F;EQUF.ST FOR APPROVAL FOR OPEl4 Pl.!OLICATIOI’i 

FROM : 5 Cl-1 DATE 25 Flay 76 CMT 1 

V. Seiglar/XNXHXNNX/57559 

1. As requested by your DF of 23 Jan 74 , subject as avow: ., the attached 

entitled "Study of kspcnse of Hu~xm Beings Accidentally E:xposed to Significant 

Fallout Radiation" 

h;s been reviewed and cleared for opcr, publication. The following infomation 

is pro\:idea; 

2. This corlpletes 

herewith. 

Incl ( 4 cys) 

’ as 

I SCN Case No: 112 

DFOI Case No: 76-01485 

Date Cleared: 20 :vlay 76 

DFOI Reviewed tie: 4 

action as requested by your DF. Copies are returned 

R. G. Ni'LES 

CHI Et, ISUI 

I(1 t’LA(.t S b1) I C)HLI !I(,. LXISIING SLIPFLIES Or WIIICI~ WILL DL 

CSULO AND USLD U’JIIL 1 FM3 03 UNLLSS SOONEli L>;W\USltD. 
. 

This docupent consists of 104 pages 

No. 15 3 of 400 copies, Series A 

Report to the Scientific Director 

OPERATION CASTLE - FINAL REPORT PROJECT 4.1 

Study of Response of Human Beings 

Accidentally Exposed to 

Significant Fallout Radiation 

* /o,Gcc( / 

E. P. Cronkite, Commander, MC, USN 

V. P. Bond, M.D., Ph.D. 

L. E. Browning, Lt. Col., MC, USA 

W. H. Chapman, Lt., MSC, USN 

S. H. Cohn, Ph.D. 

R. A. Conard, Commander, MC, US? 

C. L. Dunham, M.D. 

R. S. Farr, Lt., MC, USN 

W. S. Hall, Commander, MC, USN 

R. Sharp, Lt. (jg), USN 

N. R. Shulman, Lt., MC, USN 

October 1954 

Naval Medical Research Institute 

Bethesda, Maryland 

and 

U. S. Naval Radiological Defense Laboratory 

San Francisco, California 

/ 

-‘--.- L i / 

- 

~orizea pcm 
. 
ABSTRACT 

Following the detonation of Shot 1 on Bikini Atoll on 1 March 1954, 28 Americans and 239 

Marshallese were exposed to fallout. One hundred fifty-seven of the Marshallese were on Utirfk 

Atoll, 64 were on Rongelap Atoll, and 18 were on the neighboring atoll of Ailinginae. The 28 

Americans were on Rongerik Atoll. The presence of significant fallout on these atolls was first 

determined by a recording dosimeter, located on Rongerik, when this device went off scale at 

100 mr/hr shortly after the detonation. Emergency surveys detected radiation on the inhabited 

atolls, and evacuation of inhabitants to the Naval Station at Kwajalein was promptly carried out. 

The dose of radiation to which the individuals were exposed was calculated from the intensities 

found on the islands and the decay exponent of the fallout material. The individuals on Rongelap 

received approximately 175 r, those on Ailinginae received approximately 69 r, and the Americans on Rongerik received an average calculated dose of 78 r. The Marshallese on Utirik received approximately 14 r. The fallout on Rongelap, Ailinginae, and to a lesser extent on Rongerik was distinctly visible. No fallout was observed on Utirik. A significant number of individuals on Rongelap suffered from mild nausea and one or two individuals vomited on the day 

f of the exposure. With the exception of nausea in one Ailinginae individual, there were no other 

definite gastrointestinal symptoms in the other Marshallese or the Americans. The Marshallese on Rongelap and Ailinginae, and the Americans experienced to a varying degree burning of the eyes and itching of the skin from 1 to 3 days. Later, signs of radiation injury included 

definite epilation in the Rongelap and Ailinginae groups, and the development of spotty, superficial, hyperpigmented skin lesions that desquamated from the center of the lesions outwards. 

(I In some cases the skin damage was sufficient to result in raw, weeping lesions. There was 

no full thickness necrosis of the skin. The Americans developed only minor skin lesions without 

ulceration. There were no skin lesions in the Utirik natives. All lesions healed rapidly with 

no further breakdown of the skin noted during the period of observation. Microscopic examination of biopsies of the lesions showed changes usually associated with radiation injury. Fully 

clothed individuals and those remaining inside of buildings or huts were protected to varying 

degrees from development of lesions. Hematologic changes were definite in the Rongelap, 

Ailinginae, and the American groups. Lymphopenia appeared promptly and was persistent for 

a prolonged period of time. Neutropenia occurred in all of the individuals with initial minimum 

values occurring around the 11th day followed by an increase in the counts and a secondary 

minimum around the 40th to 45th day. The most consistent hematologic change was the depression in the platelet counts. Platelets were below normal when first counted on the 10th 

day of post-exposure and progressively decreased attaining a minimum between the 25th and 

30th day. Although recovery commenced following this minimum, the platelet counts bad not 

returned to normal by the completion of the initial study on the 76th post-exposure day. The 

incidence of various respiratory and cutaneous infections was identical in all exposure groups 

and bore no relationship to the hematologic changes. 

Urinary excretion of radioisotopes was studied. Small amounts of radioactive material 

were found. Estimates of total body burden indicate that there is no long term hazard and that 

ingestion and inhalation of isotopes did not contribute significantly to the initial radiation 

exposure. 

3-4 

FOREWORD 

This report is one of the reports presenting the results of the 34 projects participating 

in the Military Effects Program of Operation CASTLE. For readers interested in other pertinent test information, reference is made to WT-934, Report of the Commander, Task Unit 

13, Military Effects Program. This summary report includes the following information of 

possible general interest. 

(a) An over-all description of each detonation, including yield, height of burst, ground zero 

location, time of detonation, ambient atmospheric conditions at detonation time, etc., for the 

operation. 

(b) Discussion of all project results. 

(c) A summary of each project, including objectives and results. 

(d) A complete listing of all reports covering the Military Effects Test Program. 

Detailed reports on dosimetry and internal radioactive contamination will be published as 

supplements to this report. 

Much of the medical terminology in this report is explained in parentheses for the benefit 

of the layman. 

5-6 

UNUSSFlEi 

PREFACE 

Operation CASTLE did not include a biomedical program. The participants in Project 4.1 

were drawn from various laboratories and were totally unprepared for a field program when 

the joint DOD-AEC Medical Research Team was organized after the operation had begun. 

Dr. John C. Bugher, Director, Division of Biology and Medicine, AEC, and Lt Co1 L. E. 

Browning, MC, USA, Surgeon of the Armed Forces Special Weapons Project, selected the project officer and requested that the selection of technical and professional personnel be commenced immediately. Rear Admiral Clarence Brown, Deputy Surgeon General, Medical Department, USN, gave immediate and complete support of all naval medical research activities 

and assigned responsibility to CAPT Van Tipton, MC, USN, and CDR Harry Etter, MC, USN, of 

the Atomic Defense Division, Bureau of Medicine and Surgery, USN, for the implementation of 

the project. 

Since little detailed information was available about dose and initial symptomatology, the 

research team was organized to include the following talents for the constitution of the emergency medical team: internal medicine, hematology, radiation technology and radiobiology. In 

the selection of personnel the emphasis was placed on past experience in biomedical research 

in the field with atomic weapons. In addition, provisions were made for a second echelon of 

specialized personnel in case they were needed. Accordingly, a preventive medicine unit of 

the Commander-in-Chief, Pacific Fleet, was alerted for possible bacteriologic studies; blood 

bank personnel, and additional clinicians and nurses were notified in case conditions justified 

their services in the Kwajalein area. Rear Admiral Bartholomew Hogan, MC, USN, Pacific 

Fleet Medical Officer, immediately made any needed medical facilities of the Pacific Fleet 

available. 

Personnel were obtained within the Continental limits of the U. S. for the research team 

as follows: 

Naval Medical Research Institute (NMRI) 

4 medical officers (E. P. Cronkite, project officer, R. A. Conard, N. R. Shulman. and 

R. S. Farr) 

2 medical service corps officers (W. H. Chapman and R. Sharp) 

6 enlisted men (C. R. Sipe, P. K. Schork, C. P. A. Strome, W. C. Clutter, R. E. Hansell, 

J. S. Hamby) 

U. S. Naval Radiological Defense Laboratory (NRDL) 

1 civilian M.D. (V. P. Bond) 

1 medical service corps officer (L. J. Smith) 

4 enlisted men (W. H. Gibbs, J. C. Hendrie, W. S. Argonza, J. Flanagan) 

Division of Biology and Medicine, AEC 

2 civilian M.D.‘s (C. L. Dunham and G. V. LeRoy) 

Armed Forces Special Weapons Project (AFSWP) 

1 Army Medical Officer (L. E. Browning) 

Preliminary studies had been made by CDR W. S. Hall, MC, USN, Station Medical Officer 

and his staff, and decontamination of the individuals was well underway when Project 4.1 person- 
nel arrived in the field. Preliminary hematologic studies indicated that the individuals probably 

had not received acutely fatal doses of radiation. The primary responsibilities within the project group were delegated as follows: 

Clinical observations and care-LT N. R. Shulman, MC, USN 

Organization and operation of laboratory-LT R. S. Farr, MC, USN 

Compilation and daily analysis of all data-Dr. V. P. Bond 

Decontamination and radiation measurement-LT (jg) Ft. Sharp, MSC, USN 

Senior Petty Officer in charge of laboratory-P. K. Schork, HMC, USN 

As the clinical picture developed, a further breakdown in responsibility was necessary. Commander R. A. Conard, MC, USN, and Lt Co1 L. E. Browning, MC, USA, were made responsible 

for a daily survey of skin lesions, and Dr. S. H. Cohn was made responsible for studying the 

problems concerned with the excretion of radioisotopes and the estimates of body burdens in 

the exposed individuals. 

The project officer commends all of the professional and technical members of the group 

for their excellent motivation, initiative, and voluntary long hours of extra work that were essential for the accomplishment of the clinical and research objectives, and for the rapid collection of the preliminary data in the field. It is emphasized that the work was a cooperative 

endeavor in which all were mutually dependent upon each other. The willing efforts of all concerned constituted a remarkable example of team-work and sacrifice of personal ambitions and 

desires for the good of the project at large. 

The authors wish to express their gratitude and indebtedness to Dr. John C. Bugher, CAPT 

Van Tipton, and CDR Harry Etter; CAPT W. E. Kellum, MC, USN, and CAPT T. L. Willmon, 

Commanding and Executive Officers, respectively, NMRI; CAPT R. A. Hinners, USN, Director, 

NRDL, and CAPT A. R. Behnke, MC, USN, Associate Director, NRDL; all of whom gave unlimited support and reduced administrative procedures to a bare minimum, thus making it 

possible for the unit to be assembled and underway in a matter of hours. 

On arrival at Kwajalein, RADM R. S. Clarke, USN, Commanding Officer, U. S. Naval Station, Kwajalein, supported Project 4.1 with all the facilities at his disposal. As a result, a 

laboratory and clinic was established and operating within 24 hours after arrival of the project 

personnel. 

Project personnel also wish to acknowledge the outstanding contributions of Co1 C. S. 

Maupin, MC, USA, Field Command, AFSWP, CAPT H. H. Haight, MC, USN, Division of Military Application, AEC; Co1 K. Houghton, MC, USAF, Special Weapons Center; CAPT Donald 

Dement, MC, USN, CINCPAC Fleet; Drs. T. L. Shipman, T. White, and P. Harris of Los Alamos 

Scientific Laboratory; Dr. Gordon Dunning, Division of Biology and Medicine, AEC, and Dr. 

G. V. LeRoy, University of Chicago. During all phases of the early care of the exposed individuals, the foregoing participated as much as their other primary duties would permit. In 

addition the authors wish to thank them for the extensive and complete data which they collected 

in the atolls or their home laboratories and kindly furnished to the project personnel. 

The continuous help and cooperation of Trust Territory representatives and their aid in 

obtaining necessary control data on native Marshallese at Majuro is hereby acknowledged. 

The authors are particularly indebted to Mr. John Tobin. His help as an interpreter and his 

extensive knowledge of the Marshallese language and habits were invaluable. Lieutentant J. S. 

Thompson, MC, USN, furnished his records on the exposed individuals decontaminated by the 

radiation group of the VP-29 squadron stationed at Kwajalein. 

The authors wish especially to express their admiration for the excellent job done by the 

medical personnel of the U. S. Naval Dispensary, Kwajalein, in completing the extensive laboratory examinations that were required to obtain a prompt initial evaluation of the severity of 

the radiation injury. 

The authors are deeply grateful to Dr. David A. Wood of the University of California Hospital, San Francisco, and Dr. Edward L. Alpen and Miss Pat Roan of NRDL, for invaluable aid 

in carrying out the histopathological evaluation of skin lesions. The extensive contributions of 

Mr. H. H. Hechter in the statistical analyses of the data, and of Mr. C. A. Sondhaus of the 

NRDL in dosage calculations are gratefully acknowledged. 

8 
CONTENTS 

ABSTRACT . . . . . . . . 

FOREWORD . . . . . . . . 

PREFACE . . . . . . . . 

ILLUSTRATIONS . . . . . . . 

TABLES . . . . . . . . . 

CHAPTER 1 INTRODUCTION. . . . . 

1.1 Objectives . . . . . . . 

1.2 General Description of the Exposed Groups 

1.3 Evacuation and Early Care of the Exposed Groups 

1.4 Estimation of Whole Body External Dose . . 

1.5 Estimate of Maximal Skin Dose from the Ground 

CHAPTER 2 CLINICAL OBSERVATIONS AND THERAPY 

2.1 

2.2 

2.3 

2.4 

2.5 

2.6 

2.7 

2.8 

Introduction . . . . . . . 

Symptoms and Signs Related to Radiation Injury 

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Clinical Observation and Therapy as Related to Hematological 

Findings . . . . . . . . . . . 

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The Effect of an Epidemic of Upper Respiratory Infection on an Irradiated 

Population . . . . . . . . . . . . . 

Comparison with the Utirik Group of Diseases Seen in the Rongelap and 

Ailinginae Groups During the Period of Observation . . . . . 

Changes in Weight as an Indication of Disturbance in the Overall 

Metabolism . , . . . . . . . . , . 

The Effects of Pregnancy . . . . . . . . . . 

Discussion on the Use of Antibiotics in this Group and in Radiation 

Injury. . . . . . . . . . . . . . 

CHAPTER 3 SKIN LESIONS, EPILATION, AND NAIL PIGMENTATION . . . 

3.1 

3.2 

3.3 

3.4 

3.5 

3.6 

Introduction-Early Symptomatology Referable to the Skin . . . 

Skin Lesions . . . . . . . . . . . . 

Epilation . . . . . . . . . . . . . 

Nail Pigmentation . . . . . . . . . . . 

Factors Influencing the Severity of Skin Lesions . . . . . 

Correlation with Hematological Findings . . . . . . . 

9 

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CONTENTS (Continued) 

3.7 Discussion . 

........ 

3.8 Conclusions . 

........ 

CHAPTER 4 HEMATOLOGY ........ 

4.1 Introduction . 

........ 

4.2 General Methods ........ 

4.3 

4.4 

4.5 

4.6 

4.7 

4.8 

4.9 

4.10 

4.11 

4.12 

4.13 

Methods of Treating Data, Control Groups. . . . 

Hematological Findings, General . . . . . 

Rongelap Group ......... 

Ailinginae Group ........ 

Utirik Group ......... 

Rongerik Group (Americans) ...... 

Monocytes and Eosinophiles, All Groups .... 

Hematocrit, All Groups ....... 

Morphology of Peripheral Blood ..... 

Comparison of Hematological Findings in Children and Adults, 

Rongelap Group ....... 

Discussion ....... 

CHAPTER 5 INTERNAL RADIOACTIVE CONTAMINATION 

5.1 Introduction . . . . . . . 

5.2 Physical Environment Studies . . . . 

5.3 Animal Studies . . . . . . . 

5.4 Human Studies . . . . . . . 

5.5 Discussion. . . . . . . . 

5.6 Conclusion. . . . . . . . 

CHAPTER 6 RECOMMENDATIONS . . . . 

REFERENCES . . . . . . - - . 

. . . 

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. . . 

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ILLUSTRATIONS 

CHAPTER 1 INTRODUCTION 

1.1 

1.2 

1.3 

1.4 

1.5 

The Living Area on Rongelap Island, Indicating the Light, 

Open-type of Construction . . . . . . . . 

Histogram of Proportion of Total Dose Contributed by Various 

Energy Regions from the Fallout Radiation . . . . . 

Cumulative Dose as a Function of Time After the Detonation . . 

Comparative Depth Doses for Bilateral Exposure from a Small 

Source and Multiple Source 4x Exposure with Cobalt-60 . . . 

Comparative Depth Doses in a Phantom Man of Initial Atomic Bomb 

Radiation and Radiation from a Field of Fission Products . . 

CHAPTER 2 CLINICAL OBSERVATIONS AND THERAPY 

2.1 The Blood Count Changes in a Two Year Old Child with Fever . 

2.2 The Blood Count Changes in a Fifty Year Old Man with Fever . 

. . 27 

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ILLUSTRATIONS (Continued) 

CHAPTER 3 SKIN LESIONS, EPILATION, AND NAIL PIGMENTATION 

3.1 Comparison of the Incidence and Time of Appearance of Epilation 

and Neck Lesions in the Rongelap and Ailinginae Groups . . . 

Color Plates 

3.1 

3.2 

3.3 

3.4 

3.5 

3.6 

3.7 

3.8 

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3.11 

3.12 

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3.14 

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3.16 

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3.21 

3.22 

3.23 

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Early Hyperpigmented Maculopapular Neck Lesions at 15 

Days. Case 39, Age 15, F. . . . . . . . . 

Neck Lesions at 28 Days. Wet Desquamation. White Color Is 

Calamine Lotion. Case 78, Age 37, F. . . , . . . 

Repigmenting Superficial Neck Lesions at 40 Days. Hyperpigmented 

Areas not Completely Desquamated. Case 24, Age 15, F. . . 

Healed Neck Lesions at 77 Days Showing Dusky Pigmentation of 

BackofNeck. Case39,Age15F. . , . . . . . 

Hyperpigmented Raised Plaques and Bullae on Dorsum of Feet and 

Toes at 28 Days. One Lesion on Left Foot Shows Deeper Involvement. 

Feet were Painful at This Time. . . , . . . . 

Lesions 10 Days Later. Bullae Have Broken, Desquamation is 

Essentially Complete, and Lesions Have Healed. Feet no Longer Painful . 

Lesions 6 Days Later Showing Repigmentation Except for Small Scar 

on Dorsum of Left Foot at Site of Deepest Lesion . . . . 

Extensive Lesions in Boy, Age 13, Case 26 . . . . . 

Extensive Lesions in Boy, Age 13, Case 26 . . . . . 

Whole Body View of Lesions in Same Case as Plates 3.8-3.9 . . 

Whole Body View of Lesions in Same Case as Plates 3.8-3.9 . . 

Desquamation of Back of Scalp at 28 Days. Epilation Occurred 

Earlier in Desquamated Area. (See Plate 3.14.) Note Persistent 

Ulceration of Left Ear. . . . . . . . . . 

Eighteen Days Later. Scalp Lesions Have Healed With Repigmentation 

of Skin. No Hair Growth Evident in Epilated Areas. Ear Ulceration 

Persists With Little Improvement. . . , . . . . 

Epilation in Man at 18 Days. Case 79, Age 41. Scalp Lesions Present 

in Areas of Epilation. (Same Case as in Plates 3.12 and 3.13.) . . 

Spotty Epilation in Boy, Age 13, at 28 Days. Case 26. Note Scalp 

Lesions in Areas of Epilation. (Same Case as in Plates 3.8-3.11.) . 

Epilation in 7 Yr. Old Girl at 28 Days. Case 72. . . . . 

Pigmented Bands in Semilunar Area of Fingernails at 77 Days . . 

(X100, H&E) Epidermis: Extensive Transepidermal Damage With 

Less Involved Zones on Either Side . . . . . . . 

(X100, H&E) Epidermis: Arcades of Minimal Damage Occur in 

Relation to Excretory Ducts of Sweat Glands. . . . . . 

(X400, H&E) (Case #26) Transepidermal Damage With Disorganization 

of the Malpighian Layer . o . . . . . . . 

(X100, H&E) (Case #63) Transepidermal Damage With Disorganization 

of the Malpighian Layer . 

(X100, H&E) (Case t75) Loose ‘Lamiiatio: of Stratum Corneum Wid 

Outward Papillary Projections and Resultant “Rugose” Appearance . 

(X400, H&E) (Case 875) Same as 3.22. Occasional Perinuclear 

Cytoplasmic Halos in Mid Stratum Granulosum . . . . . 

(X100, H&E) (Case #39) Narrow Rugose Epidermis With Papillary 

Extensions Downward of Stratum Malpighii . . . . . 

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ILLUSTRATIONS (Cant i wed) 

CHAPTER 4 HEMATOLOGY 

4.1 

4.2 

4.3 

4.4 

4.5 

4.6 

4.7 

4.8 

4.9 

Serial Changes in Neutrophile Counts of Rongelap Group for Those 

Less than 5 Years and Greater than 5 Years of Age . . . 

Serial Changes in Lymphocyte Count of Rongelap Group for Those 

Less than 5 Years and Greater than 5 Years of Age . . . 

Comparative Serial Changes in the Total Leukocyte, Neutrophile, 

and Lymphocyte Counts in Those Greater than 5 Years Old, 

Rongelap Group . . . . . , . . . . 

Serial Platelet Changes in Those Less than 15 Years and Greater 

than 15 Years of Age of the Rongelap Group . . . . 

Serial Total Leukocyte, Neutrophile, and Lymphocyte Count in 

Exposed Americans . . . . . . . . . 

Serial Platelet Counts in Exposed Americans . . . . 

Serial Eosinophile Counts on Those Less than and Greater than 5 

Years of Age of the Rongelap Group . . . . . . 

Serial Hematocrits for All Exposed Groups . . . . 

Cumulative Neutrophile Counts for the Rongelap, Ailinginae and 

Majuro Groups at the Time of Peak Depression . . . 

4.10 Cumulative Lymphocyte Counts for the Rongelap, Ailinginae and 

Majuro Groups at the Time of Peak Depression . . . 

4.11 Cumulative Platelet Counts for the Rongelap, Ailinginae, Utirik 

and Majuro Groups at the Time of Peak Depression . . . 

CHAPTER 5 INTERNAL RADIOACTIVE CONTAMINATION 

5.1 Well, Rongelap . . . . . . . . . . . 

5.2 Cistern, Rongelap . . . . . . . . . . 

5.3 Autoradiograph of Rongelap Chicken Tibia, 1%~ , 21 Hr Exposure 

Animal Sacrificed 45 Days Post-exposure. . . . . . 

5.4 Autoradiograph of Rongelap Pig Tibia, 42 Hr Exposure. Animal 

Sacrificed 58 Days Post-exposure . . . . . . . 

TABLES 

CHAPTER 1 INTRODUCTION 

1.1 Exposed and Control Unexposed Groups . . . . . . 

CHAPTER 2 CLINICAL OBSERVATIONS AND THERAPY 

2.1 Diseases that Appeared During Observation of the Rongelap and 

Ailinginae Groups . . . . . . . . . . 

2.2 Diseases that Appeared During Observation of the Utirik Group . 

2.3 Weight Changes, Rongelap and Ailinginae Groups . . . . 

2.4 Blood Counts on Pregnant Individuals, Rongelap and Ailinginae 

Groups . . . . . . . . . . . . 

2.5 Patients Treated With Antibiotics . . . . . . . 

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12 
TABLES (Continued) 

CHAPTER 3 SKIN LESIONS, EPILATION, AND NAIL PIGMENTATION 

3.1 Lesions in Rongelap Group . . . . . . . 

3.2 Lesions in Ailinginae and Rongerik Groups . . . . 

9.3 Surface Doses in rep Required to Produce Recognizable 

Epidermal Injury . . . . . . . . . 

CHAPTER 4 HEMATOLOGY 

4.1 

4.2 

4.3 

4.4 

4.5 

4.6 

4.7 

4.8 

4.9 

4.10 

4.11 

Hematological Results, Control Groups . . . . . 

Rongelap Group, Mean Blood Counts By Day and By Age . . 

Ailinginae Group, Mean Blood Count By Day and By Age . . 

Utirik Group, Mean Blood Count By Day and By Age . . . 

Rongerik Group, Mean Blood Count By Day . . . . 

Rongelap Group, Mean Blood Counts at Time of Peak Depression 

Ailinginae Group, Mean Blood Counts at Time of Peak Depression 

Hematocrit, All Exposure Groups . . . . . . 

Comparison By Age of Mean Neutrophile, Lymphocyte and Platelet 

Counts in the Rongelap Group at the Time of Peak Depression . 

Characteristics of Available Data on the Hematological Effects of 

Penetrating Radiation . . . . . . . . 

Mean Peripheral Blood Count Values for Several Control 

Populations (x 10’) . . . . . . . . . 

CHAPTER 5 INTERNAL RADIOACTIVE CONTAMINATION 

5.1 Gross Beta Activity in Urine of Rongelap Group . . . 

5.2 Radiochemical Analysis of Tissues and Urine of Romrelan Pins 

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CHAPTER 1 

INTRODUCTION 

1.1 

out 

1.2 

OBJECTIVES 

Project 4.1 was organized with the following specific objectives: 

(1) To evaluate the severity of the radiation injury in the human beings exposed to the fallradiation. 

(2) To provide for all necessary medical care for these individuals. 

(3) To conduct a scientific study of radiation injury in human beings. 

GENERAL DESCRIPTION OF THE EXPOSED GROUPS 

Shot 1 of Operation CASTLE was detonated on 1 March 1954. Following the detonation significant amounts of radioactive materials fell on the following populated neighboring atolls: 

(1) Rongelap, (2) Ailinginae, (3) Rongerik, and (4) Utirik. Exposure groups are identified according to their geographical location at the time of exposure. The numbers of individuals involved, their location, the distance of the atoll on which they were located from the site of the 

detonation on Bikini, the calculated dose of radiation, the probable time of beginning of the fallout and its duration are tabulated in Table 1.1. The Rongelap group received the highest calculated dose. These individuals were living under relatively primitive conditions in lightly constructed palm houses (Fig. 1.1). The Ailinginae people were a part of the Rongelap group who 

were on their Ailinginae farms from the time the fallout began to the time of evacuation. Their 

l calculated dose was smaller than that of the other members of their group that had remained 

on Rongelap. The third and largest group of Marshallese, inhabitants of the atoll of Utirik, 

received the smallest dose of radiation. 

-The American military personnel exposed on Rongerik were aware of the significance of 

fallout and promptly put on additional clothing to protect the skin. As far as duties would permit, they remained inside of Butler-type buildings. In contrast, most of the native Marshallese 

remained out of doors and thus were more heavily contaminated by the material falling on the 

atolls. Some of the Marshallese, however, went swimming during the fallout and many of the 

children waded in the water; thus washing a considerable amount of the material from their 

skins. 

1.3 EVACUATION AND EARLY CARE OF THE EXPOSED GROUPS 

The American military personnel were evacuated to Kwajalein via air in two groups on 

2 March. The native Marshallese were evacuated by a combination of air and surface transY 
port&ion. Since a survey of all individuals ehtied -there was significant contamination of 

skin and clothes, prompt decontamination was instituted. Clothes were removed and laundered. 

Their skin and hair were washed repeatedly with fresh water and soap. In many individuals, 

particularly in the Marshallese, it was difficult to wash the radioactive material from the hair 

because of the heavy coconut-oil hair dressing used by these people. 

Table 1.1 EXPOSED AND CONTROL UNEXPOSED GROUPS 

Group 

Designation 

Approximate Instrument 

Total Distance Effective Readings Best Estimate 

Number from Bikini Time of Time of Used in Dose of Total Gamma 

in Group (Naut. Miles) Fallout Evacuation Calculations Dose in Air(r)* 

. 

Americans, 

Exposed 

Rongerik 

Americans, 

Control 

Kwaj-American 

Marshallese, 

Exposed 

Rongelap 

Ailinginae 

Utirik 

Marshallese, 

Control 

Majuro Group 

28 

105 

135 H + 6.8 hr H + 28.5 hr 280 mr/hr 78 

(8 men) H + 9 days 

H + 34 hr 

(20 men) 

64 

18 

157 

117 

105 

83 

270 

H+4hr H+ 50hr 375 mr/hr 175 

(16 people) H + 7 days 

H + 51 hr 

(48 people) 

H+4hr H + 58 hr 100 mr/hr 69 

H + 9 days 

H + 22 hr Started at 40 mr/hr 14 

H + 55 hr H + 8 days 

Completed at 

H + 78 hr 

Total Exposed- 267 

Total Controls - 222 

*See Section 1.4.3. 

1.4 ESTIMATION OF WHOLE BODY EXTERNAL DOSE 

The estimated values of external dose given in Table 1.1 were based on readings of 

AN/PDR-39 field instruments. Averages of a number of dose rate measurements on each 

island at a given time were used. The readings were taken in air, approximately 3 feet above 

ground, several days after the inhabitants were evacuated. Before this time, adequate surveys 

with well calibrated instruments had not been possible. 

Several variables which influence the results are indicated below. These will be discussed 

in greater detail in an addendum report on external dose, which will contain the data, methods 

and calculations by which the external dose analysis was made. 

1.4.1 Energy Distribution of the Fallout Gamma Radiation, Its Variation With Time, the 

Response of the Meter in Each Energy Region and Its Correction Factor for the Total 

Dose Spectrum 

- 

Fallout deposited as an effectively infinite plane source resulted in the dose-energy histogram shown in Fig. 1.2. Its energy distribution was the result of degradation of the original 

16 
. 

Fig. 1.1 The Living Area on Rongelap Island, Indicating the Light, Open-type of Construction 
------ ORIGINAL SOURCE SPECTRUM 

INFINITE PLANE,3’IN AIR 

200 400 600 000 1000 I500 

ENERGY (KEV) 

Fig. 1.2 Histogram of Proportion of Total Dose Contributed by Various Energy Regions 

from the Fallout Radiation 

. 
source energies, mainly by Compton scattering in air. The dose from each of the resulting 

energy intervals was calculated and plotted as a fraction of the total dose. This was seen to 

group roughly into three regions, with maxima at 100, ‘700, and 1500 kev. An exposure to such 

a source was thus the resultant effect of partial doses from each region, making the exposure 

energy conditions quite different from those of the clinic or laboratory. 

Figure 1.2 illustrates the dose spectrum of 4-day-old fallout from a cloud sample. In the 

absence of other data to the contrary, this had to be taken as representative of the fallout on 

all of the islands. At this time the proportion of low energy component was at its maximum. 

During the several days before and after this time, the general shape of the spectrum apparently did not vary grossly from that illustrated here, since the observed flux decay rates 

closely followed that of the observed gamma dose rate. For the period between fallout and 

surveys, therefore, a knowledge of instrument response to each energy region allowed a total 

correction factor to be calculated. The instruments used were calibrated just prior to the 

surveys, and their readings have been corrected for the spectrum shape here illustrated. 

1.4.2 Rate of Decay of the Fallout Mixture 

Decay rates of fallout samples were measured in the field and in the laboratory, where a 

fairly consistent pattern was observed among various locations and samples. In addition, 

theoretical considerations based on the radiochemical composition of the fallout mixture permitted decay rates to be calculated for different intervals between the times of initial exposure 

I and later survey readings. These agreed well with the experimental data, and were used both 

in the dose calculations during the exposure intervals and in extrapolating the later survey 

readings to earlier times. 

1.4.3 Time of Arrival of the Radioactive Cloud, Duration of the Fallout, and Time of Evacuation for Each Case 

Only the time of evacuation is known accurately for all the islands. On Rongerik, however, 

the time of arrival of the radioactive cloud was determined precisely by the continuously recording dose rate monitor at the weather station. The fallout became visible at the time the 

instrument first indicated the presence of a radiation field above background. The material 

had the appearance of snow. The times of beginning of fallout on Rongelap and Ailinginae 

were estimated from similar visual observations, combined with knowledge of the. relative 

distances of these atolls from Bikini and the wind velocities in the area. Fallout was not observed on Utirik, hence the estimate of arrival time there was made on the basis of the Rongerik fallout time, wind, and distance factors. 

Two extreme possibilities exist relative to the duration of the fallout: the first, that the 

fallout occurred entirely within a short time; the second, that it was gradual and extended over 

a period of many hours. The monitoring instrument on Rongerik went off-scale at 100 mr/hr, 

‘/r hour after the dose rate began to rise above background. If this rate of increase is extrapolated to a point for which subsequent decay would reduce the dose rate to the values found at 

later times, a long fallout is implied. This was taken as one limiting case, and corresponding 

doses were calculated. However, the possibility does not seem great that this actually occurred. Existing data are inconclusive, but several indications tending to favor the short time 

hypothesis are summarized below. 

First: a long fallout probably would not be uniformly heavy throughout, the first portion 

being the most intense and the balance tailing off. The total phenomenon thus tends toward 

the effect of a shorter fallout. This is supported by monitor data from other nuclear events. 

Second: the estimated durations of fallout, of about 18 hours, which result from the above 

extrapolation for Rongerik and Rongelap, appear too long to have occurred at the distances of 

these atolls from Bikini, since the wind velocity in the area was high enough for the cloud to 

pass over the islands in a considerably shorter time. 

Third: the accounts of the visibility of the fallout, although conflicting, do not seem to 

indicate such late cessation. 

19 
Fourth: doses calculated on the long fallout hypothesis are lower than those due to a short 

fallout, since a short fallout quickly deposits a large amount of activity. Gn Rongerik, a set of 

film badge readings covered the range listed below. Several badges worn both outdoors and 

P inside buildings on the island read 50-65 r, and one badge which remained outdoors over the 

28.5 hr period read 98 r. Another group kept indoors inside a refrigerator read 38 r. These 

dose values represent a variety of conditions, but considering the shielding and attenuation 

factors, are consistent with the assumption that the dose reached the calculated upper limit 

outside, again favoring the shorter fallout hypothesis. The upper limit of 98 r will result if it . 

is assumed that the fallout lasted one hour during which the intensities rose from zero to the 

maximum dose rate which then decayed to values observed later. A long fallout will not produce such a high dose of radiation. 

Fifth: on Utirik, only a short fallout time is consistent with the later dose rates observed, 

provided the fallout began as late as was estimated from wind and distance factors. A one 

hour duration* of fallout appears likely. On the other islands the actual fallout time is known 

to have exceeded one hour; however, since the approximate dose discussed above was seen to 

fit the film data on Rongerik, it was used for the other islands as listed in the calculations in 

Table 1.1. The hour limit is thus “an effective value.” 

If the long fallout case is also considered, a lower limit for the dose may also be estimated, though the upper limit is taken as most probable. The ranges are then as follows: 

rk 

Rongerik 50 r-104 r; Rongelap 102 r-175 r; Ailinginae 53 r-69 r; and Utirik -14 r. 

The dose value for Rongerik given in Table 1.1 is 75 per cent of the short fallout case 

value, averaged for 28.5 and 34 hour exposures. This best expresses the average air dose received by personnel who spent roughly half their time inside structures where the dose rate 

was later found to be roughly half that outdoors. On the other islands no such shielding was 

present. 

Figure 1.3, for the Rongelap atoll, illustrates the cumulative dose as a function of time 

after the detonation. It can be seen that the rate of delivery of the dose varied continuously, 

the major portion being received at the higher dose rate prevailing in the early portion of the 

exposure period. By the time that 90 per cent of the dose had been received, for example, the 

dose rate had fallen to less than 30 per cent of its initial value. Thus the dose rate of exposure 

differed markedly from that usually encountered using x-ray units. 

1.4.4 Geometry of the Exposures 

A third difference between the type of exposure encountered here and other external exposures lay in the geometry of the source. These doses were delivered from a plane source, 

so that the radiation field did not follow the narrow beam geometry usually employed experimentally. In such a diffuse 360” field, the decrease of dose with depth in tissue is less pronounced than that resulting from a unilateral or bilateral exposure to an X-ray beam, so that 

for a given energy, the dose at the center of the abdomen is approximately 50 per cent higher 

than a given air dose would imply for the narrow beam case. Figure 1.4 illustrates an experimental simulation of the field geometry using a spherically oriented group of Co” sources 

with a phantom placed at their center, compared with a conventional depth dose curve obtained 

with a single source. It would appear under the circumstances that the midline dose, rather 

than dose measured in air, would be the better parameter in terms predicting biological effects. On this basis, the air dose values stated in Table 1.1 should be multiplied by approximately 1.5 in order to compare their effects to those of an exposure using a narrow beam 

geometry. If this is done, assuming a fast fallout of one hour, the following doses in terms of 

an air dose under laboratory conditions result: Rongelap 260 r; Ailinginae 100 r; Rongerik 

120 r; and Utirik 21 r. 

*While it is obvious that the fallout lasted longer than one hour, calculations of dose are 

based on an assumed one hour fallout as explained in the text. 
, 

IO i 30 

TIME (HR) 

Fig. 1.3 Cumulative Dose as a Function of Time After the Detonation 

9 I I I I I I 

DIVERGING SOURCE 

0 5 IO I5 20 25 30 

CM MASONITE 

DEmi DOSE DISTRIBUTION IN CYLINDRICAL PHANTOM, co60 FACILITY, (NMRI) 

Fig. 1.4 Comparative Depth Doses for Bilateral Exposure from a Small Source and Multiple 

Source 4r Exposure with Cobalt-60 

21 
1.5 ESTIMATE OF MAXIMAL SKIN DOSE FROM THE GROUND 

In addition to the total body gamma dose, the very soft gamma and higher energy beta 

radiation from the plane source contributed to the skin dose. Further skin irradiation resulted from local deposits of fallout material on the body surface itself. The latter is impossible to estimate, but the former may be roughly attempted as follows. 

The beta dose rate in air at a height of 3 feet above the surface of an infinite plane contaminated with mixed 24-hour-old fission products is estimated to be about three times the 

P 

II 

DEPTH DOSE IN PHANTOM MAN : 

- INITIAL RADIATION I 

I 

“0” RESIDUAL FIELD I 

: 

: 

: 

I 

I 

200 j-i- i 

i 

. I’ 

100 

I 

I 

\ 

50 

” 

iI 

0 

I I I 

IO 20 : 

DEPTH (CM) 

Fig. 1.5 Comparative Depth Doses in a Phantom Man of Initial Atomic Bomb Radiation and 

Radiation from a Field of Fission Products 

gamma dose. The midline gamma dose is approximately 60 per cent of the portion of the air 

gamma dose due to 60 kv radiation or above. This portion in turn is estimated to be 90 per 

cent of the gamma dose measured in air by the instrument. Thus the dose at the surface of a 

phantom exposed to mixed fission product radiation from an external plane source might be 

expected to be 3/(0.6)(0.9) or about six times the midline dose, if both occur at 3 feet off the 

ground. Such a depth dose measurement has in fact been made experimentally at a previous 
field test,* using a phantom man exposed to both the initial and residual radiation. The depth 

I 

doses for each situation are shown in Fig. 1.5, with all data as per cent of the 3 centimeter 

dose. With the diverging initial radiation from the point of explosion, the exit dose was seen 

to be 63 per cent of the 3 cm dose, but with the diffuse residual field of fission product radiation, a surface dose some eight times greater than the 3 cm and deeper dose from the harder 

gamma components was observed. This is seen to be of the same order of magnitude as that 

estimated above. At heights above and below the 3 foot level this surface dose would become 

lower and higher respectively, but probably would not exceed 50 times the 3 foot air gamma 

’ dose or 80 times the midline dose, even in contact with the ground. An estimate of skin dose 

due to ground contamination for the Rongelap case would result, for example, in a figure of 

about 2000 rep to the dorsum of the foot, 600 rep at the hip level, and 300 rep at the head if 

continuous exposure with no shielding occurred. Some reduction in dose undoubtedly resulted 

from shielding and movement, and it seems probable that the external beta dose from local 

skin contamination far outweighed that from the ground in importance. This is emphasized by 

the fact that clothing probably reduced the beta dose from the ground by 10 to 20 per cent. 

, 

* F. W. Chambers, Project 2.2b, Residual Gamma Depth Dose Measurements in UnitDensity Material, AFSWP, WT-719, Operation UPSHOT-KNOTHOLE. 

23 
. 

CHAPTER 2 

CLINICAL OBSERVATIONS 

2.1 INTRODUCTION 

AND THERAPY 

It was known immediately that the exposed groups had received a significant amount of 

penetrating radiation to the entire body, extensive contamination of the skin, and possible internal deposition of radioactive materials. It was therefore decided that clinical observations 

would be as extensive and frequent as facilities and personnel permitted in order to recognize 

and care for radiation effects as early as possible. Accordingly complete initial histories and 

physical examinations with numerous follow-up examinations were carried out. Surveys of the 

skin were conducted at frequent intervals and the detailed skin findings are reported in chapter 

3. Extensive hematological studies were conducted, the detailed results of which are presented 

in chapter 4. Results of examinations for urinary excretion of radioisotopes are reported in 

chapter 5. 

In addition to periodic examinations, routine sick call was held twice daily. Medical care 

was available at all times and hospital facilities were available at the Kwajalein Naval Dispensary. 

In view of the widespread conflicting opinions in regard to the value of various prophylactic 

and therapeutic measures in treatment of radiation effects, it was decided in advance that 

therapy would not be given arbitrarily but would be instituted as indicated clinically for specific conditions on an individual basis. However, if severe granulocytopenia developed (below 

1000 cells/cm) the prophylactic use of antibiotics was to be considered. Whole blood transfusions were likewise to be used only in case of development of serious anemia. 

2.2 SYMPTOMS AND SIGNS RELATED TO RADIATION INJURY 

Several symptoms that developed during the first day or two after exposure probably were 

attributable to radiation. Itching and burning of the skin and eyes during this period occurred in 

over one quarter of the Rongelap population, to a lesser extent in the Ailinginae and to a very 

slight extent in the Americans. The skin symtomatology* might have been due in part to the 

marked alkalinity of the fallout material (calcium oxide). About two thirds of the Rongelap 

group reported nausea during this early period and one tenth of the group reported vomiting 

and diarrhea. Only one Ailinginae individual reported nausea. The people of Utirik and the 

Americans developed no signs or symptoms that might be related to radiation. 

*The symtomatology is based on questionings through an interpreter by several observers. 

Despite the repeated interrogations and the inevitable suggestion of the interrogators, the stories remained remarkably consistent. 

24 

. 
With the exception of the development of skin lesions and epilation, physical examinations 

at no time revealed findings in any group that could be attributed with certainty to radiation. 

The various clinical conditions encountered in the most severely exposed groups were not remarkably different from those seen in the least exposed Utirik group. The skin lesions and 

epilation appeared about the 12th to 14th post-exposure days. 

2.3 CLINICAL OBSERVATION AND THERAPY AS RELATED TO HEMATOLOGICAL 

FINDINGS 

Although detailed hematological findings are presented in chapter 4, certain considerations 

of the relation of clinical to hematological findings are discussed here. 

2.3.1 Leukocyte Counts 

Between the 33rd and 43rd post-exposure days, 10 per cent of the Rongelap individuals 

reached an absolute granulocyte level of 1000 per cubic millimeter or below. The lowest count 

observed during this period was 700 granulbcytes. During this interval the advisability of giving prophylactic antibiotic therapy to such individuals was carefully reconsidered. However, 

prophylactic antibiotics were not instituted because of the following considerations: 

(1) All individuals were under continuous medical observation so that infection would be 

discovered in its earliest stages. 

(2) Since some individuals might require antibiotics for long periods of time if infection 

occurred, the premature administration of such drugs would not only possibly obscure medical 

indication of treatment, but might potentially lead to the development of drug resistant organisms in an individual with an already lowered resistance to infection. 

(3) There is no accurate knowledge of the number of granulocytes required by man to prevent the types of infection seen in agranulocytosis. 

(4) The observed situation was’not strictly comparable to agranulocytosis with an aplastic 

marrow due to potentially lethal doses of radiation. In the latter instance, granulocytes fall 

rapidly and there are practically none in the circulation when infection occurs. In the present 

group of individuals exposed to radiation, although most counts were approximately one-fourth 

of normal, the fall to that level was gradual and there was some evidence of granulocyte regeneration . 

White counts were repeated at three or four day intervals on all of the exposed individuals 

and more frequently on those with the lowest counts. Those with symptoms or elevated temperatures were treated only after an attempt to establish a diagnosis was made, even if a period 

of observation was necessary. During the observation period, the patients were examined at 

frequent intervals and the temperature checked every few hours. 

Twenty-seven individuals had total leukocyte counts of 4000 or below or absolute neutrophile counts of 2500 or less at some time during the period of observation. Of these 27, 13 

had symptoms of disease that required evaluation for possible antibiotic therapy. Eleven of the 

13 had severe upper respiratory infections, one individual had abdominal pains and fever, and 

one had urticaria (hives) with fever. The incidence and type of symptoms in the group with low 

leukocyte counts did not differ materially from those in the remainder of the population and it 

appeared that the occurrence of disease and the preeence of leukopenia was coincidental. The 

13 instances in which it was necessary to consider the use of antibiotic therapy in neutropenic 

individuals are summarized below: 

Eleven of the 13 individuals had severe upper respiratory infections. Eight of these had 

malaise, sore throat, nasal discharge, and .temperatures that varied between 99 and 101.4”F and 

then fell to normal within a 12 hour period. Since the response of this group to upper respiratory infection appeared identical with that of individuals without neutropenia, no therapy was 

given. Two of the 11 had marked malaise, headache, abdominal pain, nausea, diarrhea, and high 

fever. Both were children, one age seven, the other age two. In both instances, the symptoms 

were out of proportion to the physical findings, which were negative except for head colds and 

mild pharyngeal injection. The seven-year old child had a temperature of 102.6 when first seen 

25 
and 4 hours later, 104. The two-year old child had an initial temperature of 101.8 degrees 

which rose to 103.5 degrees in 4 hours. Both were given intramuscular procaine penicillin 

when the sharp rise in temperature occurred, and both were without symptoms and fever the 

following day. A second injection of penicillin was given at this time, and therapy was discontinued. In spite of the fact that the neutrophiles remained depressed in both cases long after the 

fever had passed, both individuals recovered and had no further illness. In Figure 2.1 the blood 

counts and platelets of the two-year old patient and the time of the occurrence of the illness 

with fever are illustrated. A one-year old boy had symptoms of upper respiratory infection for 

several days before being brought to the clinic. When he was seen, his temperature was 100.8 

degrees. In addition to the head colds there was pharyngeal injection and numerous coarse 

rhonchi (wheezing) throughout the chest. A diagnosis of upper respiratory infection with associated bronchitis was made and the child was given a single intramuscular injection of procaine penicillin. On the following day no rales or rhonchi were heard, the temperature was 

QQ’F, and he remained asymptomatic without further treatment. 

One of the 13 individuals was a 50-year old man who reported to the clinic with weakness, 

nervousness, mild abdominal pain, and shooting pain in the upper anterior chest, bilaterally. 

He appeared moderately ill, his temperature was 99.6”F, and the only positive physical finding 

was moderate tenderness in the right upper quadrant of the abdomen. Since his granulocyte 

count remained low on repeated examination, he was seen at frequent intervals. Within a 10 hour 

period the temperature rose to 101.6”F, following which it fell gradually to normal. The abdominal tenderness continued for 24 hours and then gradually disappeared during the subsequent 

two days. A diagnosis of cholecystitis (inflamation of the gall bladder) was made. No specific 

therapy was given. In Figure 2.2 his white blood count and platelet counts in relation to the 

appearance of symptoms are shown. 

A female, 38, developed generalized urticaria, fever, and headache. Urticaria and fever 

subsided within 8 hours without any therapy. 

2.3.2 Platelet Counts 

All individuals with a platelet count of 100,000 or less were examined daily for evidence of 

hemorrhage into the shin, mucous membranes, and retinae. Urine was examined for red cells 

and albumin, and women were questioned concerning excessive menstruation. There was no 

evidence of hemorrhage into tissues even though 11 individuals reached platelet levels between 

35,000 and 65,000. Two women menstruated when their platelet counts were 150,000 and 130,000 

respectively. Both menstruated several extra days and thought that the bleeding was excessive 

but not sufficient to cause concern. 

2.3.3 Hematocrit Changes 

Nineteen individuals in the Rongelap group had hematocrits of 35 per cent or below; however, none of these were below 31 per cent. Nine of the 19 were children, aged one to five years 

who would be expected to have a lower hematocrit than normal adults; four were over 70 years 

of age, in which age group a decreased hematocrit is frequently present without obvious cause. 

Two of the 19 had had menorrhagia (Profuse menstruation) prior to the determination, two were 

three to four months pregnant and had not received supplementary iron, and two were young 

women. The low hematocrits that were observed could be explained on the basis of normal 

physiological variations rather than to the effects of irradiation on hematopoiesis (blood formation). At no time were whole blood transfusions considered since hematocrits remained 

within levels consistent with well being and normal activity. 

2.4 THE EFFECT OF AN EPIDEMIC OF UPPER RESPIRATORY INFECTION ON AN 

IRRADIATED POPULATION 

Between the 27th and 42nd post-exposure days an epidemic of upper respiratory diseases 

(URI) occurred. Fifty-eight per cent of the Rongelap group and 56 per cent of the Ailinginae 

group were involved. Seventy per cent of the affected individuals developed symptoms between 

26 
. 7-T-F 

I 
7 

6 

5 

4 

3 

IQ 

0 2 

x 

fn 

A I 

w - 

” 200 

L5C 

100 

0 

TOTAL LEUKOCYTES 

SYMPTOMS 

cl----o’ TOTAL NEUTROPHILES 

_- 

POST EXPOSURE DAY 

Fig. 2.2 The Blood Count Changes in a 50 Year Old Man with Fever 

. l . 
the 27th and 32nd post-exposure days. During the period in which individuals were developing 

symptoms of the respiratory infection, the leukocyte count of some diverged from the population trend. Fifty-two per cent of the leukocyte counts were observed to increase to higher 

levels, the increase being due primarily to granulocytes (see chapter 4). Since the increase in 

the mean granulocyte count of the entire population occurred about the time the epidemic of URI 

developed, it seemed pertinent to determine whether in individual instances the increase was 

spontaneous or was in some way related to the presence of respiratory Mection. The relationship between the observed leukocyte increase and the presence or absence of upper respiratory 

symptoms in the individuals exposed to radiation suggested that the two effects were unrelated. 

Table 2.1 DISEASES THAT APPEARED DURING OBSERVATION 

OF THE RONGELAP AND AILINGINAE GROUPS 

Disease 

Number of 

Individuals 

Furuncle (boils) 

Gum Abscess 

Cholecystitis 

(inflamation of 

gall bladder) 

Tinea (ringworm) 

Mittelschrnerz 

(intermenstrual pain) 

Generalized urticaria 

(hives) 

E rythema multiforme 

(red rash) 

Migraine headache 

2 

1 

1 

1 

1 

1 

1 

1 

Disease 

Number of 

Individuals 

Bronchitis 1 

Apyetous ulcer of tongue 1 

(canker sore) 

Spondylolisthesis 1 

(malformation of 

vertebra) 

Impetigo 5 

Tooth extractions 2 

Castroenteritis 10 

(inflamation of stomach 

and intestines) 

Upper respiratory infections 47 

Follicular tonsillitis 1 

Of the 64 individuals from Rongelap, 27 had no respiratory infection and of these 13 (48 per 

cent) without URI showed a rise in leukocytes; 3’7 had the infection, and of these, 24 (53 per 

cent) showed a rise; 7 of these 24 showed a rise three or more days before symptoms appeared. Of the 18 from Ailinginae, 8 had no respiratory infection and 3 (37 per cent) of these 

showed a rise; 10 had the infection, of these, 3 (33 per cent) showed a rise in count. 

It is also of interest that not only the irradiated individuals developed the respiratory infection but in addition the medical personnel involved in their care and study also developed 

equally severe respiratory infections. The respiratory infections consisted of moderate malaise, sore throat with prominent lymphoid follicles, pharyngitis, moderate fever on the first 

day, and a purulent (pus) nasal and tracheal discharge for 10 days. 

2.5 COMPARISON WITH THE UTIRIE GROUP OF DISEASES SEEN IN THE RONGELAP AND 

AILINGINAE GROUPS DURING THE PERIOD OF OBSERVATION 

The diseases that were seen in the Rongelap and Ailinginae group‘s during the period of 

observation are listed in Table 2.1. None of these appeared to be related to the effects of irradiation, either directly or as a result of the hematologic disturbances. For comparison, the 

diseases that were seen in the Utirik group during the period of observation are listed in Table 

2.2. The high incidence of gastroenteritis (inflammation of the stomach and intestines) in both 

groups was probably due to the Marshallese keeping perishable foods unrefrigerated for long 

periods, and was not seen after this practice was stopped. It would appear that a higher percentage of the Rongelap-Ailinglnae group developed upper respiratory infections compared to 

the Utirik group. However, all of the Rongelap-Ailinginae group were questioned concerning 

even mild symptoms of URI, whereas only those of the Utirik group with severe symptoms of 
Table 2.2 DISEASES THAT APPEARED DURING OBSERVATION 

OF THE UTIRIK GROUP 

Disease Number of Cases 

Osteoarthritis (joint disease) 4 

Epithelioma of ankle, with necrotic degeneration 1 

(cancer) 

Chronic bronchitis 1 

Furuncle of calf 1 

Chronic bronchitis and bronchiectasis 1 

Abscess of sole of foot 1 

Carbuncle on right thigh 1 

Tooth extraction 1 

Fungus infection of gums and palate 1 

Contusion, traumatic 2 

Gastroenteritis 30 

Upper respiratory infection4 15 

Arteriosclerotic heart disease, decompensated 1 

Pyelonephritis (inflamation of kidney) 1 

Insect bite, with marked palpebral edema 1 

Chorioretinitis, unknown etiology (retinal 1 

inflamation) 

Thrombophlebitis, antecubital vein (inflama- 1 

tion of vein) 

Impetigo 3 

Dysmenorrhea (painful menstruation) 1 

Exfoliative dermatophytosis (scaling fungus 1 

infection of skin) 

Ectropion, right eye (malformed eyelid) 1 

Asthma 1 

Benign hvpertension with headache (high blood 1 

pressure) 

Hypermetropia with headache (far sightedness) 1 

Myopia with headache (near sightedness) 1 

Fungus infection, auditory canal 1 

Trichomonas with cystitis (inflamation of 1 

bladder) 

Tinea (ringworm) 1 

Simple headache 3 

Bronchitis 1 

Possible ruptured intervertebral disc 1 

Fevers of tmlmown origin 1 

Mongolian idiot 1 

_ 

Pregnancy 6 

URI came to the clinic for treatment. Similarly, the per cent of the Rongelap-Ailinginae group 

that developed purulent infections appears higher than the Utirik group. However, the diseases 

are tabulated for the period of observation of each group, and the Utirik group was observed 

for only half as long since they were moved to another island when it was evident that further 

study was unnecessary. 

2.6 CHANGES IN WEIGHT AS AN INDICATION OF DISTURBANCE IN THE OVERALL METABOLISM 

The body weight of individuals in the Rongelap-Aillnginae group was followed routinely. 

Since they had an unrestricted diet and all ate well, their change in weight might be taken as 

30 

. 

an 

UHCIASSlfllO- .z . 

I . 
indication of any disturbance in their over-all metabolism. The weight changes are summarized 

in Table 2.3. It would be expected that within a period of six weeks, individuals below 16 years 

and particularly those below 8 years would gain some weight. The fact that most of them lost 

weight may indicate that they received a dose of radiation sufficient to interfere with normal 

metabolism. In spite of their relatively inactive life and hearty appetites, most of the adults 

also lost weight which may indicate some interference with their normal metabolism. There is 

little difference in observed weights between the Rongelap and Ailinginae groups. It appears 

that the difference in doses received by the two groups did not differentially affect their body 

weight. Whether the failure to gain weight was connected with radiation or changes in environTable 2.3 WEIGHT CHANGES, RONGELAP AND AILINGINAE GROUPS 

Age Categories 

Below 7 years Below 16 years Above 16 years 

Number observed 

Number that gained 

weight 

Average gain (lb) 

Spread of gain (lb) 

Number that lost 

weight 

Average loss (lb) 

Spread of loss (lb) 

Per cent of group 

that lost weight 

Number observed 

Number that gained 

weight 

Average gain (lb) 

Spread of gain (lb) 

Number that lost 

weight 

Average loss (lb) 

Spread of loss (lb) 

Per cent of group 

that lost weight 

Rongelap Group 

17 24 

4 5 

5 3 

0.5-10.0 0.5-10.0 

13 19 

2 2 4 

0.5-5.5 0.5-5.5 0.5-8 

77 80 58 

Ailinginae Group 

7 

0 

6 

2 2 

0.5-3 0.5-4.0 

00 67 

36 

14 

3.5 

1-11.5 

21 

9 

3 

2.7 

2-4 

6 

ment is open to question. Unfortunately, the weight of the individuals from Utirik was not systematically followed and no satisfactory control exists to aid in interpreting the loss in weight 

of the Rongelap-Ailingmae group. 

2.7 THE EFFECTS ON PREGNANCY 

Four women in the Rongelap group were pregnant when brought to Kwajalein. Two were in 

the first trimester, one in the second trimester, and one in the third trimester. None of these 

women had abnormal symptoms referable to pregnancy, and as far as can be determined pregnancy continued in a normal fashion. In the Ailinginae group, one woman was in the second 

trimester. No abnormality was detected. Fetal movements were unaffected in the individual 

in the third trimester. The hematologic changes of the pregnant women are listed in Table 2.4. 

Two individuals in the first trimester had marked depression of platelets but at no time was 
Table 2.4 BLOOD COUNTS ON PREGNANT INDIVIDUALS 

RONGELAP AND AILINGINAE GROUPS 

__~_ ____ 

Trimester of Lowest Platelet Lowest Lowest 

Pregnancy Count WBC Neutrophile Count 

_~_ _.~_~~ ___~_.__ 

Rongelap Group 

First 35,000 4,500 3,000 

First 50,000 5,000 2,500 

Second 150,000 4,000 3,000 

Third 120,000 10,000 7,000 

Second 

Ailinginae Group 

170,000 7,000 3,200 

. 

I 

i 

Table 2.5 PATIENTS TREATED WITH ANTIBIOTICS 

. 

Patient 

No. Condition 

No. of days Antibiotic 

treated used 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

Deep extensive slough of epidermis 

of foot 

Tooth extraction 

Tooth extraction 

Inflamed tonsils with high 

temperature and URl 

URI and bronchitis with high 

temperature 

URI, severe, with pharyngitis and 

high temperature 

Rapid progressing undermining 

impetigo 

Traumatic gangrene of foot 

Cystitis 

Furuncle on buttock 

Furuncle on forehead 

2 

1 

1 

2 

1 

2 

2 

Penicillin 

Penicillin 

Penicillin 

Penicillin 

Penicillin 

Penicillin 

Penicillin 

Penicillin 

Gantrasin 

Penicillin 

Penicillin 

32 
there any vaginal bleeding. However, all of the pregnant women were blood-typed as a precautionary measure. So far, the exposure to radiation has not had a deleterious effect on pregnancy. Since the departure of the medical group from Kwajalein, one apparently normal baby 

has been born. 

2.8 DISCUSSION ON THE USE OF ANTIBIOTICS IN THIS GROUP AND IN RADIATION’INJURY 

There were few indications for the use of antibiotics when the principles of treatment previously mentioned were used. Individuals in the Rongelap and Allinginae groups that received 

antibiotics are listed in Table 2.5. Of the individuals treated with the antibiotics, the first three 

received it prophylactically and it would have been indicated had they not been irradiated. The 

indication for its use in the next three was questionable. There was a definite indication for its 

use only in the next three individuals and again it would have been given for similar conditions 

in unirradiated individuals. The last two individuals with furuncles (boils) would probably have 

responded equally well to surgical treatment alone, since the infection was well localized and 

easily drained. 

In general, it can be concluded that human beings with the degree of depression of hematopoiesis noted did not need antibiotics prophylactically. With severer degrees of radiation lnjury resulting in a greater depression of hematopoiesis, prophylactic antibiotic therapy may be 

indicated in selected cases. If the number of individuals is small enough so that changes in the 

blood count, temperature, and clinical evidence of infection can be followed closely, it would 

appear that antibiotics should not be staxted until there is a clear-cut clinical indication for the 

use of these agents. 
. 

CHAPTER 3 

SKIN LESIONS, EPILATION, AND NAIL PIGMENTATION 

3.1 INTRODUCTION-EARLY SYMPTOMATOLOGY REFERABLE TO THE SKIN 

The Marshallese on Rongelap saw a visible fallout of powdery material that began approximately five hours after the initial flash was seen. The powder whitened the hair and adhered to 

their skin as a salt-like film. The Marshallese on Ailinginae reported a similar but less strlking fallout,‘The Americans on Rongerik also saw a fallout and described it as “mist-like.” The 

Marshallese’on Utirik did not see a fallout. The early symptoms were limited to the Rongelap, 

Ailinginae, and to a lesser extent the Americans on Rongerik. The early symptoms consisted 

of a generalized itching and burning of the skin, limited almost exclusively to the exposed parts 

of the body. A less consistent symptom was burning of the eyes accompanied by tears. The 

symptoms began the night of the fallout and continued into the next day. A few individuals had 

symptoms lasting as long as two or three days. Decontamination of the skin of the exposed individuals was initiated either aboard the destroyers while they were being evacuated or upon 

their arrival at the naval base on Kwajalein. The classical initial erythema of radiation injury 

to the skin was not noticed by the observers who examined these individuals during the first 10 

days. If an initial erythema developed in the native Marshallese, it was masked by their dark 

skin. An erythema was not seen in the white skinned Americans exposed on Rongerlk. 

3.2 SKIN LESIONS 

3.2.1 General Description 

Skin lesions first appeared in the Rongelap group after 12 to 15 days and in the Allinginae 

and Rongerik groups after 20 days. There were no skin lesions in the Utirik group. There was 

considerable difference in the length of time necessary for the development of the various lesions. However, it was found that there was a consistent pattern in the sequential development 

of lesions on various exposed parts of the body. The principal lesions occurred roughly in the 

following sequential order: scalp (with epilation); neck, axillary region, antecubital fossae, 

feet, arms, legs, and trunk. Lesions on the flexor surfaces tended to precede those on the extensor surfaces (see Table 3.1 for the time of appearance of various lesions). 

A clear cut primary erythema was not seen, nor was a late erythema. In a few cases, 

there was considerable scratching of the skin due to intense itching prior to development of 

gross lesions. In these cases, an erythema of questionable etiology was observed. This erythema may well have been due to the scratching. Erythema was likewise not observed preceding 

development of lesions in the white and Negro Americans of the Rongerik group. 

The first indication of a developing lesion was an increase in pigmentation. These pigmented areas appeared in the form of macules, papules, raised plaques, or larger areas of 

. 

34 
hyperpigmentation. The macules and papules (1 to 2 mm in diameter) usually occurred in 

clusters and sometimes coalesced into larger lesions. The latter were characteristically 

found on the scalp, neck, and the antecubital fossae. The raised plaques varied in size from a 

few millimeters to several centimeters in diameter, were thick, rough, dry, and had a leathery 

feel. This type of lesion occurred predominantly on the feet and in the antecubital fossae and 

to a much lesser extent on the neck. Areas of increased pigmentation also occurred on the 

limbs, trunk, and on the face. 

The majority of the lesions were superficial without blisters. A few days after appearance, 

dry, scaly desquamation occurred in the central.portion of the hyperpigmented areas. The desquamation left a pink to white epithelium not remarkably different in texture from the surTable 3.1 LESIONS IN RONGELAP GROUP 

Per Cent of Total in Age Group having Indicated Lesion 

Median Time 

of First 

Type of 

Lesion 

Epilation 

1 plus 

2 plus 

3 plus 

Total 

Age O-5 Age 6-15 Age 16 & Over Total Group Observation 

(13 people) (13 people) (38 people) (64 people) of Lesions* 

7.6 38.4 13.8 17.2 17 

38.6 30.7 5.5 17.2 17 

53.8 23.0 8.3 22.0 16 

100.0 92.1 27.6 56.2 16 

Skin Lesions 

Anus-Groin 

scalp 

Neck 

Axilla 

AntecubitaI 

Fossae 

Hands-Wrists 

Feet 

Arms 

Legs 

Trunk 

38.4 0.0 0.0 7.8 17 

100.0 100.0 37.0 62.5 18 

69.2 76.9 68.0 70.3 21 

61.5 7.6 15.7 23.4 21 

30.7 38.4 34.2 34.4 28 

30.7 23.0 18.4 21.8 33 

23.0 53.8 53.0 45.3 28 

15.3 15.3 10.3 12.5 31 

7.6 23.0 4.3 7.8 33 

15.3 23.0 4.3 9.4 33 

Nail Pigmentation 

* Post-exposure days. 

61.5 100.0 95.0 89.0 38 

rounding skin. As the desquamation proceeded outward, the areas developed a characteristic 

appearance of a central depigmented area fringed with a hyperpigmented zone. At a later stage, 

pigmentation began in the central areas and spread outwards. After a few weeks the cycle was 

completed, leaving in most instances a relatively normal appearing skin. 

Approximately 20 per cent of the Rongelap group developed lesions which were more severe. These lesions might be considered as comparable to second degree thermal burns. The 

deeper lesions occurred principally on the feet and to a lesser extent on the scalp and neck and 

in one case on the ear. Blister formation was not common. However, on the feet, some large 

bullae (blisters) appeared. After a few days, the hyperpigmented lesions showed wet desquamation with weeping and crusting, leaving depigmented raw surfaces of varying area. Some of 

these lesions became secondarily infected. Epithelium rapidly covered the ulcerated areas 

within a week to 10 days. Pigmentation followed during the next few weeks. As healing occurred many of the more severe lesions (particularly on the neck and antecubital fossae) developed 

a thickening of the skin with an “orange peel” appearance and a dusky, grayish-brown color 

(see Plate 3.4). 
In Table 3.1 is tabulated the incidence of the various types of lesions in the Rongelap group 

with a breakdown as to age and the median time of appearance. Similar data are presented in 

Table 3.2 for the Ailinginae and Rongerik groups. 

3.2.2 Description and Illustration of Specific Lesions 

The scalp and forehead lesions appeared 12 to 14 days following exposure along with epilation in the Rongelap group. The skin lesions were maculopapular with a spotty distribution. 

They were concentrated in the areas of epilation. These lesions are illustrated in Plates 3.12 

to 3.16. Scalp lesions continued their appearance over a period of about a month. Thus, groups 

of lesions in various stages were present in the same individual. This was particularly notable 

among the children. The incidence of scalp lesions was greatest in the 0 to 15 year group (see 

Table 3.1). 

The neck lesions were the most common and began their appearance a few days after the 

scalp lesions. These lesions appeared as hyperpigmented macules and papules which spread 

and coalesced into raised plaques. The lesions usually appeared first on the side and front of 

the neck and spread backwards. They were more common and more severe in women. Plates 

3.1 through 3.4 and 3.9 illustrate neck lesions in the various stages of development. Some of 

the deeper neck lesions tended to occur in women where their thick hair touched their necks. 

Axillary lesions were maculopapular, less abundant, and developed simultaneously with 

the neck lesions. These lesions are illustrated in Plates 3.10 and 3.11. The axillary lesions 

were more common in the young children. 

Antecubital fossae lesions appeared about a week later than did the neck and axillary lesions. These are illustrated in Plates 3.9 and 3.10. 

The foot lesions developed later than the lesions of the antecubital fossae. These lesions 

were located mainly on the dorsum of the foot between or on the toes. They were initially 

characterized by large pigmented plaques with subsequent bullous formation and in eight cases 

raw crusting lesions of varying degree followed the bullae. The foot lesions were not as common in children under 5 years of age as in the older age groups. Sequential lesions in a 14- 

year old girl are shown on Plates 3.5 to 3.7. One of the more severe foot lesions is shown in 

Plate 3.8. 

Lesions of the hands, arms, legs, and trunk were less common, less severe, and developed 

later. Areas of increased pigmentation were scattered over the abdomen, chest, arms, legs, 

and face. Increased pigmentation of the sides of the face is illustrated in Plate 3.4. A striking 

early lesion was an erythematous, weeping, excoriating lesion surrounding the anus which occurred in several of the babies and a few of the older people. These lesions were severe 

initially but healed rapidly. 

Most of the Marshallese had multiple lesions. The combination of epilation and the contrasting hyperpigmented and depigmented areas adjacent to normal skin presented a striking 

appearance. The multiple lesions are illustrated in Plates 3.8 to 3.11. 

3.2.3 Severity and Time Appearance of Lesions in the Various Exposure Groups _ 

It is not feasible to quantify accurately the severity and extensiveness of the skin lesions 

in the various groups. However, it was the uniform opinion of all observers that the most severe and extensive lesions occurred in the Rongelap group. The lesions that developed in the 

Ailinginae group were much less severe and extensive, and the Rongerik group (Americans) 

had only mild lesions. Skin lesions were completely absent in 60 per cent of the Rongerlk 

group, as opposed to approximately 10 per cent in both the Rongelap and Ailinginae groups. 

Transepidermal necrosis occurred in 20 per cent of the Rongelap and in 5 per cent of the 

Ailinginae people. No lesions of this severity were seen in the Rongerik group. 

The lesions appeared earlier in the Rongelap group suggesting a higher dose. The comparison of the incidence of epilation and neck lesions and time of appearance is illustrated in 

Fig. 3.1 for the Rongelap and Ailinginae groups. 

36 
r 

F----- 

I 

I 

I 

I 

I 

I 

I 

1 

I 

0 

\ 

0 

Ii 

: 

0 

P-3 

dnOkl9 lV101 JO IN33 83d 
3.2.4 Histopathology 

Seven biopsies were taken of neck lesions and one of an axillary lesion during the third to 

fourth week after exposure on the Rongelap people. The lesions biopsied at that time were in 

the hyperpigmented stage with little or no desquamation (shedding) having occurred. Most of 

these biopsies were taken from individuals who showed lesions of greater than average severity. A second group of biopsies from the Rongelap group (repeated in three individuals) 

were taken; four at the seventh week post-exposure and five at the eighth-week period. These 

were taken from the neck and antecubital fossae. All of these lesions had desquamated and the 

depigmented skin had repigmented to a dusky, gray color with some thickening (“orange-peel” 

appearance) of the skin. Biopsies were not taken from open lesions or from the feet for fear of 

infection. All biopsy wounds healed rapidly with no secondary complications. 

The microscopic findings are summarized as follows: 

Early biopsies- 3rd to 4th week. Epidermis 

Transepidermal damage was noted with a few intervening arcades showing less damage 

(Plates 3.18 and 3.19). The epidermis in the most extensively involved areas showed considerable atrophy with flattening of the rete pegs. In places the epidermis was reduced to a thickness of 2 to 3 cells (Plates 3.20 and 3.21). The cells of the malpighian layer showed pleomorphic 

nuclei, pyknosis and cytoplasmic halos, giant cells and in a few instances multinucleated cells. 

Pyknosis of cells of the basal layer was commonly seen. Focal disorganization of the malpighian and basal layers was usually present in the more extensively damaged arcades. Cells 

laden with pigment were frequently present throughout the epidermis and intercellular pigment 

was noted in some sections. The stratum granulosum was usually atrophic or even absent. 

Imperfect keratinization with parakeratosis was visible in all sections. Hyperkeratosis was 

also seen. The stratum corneum was loosely fibrillated. 

The arcades of minimal damage were usually found in areas where sweat ducts approached 

the epidermis (Plate 3.19). There was an apparent increase in the number of cells and mitotic 

figures in the neck of the ducts and the adjoining areas where regeneration was underway. In 

these areas the stratum granulosum was near normal width and pigmentation of the basal cells 

noted in the more severely damaged areas was lacking. 

Changes in the dermis were largely confined to the pars papillaris (Plates 3.18 through 

3.21). Mild edema in some cases was noted. Capillary loops were often indistinct and when 

discernible they frequently were associated with an increased number of pericytes. The endothelial cells showed swelling and were polygonal in shape. Telangiectatic changes (dilated 

blood vessels) were noted in areas where the overlying epidermis showed greatest damage with 

lymphocytic infiltration surrounding the telangiectatic spaces. Chromatophores, filled with 

melanin pigment, were prominent in the superficial dermis. The fine elastic fibrils running 

into the pars papillaris were often altered or absent. 

Little if any damage was seen below the superficial pars reticularis. The hair follicles 

were narrow (Plate 3.22) and in most instances devoid of shafts in this region. There was 

some telangiectasis of the capillary spaces bounded by lymphocytes and monuclear phagocytes 

in the superficial pars reticularis. Some of the large elastic fibers in this region showed 

slight swelling in some instances: No damage to fibrocytes or collagen fibers was noted. 

Second series, 7th and 8th weeks post-exposure. Epidermis 

In general, reparative processes of the epidermis appeared to have been fairly good, except for a few persistent areas of atrophy with narrowing of the epidermis and finger-like 

downgrowths of the stratum malpighii (Plate 3.24). These occurred in areas of greatest epidermal narrowing and the cells showed rather prominent pigment content. There were many 

outward epidermal excrescences covered by thickened stratum corneum which was still loosely 

laminated- such phenomenon producing a wrinkled appearance which probably accounted for 

the “orange-peel” like appearance of the skin noted grossly in the areas biopsied (Plate 3.22). 

In almost all instances the basal layer was intact with little or no disorganization noted. There 

were a few scattered areas in which occasional epithelial cells with pyknotic nuclei and perinuclear cytoplasmic halos occurred in the stratum granulosum and malpighian layers (Plate 

3.23). There were occasional arcades in which the epidermis, particularly the stratum granulosum, appeared to be actually widened. These occurred almost predominantly in relationship 

38 
to the contiguous sweat gland ducts at sites where the latter penetrated the epidermis. A narrow zone of parakeratinosis and amorphous debris was still present between the stratum 

granulosum and the loosely laminated stratum corneum. 

Dermis 

The capillary loops in the dermal papillae, although present, were not uniformly distinct. 

Pericytes remained in increased number but fewer lymphocytes were present. Generally, 

there appeared to be slight telangiectasis of the capillaries in the pars papillaris and the 

superficial pars reticularis (Plate 3.24). There was some edema of the pars papillaris (Plate 

3.22). Scattered pigment laden chromatophores were irregularly distributed in the papillary 

layer (Plate 5.23). In some cases hair shafts in the superficial pars reticularis were quite 

narrow, atrophic, and occasionally absent; in others the hair shafts appeared normal. Small 

hair follicles (Plate 3.22) and secretory sweat ducts in some cases showed mild atrophy. 

Biopsies of three pigmented mild lesions were taken from two of the white Rongerik 

Americans. Only one of the three gave evidence of damage, which was nominal and confined to 

the epidermis. 

3.2.5 Symptomatology and Treatment 

On the day of exposure, itching and burning of the skin was prevalent. This subsided and 

for a period of 10 to 14 days or longer there was neither subjective nor objective evidence of 

skin injury. Itching and burning reappeared either prior to or in the early pigmentation stage. 

With the deeper lesions there was also pain. Pain was rather marked with the foot lesions. 

During the painful period some of the foot lesions were also hot and presented a brawny 

edema. A common complaint was a tenderness in the great toes medial to the nails. However, 

visible lesions in this area were infrequent. This symptom usually preceded the appearance of 

gross lesions elsewhere on the feet. Many of the individuals who developed painful foot lesions 

were observed walking on their heels for several days. The painfulness of the foot lesions may 

have resulted from their greater severity, and may have been accentuated by the dependent 

nature of the foot. Some of the lesions of the neck and axilla were painful when turning the head 

or raising the arms. The acute reaction and pain subsided after a few days. There were no 

constitutional symptoms. 

The treatment of skin lesions was largely non-specific. Most of the superficial lesions 

were treated with calamine lotion with one per cent phenol, which in most cases relieved the 

itching, burning or pain. A few of the painful hyperpigmented lesions not relieved by calamine 

with phenol were treated with pontocaine ointment, with apparent success. When the epithelium 

desquamated the itching was relieved by daily washing with soap and water and the application 

of a water soluble vanishing type ointment which kept the injured skin soft and pliable. Raw 

areas, which became secondarily infected, were treated by washing with soap and by the application of aureomycin ointment. Bullous lesions of the feet were left intact as long as no symptoms were present. If painful, the bullae were aspirated with sterile techniques to remove the 

clear straw-colored fluid. A single aspiration was adequate since the bullae did not refill. One 

foot lesion developed an extensive, raw weeping ulcer. Prophylactic penicillin was given for 

two days, during which time the lesion developed healthy granulation tissue. Some of the lesions of the skin of the foot remained thickened, less pliable, and painful after desquamation. 

This was relieved by the use of Vaseline or cocoa butter to soften the tissues. One persistent 

ear lesion did not heal after desquamation. This was treated with warm boric acid compresses 

and washing with surgical soap to remove the eschar. Granulation tissue formed, and epitheliurn was slowly growing in from the edges of the ulcer when the initial observation period was 

terminated 74 days after exposure. Upon resurvey six months after exposure healing was complete, with a depigmented scar remaining as evidence of the previous ulcer. 

3.3 EPILATION 

The incidence of and time of appearance of epilation in the Rongelap and Ailinginae groups 

is illustrated in Tables 3.1, 3.2 and Fig. 3.1. Epilation was first observed on the 14th post- 
exposure day in the Rongelap group and was confined to the head. The epilation was divided 

arbitrarily into three degrees of severity. “l+” epilation indicates loss of hair without obvious 

thinning; “2+” indicates a loss of hair sufficient to cause obvious thin spots; and “3+” indicates 

an extensive epilation with bald spots. Table 3.1 illustrates that there was a greater degree of 

epilation in the children (0 to 15 years). Over 90 per cent developed epilation of some degree 

in the 0 to 15 years group, compared to only 28 per cent in the older age group. The preponderance of scalp lesions in the areas of epilation indicates that radiation from the fallout maTable 3.2 LESIONS IN AILINGINAE AND RONGERIK GROUPS 

Type of 

Lesion 

Ailinginae 

(18 people) 

Per Cent 

of Total Mean Time of 

with Lesions Appearance* 

Rongerik 

(28 people) 

Per Cent 

of Total Mean Time of 

with Lesions Appearance* 

Epilation 16.7 27 3.5-t 42 

Lesions of: 

Scalp & Face 

Neck and 

Shoulders 

Back 

Axilla 

AntecubitaI 

Fossae 

Hand & Wrist 

Feet 

Legs 

38.9 26 10.7 32 

61.0 27 14.3 30 

0.0 7.1 28 

22.2 24 3.5 23 

11.1 28 25.0 29 

5.6 38 3.5 47 

16.7 33 3.5 43 

5.6 44 0.0 

Nail 

Discoloration 77.7 38 17.9 

(All Negroes) 

40 

*Days post-exposure. 

t One case claimed slight epilation. Questionable. 

terial on the skin is primarily responsible for the epilation. In the Ailinginae group only three 

cases of mild epilation developed in children (Table 3.2). 

Slight regrowth of hair was observed in all individuals nine weeks after exposure. Hair 

regrowth was complete and normal six months after exposure. 

3.4 NAIL PIGMENTATION 

An unexpected observation was the discovery of a bluish-brown pigmentation of the fingernails which was first well documented on the 23rd post-exposure day. The discoloration began 

in the semilunar area of the fingernails (to a lesser extent in the toenails), and tended to spread 

outward sometimes in streaks. As the discolored area grew outwards the semilunar area 

usually became clear. In a few cases, detachment of the end of the nail from the nail bed was 

observed when the pigmentation reached the end of the nail. Plate 3.17 shows pigmented bands 

in the nails at ‘77 days. The discoloration of the nails was seen in 89 per cent of the Rongelap 

and 78 per cent of the Ailinginae group. It appeared to be a radiation response peculiar to the 

dark-skinned races since it was seen in all of the American Negroes in the Rongerik group and 

in none of the white men. This lesion was not observed in the Utirik group nor in the control 

Marshallese. Since the nail pigmentation occurred in individuals without skin lesions, it appeared to be the result of a more penetrating component of radiation than contact radiation 

which predominantly produced the skin lesions. 

40 

, 
i3.S i FACTOBS INFLUENCING TBE SEVERITY OF SKIN LESIONS 

6-: 

9.5.1 The Characteristics of the Fallout Material 

The fallout material was composed mainly of calcium oxide from coral, with adherent fission products. The skin lesions observed were undoubtedly the result primarily of beta radiation from fallout material deposited on the skin, with minimal or no contribution from chemical 

irritation. The gamma dose to the skin was small compared to the beta dose, and thus was. 

.relatively unimportant in producing the lesions. 

3.5.2 Energy of Beta Particles 

From available data on the fallout material it has been calculated that 50 to 80 per cent of 

the beta rays during the exposure period were soft with an average energy -00 kev. 

Since 80 microns of tissue produces 50 per cent attenuation of such radiation,’ the greater 

portion of energy was dissipated in the epithelium which is roughly 40 to 70 microns in thickness. The remaining 20 to 50 per cent of the beta rays were of higher energy, with an average 

of approximately 600 kev. The latter would penetrate well into the derma since it takes 800 

microns of tissue to produce 50 per cent attenuation.‘*” In addition, a wide spectrum of gamma 

energies irradiated the skin. Approximately 10 per cent of the total gamma spectrum was below 80 kev which would be absorbed largely in the superficial layers of the skin. The remainder 

of the gamma spectrum is distributed between 100 and 1600 kev with a large proportion between 600 and 800 kev. I . 

3.5.3 Physical Bose to the Skin 

There is no practical way to estimate the physical dose to the areas of skin where lesions 

were found. The entire surface of the body of the Bongelap group received approximately 175 r 

from gamma irradiation derived from fission products distributed on the ground, trees, and 

buildings. To this 175 r would have to be added the beta component. In view of the high beta to 

gamma ratio in fission products, one might expect the total beta surface dose to the skin to be 

large. The maximal skin doses from the plane field of radiation are estimated in chapter 1. To 

these doses must be added the contribution of the material deposited on the skin. The latter 

can not be calculated, or estimated biologically with any degree of accuracy. A rough approximation of dose received at the hair follicles can be made as follows: 

The hair follicles must have received a dose comparable to the known minimal epilating 

dose of about 400 r for 200 kvp X-rays. Since regrowth of hair occurred, the upper limit of 

dose at the depth of the hair follicle must not have exceeded the permanent epilating dose of 

around 700 r of 200 kvp X-ray.a 

3.5.4 Protective and Aggravating Factors 

The individuals who remained indoors or under the trees showed some protection as compared to those who were in the open during the period of the fallout. Those who went swimming 

or bathed were also protected to varying degrees. Small children who went wading developed 

fewer foot lesions. Clothing, even a single layer of cotton material, offered almost complete 

protection, as was demonstrated by the fact that lesions developed almost entirely on the exposed parts of the body. 

Since the lesions predominate in areas where perspiration is abundant such as folds of the 

neck. axillae, and antecubital fossae, it seems likely that the abundant perspiration produced 

by a hot, humid climate tended to cause the material to concentrate and adhere to these areas. 

In addition, the coconut oil hair dressing used by the Marshallese acted as an effective collecting agent for the radioactive material. This was proved since the hair was the most highly 

contaminated part of the body. The concentration of radioactive material on the hair may have 

been responsible for the large number of scalp lesions, epilation and the large number and 

severity of neck lesions in women. 

41 
There was a delay of two and one-half days before satisfactory decontamination was poasible. The presence of radioactive materials on the skin during this period increased the dose 

to the skin. However, the dose rate fell off rapidly and decontamination would have to have 

been very prompt in order to be effective. 

3.6 CORRELATION WITH HEMATOLGGICAL FINDINGS 

Attempts at correlation of the severity and extensiveness of skin lesions with maximum 

depression of platelet, lymphocyte, and neutrophile counts were made for individuals in the 

Rongelap group. No positive correlation was found. Thus the contamination of the skin apparently did not significantly contribute to the total-body dose of irradiation. 

3.7 DISCUSSION 

There has been little previous experience with radiation dermatitis resulting from exposure to fallout material from nuclear detonations, and the general consensus until now has been 

that the hazard from fallout material was negligible. With the Hiroshima and Nagasaki detonations, fallout material was not a problem since the bombs were exploded high in the air. The 

flash burns of the Japanese were purely thermal. 

From the present experience it is quite evident that following detonation of a large scale 

device close to the ground, serious exposure of personnel may occur from fallout material, 

even at considerable distances from the site of detonation. The incident described in this paper 

is the first example of large numbers of radiation burns produced by exposure to such fallout 

material. 

Knowlton, et al.’ described burns of the hands of four individuals who were handling fiesion product material following an experimental detonation. Also, following the Alamogordo 

detonation, there were a number of cattle that developed lesions due to deposit of fallout material on their backs.’ In addition, there were a number of sheep that developed lesions closely 

resembling radiation burns following a Nevada detonation. However, Lushbaugh” reported that 

the histopathological characteristics of these lesions did not conform in all respects to radiation dermatitis. It is of considerable interest to compare the present experience with that accepted in the past as the typical course of radiation burns of the skin. 

The gross lesions of the hands described by Knowlton, et al. occurred from an exposure of 

about one hour, resulting in doses between 3000 and 16,000 rep of beta radiation (maximum 

energy about 1 Mev) with a small gamma component considered to be insignificant. The lesions 

were described as developing in four phases: (1) An initial phase which began almost immediately after exposure and consisted of an erythema with tingling and burning of the hands, 

reaching a peak in 46 hours and subsiding rapidly so that by 3 to 5 days there was a relative 

absence of signs; (2) A second phase which occurred from about the 3rd to the 6th or 6th day 

and was characterized by a more severe erythema; (3) The third phase at 6 to 12 days, which 

was characterized by vesicle and bullae formation. The erythema spread to new areas during 

the following two weeks, and the active process subsided by 24 to 32 days. The bullae dried up, 

and desquamation and epithelization took place in less severely damaged areas; (4) The fourth 

phase or chronic stage was characterized by further breakdown of skin with necrosis in areas 

which were damaged sufficiently to compromise the blood supply. Atrophy of the epidermis and 

loss of epithelial structures took place, which necessitated skin grafting in some cases. 

Robbins, et al.’ reported six cases accidentally exposed to scattered cathode rays (beta) 

from a 1200 kv primary beam with exposure time of about 2 minutes and a rough estimation of 

dose to the skin of between 1000 and 2000 rep. The lesions described were similar to those 

reported by Knowlton, et al.’ with a primary erythema developing within 36 hours; secondary 

erythema with vesiculation and bullae formation appearing about 12 to 14 days later; and, in 

the more severely affected, a tertiary phase characterized by further breakdown of the skin. 

In comparison with severe roentgen ray reactions these investigators stress the unique periodicity of cathode ray burns, relative absence of deep damage to the skin, less pain, rapidity 

42 
of healing, and absence of pigmentation. These points would apply to the Marshallese except 

for the multiphasic reactions and pigmentation. Crawford* reports a case of cathode ray burns 

of the hands which were similar to those described by Robbins, et al.’ 

Experimental beta radiation burns in human beings have been reported by Low-Beer’ and 

Wirth and Raper.” Both investigators used ti2 discs applied to the flexor surfaces of the 

arms, forearms, or thighs for varying lengths of time. Low-Beer reported “monophasic” skin 

reactions. He found that a calculated dose of 143 rep to the first millimeter of skin, ignoring 

self-absorption, produced a threshold erythema. Dry, scaly, desquamation was produced by 

7200 rep in the first millimeter and bullous, wet desquamation was produced by 17,000 rep to 

the first millimeter. Erythema developed in 3 to 4 days,,followed later by pigmentation and 

desquamation with higher doses. Recovery was observed with doses of 17,000 rep. The lesions 

.later showed depigmented centers with hyperpigmented edges (also seen in the present lesions) . 

Wirth and Raper” produced primary erythema within 6 hours after exposure to a dose of 

635 to 1180 rep of 9’ radiation. Minute vesicles with dry, spotty desquamation were noted with 

1180 rep at about the 5th to 6th weeks post-exposure. 

Following the detonation on 1 March 1954, 23 Japanese fishermen were contaminated with 

fallout material. Apparently they were exposed to roughly the same total-body dose of radiation as were the Rongelap group. The skin lesions which developed are described by Morton, 

et al.“S’2 Lesions developed which were similar in most respects to those seen in the Marshalleee people, and were characterized by pigmentation, desquamation with depigmentation, 

spotty epilation of Ihe head and ulcerations developing particularly on the scalp, ears, neck, 

and hands (the latter probably from handling contaminated fishing lines). Erythema and vesicle 

formation, as well as inflammation of the eyes were more prominent than in the Marehallese. 

Pigmentation apparently was not as prominent in the Japanese. The lesions appeared earlier 

than in the Marshallese (about 7 to 8 days post-exposure). As in the Marshallese the lesions 

occurred mainly on exposed parts of the body not protected by clothing. 

In addition to the Marshallese and Japanese, seve’ral Navy men on ships in the test area 

developed a few small pigmented lesions of “belt-line” distribution, apparently due to fallout 

material. 

The lesions reported in this paper when compared to radiation lesions described in the 

past presented certain unique features which merit further discussion. 

The early symptoms of itching and burning of the skin and eyes were probably due mainly 

to skin irradiation from the fallout material. However, the chemical nature of this material 

may have contributed to the irritation. It has been noted” that irritating chemicals applied 

during or shortly after irradiation enhance the effects of radiation. 

The lack of prominence of an erythema was notable, particularly in view of the severity of 

some of the lesions that developed. Wilhelmy” states that erythema only occur8 when the dose 

reaching the papillary layer exceeds a certain level. Perhaps the dose to the dermis was insufficient to evoke the response. On the other hand, the darkness of the skin and the development of hyperpigmentation may have masked an erythema. Microscopically, a superficial 

hyperemia was not a notable finding. 

Wirth and Raper” point out that they were impressed in their studies on 9’ radiation of 

the human skin with the difficulty of distinguishing between true erythema and tanning, particularly in the skin of brunette individuals. It was unfortunate that color filters were not 

available to aid in distinguishing an erythema as suggested by Harris, et al.16 

In general the latent period before development of obvious signs and symptoms for radiation injury to the skin is inversely proportional to the dose of radiation.‘“~” In the present 

series of cases the relatively long latent period is suggestive of a low dose of radiation. However, the wide spectrum of beta energies and particulate distribution of radioactive material 

drastically altered the depth dose, as compared with that in previous experience; hence strict 

comparisons cannot be made. The later development of lesions in the Ailinginae and Rongerik 

groups as contrasted with the Rongelap people is in keeping with the relative severity of 

lesions noted. 

43 
A unique feature of the present cases was the appreciable differences in the latent periods 

observed for lesions on various parts of the body. These differences cannot be explained 

entirely on the basis of severity, since the severe foot lesions developed after most other lesions. However, the severity might have been in part due to the dependent position of the foot 

rather than greater radiation injury. Lesions on flexor surfaces in general preceded lesions 

on extensor surfaces. The present data suggest that the latent period and radiation sensitivity 

of various skin areas may differ. Previous work has shown that flexor surfaces with thiMer 

epidermis are in general more sensitive than extensor surfaces with thicker epithelium.‘s 

The destructive and atrophic changes of the epidermis, disturbances in keratinization, and 

atrophy of hair follicles are characteristic of histopathologic radiation injury of the skin.‘*l’~i*-S’ 

Severe injury to the dermis and blood vessels was not observed. The minimal dermal injury 

with severe epidermal injury is in keeping with the low energy beta component present and the 

marked decrease in depth dose over a distance of a few microns from the surface. 

Hyperpigmentation of injured areas was a consistent finding in the Marshalleae, the Japanese, and the American Negroes. Pigmented lesions were also observed to a lesser extent in 

the white Americans. Pigmentation of this nature has not been described as a constant characteristic of radiation damage to the skin. 

There is no satisfactory explanation for the darker dusky-gray color that appeared in 

some of the skin lesions as healing progressed. The color changes may be due to alterations 

in local pigment production, vascular changes, or a thinning of the epidermis, rendering it 

more translucent with resultant darker appearance of the pigment layer. Later biopsies may 

explain this phenomenon. 

There are features of the lesions described that appear unique, e.g., the absence of visible 

multiphasic responses, the presence of early hyperpigmentation, the long latent periods, and 

the severe epidermal injury with minimal dermal injury. It is possible that differences may in 

part be on a racial basis.* In addition, the marked difference in histologic response of the 

epidermis and dermis in the present series is in marked contrast to the usual radiation response of the skin produced by high energy X- or beta-rays. 

In Table 3.3 are listed the approximate minimal surface skin doses required to produce 

recognizable epidermal injury in animals. It is apparent from the table that beta ray energy is 

of considerable importance in determining the degree of injury. A number of assumptions, including knowledge of the beta ray spectrum from the fallout, would have to be made if these 

data were to be used to estimate biologically the beta dose received by the Marshallese. The 

difference in dose between that required to produce threshold skin damage and that for permanent damage in pigs is 500 to 1000 rep.r’ 

(,--’ -- 

It is impossible to estimate the probability of development of radiation cancer at the site 

%,_zf the healed lesions. The absence of scarring, telangiectasis, and extensive chronic vascular 

lesions tends to improve the prognosis since the foregoing are usually observed to precede the 

development of radiation cancer. 

/ A favorable prognosis is also suggested by the following evidence: an analysis of 1100 

/ individuals exposed to low voltage X-ray for dermatological conditions revealed no evidence of 

cancer induction 5 to 23 years after treatment. MacKeelS states that epitheliomata rarely 

develop after a single dose of radiation to the skin. Lastly, the incidence of skin cancer in 

Negroes is one sixth to one ninth the incidence in Caucasians.s’ 

! If neoplasia can develop purely as the result of epidermal irradiation, the incidence of late 

i 

cancers may be enhanced since the dose of radiation and the visible gross and microscopic injury to the epidermis greatly exceeded that to the dermis. Since many children and young 

adults were involved, the life expectancy of a large number of the exposed people will exceed 

he long induction period for development of radiation cancer observed in radiologists. Long 

* Reported clinical experience with radiatlon skin lesions is based predominantly on the 

response of white-skinned people, whereas the type of lesions described herein, with one clear 

cut exception, were observed in Japanese, Marshallese (negroid), and American Negroes. The 

exception was a dark brunette individual. 

44 
exposure to tropical sunlight, potentially carcinogenic in itself, may increase the probability of 

neoplastic change. The influence of the sub-lethal whole body exposure received by these 

people on skin cancer induction is not known. 

The transverse band of pigmentation that was observed in the fingernails has been previously observed by Sutton” in a negress who received 150 r of soft X-ray to the hands. The 

Table 3.3 SURFACE DOSES IN REP REQUIRED TO PRODUCE RECOGNIZABLE 

EPIDERMAL INJURY 

Investigator Animal Isotope 

Average 

Energy (Mev) 

Surface 

Dose (rep) 

Henshaw, et al” 

Raper 6 Barnes’” 

Raper & Barnes2” 

Raper 8 Barnes*” 

Lushbaugh6 

Moritz and 

Henriques” 

Moritz and 

Henriques” 

Moritz and 

HenriquesSo 

Moritz and 

HenriquesSo 

Moritz and 

Henrique8’ 

Moritz and 

HenriquesSo 

Rats 

Rats 

Mice 

Rabbits 

Sheep 

Pigs 5”” 0.05 20,000-30,000 

Pigs 

Pigs 

Pigs 

Pigs 

mzs YOO 0.7 1,500-2,000 

co”0 

CLP’ 

Sr” 

Y”’ 

0.5 1,500-4,000 

0.5 4,000 

0.5 1,500 

0.5 5,000 

0.3 2,500-5,000 

0.1 

0.2 2,000-3,000 

0.3 1,500-2,000 

0.5 1,500-2,000 

4,000-5,000 

nature of the pigment is not known. Since it occurred in all exposed American Negroes, many 

of the Marshallese, and none of the American whites, it is a radiation response peculiar to 

negroid races. The pigmentation was apparently produced by as little as 75 r of gamma radiation since the American Negroes developed the phenomenon in the absence of significant contamination of the hands. 

9.8 CONCLUSIONS 

As a result of this accident the following conclusions can be drawn with respect to beta 

I damage to the skin. 

a. Serious skin contamination of personnel from fallout may occur many miles from the 

it detonation of a nuclear device. Resultant radiation damage to the skin may be the major ra- 

‘; diation effect under conditions where early evacuation from the field of radiation reduces the 

whole body exposure. 

b. Fairly extensive skin lesions resulting from fallout beta radiation apparently produce 

little or no systemic or hematological effects. 

c. Decontamination of the skin must be prompt to be effective because of the initial high 

beta dose rate. 

d. A latent period of a few days to three to four weeks may elapse before signs and symptoms of skin damage are evident. 

e. Clothing and/or any type of shelter gives almost complete protection to the skin. 
NOTE 

For purposes of documentation the following 

color plates (Plates 3.1 through 3.24) numbered 

with letters a, b, c, cl, d, e, f, and g are considered to be pages 47-57, 59, and 61-62. 
Place 3 1 Elr::< hq’perplgmented n:acul~~p;ipul~ir Plate 3.2 Keck ieslox nt 28 days. IVet desquaneck 1eSionS zt 15 clay5 Case 39. age 15, F rnation. White color is calamine lotion. Case 78, 

age 37, F. 

Pldtes 3.5-3 7 Secji:e[:tl:ll chnnges in foot I 

Cnse 67 age 14. F 

esion.5. 

. I ,- 

‘-, : 7‘ 77-l 

t,.,- I. .., ; ,% , I 

,_ l 

. ..’ : _ “!. ,‘..:, 

I- -t . 

_._..__._ 

. . . . . 

- 

. 

Place 3.14 Epilation in n;an at 18 days. Case 79. Plate 3.15 Spotty epilatlon ix boy. age 13, at 28 

age 41. Scalp lesions present in axds of epilation. days. Cxe 26. Sote scalp lesions ir. areas of 

ISame case as in Plates 3.17 and 3.13.1 epllation. t Same case as in Plates 3 8-3 i1.J 
C’ILOR PL.ITES 
Plate 3.20 Plate ‘ 3.“1 I 
COLOR PLATES 

Plate 3.22 1X100, HCEi \Csse r7.5, Loose lnmtnation of stratum corneum bvith outward papilI A “J proJections anil resultant “rug~ise” appearance. Stratum granulosum of good width. 

Fl~;al :tnd m.llptphi.tn layers distinct with ptgmcnt present. Slight edema of corlum with mtld 

tel.t;,g:?c!:i.i~s and ,ll;:ht !ncr-ease m p~:rlra~zul~r lymph(x) tes and per~c)~tes. Small, atrophic 

hxi: follicle adjacent to sebxcef,us gland-in mid pars retlculnris. 

Piate :1.23 IS-liN, H&-El (Case S7.5) Same as :3.22. Occasional pertnuclear cJtoplasmic halos 

in rn!,? srrattrm gran.t!osum. Lcroselv laminated stratum corneum. Pigment laden chromatoph81rt’s in superflci:tl corlum a11~n~ :$lth occasionnl ljmphoc)-tes and mononuclear phagocytes. 

PlJ?? :.2-l sh,>ws leston~ tjccond hiopsvi at 46 days p-tst-exposure. 

Pl.itr .3.34 iX!WI, H&E) ~Case a391 Narrow rugose epidermis with papillary extensions doan- 

,s:~r~i af str::tum malphtgii. Latter are heavll;,, laden ,.rlth mclanotic pigment. Sltght telanglecta5is of pars papIllaris and pars retlcui;lr1; of dermis. Occasional pigment laden chromat,)pi:87rcs 111 5upe .-flclal dermis. 

60 
PlTte L 3 2’2 Pl3te L. 323 

CHAPTER 4 

HEMATOLOGY 

4.1 INTRODUCTION 

c 

Since it is generally agreed that a depression in the formed elements of the peripheral 

blood is the most useful practical clinical index of the degree of exposure to ionizing radiation, 

a systematic study of the leukocytes and platelets was relied upon as a major aid in evaluating 

the clinical status, severity of the radiation injury, and prognosis of the exposed individuals. 

Animal experimentation had previously shown that the rate of development and magnitude of 

the depression were equally important in evaluating the severity of radiation injury. Since 

there had been no previous exposure of human beings to significant amounts of fallout radiation, 

no hematological data known to be strictly applicable* were available for use as a guide in the 

evaluation of the exposed Americans and Marshallese. Accordingly emphasis was placed on 

systematic serial studies, utilizing a few highly standardized hematologic determinations to 

insure that individual and group trends would have maximum validity. Since it was known that 

the Utirik group had received a very small dose of radiation compared to the other exposure 

groups, less extensive determinations were carried out on these people. 

4.2 GENERAL METHODS 

Hematological examinations included total leukocyte, neutrophile, lymphocyte and platelet 

counts, and hematocrit determinations. Whenever possible an entire exposure group was 

studied in a single day. Occasionally two days were required to complete the larger groups. 

Capillary blood was used, usually obtained from the finger but occasionally from the heel 

or ear. Two pipettes each for total leukocyte and platelet counts were filled. From each pipette 

a single hemocytometer chamber was filled. All pipettes were rotated for 10 minutes, and the 

cells were allowed to settle for 10 minutes in the hemocytometer chamber before counting. A 

3 per cent acetic acid diluting fluid was used for total leukocyte counts. The blood was diluted 

with 1 per cent ammonium oxalate for platelet counts and counted in flat bottom hemocytometers using a dark phase contrast microscope.s6 Two blood smears were made with each examination, using a beveled end glass slide for spreading. One blood smear was fixed in methyl 

alcohol. The other was stained by Wright’s method, from which a 100 cell differential count 

was made. Hematocrits were performed using heparinized capillary tubes. One end of the 

capillary tube was heat sealed and the tube was centrifuged in an ALOE centrifuge at 12,500 

rpm for 5 minutes. 

- 

*A large literature on the hematologic effects of radiation exists; however, these data were 

not relied upon for direct comparison and evaluation of the exposed individuals for reasons that 

will be indicated later in the discussion. 

63 
Every effort was made to maintain uniform procedures in every phase of the laboratory 

work. The number of personnel changes for a given procedure was held to a minimum; personnel drawing blood from a single puncture were sufficient in number to allow all samples to 

be taken in rapid succession. All time intervals were rigidly controlled. 

4.3 METHODS OF TREATING DATA, CONTROL GROUPS 

Pre-exposure blood counts were not available on the exposed Marshallese or Americans; 

hence the individuals could not be used as their own controls. In order to estimate the severity 

of the hematologic response it was necessary to establish control groups as comparable as 

possible in respect to age, race, sex, background, and habits. A Marshallese control group 

living on Majuro, comparable with respect to age and sex to the Rongelap people, was used as 

Table 4.1 HEMATOLOGICAL RESULTS, CONTROL GROUPS 

Control 

Group 

No. 

Hematocrit* 

Age in WBC Neutrophiles Lymphocytes Platelets 

(Per Cent) 

(yr) GP. (x 103) (x 103) (x 10s) (x 10’) M F Comb 

Majuro o-5 22 13.2 4.8 7.4 38.8 38.5 

(10) 

6-15 14 10.6 4.8 5.1 38.6 41.3 

(6) 

15-50 63 9.4 4.8 4.0 30.9 46.8 

(29) 

>50 14 9.6 5.0 3.7 30.7 43.6 

(10) 

>5 91 9.7 4.8 4.1 33.6 45.2 

<15 37 38.5 

>15 76 30.8 

37.3 

(12) 

40.6 

(8) 

40.4 

(34) 

41.8 

(4) 

40.6 

Kwaj- >18 28 7.0 4.1 3.1 23.8 44.9 

Americans 

37.8 

(22) 

40.9 

(14) 

43.3 

(63) 

43.0 

(14) 

* Numbers in parentheses indicate number of individuals in the group, 

the Marshallese control group. For comparison with the exposed Americans, blood counts 

were made on approximately 85 American males, on duty at Kwajalein. All who had not been 

on duty in the tropics for more than two months were excluded since the exposed Americans on 

Rongerik had been in the area for about two months before exposure. In addition several who 

were recently associated with radioactive materials were excluded. The resulting smaller 

group of 67 was used as the Kwaj-American control group. 

Preparatory to analyzing the hematological results on the exposed Marshallese, data from 

the control Majuro Group were examined to determine if there was an age or sex dependence 

in the hematologic observations (Table 4.1). Although the neutrophile count was independent of 

age, the lymphocyte counts were significantly higher in children below the age of 5. Similarly 

the platelet count was higher in the younger age groups; however, a relative depression appeared to occur at about age 15. 

The total leukocyte, neutrophile and lymphocyte counts were independent of sex. The hematocrit of females was lower than that of males, particularly in the child bearing age group. The 

age and sex dependency of these endpoints is comparable to that in published data.“.” 

To obtain valid comparisons within and among the various exposure groups, they were 

stratified in accordance with age or sex dependency noted for the control groups. Although 

each individual in all groups was studied hematologically, those Marshallese with serious longstanding diseases were omitted from the analysis. A total of two from the Rongelap and two 

from the Majuro groups were omitted on this basis. 

64 

. 







250 

200 - 

100 

DlSPENSl 

COUNT 

5 

: 

: 

: 

: 

+ 

: 

: 

;--- 

: 

: 

: 

: 

: 

: 

. 

: 

: 

: 

: 

: 

. 

: 

: 

. 

: 

: 

. 

: 

: 

: 

: 

. 

: 

. 

: 

i PROJI 

.:- co1 

. 

f 

I I 

KWAJALEIN AMERICAN CONTROLS I 1 I 

a 

RONGERIK 

Platelets 

50 - 

IO 15 16 20 25 30 35 40 45 50 55 60 

POST EXPOSURE DAY 

Fig. 4.6 Serial Platelet Counts in Exposed Americans 

.l , 
ILS-AGE <5 

I 

IO 

9 

7 

L 

5 

: 

: 

: . 

: 

. 

: 

. 

: 

: 

: 

: 

: 

: 

: 

: 

: 

. 

RONGELAP 

Eosinophiles 

MAJURO CONTRO 

t 

MAJURO CONTROLS-AGE >5 

0 89 16 24 32 40 48 56 64 72 80 

POST EXPOSURE DAY 

Fig. 4.7 Serial Eosinophile Counts on Those Less Than and Greater Than 5 Years of Age of the Rongelap Group 
sdno.rD pasodxg 11~ 303 s~!mo~srna~ [E!J~S 8’P ‘%d 

SlOlllN03 h 

-Nl3lWf’WM)I F 

1 

r 

AVCI 3tiIlSOdX3 1SOd 

Ob Zf tz 91 8 0 

I 

OE 

-I S<abv-y!Jarn pUDWJ!bU!l!~ 

dqabuoa ‘y!~abuo~ 

I llt1301VW3H 

I 

I 

I 
c 

3 4 5 6 

I 

-hlAJUkO (91) I 

NEUTROPHILES 

Cumulative - Age>5 I7 8 9 IO II I2 13 

NEUTROPHILES x IO3 

Fig. 4.9 Cumulative Neutrophile Counts for the Rongelap, Ailinginae and Majuro Groups at the 

Time of Peak Depression 

14 
b 

i I I I I L z 0 0 0 0 0 0 0 0 

m a, rc u3 In s m-l :: - 

IN33 M3d 3hllWlnWn3 

-I 

, 

I 

, 

, 

. 

. 

76 
c 8 0 

u-3 : 8 

IN33 kl3d 3hllvinRn3 

0 

0 
Table 4.6 RONGELAP GROUP MEAN BLOOD COUNTS AT TIME OF PEAK DEPRESSION 

Case No. 

W.B.C. 

(Average from 

Day 39 to 51) 

Platelets x 10s 

(Average from 

Day 26 to 30) 

Neutrophilee 

(Average from 

Day 39 to 51) 

LymphOCytekI 

(Average from 

Day 39 to 51) 

2 7220 110 2870 405 

3 7320 155 2770 420 

5 5620 115 2570 265 

11 6230 105 3350 265 

19 5650 115 3070 240 

21 4750 85 2670 195 

23 7150 195 4100 280 

32 5450 95 2600 265 

33 5600 85 1670 357 

42 5500 80 2520 292 

54 4750 145 2620 195 

65 6050 105 2520 240 

69 4770 115 1420 317 

Age 5 to 15 

15 3920 200 1470 232 

20 5020 120 3020 195 

24 5620 195 3450 197 

26 6020 145 3470 232 

35 5100 140 2700 215 

36 5120 130 2520 247 

39 4720 165 2900 155 

41 1220 120 4120 225 

61 5600 105 2500 297 

61 5120 115 2970 192 

12 4100 185 1800 197 

75 4200 110 2320 172 

16 5750 150 2800 287 

Age Greater Than 15 

4 6420 130 2650 355 

7 5220 195 2520 252 

9 5470 125 2700 242 

10 4550 105 2770 157 

11 3120 65 1570 135 

12 4670 150 3270 127 

13 4050 105 2370 152 

14 4570 55 2770 170 

18 6100 45 4320 165 

22 4470 130 2500 190 

25 6250 110 4050 212 

27 6620 110 3600 265 

30 5700 85 3920 160 

34 5900 125 3650 235 

37 5970 130 3120 257 

40 5600 140 2450 287 

46 4620 135 2350 210 

49 6620 180 4050 222 

52 5620 160 2970 245 

55 4400 135 1450 212 

56 6170 125 3520 255 

57 so20 55 2020 270 

56 4760 80 2600 185 

60 6970 160 4050 247 

62 8300 110 5110 282 

63 4270 65 2550 152 

64 5600 70 3220 205 

66 6100 145 2820 312 

68 4600 120 2400 202 

71 7950 105 4950 270 

73 3970 60 2630 126 

14 9900 155 7250 255 

78 5400 95 3350 195 

79 7800 70 5120 250 

80 5670 100 2920 252 

82 ,i250 130 2620 247 

Age Less Than 5 

. 

78 
Table 4.7 AILINGINAE GROUP MEAN BLOOD COUNTS AT TIME OF PEAK DEPRESSION 

W.B.C. Platelets X 10s Neutrophiles Lymphocytes 

(Average from (Average from (Average from (Average from 

Case No. Day 39 to 51) Day 26 to 30) Day 39 to 51) Day 39 to 51) 

6 9750 

El 8350 

44 4570 

48 6220 

53 6170 

81 4700 

1 6170 175 3570 2370 

16 4670 195 2200 2270 

28 6270 115 3720 2270 

29 6750 115 4100 2220 

31 5650 145 2950 2450 

41 5120 110 3050 2270 

43 6150 215 3700 2000 

45 5650 180 4170 1470 

50 7050 95 3970 2900 

51 7750 170 4620 2950 

59 12400 105 . 8120 3670 

70 5070 185 3000 1750 

Age Less Than 5 

215 

185 

180 

Age 6 to 15 

210 

240 

240 

Age Greater Than 15 

3470 5600 

3520 4350 

2350 2070 

2970 3150 

3700 2500 

2320 2150 

4.5 RONGELAP GROUP 

The absolute neutrophile count of both the younger and older age groups fell during the 

second week to a value, approximately 70 to 80 per cent of that of the controls (see Fig. 4.1). 

Following the depression of the total neutrophile count during the second week, the values were 

unstable until the fifth week. At this time the beginning of a second drop (P < 0.01) was noted 

for both age groups, and a low value of approximately 50 per cent of controls was reached. The 

count was maintained at approximately 75 per cent of control values from the seventh week to 

the end of the study. Although both age groups followed the same general time pattern of response, the lower age group was below that of the older group throughout most of the observation period. 

The absolute lymphocyte count of the older age group (Fig. 4.2) had fallen by the third day 

to a value approximately 55 per cent of the control group. This value was maintained throughout the study, and there was no definite evidence of an upward trend during the study. The 

values for the younger age group likewise fell before the third day to a value approximately 25 

per cent of the control, following which there was a significant upward trend. With the total 

lymphocyte count, there is a consistent difference between the two age groups. However, during 

the first four weeks the difference is accentuated when expressed as per cent decrease because 

of the relatively high lymphocyte levels in the lower age control group. After this period the 

differences expressed as per cent are less marked since recovery was more rapid in the 

younger age group. 

The cellular elements chiefly responsible for the fluctuations in total white blood cell 

count can be determined by comparing the total white, neutrophile and lymphocyte counts (Fig. 

4.2). It is seen that the lymphocyte count remained essentially constant throughout the period 

of study, while the total neutrophile count fluctuated with a pattern essentially identical to that 

79 
of the total white blood count (coefficient of correlation of 0.9). Thus the fluctuations in total 

count were due to changes in the neutrophile count. This was true of both the older and younger 

age groups. It can be seen from Table 4.2 that the neutrophile count was consistently greater 

than the lymphocyte count in the older age group. In the younger groups, differences in the neutrophile and lymphocyte count were less marked and on six occasions the lymphocyte count was 

greater than the neutrophile count. 

Platelets were first counted 10 days after exposure, at which time platelet values of the 

older age groups were approximately 70 per cent of the control group (Fig. 4.4). Following this, 

the platelet count fell reaching a low of approximately 35 per cent of control value during the 

fourth week. The platelet count rose during the 5th week and reached the value noted for the 

initial counts on the 10th day. A second decrease in the platelet count (P < 0.01) developed during the 7th and 8th weeks, and values remained at approximately 70 per cent of the control 

group during the remainder of the observation period. The pattern of platelet counts in the below 15-year group was remarkably similar to that noted in the older age groups. Differences 

between the age groups were less apparent if the platelet counts were expressed as per cent of 

the control group. 

4.6 AILINGINAE GROUP 

In this group there were only three individuals below age 5. For this reason, remarks will 

be confined essentially to the older age group. 

The absolute neutrophile count fluctuated around the control value for the first six weeks 

of observation (Table 4.3). At this time the counts began to fall, and a value approximately 75 

per cent of the control count was reached and maintained throughout the duration of the obeervation period. The lymphocytes in this group fell to a value of 55 per cent of normal during the 

first week. The counts then fluctuated around this value throughout the period of observation, 

and no definite upward trend of the lymphocyte count was noted during the period of observation. 

As was noted in the Rongelap group the lymphocyte counts remained at an essentially constant low level throughout the period of observation. The total leukocyte count in this group 

also reflected changes in the neutrophile count. 

The platelet counts in the Ailinginae group were low, approximately 75 per cent of normal, 

when first enumerated on post-exposure day 10. The counts remained at this level during the 

second and third week; however, a definite fall in count was noted during the fourth week when 

a low value 45 per cent of control was attained. The counts returned during the fifth week to a 

value approximately 70 per cent of the control level, where they remained for the duration of 

the observation period. A secondary fall, as observed in the Rongelap group was not detected. 

4.7 UTIRIK GROUP 

- 

In the greater than 5 age group the total white blood cell and neutrophile counts were depressed slightly below control values during the first and second weeks (Table 4.4). The 

lymphocyte counts were below control levels consistently, and the total white count equal to 

the control value obtained on day 29 was due to a neutrophilic leukocytosis. 

Platelet counts on the 29th day were significantly lower than on the 19th day and were 

lower than control values. The 29th day coincides with the time of maximum depression for 

the more heavily exposed groups. 

4.? RONGERIK GROUP (AMERICANS) 

The neutrophile count in general reflected the time course of the total leukocyte count 

(Fig. 4.5). Neutrophiles accounted almost entirely for the marked rise in total count on postexposure day one, and the values for absolute neutrophile count fluctuated near the control 

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