection, 

plankton-tow and mid-lagoon trolling with 

rod and reel. This small boat proved 

very satisfactory for these collections. 

In all, 43 of the 126 sediment grabs, 21 

water samples, many open lagoon fish, 

and several plankton samples were collected by the whaler during the survey 

in spite of bad weather which seriously 

hampered its operation in the lagoon. On 

a number of days, operations were curtailed because of wind and sea conditions. 

A landing craft utility (LCU) was provided for the survey and used to support 

all survey programs. Its use for the 

marine program was on an availability 

basis, but the time allotted was sufficient 

to complete the program. A portable 

winch powered by a gasoline engine was 

mounted on the stern of the vehicle deck. 

The winch contained 1000 ft of 3/32-in. 

stainless steel hydrographic cable which 

passed through a metering sheave 

secured to the port-side davit of the vess-cl. All sampling operations Lvere con_ 

ducted from the port s;lde with equipment 

aTtached to the hydrowire. 

The bridge-height of the LCU was 

sufficient to sight on land from any 

location in the lagoon and the Navy crew 

provided all fixes necessary for locating station positions. Sample depths 

were determined from the wire-out 

readings recorded on the sheave. Water 

samples, sediment samples, and fish 

and plankton samples were obtained. 

Bad weather limited many operations 

from the LCU. 

A 24-ft launch belonging to the 

USAEC has been stored and used at 

Enewetak since May 1972. It is powered 

by two 120-hp inboard-outboard engines 

and is equipped with a depth sounder. 

This boat was used for transportation 

between sampling locations during all 

portions of the Enewetak Survey and for 

the in situ -- gamma probe work. The boat 

was adequate for both purposes, since it 

was large enough to handle the normal 

wind and wave conditions found in the 

lagoon, yet maneuverable enough to work 

in the shallow near-shore waters. 

Equipment and Other Facilities 

Both the Whaler and the LCU had 

complete pumping systems aboard. Surface and subsurface water samples were 

collected with battery-operated pumps 

through a weighted hose-line which was 

lowered to the desired depth. Each 

sampling operation was preceded by pumping for at least 10 min to flush out the 

entire system. The 55 liter black (Deldflc 

polyethylene collection barrels were first 

rinsed with the sample water and then 

filled at the rate of 8 liters per min. 

-132-
I 

15 [vet-c con 

th equ lpme, 

_C C was 

‘ram any 

Navy CreH 

- for locat. 

1 depths 

.Ire -out 

ive. Watel 

and fish 

tained, 

rations 

the 

?d at 

i powered 

i engines 

mder. 

portation 

ing all 

and for 

The boat 

since it 

ormal 

n the 

1 to work 

5-

lad 

Ll. Surs were 

mps 

h was 

oh 

‘y pumpthe 

( DeldrPfl 

‘e first 

len 

1. 

b,,L!!l,lent grab samples x’ere collecled 

,,.),I, , lrhcr Shipek. Ponar, or Ekman 

were collected in ,+Ltlllj)ict-~. Plankton 

\;,,. (; ilr No. 10 nets, 1 m in diam. Fish 

,,.,‘rc i-ollected by trolling with rod and 

,.,\(,l ,h the lagoon or with nets in the shallo,,’ hear-shore areas. Invertebrates were 

I,~,~~Jcollected. Crater sediments in 

\IlliI- .;nd KOA craters were sampled \vith

IRENE* 

Coral Head 0 

(MACK) 

l”if-54 I. Major collection locations (starred) 

Atoll, October to December, 1972. 

-133-

a ” nenthos” model 3 -in. - r!iam gral-ity 

corer. 

Every precaution was taken to ensure 

against contamination of the samples. All 

samples were placed in plastic bags, jars, 

or barrels, immediately after collection. 

After each day’s cruise, all decks and equipment were washed to remove any sediment 

debris accidentally spilled and overlooked,. 

North Pacific Ocean 

OSCAR 

/ 

Wide Passage 

of marine biological samples at Enewetak 
Fish 

Introduction 

There are more than 700 species of 

fish at Enewetak .Atoll, but only a few 

species of reef, benthic, and pelagic 

fishes were selected for use in this study. 

The common anglicized names of the 

fishes are used in the text, but the scientific names and the Enewetakese common 

names, when known, are listed in 

Table 25. The Enewetakese names were 

those used by Smith Gideon, Enewetak 

magistrate, in his conversations with 

Victor Nelson at Enewetak in July 1973, 

and from Goo and Banner (1963). 

The species selected were chosen for 

one or more of the following reasons: 

(1) they are commonly eaten by the 

Marshallese; (2) they are relatively 

aboundant at most of the collection sites; 

(3) they are representative of a feeding 

habit; or (4) there is previous relevant 

radiometric information about the species. 

The species of reef fishes selected as 

being representative of feeding habits include the mullet (a plankton and detritus 

feeder), convict surgeon (a grazing 

herbivore), goatfish (a bottom-feeding 

carnivore) and parrot-fish (a coral eater). 

The tunas, jacks, and dolphins - pelagic 

fish - and the snappers and groupers -

benthic fish - are carnivores of high order 

in the food chain leading to man. Information about the radioactivity in Enewetak 

fish,during the last 25 yr, including the 

species selected for this study, can be 

found in the reports of the University of 

Washington, Laboratory of Radiation 

Ecology, which include the following: 

Held, 1973a; Beasley and Held, 1972b; 

Held, 1971’; Welander, 1967d; Welander 

et al., 1967e ; Held, 

5 

Sample Collections 

Reef Fishes-The nine major collectioo 

stations are shown in Fig. 41. They are 

listed in clockwise order around theAtall, 

and beginning with the most northern 

station are as follows: BELLE, IRENE, 

JANET, TILDA-URSULA, YVONNE, 

aE. E. Held “Fallout Radionuclides in 

Pacific Ocean Tuna,” in Proc. Third 

National Symposium on Radioecology 

lo-12 May 1971 (Oak Ridge, Tennessee) 

CONF 710501, p. 689. 

bT. M. Beasley and E. E. Held, 

“Silver-108m in Biota and Sediments at 

Bikini and Eniwetok Atolls,” Nature 

230(5294), 450 (1971). 

‘E. E. Held, Radiological Resurvey of 

Animals, Soils and Groundwater at 

Bikini Atoll 1969-1970, U. S. Atomic 

Energy Commission, Rept. NVO-269-8 

(1971). 

dA. D. Welander, “Distribution of 

Radionuclides in the Environment of 

Eniwetok and Bikini Atolls, August 1964,” 

in Symposium on Radioecology Proc. 

Second National Symposium, lb-17 May 

1967 (Ann Arbor, Michigan) CONF-670503, 

p. 346 (1969). 

eA. D. Welander et al., Bikini-Eniwetok 

Studies, 1964: Part II. Radiobiological 

Studies, U S Atomic Energy Commission, 

Rept. UWFL’-93 (Pt. II) (1967). 

f

A. H. Seymour “Radioactivity of 

Marine Organisms from Guam, Palau, 

and the Gulf of Siam, 1958-1959,” in 

Radioecology, V. Schultz and A. W. 

Klement Jr., Eds. (Reinhold, New York, 

and Amer. Inst. Biol. Sci., Washington, 

D.C., 1963) p. 151. 

gE. E. Held “Qualitative Distribution 

of Radionuclides at Rongelap Atoll,” in 

Radioecology, V. Schultz and A. W. 

Klement, Jr. Eds, (Reinhold, New York, 

1963) p. 167. 

hF. G. Low man, “Marine Biological 

Investigations at the Eniwetok Test Site,” 

in Proc. Conference on Disposal of Radioactive Wastes, Monaco, Nov. 16-21, 1959 

(IAEA, Vienna, 1960) p. 105. 

-134-
lection 

Y are 

: Atoll, 

n 

XE, 

‘> 

?s in 

i 

_’ 

See) 

at 

9-8 

964,” 

:. 

lay 

7050: 

iwetc 

al 

ssio 

1, 

on 

1 

Jrk, 

31 

te,’ 

adi( 

z 

common, scientific > 2nd Marshallese names and wet weight to dry ,.;,I,)(’ 25. 

ratios of tissues from aquatic organisms collected at Enewetak and 

Kwajalein Atolls, 0c:ober to December 1972. 

Marshallesea Number of 

Scientific name name Tissue samples (.~r,,lr~lOnname 

Fishes 

Nidw a >Iuscle 

Bone 1 

Albula vulpes Muscle 1 

Viscera 1 

(solids and lipids1 

>ic,l),iack Euthynnus vaito Loj Light muscle 9 

Dark muscle 9 

Liver 9 

Bone 9 

i;,,ttcrflyfish Chaetodon auriga Dribob Evisc. whole 1 

Viscera 1 

(‘0nvict surgeon Acanthurus Kuban Evisc. whole 30 

triostegus Viscera 28 

I)nmselfish Abudefduf sp. Entire 1 

I)olphin Coryphaena Muscle 2 

hippu ru s Liver 2 

I%q$ail Kuhlia taeniura Jerot Evis. whole 1 

Viscera 1 

Entire 2 

Goatfish Jome Evisc. whole 1 

Viscera 1 

Goatfish Mulloidichthys Jo Evisc. whole 13 

samoens is Viscera 13 

Goatfish Parapeneus Jerrobe Evisc. whole 4 

barberinus Viscera 3 

Goatfish Jerrobe Eirisc. whole 2 

$Z%% Viscera 2 

Goatfish M. samoensis 8; Evisc. whole 1 

M. auriflamma Viscera 1 

Grouper Epinephelus Momo Evisc. whole 1 

merra Viscera 2 

Muscle 1 

Entire 1 

Bone 1 

Grouper Epinephelus Momo Muscle 1 

spilotoceps Liver 1 

Grouper Epinephelus sp. Momo Evisc. whole 1 

Viscera 1 

Crouper Variola louti Kaikbe Muscle 1 

Liver 1 

Bone 1 

Ufbeak Hemirhamphus K ibu Entire 1 

laticens 

weight 

Wet/dry 

ratio 

4.36 

3.38 

1.57 

3.51 

3.58 

3.60 

3.06 

4.38 

3.54 

5.26 

3.09 

4.01 

3.47 

2.76 

3.09 

3.29 

3.26 

3.65 

3.38 

3.50 

3.78 

4.31 

3.29 

4.03 

3.24 

3.82 

3.28 

3.63 

4.90 

3.37 

4.03 

2.16 

3.50 

3.52 

4.76 

3.04 

4.57 

-135-
Common name 

Jack 

.Tack 

Mackerel 

hlu Ret 

Mullet 

Mullett 

Mullet 

Needlefish 

Parrotfish 

Rabbitfish 

Rudderfish 

Skipjack tuna 

Snapper 

Snapper 

Snapper 

Snapper 

Scientific name 

Caranx 

melampygus 

Caranx 

sexfasciatus 

Grammatorcynus 

bilineatus 

Crenimugil 

crenilabis 

Plicomugil 

labiosu s 

Mugil sp. 

Neomyxus 

chaptalii 

Strongylu ra 

incisa 

Scarus 

sordidus 

Siganus 

rostratus 

Kyphosu s 

cinerascens 

Euthvnnus 

pelamis 

Aphaerus 

furcatus 

Apr ion 

virescens 

Lethrinus 

kallonterus 

Lutjanus 

monostigmus 

Table 25 (continued). 

Marshallesea 

name 

Fishes (continued) 

Deltokrok 

151 

Ikari 

Jomou 

Ikari 

Tak 

Mao 

Elik 

Bagrok 

Chilu 

Eowae 

Jalia 

Tissue 

Muscle 

Viscera 

Bone 

Evisc. whole 

T’iscera 

Muscle 

Viscera 

Bone 

Evisc. whole 

Viscera 

Muscle 

Remainder 

Evisc. whole 

Viscera 

Evisc. whole 

Viscera 

Evisc. whole 

Viscera 

Muscle 

Muscle 

Viscera 

Evisc. whole 

Viscera 

Muscle 

Bone 

Evisc. whole 

Muscle 

Viscera 

Remainder 

Light muscle 

Dark muscle 

Liver 

Bone 

Muscle 

Viscera 

Muscle 

Viscera 

Muscle 

Liver 

Viscera 

Bone 

Muscle 

Viscera 

Liver 

Skin 

Remainder 

Bone 

Number of 

samples 

4 

4 

2 

1 

1 

3 

2 

1 

1 

1 

3 

3 

13 

13 

6 

1 

1 

2 

10 

9 

9 

1 

1 

1 

1 

2 

2 

2 

1 

1 

1 

1 

1 

2 

1 

1 

1 

2 

2 

1 

1 

1 

1 

Wet ‘dry 

ratio . 

-

4.36 

3.73 

3.86 

4.26 

4.10 

3.72 

2.85 

2.68 

3.9-1 

2.40 

3.25 

3.06 

3.76 

2.32 

2.97 

2.83 

3.86 

4.41 

3.67 

3.85 

2.95 

4.92 

3.91 

4.95 

5.69 

3.15 

3.51 

3,55 

3.52 

4.62 

3.69 

4.34 

4.18 

4.78 

3.38 

3.71 

4.34 

3.20 

3.09 

1.91 

2.90 

-136-
I 

-I.36 

3.73 

3.88 

1.26 

1.10 

3.72 

2.2,;; 

2.68 

3.94 

2.40 

3.25 

3.06 

3.76 

2.32 

2.97 

2.83 

3.86 

-1.41 

3.67 

3.85 

2.95 

4.92 

3.91 

-1.95 

5.69 

3.15 

3.51 

3,55 

3.52 

4.62 

3.69 

4.34 

4.18 

4.78 

3.38 

3.71 

4.34 

3.20 

3.09 

1.91 

2.90 

;mpper 

,,, ,-ceonfish 

yli ,.geonfish 

\\ .ihOO 

\!‘r:lsse 

Ycxllowfin tuna 

IJ,nncil urchin 

SC;~ cucumber 

sea cucumber 

+a cucumber 

51*a cucumber 

S(,:I cucumber 

Spincy lobster 

‘Fop snail 

Tridacna 

Table 25 (continued). 

Scientific name 

Marshallesea 

name Tissue 

Number 

samples 

of Wet .‘dry 

ratio 

Fishes (continued) 

Luqanus Ban Evisc. whole 1 3.41 

vaigiensis 

L. monostoemus 1Iuscle 1 4.71 

& L. vaigiensis Remainder 1 3.05 

Ctenochaetuj Evisc. whole 1 3.97 

striatus \.iscera 1 3.16 

Saso lituratus Balak Muscle 1 4.70 

l’iscera 1 5.97 

Remainder 1 2.42 

_Acanthocvbium Muscle 3 3.88 

solanderi Liver 3 2.97 

Goris sp. 1Iuscle 1 4.83 

Viscera 1 3.22 

Bone 1 

Thunnus Pwepwe Light muscle 5 3.78 

albacares Dark muscle 4 3.75 

Liver 5 3.80 

Bone 3 

Invertebrates 

Soft parts 1 2.92 

Hard parts 1 

Actinopygia Evisc. whole 2 6.49 

mauritiana Viscera 2 5.51 

Holothuria atra Evisc. whole 2 8.21 

Viscera 2 2.92 

Holothuria Evisc. whole 3 9.02 

leucospilota Viscera 3 3.32 

Holothuria sp. Evisc. whole 5 7.56 

Viscera 5 5.31 

Unidentified Entire 1 2.26 

Panulirus Muscle 1 4.32 

nenicillatus Hepatopancreas 1 2.94 

Exoskeleton 1 7.61 

Trochus sp. Soft parts 1 4.57 

Tridacna gigas Kabwur Muscle 2 4.29 

Mantle 2 7.43 

Muscle & mantle 4 6.44 

Kidney 5 3.36 

Viscera 5 6.79 

Kidney & 

viscera 1 4.78 

Gills 1 7.82 

-137-
Table 25 (continued). 

lIarshallesea Zumbrr of Wet,/2 

Comrr.an name Scientific name name Tissue sampies ratio‘ 

Invertebrates (continued) \ 

Tridacxa Tridacna sp. hluscle 6r mantle 11 6.17 

Viscera & 

kidney i 5.02 

Viscera ‘7 6.85 

Kidney 6 4.37 

Entire 3 5.03 

Algae 

Calcareous Halimeda Entire 2 2.59 

algae 

Turtle 

Sea turtle Chelonia sp. Muscle 1 7.43 

Liver 1 4.33 

Kidney 1 6.64 

Lungs 1 8.85 

Heart 1 6.49 

Mesenteries 1 24.37 

aMarshallese names from the 1963 unpublished manuscript, “A preliminary compilation of Marshallese animal and plant names,” by F. C. Goo and A. H. Banner, Hawaii 

Marine Laboratory, University of Hawaii, Honolulu, and from personal communications 

with Smith Gideon, Ujilang Magistrate in 1973. 

DAVID, FRED, GLENN-HENRY and (1 species), and 40 other reef fish (12 

LEROY. These areas were selected be- species). The miscellaneous species incause they are potential resettlement cluded flagtail, rabbitfish, wrasse, 

sites and/or were previous collection surgeon, butterflyfish, damselfish, and 

sites. In addition, “control” fish from bonefish. The catch of reef fish by speci 

a noncontaminated area were obtained and location is given in Table 26. 

from Enewetak, Kwajalein, and Meek 

Islands in Kwajalein Atoll. Pelagic and Benethic Fishes - Large 

Most of the reef fish were caught in pelagic fishes (tuna, jacks, dolphins) and 

variable mesh monofilament gillnets benthic fishes (snapper, grouper) were 

25 to 125 ft in length and 6 ft deep. Gill- collected, since they will presumably be 

nets were watched closely and unwanted captured and eaten by the Enewetak peopl 

fish were usually released alive. Throw- and they represent carnivores of high 

nets were also used in some instances. order in the food chain leading to man. 

In most cases, these methods of capture They were collected primarily on sportaliowed us to collect only fish which were fishing gear, using feathered jigs and 

needed for analysis. spoons as lures while trolling in the la@ 

The total catch was about 200 mullet and in the passes leading to the ocean. 

(4 species), 100 goatfish (4 species), 400 Most of the large yellowfin tuna and dolP 

convict surgeon (1 species), 40 parrotfish were caught in the passes between the 

-138-
[ilet ‘dr...’ 

ratio 

. 

6.17 

5.02 

6.85 

4.37 

5.03 

2.59 

7.43 

4.33 

6.64 

8.85 

6.49 

24.37 

compilaHawaii 

nications 

h (12 

ties ine, 

h, and 

)y specie 

Large 

ns) and 

were 

lbly be 

k people 

!igh 

nan. 

iportand 

\e lag@ 

?an. 

d do@ 

the 

lumber of organisms c:ollected z.: Enewetak Atoll and Kwajalein -Atoll near- !~>,},l(~ “fi. -snore sites, October to December 1272. 

l<leoon and the ocean, 

skipjack, mackerel, 

,n the lagoon proper. 

troupers were caught 

~~:~ter of the reef and 

K;Iters. The number 

fl.sh caught is given 

Sample Analyses 

Field Processing 

fish were segregated 

fish, mullet, etc.), 

and transferred 

cjry ice as soon 

sifter collection). 

most fish were 

to 

as 

while the smaller 

and ulua were caught 

The snappers and 

in both the shalIow 

the deep lagoon 

of large carnivorous 

in Table 27. 

- After capture, 

by type (e. g., goatplaced in plastic bags, 

ice chests 

practical (1 

At the main 

frozen, either 

containing 

to 4 hr 

camp, 

in dry ice 

()r In freezer units. Occasionally, fish 

\v(‘rc dissected fresh, the tissue dried, 

;Ind then frozen, 

C)riginally, it was planned that most 

Of the marine biological samples would 

be processed at Enewetak by people from 

the Laboratory of Radiation Ecology. 

However, the disruption to the program 

caused by Typhoon Olga made sample 

processing at Enewetak impractical; 

therefore, the majority of the samples 

were processed at the home laboratory 

in Seattle, Washington. 

Laboratory Preparati.on - The samples 

were frozen at Enewetak and remained 

frozen until processed at the Seattle 

laboratory. To begin preparation of the 

samples for analyses, the fish were 

partially thawed and dissected into the 

tissue types shown 

types chosen were 

estimation of the 

of sufficient size 

in Table 25. Tissue 

those most useful for 

radiation dose and were 

to yield a dried sample 

of adequate size for gamma spectroscopy or radiochemical analyses. After 

139-
Table 27. Sum’:er of carnivorous fish collecTed from the Enewetak and Kwajalein off_ 

shore :zgoon sites, October to December 1972. 

Collection YellLivfin Organism 

site ::: na skipjack Mackerel Dolphin Snapper Grouper Ulua Total 

-

Enewetak I: I) 3 2 8 8 8 40 

Kwalalein i 1 2 6 

-

Total r. 10 3 2 8 10 8 46 

dissection, the rissues were dried at 

about 80°C until 2 constant dry weight 

was reached. T..;:o to three days were 

usually required for this process; oily 

samples (viscera, liver) took longer. 

The dried samples were then ground 

in a food blender and packaged in standardsize containers for gamma counting. 

Packages were of two basic types. Dried 

samples larger rhan 25 g were packaged 

in containers made from sections of polyvinyl chloride (PVC) pipe. The PVC 

sample holders were of two sizes - 2-in. 

diam by 1 l2-in. high for 25-g samples 

and 2 in. by 1 in. for 50-g samples. Dried 

samples were placed in the sample holder 

and then compacted with a press to conform to the dimensions of the container. 

The amount of sample used was the amount 

required to yield a sample density within 

the container of 1.1. Dried samples less 

than 25 g were packaged in plastic petri 

dishes of two sizes (23 cm3 and 6 cm31. 

These samples were not compacted and, 

therefore, the sample weight was not 

constant; however, sample density was 

calculated from the weight and volume. 

Counting Methods - Packaged samples 

were shipped to Lawrence Livermore 

Laboratory for gamma spectroscopic 

analyses. _%fter gamma analysis, most 

marine biological samples were analyzed 

55 90 for Fe, Sr, and 23gPu. These analyses were done at the Laboratory of 

Radiation Ecology (LRE), Lawrence 

Livermore Laboratory (LLL), McClellan 

Central Laboratory (MCL), and LFE 

Environmental Laboratory (LFE). A 

limited number of samples were analyzed 

for 113mCd 12g1 14C 151S, 147p, I 9 > 

63Ni, and 3H. Detailed descriptions of 

methods used for these analyses are 

given in the section on the Analysis 

Program. 

Results and Discussion 

The fish samples have been analyzed 

for gamma-emitting radionuclides, 55Fe, 

90Sr, and 23g~u. The gamma-emitting 

radionuclides detected by the Ge(Li) diodr 

system included naturally occurring 4oK 

and 228 Th and fission and activation 

60co 65Zn 10IRh 102mRh products - , , 

’ 1553, (’ 108mAg, 125Sb, 137Cs, 152Eu, , 

207Bi > and 241Am . It should be noted 

that the radioactivity values for the fish 

are given as of the date of collection in 

terms of dry sample weight but can be 

converted to wet weight values by use Of 

the conversion factors given in Table 25 

for all samples except bone. The result! 

I140-
zin off_ 

-

Total 

40 

6 

46 

most 

nalyz ed 

;e analof 

‘1~ e 

,Clellan 

FE 

A 

analyzed 

47PIll, 

Jns of 

are 

Jsis 

ilyzed 

;> 55Fe, 

1 itt ing 

,i) diode 

4oK ng 

On 

)2mRh, 

55Eu,. 

:oted 

.e fish 

on in 

.n be 

use of 

.ble 25 

results 

2 are usually- in terms of )r !I,,’ ,mlvseram of dry tissue because ,,:,.oc,lIf~~~ per g 

: !,(’ I I-II c ?r;et lr,elght of some samples is 

i,Tf,c.,,![ to determine. 

‘1.1,~ kwaJale!n data are presented in 

:ables since the number of a!:!\ tn’o 

,~llnples is relatively small, but the 

!::,(,,(!Ctak data have been grouped into 

,,.p;arat~ tables by species. 

K\v;ilalein Atoll - KwaJalein is environ-

,:,,,,r,tL1llvsimilar to Enewetak, but has not 

,,,,,,,, cc,ntaminated by radionuclides from 

:,I,-;ll fallout. Saturally occurring radio-

:;:!c.licjes and radionuclides from world-

,r,I1c> fallout are present in Kwajalein fish 

,I,c1 s;lmilar quantities would be expected 

!,I I,:newetak fish. Hence, the Kwajalein 

f,.-;ll can be considered as “control” fish 

.,JI[~the difference in the radioactivity of 

:h(, Kwajalein and Enewetak fish of simi-

;.l,- type is an estimate of the contribution 

:,f the nuclear testing program at Enewetak 

I\toll to the radioactivity in the Enewetak 

fish. 

Not all of the species of fish collected 

nt I,:newetak were collected at Kwajalein. 

The catch at Kwajalein included convict 

SurEeon, parrotfish, yellowfin tuna, 

tlolillo, and groupers, but not mullet, 

coatfish or snappers (Tables 26 and 27). 

The results of the analyses are tabulated 

in Tables 28 and 29. 

Reef fish - Reef fish from Kwajalein 

:itoll had tissue concentrations of naturally 

occurring 4oK which averaged 15 pCi/g, 

?f, and ranged from 7.3 to 52 pCi/g, dry 

(Table 28). These concentrations are 

‘lightly higher than values found in fish 

lrorn Enewetak Atoll. In addition, 2 of 16 

fish from Kwajalein Atoll had 125Sb (0.21 

and C.25 pCi,‘g in kuhlia and convict 

surgeon) and one rabbitfish had 0.11 pCi 

137 of Cs per gram of dry tissue. Similar 

or higher concentrations of 125Sb and 

137 Cs were found in Enewetak fish 

samples. Levels of 125Sb are not included in the tables of the radionuclide 

concentrations in the Enewetak fish because they appear on such a sporadic 

basis. 

Cobalt-60, one of the most abundant 

gamma-emitters found in the Enewetak 

fish, was not stected In fish from 

207Bi Kwajalein. Europium-135 and , 

both commonly present. in Enewetak fish, 

were also absent in fish from Kwajalein. 

In the samples analyzed, the average 

55 Fe value was less than 1 pCi/g, dry, 

55 while the highest Fe \:alue was about 

13 pCi/g, dry, in the reef fish and 

83 pCi/g, dry, in the light muscle of a 

55 wahoo. These Fe levels are at or below 55 Fe concentrations found in similar 

species from the southern sector of 

Enew etak _At 011. 

Strontium-90 levels were all less than 

0.5 pCi/g, dry. Plutonium-239, 240 

concentrations ranged up to 0.5 pCi/g, 

dry, in a halfbeak from Kwajalein Island, 

but most other samples had less than 

0.1 pCi/g, dry. 

Lagoon fish - The background levels 

of 4o K in tissues of lagoon fish from 

Kwajalein (Table 29) tissues averaged 

14 pCi/g, dry (range, 3.1 to 23 pCi/g, 

dry). Eight of 26 samples had detectable 

levels of 137 CS, averaging 0.17 pCi/g, 

dry (range of 0.12 to 0.22 pCi/g, dry), 

which was slightly above the mean limit 

of detection, 0.13 pCi/g, dry, found for 

the other 18 samples. Two skipjack and 

-141-
Table 28. Radionuclides in reef fish and tridacna clams collected at I<wajalein Atoll, l>ocember 1972. 

Sample 

number Island Organism Tissue 4OK I 2FJs, 

8007 

8006 

Enewetak 

Enewetak 

Convict 

surgeon 

11. whole’) 

Viscera 

9.0 t 

52 t 

1.1 

6.U 

0.18 

I.!) 

t 

I 

0.011 

0.5 

co.17 

< 0.05 

0.21 

1.5 

I 0.1n 0.0 :3 I 

O.,lI I 

0.0 1 

0.1:1 

8008 

8011 

8010 

Enewetak 

Enewetak 

Enew etak 

Damselfish 

Parrotfish 

Parrotfish 

1:nt ire 

E. whole 

Viscern 

15 

15 

NC” 

1 1.8 

f 1.3 

O.fiU 

0.16 

0.86 

f 0.1-1 

f 0.08 

t 0.30 

--0.14 

CO.18 

‘: 0.40 

().:$!I 

‘X 0.23 

0.79 

0.117 

‘. 0.02 

0.01 

I 0.0.1 

0485 

0487 

0486 

Kwajalein 

Kwajalein 

Kwajalein 

Convict 

surgeon 

E. whole 

E. whole 

Viscera 

7.7 1 

13 1 

16 1 

1.3 

1.0 

1.4 

0.12 zt 0.03 

1.4 f 0.2 

0.511 i 0.09 

< 0.14 

<0.1:1 

c 0.20 

< 0.26 

co.15 

< 0.30 

s’ 0.05 

0.0.1 

0.25 

I 

t 

o.o:< 

0.01i 

8013 

8012 

Kwajalein 

Kwajalein 

Convict 

surgeon 

E. whole 

Visctxra 

16 

NC 

f 2.6 

I :j 

-

! 0.5 

co.19 

,’ 0.17 

c: 0 .4 8 

0.7:) o.of; 

_ 

t o.o:i 

0763 

0766 

Kwajalein 

Kwajalein 

Grouper 

(E. merra) 

Snapper 

(L. vaigiensis) 

Icntirc 

1:. whole 

7.3 t 

11 I 

1 .o 

1.1 

0.3(i 

1.!1 

I O.O!) 

I 0.3 

._ 0.0.4 

.’ 0.07 

0.11 

,’ 0. I :; 

0.0 I 

0.02 

2 

W 

I 

07 64 

8003 

8004 

Kwajalein 

Kwajalein 

Kwajalein 

IIalfheak 

Kuhlia 

Ku hlia 

Is:ntirc: 

Entire 

Entire 

!I.2 I 

9.8 i 

NC 

1.1 

1.1 

-

-

0.50 k 0.31 

‘. 0.0 !-) 

CO.16 

< 0.03 

0. I:! 

0.25 

= 0.09 

! 0.10 

0.0 I 

0.0 2 

‘.: 0.0 1 

I 0.0 1 

0765 Kwajalein Rabbitfish E. wholed 13 i 1.6 - < 0.07 ,: 0.13 < 0.01 

0767 

0768 

Kwajalein 

Kwajalein 

Tridacna 

Tridacna 

Muscle and 

mantle 

Viscera 

and kidney 

12 

13 

f 

t 

2.3 

1.6 1.3 

-

i 0.1 

0.22 

2.x 

f O.O!) 

i 0.20 

0.17 

(’ 0 .3 2 

0.00 I 

0.0 ‘1 

o.::i 

0 I .J 

I O.OI 

I CJ.(ll 

aError values are one-sigma, counting errors. 

bEviscerated whole is the entire fish, less the viscera. 

cNC = not computed. 

dThis sample also contained 137Cs (0.11 k 0.05 pCi/g, dry). 
Sample 

number Island 

Common 

name 

074 1 

0742 

0740 

0773 

Kwajalein 

KwaJalein 

Kwajalein 

Kwajalein 

Skipjack 

Skipjack 

Skipjack 

Skipjark 

L,ight 

Dark 

Liver 

Hone 

muscle 

muscle 

11 

14 

NC 

NC 

1 1.3 

i 2.0 

2.11 i 0.1 

12 t 0.1 -

2.1; t 0.2 

NC” 

NC 

NC 

NC 

0.02ti 

0.07 

0.40 

n.11 

I n.o\:I 

I 0.05 

I 0.03 

0779 

0780 

0778 

0777 

Kwajalein 

Kwajalein 

Kwajaleln 

Kwajalein 

Skipjack 

Skipjack 

Sklpj& 

Skipjack 

L,ight 

Dark 

Liver 

Bone 

muscle 

muscle 

‘I.1 t 

12 * 

7.7 i 

NC 

1.5 

1.0 

I.4 

2.0 

12 

0. 7 

4.7 

t 0.1 

t 0.6 

f 0.1 

f O.-l 

NC 

NC 

i .I( 

NC 

t 0.3 

,.’ I). I 2 

,:’ 0 . I 1 

h. (J.oii 

,' 0.21 

0.01 I 

,- 0 . 0 I 5 

c 0.022 

co.015 

O.OOi, 

0.15 

o.no5 

0.15 

! 0.00 I 

, 0.12 

! o.noi 

! Q.OI 

0595 

0594 

0595 

Meek 

Meek 

Meek 

Skipjack 

Skipjack 

Skipjack 

Light 

Dark 

Liver 

muscle 

muscle 

12 

11 

12 

t 

t 

I 

1.7 

1.3 

1.7 

7.2 

30 

1 3 

i 

f 

I 

0.5 

0.9 

1.:i 

NC 

NC 

0.5 I 0.2 

(0.09 

CO.10 

().()I: 

0.02!, 

0.02 

0.0 1 I 

I 0.002 O.OO’l I 0.00:~ 

0.011: I i).l)Ol 

o.oof; I o.oo:! 

0583 

0584 

Meek 

Meek 

Wahoo 

Wahoo 

Light 

Liver 

muscle 17 

14 

i 

f 

1.2 

1.4 

8 3 

11 

f 

* 

0.a 

1.0 

N c 

NC 

0.12 

0.19 

f 0.0-l 

! 0.07 

0.008 

< 0.026 

* 0.00 0.012 

0.001; 

I 

1 

O.rJK? 

n.on:j 

I 

z 

w

I 

0585 

0586 

0771 

0772 

Meek 

Meek 

Meek 

Meek 

wahoo 

Wahoo 

Wahoo 

Wahoo 

Light 

Liver 

Muscle 

Liver 

muscle 18 f 

23 i 

13 * 

3.1 i 

1.5 

6.2 

1.4 

1.0 

-

-

0.24 i 

26 t 

0.04 

0.11 

NC 

NC 

NC 

0.4 I 0.1 

0.111 

I’ 0 .2 tl 

‘. 0.0;) 

c 0.05 

F 0.05 ,c’ 0 . 0 0 G 

0.039 * 0.020 

0011 to055 

0:004 I 0:002 

0.00-I 

0.16 

0.05 

0.034 

! o.oo:i 

! 0.00 

I 0.002 

I 

0542 

0462 

0463 

Kwajalein 

Kwajalein 

Kwajalein 

Y ellowfin 

Y ellowfin 

Y ellowfin 

Light 

Liver 

Bone 

muscle 1 I$ 

20 

NC 

1 1.2 

I 3.U 

0.01 

7.2 

1.7 

I 0.4 

i 0.3 

INc . N C: 

NC 

0.22 

~ ().I!1 

c 0. I f, 

O.Ofi 0.01 

0. I I 

0. u 7 

I 

t 

o.o:j 

0.04 

0.007 

0. IO 

0.024 

! (1.011:! 

/ ll.ll:! 

: 1).01)., 

0587 

0588 

0589 

Meek 

Meek 

Meek 

Y ellowfin 

Y ellowfin 

Y ellowfin 

Light 

Dark 

Liver 

muscles 

muscle 

1.4 

11 

18 

I I.0 

t 1.2 

I 2.2 

1.2 

1 II 

! 0.1 

I O.!) 

NC 

NC 

NC 

0. I (i 

0. 1 !I 

0.12 

! 

’ 

n,o-I 

0.05 

‘- n.nn!~ 

O.OO!l 

0.01 I 

0.003 

n.006 I 0.001 

0.01:~ I ll.oo:i 

0591 

0590 

0592 

Meek 

Meek 

Meek 

Y cllowfin 

Y ellowfin 

Yellowfin 

L,igllt 

Dark 

Liver 

m11sc1~~ 

muscle 

12 

20 

19 

t 

I 

f 

I.11 

1.5 

5.1 

I.0 

1 .II -

IO.1 

t O.!J 

NC‘ 

NC 

NC 

’ 

i 

O.O!I 

0.10 

0.2-1 

0.00~I 

0 . 0 I 4 

0.12 

! 0.0011 

O.Ol 

0. I I 

0. In 

1 I 

! 

I 

o.llll:! 

‘rr.ot 

0.0 I 

aError values are 

bNC = not computed. 

one-sigma, counting errors. 
one wahoo had 65Zn concentrations in 

their liver tissue of 1.8, 0.5, and 0.4 

pCi/g, dry, respectively. Zinc-65 levels 

were not computed in the other 23 samples 

because the levels were below the limits 

of detection_ As for the Kwaialein reef 

fish, no 6oc~, 153~u, or 'O'Bi was 

detected in any of the 26 lagoon fish 

239, 240pu samples analyzed. The highest 

and go Sr levels in Kwajalein fish appear 

to be similar to average levels found in 

fish from the southern portion of Enewetak 

Atoll. 

Enewetak Atoll - The results of the 

gamma-spectrum analyses grouped by 

Column legend 

A 55Fe - eviscemted whole 

B 55Fe - viscera 10,000 -

c 6oco - viscem 5,000 -

3,000 - D 6oCo - eviscemted whole 

1,000 -

500 -

300 -

100 -

50 -

30 -

. 10 -

5-

3-

1.0 -

0.5 -

0.3 -

t 0.1 ’ Bc 

species - goatfish, convict surgeon, mul_ 

let, parrotfish, snapper, grouper, ulua 

and tuna - are given in Tables 30 to 36.’ 

When some samples in a group of samples 

which were averaged did not have detect. 

able levels of a radionuclide, the limit 0t 

detection value was used. For example, 

in a group of four samples of eviscerated 

goatfish from DAVID, three samples had 

net ‘O Co values greater than the one 

standard deviation propagated counting 

error (0.98, 0.65, and 0.48 pCi/g, dry) 

and the other sample had a limit of 

detection of 0.16 pCi/g, dry. For this 

group of four samples, the mean value 

was 0.57 pCi/g. 

fish 

fish Mean 4o K concentration 

-< 

D L 

BELLE ENE INNI AVID FRED GLENN NR Y LEI 

Collection site 

55

Fig. 42. Average Fe and ” Co concentration in goatfish from Enewetak Atoll, Octc 

to December, 1972. The 40K v a 1ue is the mean from all goatfish samples. 

-144-
-- - 

1 

3le.s had 

one 

., 

lnting 

dry) 

r 

of 

this 

value 

N -

d 2: 0, 

LEI 
Table 31. Predominant radi;nuclides in convict surgeon collected at Enewetak Atoll, October to December 1.972. -

Radionuclide average f deviationa in pCi/g, dry 

No. of 137Cs 1 5 5 ,,‘,I DO 230,240 Island Tissue samples 4oK 55Fe GOCo 207T3i Sr I ‘II 

J3ELLE E. whole 3 11 f 3.1 12 ( 0.6 2.3 I 0.4 1.1 I 0.2 ,:I 0 .o !I 0. 1 I 1 0.0 5 I).!rl I o.o:i fl.11’7 I ~I.fll: 

ViSCcr:l 3b 14 f 11 150 I 50 I 0 I 2.4 1.0 f 0.U 0.4!) I O.lJ!l 2.0 I 1.b I .!I I 0.7 I .:I I 0.4 

IRENE E. whole 1 13 f 1.1 10 f 0.1 28 f 0.4 G.7 f 0.2 < 0.14 0.15 1.2 1 O.OG 0.11 I 0.01 

Viscera 1 14 f 2.0 160 -I 12 210 f3 6.0 f 0.4 5.8 t 0.3 1.1 f 0.2 I7 i 1 I5 t I.5 

JANET E. whole 2 9.6 t 0.7 5.4 L 2.0 0.22 i 0.02 0.23 f 0.03 ‘. 0.04 j 0.01 0.03 to.01 0.31 i 0.01 0.03 I o.o:i 

Viscera 2 10 f 0.8 28 f- 4.2 0.96 f 0.20 0.16 f 0.12 0.17 1 0.10 0.20 -F 0.01 0.17 f o.o‘l 0.3G i 0.25 

URSULA E. whole 3 8.9 f 1.2 3.0 t 0.9 0.22 f 0.08 0.17 f 0.07 -:0.01 i 0.01 ‘-0.02 f 0.01 0.25 1 0.28 0.071 t O.Ofli 

Viscera 3 14 It 4.8 19 t 7.8 0.98 f 0.37 0.19 * 0.10 0.18 f 0.15 0.17 f 0.09 0.23 f 0.06 0.81 I 0.02” 

YVONNE E. whole 3 8.2 * 0.7 1.9 f 0.8 1.2 f 0.6 0.58 f 0.2-1 ,-:0.04 f 0.01 ,‘0.02 1 0.01 O.lII f 0.22 0.022 I 0.01 (i 

Viscera 3 10 f 3.3 2.8 t 6.4 5.7 f 1.6 0.72 f 0.25 0.20 1 0.0:) 0.33 1 0.24 0.17 1 0.01 O.GO f 0.4:i 

DAVID E. whole 4 10 f 3.4 1.6 f 0.7 0.21 f 0.09 0.13 i 0.05 ‘CO.13 .t 0.08 ,:o.ou * 0.05 0.08 f 0.10 0.02G ! 0.0111 

Viscera 4 17 f 3.4 17 f 4.3 2.1 f 2.1 0.14 k 0.08 <O.lG k 0.13 0.21 f 0.04 0.42 f 0.23 0.031 t 0.010 

FRED E. whole 3 11 f 2.9 0.33 k 0.2 <:0.10 f 0.05 0.11 t 0.04 <o.oo 1 0.05 -0.05 k 0.03 0.02 1 0.01 0.08 k 0.09 

Viscera 3 12 f 3.8 3.1 f 0.8 0.57 * 0.19 0.09 f 0.04 co.10 1 0.05 c 0.10 f 0.05 0.05 * 0.02 0.031 t 0.0x.3 

GLENN E. whole - 1 11 f 1.2 0.4 1 0.40 0.18 t 0.03 s-o.17 O.OG f 0.02 sx 0.01 O.!IL) I O.OL’ 

Viscera 1 16 f 0.7 12 -f 0.7 3.3 f 0.08 0.15 f 0.04 < O.OG 0.74 f 0.04 ,‘0.20 0.05 ! 0.01 

HENRY E. whole 3 8.9 f 0.7 8.2 f 0.5 0.47 I 0.32 0.10 k 0.05 co.09 * 0.07 ,-0.15 IO.00 0.02 f- 0.01 0.074 t 0.12 

Viscera 2 11 f 1.3 78 * 3.5 2.0 f 2.6 0.15 f 0.09 < 0.13 t 0.02 0.96 f 0.02 0.02 -f 0.01 0.0.15 t o.on-i 

LEROY E. whole 3 10 t 3.5 16 i 6.0 1.0 f 0.3 0.16 k 0.05 <0.08 f O.Ofi 0.25 f 0.07 0.1.1 L 0.07 0.0011 I O.OOL’ 

Viscera 2 13 >l 160 i 40 3.4 k 4.2 0.26 f 0.20 kO.13 3.1 f1.7 0.24 f 0.03 0.27 I 0.15 

-

aSingle sample error values are one-sigma counting errors, while error values for two or more samples are one sample starxlarrl clt:vi:\tir)n 

without consideration of counting error. 

b 24 1 Two samples of viscera from convict surgeon collected at l3l:I,J,J: harl an average Am l(:vc~J of 0.7.1 [‘(‘i/g, t1l.y. :~fn~~t~ic~llitr~-2~11 w;v_, ,SIL)O 

found in two samples of viscera from IJRSIILA (average, 0.34 pCi/g, dry) and one sample of visrcrn frorrl YVONn’i:: (3.7 pCi/q, (fry). 
4 

‘. Table 32. Predominant radionuclidcs in mullet collcctecl at I,;nev.‘ctak Atoll, 0~ tol)cr to l)*accm\)+:r 1!)72. --___ 

Island Tissue 

No. of 

samples 4oK 

Radiontrrlide, 

55Fe 

average 

G°CO 

i standard 

l3?Cs 

clc~:iation ” in 

155[:u 

p(Il/g, ‘Iry 

20713i OOSr ZLi’J,UO 1’U -

BELLE Muscle 

E. whols 

Viscera 

1 

3 

3 

15 f 

6.9 f 

4.5 f 

1.2 

2.3 

0.4 

6.8 

7.1 

100 

f 

f 

f 

0.2 

0.6 

fro 

3.7 

2.8 

9.4 

& 0.2 

f 0.3 

f 2.3 

0.63 

0.34 

1.5 

f 0.09 

-t 0.10 

+ 0.4 

< 0.10 

10.05 

3.0 

1 0.01 

t 0.2 

0.13 

I. 0.05 

O.Gl 

f 

f 

I 

0.05 

0.03 

0.16 

0.16 

6.1 

-

1 0.04 

I 1.11 

0.006 

0 .n-1 

#.I) 

f 

t 

I 

0.001 

0 .o:3 

“.(I 

IRENE Muscle 

E. whole 

Viscera 

1 

1 

1 

15 * 

5.2 f 

3.5 f 

1.3 

1.0 

1.6 

14 

13 

220 

k 0.56 

f 0.4 

-t 0.1 

20 

18 

90 

i 

* 

f 

0.5 

0.5 

1.1 

4.3 

1.8 

D.fl 

t 0.2 

+z 0.2 

t 0.5 

< 0.14 

< 0.14 

22 t 0.3 

0.20 

0.14 

2.2 

f 0.0:) 

i 0.2 

0.0 1 

0.06 

0.02 

f 0.01 

0.020 

0.19 

24 

I O.OO:$ 

4 0.01 

t 0.5 

JANET Muscle 

E. whole 

Viscera’ 

2 

2 

2 

10 f 

3.9 f 

3.9 f 

1.5 

1.3 

0.1 

1.3 

1.4 

19 

I 0.4 

I 0.4 

i 0.7 

0.4‘1 

0.23 

1.1 

1 0.~10 

f 0.1 I 

* 0.6 

0 . I :I 

0. I:, 

0.06 

! 0 .03 

F 0.08 

i 0.04 

0. 1 I 

co.10 

c’O.03 

I 0.0 fi 

! 0.07 

? O.OG 

O.O!i 

’ 0.05 

,c 0.04 

I 0.03 

t 0.03 

t 0.01 

0.05 1 0.01 

0.0 3 I 0.0 3 

0.46 I O:i7 

0.00 I 

0.017 

0.2 !I 

I O.llfl I 

I O.OIli 

I o.:((l 

TILDA Muscle 

E. whole 

Viscera 

1 

2 

2 

17 *2 

7.4 f 3.4 

4.7 f 0.9 

1.9 

1.3 

13 

* 

f 

f 

0.3 

0.5 

16 

co.19 

co.17 

0.79 

f 

f 

0.02 

0.13 

co.12 

co.10 

0.08 

f 

f 

0.01 

0.02 

< 0.15 

co.15 

0.18 

i 

f 

0.01 

0.03 

,: 0.0 8 

( 0.07 * 0.02 

0.06 f 0.01 

~’0.03 

0.05 

0.56 

* 0.05 

f 0.16 

’ 0.027 

5 .8 

0.63 

t II 

t 0.29 

1 

YVONNE E. whole 

Viscera 

3 

3 

6.6 f 

5.2 f 

1.8 

1.9 

0.95 

11 

t 

f 

0.82 

8.6 

co.13 

2.2 

f 

i 

0.04 

1.8 

‘_ 0.07 

0.12 

* 0.01 

t 0.04 

0.03 

0.70 

f 

f 

0.02 

0.27 

0.0 1 (i f 0.0 I <i 

3 . II f 4.7 

2

4 

1 

GLENN E. whole 

Viscera 

1 

1 

7.2 f 

5.5 f 

1.6 

1.2 28 

-

i 1.1 

,: 0 . I 6 

0.17 1 o.o:j o.n:c 

1.U to.1 

0.01 

0.26 j 0.02 

(I.fi3 

0.30 

I O.OI 

I 0.02 

HENRY E. whole 

Viscera 

4 

4 

6.3 f 

4.2 f 

1.1 

0.5 

2.7 

21 

i 0.8 0.10 

0.11 

t 0.06 

f 0.07 

0.04 

0.13 

f 0.01 

t 0.05 

0.07 

0.01 

f 0.07 

I 0.01 

fl.Oll 

o.:iir 

I O.OlO 

I o.l;rl 

LEROY Muscle 

E. whole 

Viscera 

2 

3 

3 

11 f 

6.6 f 

3.6 f 

1.6 

2.9 

0.0 

4.1 

32 

92 

k 0.0 

f 48 

1 63 

co.11 

~-0.10 

0.20 

t o.otj 

! 0.04 

t 0.05 

0.06 t 0.04 

0.05 f 0.03 

0.73 t 0.1)) 

0.07 f 0.0-l 

0.04 t 0.02 

0.:111 I 0.22 

0 . :j -1 t 0:lll 

O.r)Oi / O.Ofll 

o.:I:( t 0.1.1 

aSingle sample error values 

without consideration of counting 

b The viscera sam les from 

YVONNE also had 2g 1Am levels 

are one-sigma 

error. 

BELLE also 

of 0.22 and 

counting errors, while error 

24 1 had an average Am level of 

1.6 pCi/g, dry, respectively. 

values for 

4.0 pCi/g, 

two 

dry. 

UT more samples are 

0ne viscera sample 

oncx 

from 

sample 

l’II,DA 

st:incl;lrll (lcvi;~t~on 

an(l three! from 
••

Table 33. Predominant radionuclides in parrotfish collected at Enewetak Atoll, October to I>eccmber 1072. 

Radionuclide, average k standard deviation a III pCi/g, dry I__--

No. of 4oK Island Tissue samples 

BELLE E. whols 1 12 k 1.1 13 f 0.4 4.4 t 0.1 3.0 t 0.1 c 0.06 0.04 0.75 I o.o:, o.o:! I I).OOL’ 

Viscera 1 21 f 5.3 150 t 5.0 13 I 1.0 2.5 I 0.5 1.2 I Il.(i 0 . ” ‘5I :,.:i 1 o.:<o Z.!) I n.:lo 

JANET Muscle 1 22 f 1.6 0.3G zt 0.04 c 0.23 0.!16 i 0.00 0.12 0.07 O.Oli 0. I 4 IO.12 

Viscera 5.6 f 1.0 14 f 0.5 0.39 k 0.12 0.25 f 0.07 0.17 t O.Oti I’ 0.07 I.9 10.1 0.24 I n.01 

Bone NCc 1.3 k 0.6 x: 0.31 ~ 0.2fj 0.44 0. I II o.“‘/ 1 0.12 . . &, 

() ‘2 ‘, 

TILDA Muscle 22 f 1.6 0.12 k 0.07 i 0.20 0.42 t 0.07 -.O.lO 0.02 ‘. 0.03 0.05 1 0.01 

Viscera 6.7 k 0.8 4.9 f 0.1 0.36 t 0.10 0.12 f 0.01 0.20 t O.OG s: 0.05 s: 0. 1 f% 0.45 t 0.01 

Bone NC 0.76 f 0.20 CO.16 <:0.13 c 0.02 0.11 ~:0.12 0.018 t 0.003 

YVONNE Muscle 19 f 6.4 0.15 f 0.04 CO.16 * 0.03 0.49 f 0.30 co.10 f 0.05 < 0.06 k 0.01 0.02 t 0.01 0.02G 10.021 

Viscera 6.7 f 0.8 7.5 f 3.2 2.5 f 2.9 0.20 f 0.16 0.88 k 0.66 O.GS f 0.87 0.42 t 0.30 1 .fl i 2.0 

Bone 8.1 f 0.7 2.0 f 2.2 0.30 f 0.16 co.12 -f 0.01 co.07 f 0.01 0.08 f 0.01 0.07 j 0.03 2.5 

DAVID Muscle 14 f 5.7 < 1.7 co.05 f 0.02 0.07 * 0.06 <0,04 f 0.01 0.03 f 0.01 CO.18 :: 0.01 

Viscera 9.4 f 3.7 4.6 t 3.6 0.33 f 0.22 co.09 f 0.04 co.10 k 0.03 0.10 i 0.02 0.17 I 0.21 O.lS i 0.21 

Bone 11 f 1.4 < 5.5 ~-0.22 f 0.13 0.16 k 0.10 0.26 t 0.16 I. 0. I1 t 0.01i 2.2 12.4 0.03:j I 0.0011 

I 

z 

03I FRED Muscle 22 f 1.5 2.7 i 0.7 < 0.23 I.8 f 0.1 co.11 0.07 ,‘O.OI : 0,019 

Viscera 3.8 f 0.9 170 f 12 0.47 f 0.12 ;0.11 c 0.11 I.4 i 0.1 0.07 t 0.05 O.lfl I 0.02 

Bone 14 f 22 2.4 f 0.1 < 0.23 0.23 I- 0.21 0. I.1 0.15 ! 0.05 0.00-l t o.on2 

HENRY Muscle 1 27 f 2.2 5.0 i 0.3 < 0.20 O:lO i 0.10 0.24 (1.1 1 0.0 I 

Bone 1 NC - 0.20 I o.o:i 0_07 ! 0.02 0 .05 o.cr:! 0.07 I O.(II 0.(1(1 I 

LEROY Muscle 1 23 * 1.4 10 1 0.9 ‘. 0.09 0.211 t 0.05 O.Of1 0 .(I-! u.r1 I !I rI.orI:, 

Viscera 1 3.9 f 1.0 300 f 3.2 1.9 i 0.2 LO.07 0.35 IO.11 1 .:i I 0.1 1.5 10.1 0.45 : u.:ju 

aSingle sample error values are one-sigma counting errors, while error values for two or more snmpl(,s are one s;~mplc stancinrcl (!czvi:itiori 

without consideration of ccamting error. 

b 241 This sample also had an Am level of 1.4 pCi/g, dry. Americium-241 was also detected in a viscera sample from TIL,I)A (0.21 pCiig, clry) 

and one viscera sample from YVONNE (0.58 pCi/g, dry). 

‘NC not computed. 
0447 

0448 

IRENIS Muscle 

Remainder 

4 

4 

L. monostigmus 

?140-240) 

21 i 

8.1 f 

2.5 

1.0 

7.2 

36 

i 

f 

1.0 

0.3 

11 

35 

t 0.4 

i 0.5 

2.1 

0.72 

I 0.17 

f 0.17 

0.1-l 

0.22 t 0.10 

0.114 

0.7:) f o.o:i 

0488 TILDA Muscle 2 17 i 1.7 G.5 f 0.G .‘O.ZU 0.32 I 0.0’1 O.O!) 0.23 

0489 

0490 

Viscera 

Remainder 

2 

2 

13 f 

9.8 i 

1.4 

1.1 

120 

s.5 

i -1.:) < 0.45 

I 0.17 

0.28 

0.11 

0.20 

0.01; 

-

1.4 I 0.1 

0575 

0576 

0577 

TILDA Muscle 

Liver 

Bone 

4 

4 

4 

L. monostigmus 

X195-333) 

NC” 

19 

3.4 

i 5.7 

* 0.9 

4.7 

G4 0 

2.G 

t 0.3 

i 13 

i 0.5 

<:0.15 

3.1 

CO.07 

f O.-i 

0.17 

(’ 0.32 

0.10 to.03 

0.15 

,‘0.23 

0.03 

0.11 

2.:) 

0.25 

t 0.12 

-

0.04 3 

0.0 I 3 

1 l1.l101~ 

0578 Viscera 4 4.5 f 0.8 37 t 0.8 0.28 IO.05 0.05 0.04 o.ofl1 I 0.002 0.023 f O.OOl 

0579 Skin 4 4.6 + 1.2 4.3 f 0.6 0.07 ,‘0.05 ” 0 0 3 0.23 0.4-l t 0.03 

0580 

0581 

TILDA Muscle 

Viscera 

1 

1 

$&llopterus 18 

19 

i 1.3 

13.2 

0.50 

19 

t O.OG 

f 2.3 

O.OG f 0.01; 

o.ncc : 0.22 

0.14 

O.lG 

I 0.0:1 0.12 

0.14 

t 0.03 0.01 

0.2!) 

f 0.001 

t O.OG 

0.005 f 1).1lOi 

0.10 ! 0.01 

0582 Bone 1 NC .0.33 0.X!) 0.28 0.21 0.92 0.042 

0437 ELMER Muscle 1 A. viresccns 20 t 1.2 2.11 I 0.3 0. :I fi I 0.0 5 0, I:< j O.(li~ 0:i.i I 0.0-1 0. IO l1,no.i 

g

CDI 

0438 

0400 

0401 

FRED 

Viscera 

Muscle 

Liver 

1 

1 

1 

7360) 

k&llopterus 

16 

16 

NC 

f 

i 

3.0 

1.4 

3 1 0 

3.1 

i 7.0 

i 0.1 -

A.!1 

,:0.15 

5.8 

f 

f 

0.3 

0.11 

0.15 

0.10 

0.49 

0.42 

0.07 

1.5 

I 0.11 

t 0.4 

I .o 

0.01 

0.11 

I 0.01)1 

f 0.211 

0 . 00 I 

0.0’) t O.(ll 

0398 

0397 

GLENN Muscle 

Viscera 

1 

1 

A. furcatus 

7302) 

25 

NC 

I 2.3 II.3 

:j GO 

t 0.2 

I IS.0 

O.lili 

22 

I 0.1 I 

t 0.51 

(I.31 

0.25 

I O.I’i I ,!I 

2.0 

I 0.1 

I 0.2 

0.0 I I 

I .:j 

! O.(ll)I 0.111)0 /ll.1)0 I 

0.07 
1 

3 

Table 35. Predominant radionuclides in single, pooled samples of groupersa collected at Enewetak Atoll, October to 

December 1972. 

Radionuclide, average f standard deviation tl In pCi/g, dry 

Sample 

number Island Tissue 

No. of 

fish 

40 

K 

0543 0544 TILDA E. whole Viscera 22 NCc 14 

f 3.8 

1.3 f 

94 f 

0.3 

3.5 

co.17 

1.1 f 0.3 

co.11 

co.19 

< 0.09 

0.17 

CO.08 

0.70 

k’0,003 

0.043 

8022 8023 

8024 

YVONNE Viscera Muscle

Bone 

1 

1 

19 18

NC 

f 1.4 

i- 2.7 

5.ti 

430 

3.1 

IO.1 

f 1.3 

f 0.2 

~.0.74 

s: 36

0.23 

f 0.12 

f 0.6 

0.33 t 

co.24 

co.15 

0.09 2.5 i 0.1 

4.6 f 0.2 

0.13 

0.03 

“ 0.10 

0.04 

L 0.07 

0.001 

0.03!; 

0.50 

t O.Ol!l 

t 0.04 

0403 0404 FRED Muscle Liver 11 15 

3.1 

f * 1.1 

0.8 

0.47 

160 

* 0.05 

f 0.5 

co.14 

2.1 f 0.1 

0.53 

< 0.05 

I 0.07 2.1 f 0.1 k,0.03 

1.1 f 0.1 0.14 1 0.01 

;0.01-1 

0.11 I 0.O.l 

0405 0406 

0407 

FRED Muscle Liver 

Bone 

11 

1 

15 _t 1.5 

NC 

9.7 * 3.1 

13 

4900 

13 

1 0.3 

f 50 

~CO.43f 0.11 

94 f2 

2.0 f 0.3 

0.51 

c:0.53 

CO.18 

j 0.09 O.IXj k 0.07 

0.40 

co.13 

LO.01 

< 0.22 

0.09 zt 0.04 

0.007 10.001 

0.038 f 0.007 

0.034 1 0.003 

I 

F 

u-l 

0 

I 

0369 FRED E. whole 0370 Viscera 3 8.4 f 1.2 

NC 

aAll groupers were Epinephelus sp. except one grouper bError values are one-sigma, counting errors. 

‘NC = not computed. 

1.1 f 0.1 ,:0.10 < 0.06 

1.3 k 0.2 co.12 

from FRED (0405-0407) vh ich was variola 

0.06 

(\0.10 

louti. 

I, 0.02 

0.05 * 0.01 

0.003 

0.13 

I 0.001 

f 0.01 
I, Radionucll(le, average t standsril tlr’vi;lrli,n 

Sample No. of 

60Co 137c’s !)O 2X!1,2 10 ,‘,, number Island Tissue fish 4oK 55b‘e ‘07 ISi s I’ 

0545 TILDA Muscle 15 f 1.0 5.6 f 0.2 0.06 0.24 f 0.05 0.25 I 0.0-l CO.11 0.001 

0546 Viscera 9.6 f 1.1 - 0.60 j 0.08 = 0.08 II t 0.2 0.11 I O.(ll 0.0 I 1 O.IIO I 

0547 Bone 3.2 f 1.1 4.0 i 0.2 0.05 0. I3 1 0.05 ‘( .o ! 0.11 o.:j7 I 0.05 0.5~1 (1.o I 

0032 YVONNP: Muscle 1 )I I 1.f; IO I 0.1 1 .:I I 0.12 0.4 I) IO.1 0. i’s ! 0. I I II.0 I 

6033 Viscera 15 1 1.8 :150 1 1 I 3 I 2.1 0. 15 12. i, 1 ().I? 0.0’7 o.ll.i:! 0 0011 

8034 Bone NCC 3.X * 0.2 ,.’ 0.20 0.20 O.G2 i O.l!I 0.10 I o.oi 0.0 I (i 

0457 ELMER Muscle 1 19 f 1.2 25 i 0.3 1.5 k 0.15 0.54 -f 0.08 0.!12 t 0.06 0.11 ‘- 0.002 

0456 Viscera 1 NC 33 f 1.0 I.5 i 0.75 ‘ 0.27 2.11 1 0.27 1.5 0.002 0.00 I 

0434 FRED Muscle 1 21 i 1.4 150 i 0.F 2.2 f O.l!J 0.3 6 I 0.10 il.7 I 0.13 n.o:, I 0.01 n.00:i 0.00 1 

0435 Viscera 1 NC 510 f3 8.9 k 0.52 ~~0.F-l 2 0 6 ? IT.0 0.24 t 0.05 15 O.‘i 

0266 HENRY E. whole 2 16 f 2.6 20 1 0.G 3 . 0 1 0.3 9 1.0 1 0.29 2-Iii t 1.5 0.411 ! 0.02 0.004 O.f101 

1 

GI aAll ulua were Caranx melampygus except fish from IIENRY, which wvrc C. sexfasciatus.

W b

1 Error values are one-sigma counting errors.

‘NC = not computed. 

_ ^ ^ . _ , . . , . . . . . . . -
I 

Goatfish - The results of the radio- 155Eu_ ~~mericcum-241 was found in 3 ,,f 

logical analyses of the goatfish tissues 19 viscera samples, 1 from BELLE and 

are gilTen in Table 30. Each sample was 2 from YV ‘ONCE, while “Sr, 55Fe, sod 

239, 240Pu made up of the tissues from an average were found in most samples. 

pool of five fish. .Uthough four species Potassium-40 levels showed little 

of goatfish of various size classes were variability between sampling locations or 

present in the samples, no apparent between eviscerated whole fish and visce 

species or size differences in radio- samples. The ” K values for all areas 

nuclide content were noted and samples and the two tissue types averaged 9.8 pCi\ 

from all species and sizes were pooled g, dry. These levels are similar to *OK , 

to form the data in Table 30. Seventy- levels found in goatfish collected from 

i five percent of the goatfish collected for other areas and times in the Central + 

4 

samples were Mulloidichthys samoensis. Pacific and indicate the natural levels of 

40 The two most prevalent radionuclides K in goatfish from that area. a! 

55 60 found in the goatfish were Fe and 6oco , Iron- 55 and Co were the predominant 

<OK followed by , 207Bi , 137Cs, and man- produced radionuclides in the 

-

1 40 

Mean K concentmtion 

10 - ,---- J ----------

\” Column legend 

is, 

Q 5- A ‘55Eu - eviscemted whole fish 

I 

B ‘55Eu - viscera z

?I 3-

.- C 207Bi - viscem 

x D 207Bi _ eviscerated whole fish 

-z 

C 

.-

2 

-‘e 1.0 -

2 

g 

4u 0.5 -

._ 

3 

; 0.3 -

s 

CS 

4B( :D AE D B C I 

s 

0.1 

BELLE IRENE JANET 

nI 

TILDA YVON 

:

1

NE DAVID FRED 

i’

GLENN LEROY 

Collection site 

40K 155Eu and 207 . Fig. 43. Average BI concentration in goatfish from Enewetak 

Atoll, Octoblr to Dekember, 1972. The *OK value is the mean of all goatfish samples. 

-152-
7 

_ I 

j :n3 ol 3 L I:, -il. -4 iomparison ?f the amounts oi while :he goatfish x-isccra from GLENS 

55 >E and <ii,. r,:, b-;c, and 6 0 Co in goatfish is shown had the highest Fe level (1700 pCi/g, I\1 60 eJ and :I] j..IC. 12. Iron- 53 and CO were higher dry). Goatfish from LEROY, JANET, and 

--plcs. L.iscera than in the eviscerated YL’OSSE also had comparatively high ::, the 

tle ,,$i,c,lt, fish by a factor of about 20 for j5Fe levels of 55 Fe, while goatfish from 

ions or .,l?;i7 [or %o. The viscera sample from LEROY, BELLE, 17T70NNE, and GLENN 

i viscera ,.,,:,tfish collected at IRENE had the had higher than average levels of 6oco reas ,z!L’)I~~~tlevels of 6oCo (160 pCi/g, dry), for goatfish collected at Enewetak. 

j-8 pCi/ 

3 4OK ’ r 

‘OFI Column legend 

rl 

A 9oSr - eviscerated whole Fish 

?lS of B “8, - viscera 

C 239,240pu - eviscerated whole fish 

‘minant D 239,240pu - viscera 

-------m- 10 -m- -- -m-. 

\ Mean 4oK concentration 5 

3 

1 

0.5 

0.3 

0.1 

.;1hr 0.05 

0.03 

B 

LE IRENE JANET TIL INNE DAVID 

0.01 B C 

FRED GLt INN LEROY 

Collection site 

Fk. 43a. Average ‘OS, ad 23g’240Pu concentration in goatfish from Enewetak Atoll, ‘_ 1 October to December, 19’72. The 4oK value is the mean for all goatfish

samples. 

-153-

1 

4 
••

Bismuth- 207 v:as detected in most _- 137 samples, but Cs and 1” ELI were detected in less than 50% of the samples. _L 

155 comparison between Eu and 207Bi 

levels in the goatfish is shown in Fig. 43. 

Levels of 207Bi, ‘j5Eu, and 137Cs were 

generally less than 3, 0.8, and 0.4 pCi/g, 

dry, respectively. The viscera samples 

from goatfish collected at BELLE had the 

highest levels of 207Bi (24 pCi/g, dry) 

and 155 Eu (2.6 pCi.‘g, dry). Cesium-137 

was highest in eviscerated whole goatfish 

from 1RENE (0.98 pCi/g, dry). Europium155 and 207 Bi concentrations were higher 

in the viscera of the goatfish than in the 

eviscerated whole fish by factors of up 

to 43 for 155 Eu and 62 for 207Bi but the 

’ 155Eu 

average ratio was less than 5 for 

and 5 for 207Bi. Cesium- 137 levels 

were similar in the two tissue types 

analyzed. 

Strontium-90 and Pu data indicate 

that higher levels are found in the viscera 

than in the eviscerated whole fish. The 

highest level of these radionuclides is 

found in the viscera of goatfish from 

BELLE (“Sr = 7.0 pCi/g), (23g’240Pu 

5.0 pCi/g). Goatfish from the northeast sector (BELLE to YVONNE) of the 

Atoll generally had higher levels of these 

two radionuclides than fish from the 

southwest sector (DAVID to LEROY). 

Strontium-90 and 23g’240Pu (viscera 

samples) concentrations averaged less 

than 0.5 and 0.05 pCi/g, dry, in the 

northern and southern sectors of the atoll, 

respectively. 

Convict Surgeon - The results of 

the radiological analyses of the convict 

surgeon samples are given in Table 31. 

Each sample was made up of the tissues 

from an al-erage pool of 15 fish, and all 

stations except IRENE and GLENN had 

2 or more samples of both eviscerated 30( 

whole fish and viscera. All fish were one < 

species, 

ferences 

Xcanthurus 

due to size 

triostegus. 

of fish pooled 

No dif_ 

for a 

“, 

I 

10( 

sample were noted and samples from all ii 5( usize classes 

in Table 31. 

were pooled to form the data .: 

? 

u 

3( 

Naturally occurring :0 

K and man-made C 

.-

55 Fe and 60Co were the predominant zi

.- 1( 

radionuclides in the convict surgeon, i I 

Cesium-137, 155Eu, and 207Bi were also 0, 

; : 

present in the samples from 50070or more ,o 

of the collection sites. Americium-241 4 

.-

was found in 5 of 24 viscera samples, 2 u 

2 l.( 

each from BELLE and YVONNE and 1 0

.-

; 0.: 

from IRENE, while 23gJ240Pu and “Sr 

were found in most samples. Potassium- 0 . .’ 

40 levels showed little variability between 

sampling sites. The viscera samples, 0 * .I 

however, had a greater 40 K concentration 

(13 pCi/g, dry) than did the eviscerated 

whole fish sample (9.9 pCi/g, dry). Iron- Fig. 44. 

55 concentrations were about 10 times 

higher in the viscera than in the eviscerate 

whole fish and were highest in the viscera 

of convict surgeon from LEROY and Ces: 

IRENE (160 pCi/g, dry). Viscera samples centrat 

from convict surgeon collected from in all s 

YVONNE to GLENN averaged < 10 pCi/g, 1 PCi/g 

dry. The viscera and eviscerated whole 13ks ; 

fish samples from convict surgeon 

collected from the Seminole Crater area 

su rgeoi 

207 Ri 1 

of IRENE had the highest 60 Co content from L 

155Eu 

(210 and 28 pCi/g, dry, respectively) of , 

any of the convict surgeon samples. The su rgeo: 

viscera of convict surgeon from BELLE Iron 

had 16 pCi of 60Co/g, dry, and all other levels 

samples had < 5.2 pCi/g, dry. The levels of the ( 

of 6oCo > 55Fe, and 4oK in the convict eviscel 

surgeon are compared in Fig. 44. tween t 

154-
Column legend 

A 55 Fe - eviscerated whole fish 300 

B 55Fe - viscera 

One P 

.- c 6oco - viscera 

if- 100 D 6oco - eviscetuted whole fish a I 

41 v, Y 50 1 ::

.- ‘ata f Mean ‘OK concentration _ 30 > 

+ 

c.- -- _- -a& C

0 10 - .-

i 

7 5 - u Is0 2 3-

I kl ,0 Ire 

4 1 .-

u

2 1.0- ? 0 

2 0.5-

0( 

0.3 - m-

‘en 

- 0.1 - E JAN YVONNEDAVID FRED C NN HE 

ion 

Collection site 

i 

n- 4OK 55Fe 60

I’ic. 44. Average Co concentration in convict surgeon from Enewetak 

Atoll, Octobir to Dkcember, 1972. The 4oK value is the mean for all convict surgeon samples. ratec 

ra 

Cesium-137, 155Eu, and 207Bi con- in the goatfish. Cesium-137 was equally 

)les centrations were less than 7 pCi/g, dry, distributed in the viscera and eviscerated 

in all samples and averaged less than whole fish. 

1 PCi/g, dry. The highest levels of Data on 90Sr and 23g’240Pu concentra137Cs and 155 mu were found in convict tions in the convict surgeon indicate that 

surgeon collected from IRENE, while the viscera of convict surgeon from 

207Bi was highest in convict surgeon IRENE has the highest concentration of 

from LEROY _ A comnarison of 137cs . both go Sr (17 pCi/g, dry) and 23g’240Pu 

155 

EU, and 267 Bi levels’ in the convict (15 pCi/g, dry) of any of the convict 

ie surgeon is shown in Fig. 45. surgeon samples analyzed so far. Convict 

Iron-55, 6oc~ , 155~u , and 207Bi surgeon from BELLE also have higher 

levels were generally higher in the viscera than average concentrations of these radioof the convict surgeon than in the nuclides. Convict surgeon collected from 

eviscerated whole fish. Differences be- DAVID to HENRY had “Sr and 23g1240Pu 

tween tissues were similar to those found tissue concentrations of ~0.1 pCi/g, dry. 

-155-
LO

Mean K concentration 

---~~---~~~~-~_ f 

10 ‘ss 

Column legend 

\” 

A 13’C5 - entire fish u, 5 

B ‘55Eu - eviscerated whole fish 

I 3 

C ‘55Eu - viscera ? 

z._ D 2070i - viscera 

E 207Bi - eviscerated whole fish n”x 1.0 

C 

._ 

.E 0.5 

.G 

,’ 0.3 

b

” 

; 

2 0.1 

J 

2

0 0.05 

0 

s 0.03 

ICDE i ~ ABCC 1 1 )E h1A I 0.01 

BELLE IRENE JANET URSULA YVONNE DAVID FRED HENRY LEROY 

Collection site 

3n7 

Fig. 45. Average 137Cs, 155Eu, and &“’ Bi concentration in convict surgeon from 

Enewetak Atoll, October to December, 1972. The 4oK value is the mean for 

all convict surgeon samples. 

60 Mullet - The results of the radio- found in all samples, while Co was four 

logical analyses of the mullet tissues are in over 90% of the samples. Cesium-137, 

155 given in Table 32. Each sample was Eu, and 207Bi were found in 44%, 26% 

made up vise of the tissues from an average and 26% of the samples, respectively. 

rcq pool of 10 fish. Although four species of Americium-241 was found in all the 

mullet =F, of various size classes were viscera samples from BELLE and 

Fig. present in the samples, no correlation of YVONNE and in one of two viscera sampl c,OC 

radionuclide concentration with species from TILDA. Plutonium-239,240 and 

90 rad’ or size was noted and samples from all Sr were found in most samples. 

40 in t. species and sizes were pooled to form the Variability of K levels between 

evir data in Table 32. Sixty percent of the sampling locations was within the normal 

had mullet collected for samples were range of expected values. Muscle tissue 155

40 Neomyxus chaptalii. had the highest average K concentratio, 

the Of the three commonest radionuclides 13 pCi/g, dry, of the three tissue types

55 in 1 found in the mullet, 4oK and Fe were analyzed. Eviscerated whole fish and 

-156-
40 

Mean K concentration 

_L!-

i3 

Col timn legend 

9os, - eviscemted whole fish 

9oS, - viscera 

239,240PU _ eviscerated whole fish 

239,240pu - viscera 

:

bD

IRENE JANET -URSULA -YVONNE- DAVID FRED GLENN LEROY 

n for Collection site 

9os, and 239,240fi I:ip. 45a. Average concentration in convict surgeon from Enewetak 

Atoll, -October to December, 1972. The -10~ value is the mean for all con- j found vict surgeon samples. 

- 137, 

26%, 

. 

. viscera averaged 6.3 and 4.3 pCi/g, dry, was detected, it was present in higher 

137 respectively. A comparison of 4oK , concentrations than either Cs or 207Bi. 

55 

Fe, and 6o Co in the mullet is shown in The highest concentration of each of 

55 imples Fig. 46. Concentrations of Fe and the predominant man- made radionuclides 

60 

1 Co, the most abundant man-produced was found in the viscera samples taken 

radionuclides in the mullet, were higher from mullet collected at IRENE. These 

in the viscera than in the muscle or concentrations in pCi/g, dry, are as 

*ma1 eviscerated whole fish, two tissues which follows: 55Fe (2201, 6oCo (901, 137Cs 

#sue had similar concentrations. Cesium-137, (9.81, 155Eu (221, and 207Bi (2 . 2) . Viscera 

155& 

ation, , and 207 Bi were also present in samples from mullet collected at BELLE 

es the viscera in higher concentrations than and Y\‘ONNE also had higher than average 

155Eu 

I in the other two tissues. Where man-made radionuclide levels, but the 

-157-
300 

Column leGend 

A 55Fe - eviscemtec whole fish &OK

100 ,-Mean

B 55Fe - viscem concertration 

c 6oco- viscera 

/

i 

50 

D 6oCo - eviscemtec whole fish 

30 

1 

10 

5 

3 

1 .o 

0.5 

0.3 

0.1 .A! 

BELLE IRENE JA NET TILDA YVONNE GLENN LEROY 

Collection site 

4OK

Fig. 46. -4verage 55Fe and ” Co concentration in mullet collected at Enewetak 

Atoll, October to December, 19’72. The 4oK value is the mean from all 0.c 

mullet samples. 

levels were lower than those in IRENE The highest “Sr level (6.1 pCi/g, dry) 0.f 

fish by factors of roughly 8 (BELLE) and in the mullet was found in the viscera of 

20 (YVONNE). Generally, levels of the mullet from BELLE, while the viscera 

man-made radionuclides in fish from of mullet from IRENE have the highest I:ig. 

GLENN, HENRY, and LEROY were 23gJ240Pu content (24 pCi/g, dry). Con239,240 slightly lower than levels of the same centrations of Pu in the viscera of 

radionuclide in YVONNE mullet; however, mullet from BELLE were also higher 

23 9, 240p one viscera sample from mullet collected (8.0 pCi/g, dry) than the average ItpCC: 

from GLENN had 1.8 pCi/g, dry, of concentration of < 1 pCi/g, dry. of th, 

207 Bi, which was only slightly lower than Parrotfish - The results of the radio 1’1 

the 207 Bi content in the viscera sample logical analyses of the parrotfish tissues natul 

from IRENE mullet. Mullet from JANET are given in Table 33. Each sample was dctec 

had the lowest man-made gamma-emitting made up of the tissues from an average ore 

radionuclide content. pool of four fish. All fish were a single only 

-158-
I 

Column legend 

A 9oS, - eviscerated whole fish 

B 9oSi- - viscera 

c 239,240P,, _ eviscerated whole fish 

D 239,240Pu - viscera 

10 

--mm- mm----_ 

< t Mean 4o K concentration 

$ 5 

’ 3 

Y 

‘c.-

z 

+ 

C 

.- 1 C 

0

.-

5 

2 0.5 

Z 

G

0 0.3 

4.-

‘; 

2 

0 

.-

j 0.1 

0.05 

0.03 cABC

0.01 

BELLE IRENE HEN

Col lecfion site 

90Sr and 239,240 bz. 46a. Average Pu concentration in mullet collected at Enewetak 

Atoll, October to December, 1972. The 40K value is the mean for all 

mullet samples. 

species, Scarus sordidus, and most were more than 50bc of the samples. 

Of the same size class (24 to 36 cm). Cobalt-60, 155Eu, and 207Bi were 

Potassium-40 was the most abundant detected in 44%, 22oJ, and 15% of the 

nahrrally occurring radionuclide and was samples, respectively. Americium-241 

detected in all of the parrotfish samples. was detected in three viscera samples, 

Ofthe man-produced radionuclides, one each from BELLE (1.4 pCi/g, dry), 

only 55

Fe and 137 Cs were present in TILDA (0.21 pCi/g, dry), and YVONNE 

-159-
300 

Coiumn legend 

A 55Fe - muscle 

B 55Fe - viscera 

100 c 6oco - viscera 1; 

D 6oCo - muscle 

50 .p ! 

i-1 

-? 0 

Gj 30 I 

c 

I Meon 4o K concentration !! 

.-

. . 

4 e. 

z -_ ---w .- + \.(

c 2-u 10 .-

._ 

C .-5,

> 0 .! . E ._ F 2 5.0 “, 0.: 

2 5 z 

5 3.0 4.- v u 

4 

._ i 0: 

_; 

2 s 

G I.0 0.01 CS 

0.0: 

0.5 

0.3 

0.0’ 

:D :D / h,h, h:D Fig. . 0.1 

JPrNET TILDA YVONNE ID FRED L 

Cal lection site 

Fig. 47. Average 4oK 55Fe and 6o Co concentration in muscle and viscera samples :I co1 from arrotfish collected at Enewetak Atoll, October to December, 1972. 

The 48 K value is the mean for all parrotfish muscle and viscera samples. Icvc~s 

(0.58 pCi/g, dry). Plutonium-239,240 

and go Sr were detected in most samples. 

Potassium-40 levels showed little 

variability between sampling locations, 

except for one viscera sample from fish 

collected at BELLE, which had a 4oK 

f:ig. 1 

concentration of 21 pCi/g, 

about three times greater 

dry, which was 

than the average 

It-0 

produ 

value for parrotfish viscera. All samples 

had 4o K values within the expected range 

of natural levels, with muscle and viscera 

averaging 18 and 6.5 pC i /g, dry, respectiveIF 

4

i 

parro 

levels 

fi. dr: 

i,KRC 

-160-
-- 

/Mean 4oK concentration 

_--- -m-m 1

Column legend 10 

90,_JI - eviscerated whole fish 

9osr - viscera \” 5 

239,240pu - eviscerated whole fish i;l 

a 239,240pu - viscera 

I 3 

u 

? 

.Li- 1.0 

c.-

; 

.i 0.5 

=t 

z: 0.3 

” 

-0”

.-

u 

> 

s 0.1 

S 

s 

0.05 

0.03 

A 

B_c_l E nBCD 0.01 

rNE1 IDA FRED HENRY LEROY 

Collection site 

90 sr and 239,240 1Qg. 47a. Average Pu concentration in muscle and viscera samples 

from arrotfish collected at Enewetak Atoll, October to December, 1972. 

The 4BK value is the mean for all parrotfish muscle and viscera samples. 

40K 55 A comparison of , Fe, and 6oco 2.6 pCi/g, dry, in muscle and 82 pCi/g, 

levels in the parrotfish is shown in dry, in viscera. 

I’ig. 47. The other two common man-made 

Iron-55 was the most abundant man- gamma-emitting radionuclides detected 

Produced radionuclide detected in the in the parrotfish were 6oCo and 137Cs. 

Parrotfish samples. The highest 55Fe Cesium was detected in more samples 

levels were found in the viscera (300 pCi/ (55%) than 6o Co (44%), but the highest 

60 gn dry’) and muscle of parrotfish from Co level (13 pCi/g, dry) in viscera from 

LEROY, while the average level was BELLE parrotfish was higher than the 

-161-
1 

highest 1 37 Cs level (3.0 pCi/g, dry) in 

eviscerated whole iish from BELLE. In 

addition to the samples from BELLE, 

6oCo was high in x-iscera from YVONNE 

(2.5 pCi:g;3Fy) and LEROY (1.9 pCi/g, 

dry). and Cs was high in muscle from 

60

FRED (1.8 pCi/g, dry). Other Co and 

137 Cs concentrations averaged less than 

0.40 pCi/g, dry. 

207 Europium-155 and Bi were present 

in only a few samples. Europium-155 

was high in viscera from BELLE (1.2 

pCi/g, dry) and YT-ONNE (0.88 pCi/g, 

207 dry), while BL was high in viscera 

from FRED (1.4 pCiig, dry) and LEROY 

(1.3 pCi/g, dry). 

Of the five man-produced radionuelides discussed above, only 137Cs was 

present in higher amounts in the muscle 

than in the viscera. Iron-55, 6oco, 

155 204 Eu, and BL levels were greater 

in the viscera than in the muscle of 

parrotfish. 

90 The highest Sr and 23g’240Pu concentrations in the parrotfish were found 

in the viscera sample from BELLE 

(“Sr = 5.3 pCi/g, dry; 23g’240Pu 

= 2.9 pCi/g, dry). Plutonium was also 

high in parrotfish from YVONNE 

(1.8 pCi/g in the viscera). Other samples had ~1 pCi/g, dry, of these radionuclides. Strontium-90 and 23ga240Pu 

levels were higher in the viscera than 

in the muscle by factors of 8 and 10, 

respectively. 

Snappers and Groupers - The results of the radiological analyses of the 

snappers and groupers are given in 

Tables 34 and 35. These fish will be considered together because of the similarity 

in the results of the radiological analyses, 

which probably is a consequence of the 

similaritv in t,heir feeding habits. 

The three most abundant radionuclid,, 

found In the snappers and groupers Were 

‘1OK 5”Fe and 60co . Cesium-137 and 

207*. ’ BI tn lesser amounts were found in 

about one-third of the samples. A small 

amount of 155 Eu (0.13 pCi/g, dry) was 

found in one liver sample from a grouper 

collected at FRED, xvhile 241Am 

(1.4 pCilg, dry) was found in one bone 

sample from a grouper collected from 

239 YVOXEE. Strontium-90 and Pu Were 

detected in about 50% of the samples. 

30 Naturally occurring K levels were 

similar at all collection sites. Muscle 

and viscera tissue samples averaged 19 

and 14 pCi/g, dry, respectively. 

Iron-55 and 6o Co were the predominant 

man-produced radionuclides found in the 

snappers and groupers. These two radionuclides were present in the viscera or 

liver in concentrations over 10 times 

higher than those found in the muscle. 

55 The highest Fe level, by a factor of 8, 

(4900 pCi/g, dry) was in a liver sample 

from a grouper collected at FRED. 

Several snapper and grouper viscera or 

liver samples from GLENN, ELMER, 

55 TILDA, and YVONNE also had Fe concentrations from 310 to 640 pCi/g, dry. 

Cobalt-60 levels were highest in grouper 

liver from FRED (94 pCi/g, dry), grouper 

viscera from YVONNE (36 pCi/g, dry), and 

snapper remainder (including viscera) 

from GLENN (22 pCi/g, dry). Only the 

muscle from the snapper sample from 

60 IRENE had a Co concentration above 

1 pCi/g, dry (11 pCi/g, dry). Cobalt-60 

concentrations in muscle samples averaged 

60 1.4 pCi/g, dry, while Co in viscera or 

liver samples averaged 16 pCi/g, dry. 

-162-
l<isnluth_207__concentrations \Vere lower samples. Cobalt-60 and 137 Cs were found 

:jl(‘il 

35 t’e and ““CO concentrations, but in over 50% of the samples, but at lower 

,,kt. those radionuclides, 2oiBi levels levels than 55Fe and 207Bi. Europium-155 

:~c,r(, higher in the viscera or liver than and 241 _Xtn were not detected in any of the 

The degree of !1]the muscle207 Bi. concentrations t,c.llrreen the 

difference 

in the 

ulua samples analyzed. 

239,240 Pu were found in 

Strontium-90 

50 and 7570 of 

and 

,,~o tyi,i’s L I of tissue was less than twofold the samples, respectively. 

L,nd WaS not nearly as great as it was for Iron-55 was the most abundant man-

“Ore and 55Fe. The highest 207 Bi con- made radionuclide found in the ulua. 

,ne 

,.,,“tration was found in the viscera Iron-55 concentrations of up to 510 pCi!g, 

1 ,-l_(; pCi/g, dry) and muscle (2.5 pCi/g, dry, were found in the viscera of a ulua 

.>re (jr!,) of a grouper collected at TVONNE. from FRED. T’iscera concentrations in 

1 Crouoer and a snapper from FRED and ulua from YT’ONNE and ELMER were 350 

,, snapper from GLENN also had 207Bi and 33 pCi/g, dry, respectively, while 

lcaveis of between one and two pCi/g, dry, muscle averaged 60 pCi/g, dry, in 

e 

0 ,n their tissues. Other 207Bi levels four samples, including the FRED ulua 

;Ivcraged less than 0.17 pCi/g, dry. which had 150 pCi.‘g, dry, in its muscle 

nant 

Cesium-137 levels in the grcxlpers tissue. 

he generally were less than 0.5 and averaged Bismuth-207 concentrations were quite 

die- 0.25 pCi/g, dry, while one .snapper variable between collection sites. One 

muscle sample from IRENE had a 137Cs ulua from FRED had a 207Bi concentration r 

level of 2.1 pCi/g, dry, and the remainder in its viscera of 206 pCi/g, dry, and a 

of the samples averaged less than sample of two eviscerated whole ulua from 

u 0.22 pCi/g, dry. 

The highest “Sr concentration (2.9 

HENRY had a 207Bi concentration of 

207 248 pCi/g, dry. The Bi concentrations e 

pCi/g, dry) was found in the liver of a averaged 3.0 pCi/g, dry, in the other nine 

r snapper collected 

!,I)Sr levels were 

off TILDA. 

< 1 pCi/g, 

Most other 

dry. The 

samples of 

Cobalt-60 

muscle 

levels 

and viscera. 

were 8 times higher 

jiighest 239,240 Pu concentration (0.6 in the viscera samples than in the muscle n- PCi/g, dry) was detected in the viscera of samples. The greatest amount (13 pCi/g, 

‘r 

)er 

and 

;t SnaPPer collected off TILDA. Most 

other 239,240 Pu levels were < 0.1 pCi/g, 

dry, with most of the Pu concentrated in 

the viscera, 

dry) was 

collected 

1.3 pCi/g 

7.5 pCi/g 

in the viscera 

at YVONNE. 

in the muscle 

in the viscera 

of two ulua 

Cobalt-60 averaged 

samples and 

samples. 

Cesium-137 levels ranged from 

Ulua - The results of the radiologi- 1.0 pCi/g, dry (HENRY - eviscerated 

cal analyses of the ulua tissues are given whole) to less than 0.08 pCi/g, dry, with 

J_l 

zd 

in Table 36. 

in all tissues 

of 15 pCi/g, 

Potassium-40 

at an average 

dry. Iron-55 

was present 

concentration 

207 and Bi were 

an average 

0.37 pCi/g, 

tions were 

concentration of less than 

dry. Cesium-137 concentrahigher in the muscle than in 

the most abundant man-made radionuclides the viscera. An exact factor of the tissue 

and they were detected in all the ulua difference could not be determined, since 

-163-
I 

all the 13’ Cs levels in the viscera were 

below the limits of detection. 

90 The highest Sr concentration (0.5 

pCi.‘g, dry) was found in an eviscerated 

whole ulua collected off HENRY. Other 

90 ulua samples analyzed for Sr averaged 

CO.2 pCi/g, dry. Plutonium- 239,240 

levels were below 1.0 pCi/g, dry, except 

for the viscera sample from ulua collected 

at FRED which contained 15 pCi/g, dry. 

Tuna and Other Large Pelagic 

Lagoon Fish - The results of the radiological analyses of large pelagic lagoon fish 

are given in Table 37. These fish include 

skipjack, yellowfin tuna, mackerel, dolphin, 

and barracuda. Of these fish the yellowfin tuna and the dolphin are likely to be 

resident in the lagoon on a more temporary 

basis than the skipjack, mackerel, or 

barracuda. Each tissue sample was from 

an individual fish except for mackerel 

sample No. 0440, which was a composite 

sample from two fish. 

The results indicate that naturally 

40 occurring K is present in background 

amounts. All samples averaged 14 pCi/g, 

dry, with light muscle, dark muscle, and 

liver or viscera averaging 16, 12, and 

11 pCi/g, dry, respectively. These levels 

are similar to those found at Kwajalein 

Atoll where pelagic lagoon fish had an 

40 

average K tissue concentration of 

14 pCi/g, dry. 

Of the man-produced radionuclides 

55 found in these fish, Fe was by far the 

most abundant (Fig. 48). Iron-55 levels 

in the large pelagic fish were generally 

higher than levels found in other fish types, 

with the liver of the skipjack having the 

highest concentrations (maximum - 2500 

pCi/g, dry: average - 840 pCi/ g, dry) of 

the tissues analyzed. Iron-55 in the skip_ 

jack was less in the light muscle than is 

the liver or dark muscle by factors of 

18 and 7, respectively. 

Cobalt-60 was found in most samples oy 

lagoon fish, but at lower levels than 55Fe . 

The highest 6oC~ concentration in the 

pelagic lagoon fish was 36 pCi/g, dry, in 

the liver of a skipjack captured near 

YVONNE. Light muscle of tuna and 

muscle of the other fish averaged 0.58 

pCi,‘g, dry, while dark muscle of tuna and 

liver or viscera of all these pelagic lagoor 

fish averaged 8.4 and 11 pCi/g, dry, 

respectively. There was considerable 

variation in the amount of 60 

Co present in 

tissue samples from the same species of 

fish. For instance, a yellowfin tuna take!: 

from the Deep Channel had 6o Co concentr; 

tions of 8.4 and 2.1 pCi/g, dry, in the 

dark muscle and liver, while a yellowfin 

taken off the ocean side of GLENN, had 

0.55 pCi/g, dry, in its dark muscle and 

less than 0.61 pCi/g, dry, in its liver. Tl 

two dolphin exhibited similar differences. 

This indicates that the residence time Of 

some of these fish near or in the lagoon, 

60 which is the major source of the Co and 

other man-produced radionuclides in thei1 

tissues, is quite variable. Fish(i.e., skip 

jack) which tend to stay within the atoll 

had a more consistent distribution of 

radionuclides among individuals, although 

there is still a wide variability between 

individuals and the average radionuclide 

concentration of the total group of fish. 

For instance, livers from three skipjack 

taken off YVONNE averaged 23 pCi/g, drJ 

and had a range from 5.2 to 36 pCi/g, dry 

while liver tissue from five skipjack take 

from the southern end of the atoll averag’ 

12 pCi/g, dry, with a range of CO.68 to 

-164-
15 in the ski,. 

luscle than ,r,,I 

‘actors of 

'St samples o1 

bls than j5pt 

on in the 

i/g, dry, in 

ed near 

na and 

qed 0.58 

e of tuna aat! 

elagic lagoon 

:, dry, 

siderable 

‘0 present in 

species of 

in tuna taken 

20 concentra 

‘, in the 

1 yellowfin 

SNN, had 

uscle and 

ts liver. The 

lifferences. 

ce time of 

he lagoon, 

le 6o Co and 

des in their 

1(i.e., skipn the atoll 

:ion of 

s, although 

between 

ionu elide 

of fish. 

3 skipjack 

pci/g, dry, 

,ci/g, drYI 

3jack taken 

111 averaged 

= 0.68 t0 

Column legend 

A Light muscle 

6 Dark muscle 

C Liver 

40 

Average K concentmtion 

(all tissues) / . I------------

BC 

[‘if& 48. Average concentration of seven radionuclides in the light muscle (A), dark 

muscle (B), and liver (C) of three skipjack from Enewetak Atoll, October 

to December, 1972. 

I!) pCi/g, dry. This difference between and light muscle tissue from all skipjack 

skipjack from the portions of the atoll was taken at Enewetak had average 

60Co confound to be not significant when tested centrations of 9.4 and 9.8 pCi/g, dry, 

wtth analysis of variance methods. Dark respectively, There was no significant 

- 165-
_^- _ -

d d 

3-

__. _ --k 

O^cod -rcl@J* I--TN --cr.,-

=’ d d d =’ s d d 

222 

VVU 

z I? 

G 

o-P?0 _-

m -7 m-0.T . . . . d N N d --OC 

il-__ ++I+-

c. (3 0 -3C-0 . . . . . 

0-m - _ N’ 1 

-166-