ORP/CSD 72-1
ESTIMATES OF IONIZING RADIATION
DOSES IN THE UNITED STATES
1960-2000
,
f
I'.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Radiation Programs
Division of Criteria and Standards
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ESTIMATES OF IONIZING RADIATtON^<
DOSES IN THE UNITED STATES
1960-2000
Special Studies Group
Alfred W. Klement, Jr.
Carl R. Miller
Ramon P. Minx
Bernard Shleien
AUGUST 1972
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Radiation Programs
Division of Criteria and Standards
Rockville, Maryland 20852
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 • Price $1.60
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PREFACE
The Federal Radiation Council* was established in 1959 to ". , .
advise the President with respect to radiation matters, directly or
indirectly affecting health, including guidance for all Federal agencies
in the formulation of radiation standards and in the establishment and
execution of programs of cooperation with States , . ," During that year
a study was initiated to provide recommendations on radiation protection.
As a result of these studies guidance was issued in 1960 and 1961.
In early 1970.the Federal Radiation Council recommended a review of
the bases for and considerations of basic radiation guidance previously
issued. The review was initiated in November 1970 by the appointment of
temporary Council staff members by the participating agencies and con-
tracting with the National Academy of Sciences and the National Council
on Radiation Protection and Measurements for various parts of the review.
Soon after, the Environmental Protection Agency was formed to which the
Council's functions were transferred. The interagency review was contin-
ued under the auspices of this new agency in the Division of Criteria and
Standards, Office of Radiation Programs, in which the Council temporary
staff was assigned as the Special Studies Group,
This report is the first of several expected to result from the review
of radiation guidance. It is an assessment of radiation doses in the
United States from 1960 to 1970 and predictions to the year 2000, Its
primary purpose is to provide other groups with some estimates of future
doses to the United States population and major contributors to these
doses that may assist in the formulation of general and specific radiation
protection guidance,
^Members of the Council were the Secretaries of Agriculture;Commerce;
Defense; Health, Education, and Welfare; Interior; and Labor; and the
Chairman of the Atomic Energy Commission. The Council's functions were
transferred to the Environmental Protection Agency when the Agency was
established in late 1970. (42 U.S.C. 2021 (h).)
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The report was made possible through the appointment of full-time
staff and data furnished by the participating agencies. A number of
other Federal and State agencies provided valuable information as well.
A large number of persons in the participating and other agencies provid-
ed useful comments on the report as did a number of private organizations
and individuals.
The participating agencies and their appointees were::
Department of Defense Ramon P. Minx, LTC, MSC, USA
Department of Health, Education,
and Welfare Bernard Shleien, Pharm. D,
Atomic Energy Commission Alfred W. Klement, Jr.
Office of Water Programs,
Environmental Protection Agency Carl R. Miller
A number of studies in progress or initiated during the review will
provide additional information which will be valuable in assessing rad-
iation doses in the future. More sophisticated methods are being devel-
oped and several sources are receiving more detailed study than they had
prior to this review. In particular some sources are being studied which
did not appear to contribute significantly to overall doses to the total
United States population, but do contribute significantly to some individ-
ual doses. These and other studies of sources in this category would
greatly assist in making more definitive dose estimates in future reviews
of this nature.
In addition to the acknowledgements above, the authors gratefully
acknowledge the assistance of Mr. Samuel Wieder, Editor, Radiological
Health Data and Reports, for his editorial advice and assistance with the
mechanics of preparation for publishing the report; Mrs. Yvonne Countee
and Miss Barbara Stephens for assistance with early drafts of the report;
and Mrs. Betty Cooke for preparation of the final typescript.
11
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CONTENTS
PREFACE
I. INTRODUCTION
Page No .
A. Purpose and Scope ----------------------------------- 1
B. General Procedures ----------------------------- • ----- 2
C. Population Estimates -------------------------------- 4
REFERENCES ---------------------------------------------- 5
II. ENVIRONMENTAL RADIATION -- ..... - ......... - ..... ---------- 7
A. Natural Radiation ----------------------------------- 7
1. Cosmic Radiation --------------------------------- 7
2. Terrestrial Radioactivity ------------------------ 8
a. External Gamma Radiation ---------------------- 9
b. Internal Radiation ---------------------------- 11
3. Summary ------------------------------------------ 13
B. Global Fallout from Nuclear Tests -------------------- 13
1. External Gamma Radiation ------------------------- 14
2. Internal Radiation ---------------- - -------------- 15
a. Inhalation ------------------------------------ 15
b. Ingestion ------------------------------------- 15
3. Summary ------------------------------------------ 18
C. Peaceful Applications of Nuclear Explosives ---------- 18
D. Nuclear Electric Power ----------------------------- -- 22
1. Nuclear Electric Power Supply Requirements ----- --- 22
2. Estimated Radiation Doses ------------------------- 26
a. Uranium Mines ---------------------------------- 27
b. Uranium Mills ------------ ........ -------------- 27
c. Fabrication Plants ----------------------------- 28
d. Nuclear Power Plants --------------------------- 28
e. Fuel Reprocessing Plants ---------------------- - 30
3. Worldwide Radioactivity --------------------------- 41
a. Tritium ---------------------------------------- 43
b. Krypton-85 ------------ ..... - ---------- ....... -- 47
E. Government Facilities ------- ------------------------- 48
1. Nevada Test Site ----------------- ...... --------- -- 50
2. Nuclear Rocket Development Station ---------------- 51
3. Peaceful Nuclear Explosive Tests ------------------ 52
a. Project Gnome ---------------------------------- 53
b. Project Gasbuggy ------------------------------- 53
4. Other Atomic Energy Commission Facilities --------- 53
5. Other Government Facilities ----------------------- 57
F. Private Facilities ----------------------------------- 58
G. Summary ---------------------------------------------- 59
REFERENCES ---------------------------------- ......... --- 61
iii
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APPENDICES TO ENVIRONMENTAL RADIATION SECTION 70
90
APPENDIX II-A Accumulated Bone Dose from Sr vs. Age 73
APPENDIX II-B Dose Calculational Methods for Fuel
Reprocessing '--' 77
III. MEDICAL RADIATION 83
A. Dose Estimates 83
1. Medical and Dental Radiology 83
a. Methodology and Results of United States Studies;
Genetically Significant Dose 84
b. Extrapolation of Other Doses 86
2. Diagnostic Use of Radiopharmaceuticals 90
a. Genetically Significant Dose 90
b. Extrapolations of Other Doses : 90
3. Radiation Therapy • 93
a. Radiation Treatment of Cancer 93
b. Radiation Treatment of Nonmalignant Diseases 95
4. Medical Occupational Exposure 96
B. Projected Doses 96
1. Medical and Dental Radiology 96
2. Radiation Therapy 99
3. Diagnostic Radiopharmaceuticals 99
4. Medical Occupational Exposure < 100
C. Summary T 100
REFERENCES 107
APPENDICES TO MEDICAL RADIATION SECTION 111
APPENDIX III-A Summary of Information Relating to United
States Studies for Determination of GSD --- 113
APPENDIX III-B Estimated Thyroid Dose - 1964 118
APPENDIX III-C Radiopharmaceuticals • 121
APPENDIX III-D Radiation Therapy 125
IV. OCCUPATIONAL RADIATION 133
A. Assumptions and Limitations of Data 135
B. Summary of Data from Reporting Agencies 136
1. Federal Agencies 136
a. Army 136
b. Air Force 137
c. Navy 138
d. Atomic Energy Commission 139
e. Public Health Service 139
f. Other Federal agencies 139
2. Nonfederal Activities 140
a. Atomic Energy Commission Licensees 140
b. Agreement State Licensees 142
c. X-ray Use in the Healing Arts 142
d. Medical Use of Radium 145
3. Summary 145
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C. Internal Doses Incident to Occupation 145
D. Population Dose from Occupational Exposure 147
E. Population Dose from Occupational Exposure, 1960-to 1970 147
F. Population Dose from Occupational Exposure,1980 to 2000 150
REFERENCES 152
V. MISCELLANEOUS RADIATION 155
A. Television Receivers 157
B. Consumer Products Containing Radioactive Material 158
C. Air Transport 159
D. Summary 160
REFERENCES - 161
VI. SUMMARY - - -- 163
A. Environmental Radiation 165
B. Medical Radiation 165
C. Occupational Radiation 170
D. Miscellaneous Radiation 171
E. Total Man-rem 171
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TABLES
Page No,
II-l Estimated Annual Cosmic-ray Whole-body Doses 8
II-2 Estimated Annual External Gamma Whole-body Doses
from Natural Terrestrial Radioactivity 10
II-3 Estimated Average Annual Internal Radiation Doses
from Natural Radioactivity in the United States 12
II-4 Estimated Total Annual Average Whole-body Doses from
Natural Radiation in the United States • 13
II-5 Estimated Total Annual Whole-body Man-rem from
Natural Radiation in the United States • 13
II-6 Estimated per Capita Organ Doses from Inhalation
of Radioactive Fallout 16
II-7 Estimated Dose from Ingestion of Radioactive
Fallout - ---- 19
II-8 Total Annual Whole-body Doses from Global Fallout -- 22
II-9 Estimated Nuclear Generating Plant Sites - 1990 ---- 23
11-10 Estimated Number of Operating Reactor Plant Sites
by Year and Region 26
11-11 Estimated External Gamma Whole-body Doses from
Reactor Gaseous Effluents 31
11-12 Projected Quantity of Reprocessed Fuel 33
11-13 Radionuclide Content of LWR Fuel Decayed 150 Days
and FBR Fuel Decayed 30 Days _____ 34
11-14 Estimated Fractional Release for Radionuclides
Present at Time of Reprocessing • • 35
11-15 Air Concentration Distance Correction Factors 36
11-16 Estimated Annual Dose Accrued at 3,000 Meters from
a Fuel Reprocessing Plant per 300 Metric Tons of Fuel
Reprocessed per Year 37
11-17 Summary of Table 11-16 39
11-18 Average Annual Dose Accrued to the Population Within
100 Kilometers of a Fuel Reprocessing Plant 40
11-19 Estimated Annual Dose Accrued to the United States
Population from Fuel Reprocessing 42
11-20 Projected World Reactor Power Capacity 45
3
11-21 Estimated Annual Whole-body Dose from Worldwide H - 47
11-22 Estimated Annual Doses to the United Stateg.
Population from Worldwide Distribution of Kr 48
11-23 Major Atomic Energy Commission Installations 55
vi
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11-24 Estimated Total Annual Whole-body Doses from Other
Atomic Energy Commission Installations 56
11-25 Estimated Internal Doses from Other Atomic Energy
Commission Facilities 57
11-26 Summary of Estimates of Whole-body Environmental
Radiation Doses to the United States Population 60
IIA-1 Strontium-90 Intake 74
90
IIA-2 Fraction of 50-Year Sr Bone Dose Delivered After
Intake 76
III-l Estimated Abdominal Dose from Diagnostic Radiology - 88
III-2 Estimated Thyroid Doses from Diagnostic Radiology -- 89
III-3 Estimated Doses from the Diagnostic Uses of
Radiopharmaceuticals - 1966 92
III-4 Estimated Total Man-rem to the United States
Population from Medical Diagnostic Radiology, 1960 to
2000 -- 99
III-5 Summary of Estimated Doses from Medical and Dental
Radiation 101
IIIA-1 Summary of Information Relating to United States
Studies for Determination of GSD 115
IIIA-2 Summary of Information Relating to United States
Studies for Determination of GSD 117
IIIC-1 Patient Administration and Dose Administered - 1966 - 121
IIIC-2 Dose per Administration - - 123
IIID-1 Exposed Population Radiation Therapy (Malignancies)
Age <30 - • - 125
IIID-2 Treatment of Cancer (Diagnosed 1955-1964) with
Radiation - Age <30 - --- 126
IIID-3 Estimated Gonad Dose per Treatment 129
IIID-4 Gonad Dose from Radiation Therapy of Malignancies
to Less Than 30 Age Group 130
IIID-5 Estimated GSD from Radiation Therapy (Malignant
Diseases) --• 132
IV-1 Summary of Army Annual Occupational Doses - 1969 to
1970 -- 137
IV-2 Summary of Air Force Occupational Doses - 1969 to
1970 138
IV-3 Summary of Navy Occupational Doses - 1969 to 1970 -- 139
IV-4 Summary of Atomic Energy Commission Occupational
Doses - 1969 - - - 140
vii
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IV-5 Summary of Reporting Atomic Energy Commission (AEG)
Licensee and Agreement State Licensee Occupational
Doses - 1969 141
IV-6 Mean Annual Doses for Reporting Atomic Energy
Commission Licensees - 1969 : '- 142
IV-7 Mean Annual Occupational Doses for Agreement State
Licensees - 1970; - 143
IV-8 Wisconsin Dental Facility Survey - 1969 to 1970 143
IV-9 Summary of Illinois Whole-body Radiation Doses - 1970 144
IV-10 Total Annual Whole-body Man-rem by Reporting Group
and Occupation - 1969 to 1970 146
IV-11 Total Annual Occupational Whole-body Doses - 1969
to 1970 148
IV-12 Percent of Employees in Annual Dose Ranges - 1969
to 1970 149
IV-13 Job Category Data - 1969 to 1970 -- 149
IV-14 Estimated Annual Whole-body Doses to the United
States Population from Occupational Exposure 150
V-l Total Annual Average Whole-body Doses from
Television Receivers - 1970 to 2000 158
V-2 Total Annual Average Whole-body Doses to the United
States Population from Miscellaneous Sources 160
VI-1 Summary of Whole-body Annual Radiation Doses in the
United States - 1960 to 2000 168
viii
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FIGURES
Page No,
II-l Respiratory Lymph Node Dose from a One-Time Exposure
to Plutonium 17
90
II-2 Accumulated Bone Dose from Sr for Various Ages
(U.S. Average) -- 20
90
II-3 Accumulated Sr Bone Dose by Several Cohort
Populations (U.S. Average) 21
II-4 Predicted World and United States Nuclear Electric
Power Requirements 24
II-5 National Electric Power Survey Regions 25
II-6 Estimated World Inventory of Tritium in the
Atmosphere and in Surface Waters 44
85
II-7 Estimated Kr Concentrations in the Northern
Hemisphere from Nuclear Electric Power Production -- 49
VI-1 Summary of Estimated Whole-body Radiation Man-rem
Doses in the'United States '• 166
VI-2 Summary of Estimated Average Whole-body Radiation
Doses in the United States (mrem/person) 167
ix
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INTRODUCTION
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I. INTRODUCTION
In June 1970^the Federal Radiation Council initiated a review of
the bases for and considerations of basic radiation exposure guidance
2 3
issued in 1960 and 1961.' The study was continued by the Environmental
Protection Agency following the transfer of the Council's functions to
4
that agency. This report contains the results of that part of the over-
all review concerned with estimates and predictions of radiation doses
to United States populations - past, present, and future. Other parts
of the review include a study of the scientific bases for estimating
risk by a committee of the National Academy of Sciences, a review of
models for estimating radiation doses by the National Council on Radi-
ation Protection and Measurements, and a study of risk-benefit balanc-
ing. The overall study is scheduled to be completed by January 1973.
A. Purpose and Scope
The plan for study listed as a component: "Collection and analy-
sis of radiation exposure data relevant to the evaluation of risk and
projections of major contributors anticipated in the future." To im-
plement this provision of the plan the Special Studies Group (Tempo-
rary Staff) was directed to (1) collect, collate, and analyze infor-
mation on radiation sources that contribute to radiation exposures of
the general public and occupational exposures and (2) estimate the dose
associated with each source or activity and total population dose.
The overall study was concerned with radiation guidance and the
subject of other components of the study. The review reported here was
made without regard to numerical values of current or possible future
standards or regulations. Instead, practices believed prevalent during
the periods under review were considered in order to provide an in-
formation base on which to evaluate current guidance.
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Except for the obvious implication that radiation dose is related
to effects, no expression or implication with regard to radiation effects
is intended. This is a function of another component of the overall
study.
Since estimation of radiation dose to human populations is the
objective here, no discussion of the geographic distribution of radio-
activity or radiation sources is included except where necessary to in-
dicate procedures used for dose estimation. Such discussions are ade-
quately included in other studies (e.g., Reference 6). Because the
study is directed toward estimates and predictions of radiation doses
to the population of the United States, emphasis is placed on the entire
population averages. While special groups and unusual situations are
considered and are included in the averages, no attempt is made to em-
phasize them. Although it was intended that only "major contributors
anticipated in the future" be considered, some consideration was given
to all sources to determine their degree of contribution. However,
accidents and nuclear war were not considered. Obviously, some sources
(including special cases mentioned above) were found to warrant only
mention for completeness. It is recognized, however, that some of these
pose serious problems in localized situations and are undergoing study
by agencies responsible. Throughout this report the term "significant"
is used in the sense that the estimates are or are not sufficient to be
additive with regard to the accuracy of the estimates, considering the
number of significant digits deemed appropriate. The term as used here
is not related to radiation effects or risks.
The sources considered are categorized in sections as shown in the
Table of Contents under the following topics: Environmental, Medical,
Occupational, and Miscellaneous Radiation. Because of the nature of the
various radiation sources and/or the nature of the available data, the
sections differ in the manner of presentation.
B. General Procedures
For estimates of past doses from radiation the year 1960 was select-
ed since Federal Radiation Council guidance was issued at about that time.
For some categories other years were selected to provide a better over-
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all view of the category. For the present, the year 1970 was selected,
and for estimates of future doses, the years 1980, 1990, and 2000 were
used.
Radiation doses are estimated* in most cases as annual doses. For
90 239
long-lived radionuclides (e.g., Sr and Pu) 50-year internal doses
are usually estimated; i.e., the dose accrued over 50 years from inges-
tion or inhalation of a nuclide during 1 year. Emphasis is placed on
whole-body doses although organ doses are estimated when appropriate.
Whole-body dose is defined as the average dose to the whole body. Use
of the term somatic dose also refers to the average dose to the whole
body, the magnitude of which, for purposes of this report, is assumed to
be numerically equal to the average gonad dose. In all cases estimates
are made of average doses to the population at risk (the population
directly exposed by a radiation source) and to the entire United States
population. This permits intercomparison of data from previous studies
as well as from different radiation sources to both the population at
risk and total populations. Doses are given in several ways suggested
by some potential users of the information reported. The number of man-
rem as used here is the product of an average dose and the population
at risk associated with the average dose. The use of this unit is a
convenient means of comparing doses from various sources, as well as
averaging. All average annual doses are computed from the total man-rem
divided by the total population for each population unit considered.
An attempt was made to make dose estimates as accurately as possible
with the best data available. Estimates made by others were considered
throughout the study. However, independent estimates were made during
the study, although, as may be expected, many were in good agreement with
estimates made by others. In a number of cases, no adequate similar
projections were found. In nearly all cases, data available are only
partially adequate for calculation of accurate doses since dose esti-
mation in general is not the objective of data collection. In these
cases, the assumptions made, the source of data, and the methods used
are stated or referenced. In general, the nature of the data and the
*Reference 7 was used for basic concepts and data throughout.
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lack of good tests of the methods or models for dose estimation
against measured doses are such that reasonably good estimates of
the accuracy of the dose projections are impossible. The dose esti-
mates for the past and present are believed to be correct well with-
in a factor of two. Estimates for the future are probably correct
within an order of magnitude. For some estimates, the number of digits
shown is more than is warranted by the accuracy of the estimate. The
purpose of this was to show trends which would not otherwise be seen,
or to carry out additions to other values before rounding off.
C. Population Estimates
In this report, estimates of populations used for 1960 and 1970
Q Q
are based on censuses ' for those years. Estimates of future popu-
lations were based on the Bureau of the Census Fertility Assumption
Series B. For estimates of the size of populations at risk, generally
those of others as referenced are used, but in some cases estimates
were made during the study based on the 1960 census and extrapolated
to the year 2000. Extrapolations are based on the same rate of increase
as that for the entire United States or at the same rate as past years
where data on populations at risk are available.
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REFERENCES
1. Federal Radiation Council. 1970. Radiation protection policy.
Action paper FRC/2/10/6. Washington. 16 pp.
2. Federal Radiation Council. 1960. Background material for the
development of radiation protection standards, staff report. Wash-
ington, Report No. 1. iii. 39 pp.
3. Federal Radiation Council. 1961. Ibid. Report No. 2. iii, 19 pp.
4. The President. 1970. Environmental Protection Agency, Reorganization
Plan No. 3 of 1970, Title 3 - The President, Presidential Documents.
Federal Register 35(194): 15623-15626.
5. Federal Radiation Council Staff. 1970. Plan for conduct of the FRC
review of its basic guidance for radiation protection. (Draft
concurred in by responsible member agencies.) Washington. 5 pp.
6. United Nations. 1972. Report of the United Nations Scientific Com-
mittee on the Effects of Atomic Radiation. New York. (In prepara-
tion. )
7. International Commission on Radiological Protection. 1960. Recom-
mendations of the International Commission on Radiological Protection,
report of the Committee II on permissible dose for internal radiation
(1959). Publication 2. Pergamon, New York. viii, 233 pp.
8. Bureau of the Census. 1961. U.S. Census o_f Populations: 1960,
Vol. 1, Characteristics cxf the Population. Part A, Number of
Inhabitants. Washington, var. pp.
9. Bureau of the Census. 1970. Ibid. Preliminary reports, var. pp.
10. Bureau of the Census. 1970. Projections of the population of the
United States, by age and sex (interim revisions). 1970 to 2020.
Washington, Series I, P-25, No. 448. 50 pp.
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II. ENVIRONMENTAL RADIATION
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II. ENVIRONMENTAL RADIATION
In this section, doses to the United States population resulting
from all sources of environmental radiation are discussed. The sources
include naturally occurring radionuclides and man-made environmental
radioactive material resulting from nuclear explosives, the electrical
power production process, and other governmental, industrial, medical,
and research uses. For purposes of dose calculations, it is assumed that
3
whole-body and gonadal doses are the same. Doses from worldwide H and
85
Kr are discussed in Section D.
A. Natural Radiation
Man is exposed in varying degrees to sources of radiation found in
nature depending on his activities and location. Cosmic radiation enter-
ing the earth's atmosphere and crust is one natural source of exposure.
Nuclear interactions of cosmic rays with matter produce radiations and
radionuclides to which man is exposed. Other sources of natural radia-
tion affecting man are elements found in the earth's crust which are
composed of one or more radioisotopes. These sources and estimates of
their impact on United States populations are discussed below.
1. Cosmic Radiation
A number of reviews and data on cosmic radiation and cosmic radi-
ation doses have been published. The data from Reference 1 were
used in the current estimates. Cosmic-ray dose rates vary with alti-
tude and geomagnetic latitude up to about 50 . For example, whole-body
dose rates at sea level from Alaska to Florida range from about 45 to
30 mrem/yr., and at 45° N. from sea level to 8,000 ft. altitude, the
range is about 40 to 200 mrem/yr. Based on such relationships, estimates
of doses were made for each county or similar political unit in the
United States. Averages for each major political unit of the United
-------
States, calculated from the man-rem totals of the smaller political units,
are shown in Table II-l. These are similar to estimates made by others
Q
using similar methods. (Revisions of Reference 7 in preparation at the
*
time this report was being finalized indicate that the estimates at the
9
highest altitudes may be somewhat too high. However, the overall average
would not be significantly different.)
Table II-l
Estimated Annual Cosmic-ray Whole-body Doses
(mrem/person)
Average Annual Average Annual
Political Unit
Al abama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
2.
Dose
40
45
60
40
40
120
40
40
35
40
30
85
45
45
50
50
45
35
50
40
40
50
55
40
45
90
75
85
45
Terrestrial
Political Unit
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Okl ahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Canal Zone
Guam
Puerto Rico
Samoa
Virgin Islands
District of Columbia
Total United States
Radioactivity
Dose
40
105,
45
45
60
50
50
50
45
40
40
70
45
45
115
50
45
50
50
50
130
30
35
30
30
30
40
45
Terrestrial radioactive material is present in the environment because
naturally radioactive isotopes are constituents of a number of elements
-------
in the earth's crust. The nuclear interaction of cosmic rays with
nuclei in the atmosphere, soil, and water also produce several radio-
nuclides. The naturally occurring radionuclides give rise to both
external and internal irradiation of man. Reviews and listings of
literature on environmental levels of these nuclides are available.
a. External Gamma Radiation
40
The significant external gamma exposures are produced by K and thi
decay products of the uranium and thorium series. Exposures from radon
and radon daughters vary significantly with atmospheric conditions which
affect radon concentrations at ground level as discussed below. Also,
the condition of the surface (soil moisture, porosity, cultivation, pave
ment, etc.) affects exposure rates. Therefore, in addition to variation
with geological and geographical factors, exposure rates vary in time
and specific location.
13-16
Based on several hundred reported measurements with scintil-
1 fi 17
lation spectrometers, estimates have been made ' of the range and
mean of whole-body doses by population and by areas for the United
States. Ninety percent of all areas fall in the range of 15 to 130
mrem/yr., while 90% of the population falls in the range of 30 to 95
mrem/yr. The estimated mean was given as 55 mrem/yr.
In the present study, the above referenced data were used to esti-
mate average dose rates for counties where measurements were made.
From these county measurements, an average was calculated for each
State. These were then used to estimate the average for the United
States population. For these estimates it is assumed that the vari-
ability within and among the various political units is the same as
that of the reported measurements. Where measurements were made at
different times in the same locations, the average was used to account
for variations in time so far as the data permitted. Based on these
assumptions and procedures, the overall United States average dose
was estimated to be 60 mrem/yr., which is near that estimated by other
procedures mentioned above. The averages for each State are shown in
Table II-2. Populations of political units shown by asterisks were
assumed to have the same doses as the United States average as reasonab]
-------
estimates. A factor of unity was used in these estimates for conversion
of open-field air-dose measurements to whole-body doses.
Estimated Annual
from Natural
Table I 1-2
External Gamma Whole-body Doses
Terrestrial Radioactivity
(mrem/person)
Average Annual Average Annual
Political Unit
Al abama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
^Assumed to be
United States
Dose
70
60*
60*
75
50
105
60
60*
60*
60*
60*
60*
65
55
60
60*
60*
40
75
55
75
i 60*
70
65
60*
60*
55
40
65
equal to the
average .
Political Unit
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Okl ahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Canal Zone
Guam
Puerto Rico
Samoa
Virgin Islands
District of Columbia
Others i
Total United States
Doses
60
70
65
75
60*
65
60
60*
55
65
70
115
70
30
40
45
55
60*
60*
55
90
60*
60*
60*
60*
60*
55
60*
60
There have been unpublished reports of residences built on tailings
piles at some abandoned uranium mills, as well as various uses of tail-
ings, such as in construction materials. Based on the little infor-
mation available, doses from these sources received by relatively small
populations are estimated to be insignificant in terms of overall
10
-------
18
averages or total man-rem. For example, measurements have been made
at Grand Junction, Colorado, from which dose estimates can be made.
These measurements showed an average of 107 mrem/yr. in living areas
of residences (above outdoor doses) to a population of about 1,800,
or about 200 man-rem/yr. A very gross estimate for all such situations
may be 10 to 20 times this value. This could increase the average dose
for the population of Colorado by less than 0.1 mrem/yr. Since reme-
dial measures are being taken to prevent similar situations in the
future and to reduce these doses, future doses are expected to be less
than current ones.
b. Internal Radiation
While all of the natural radionuclides contribute to internal radi-
3
ation doses, only a few are found to be significant. These include H,
14 40 226 228
C, K, and Ra and Ra and their decay products. Within the
3 14
United States H and C are relatively uniformly distributed so that
their levels in foods and water do not vary appreciably with geograph-
40
ical location. This is largely true for K because of agricultural
practice (fertilizing, cultivation methods, etc.). Radium and Po
are similarly affected to some extent. These facts and the practice in
the United States of widespread manufacturing and transportation of
foods and people have an "averaging" effect on radionuclide contents of
diets throughout all geographical areas. For example, the concentrations
226
of Ra in dietary samples vary as much or more at individual locations
than overall location averages differ from an average for the United
10 17 19
States. ' ' Because of this, it appears reasonable to assess internal
radiation doses from dietary sources in the United States as a whole
rather than attempt an assessment by geographical or political unit.
Radon is the only significant natural radionuclide leading to wide-
spread exposure through inhalation. It is released from soil, rock,
and building materials and contained in natural gas and other fossil
fuels. Radon concentrations vary considerably with atmospheric and
soil conditions as mentioned above. Continuous monitoring records
show that in many locations over extended periods of time air con-
centrations vary both diurnally and seasonally. ' Rainstorm and
11
-------
21
wind effects are also seen. Further variations in concentrations
would be expected with regard to radon resulting from burning of nat-
ural gas and other fossil fuels. Radon in natural gas would increase
ambient concentrations in dwellings, as well as the general environ-
ment, depending on type of construction and ventilation of dwellings
22
and perhaps some other factors. While some studies are in progress
in this regard, insufficient data are available at this time to pro-
vide a basis for a reasonable estimate of the natural gas contribution
to population doses. Other fossil fuels would contribute additional
radon to the general environment, and would be included in outdoor
measurements. The estimated whole-body dose from dissolved radon in
the body is 3 mrem/yr. Estimates for lung doses from inhaled radon
have ranged from about 100 to 900 mrem/yr.
The estimated average internal dose rates to the population of the
United States are summarized in Table II-3. These estimates are quite
similar to those reported by others.' '
Table I1-3
Estimated Average Annual Internal Radiation Doses
from Natural Radioactivity in the United States
Annual Doses (mrem/person)
Radionuclide*
3
H
14
C
40
K
87
Rb
210
Po
222
Rn
226,.,
Ra
228
Ra
TOTAL
Whole-body
0.004
1 .0
17
0.6
3.0
3.0
-
—
25
Endosteal Cells (Bone)
0.004
1.6
8
0.4
21
3.0
6.1
7
47
Bone Marrow
0.004
1.6
15
0.6
3.0
3.0
0.3
0.3
24
*0ther natural radionuclides would contribute to doses but ouch a small
fraction that they would not affect the totals within the accuracy of
these estimates. As an example, doses from 3H are shown here.
12
-------
3. Summary
The overall estimates of doses from natural radiation are sum-
marized in Tables II-4 and II-5.
Table II-4
Estimated Total Annual Average Whole-body Doses from Natural Radiation
in the United States
(mrem/person)
Source Annual Doses
Cosmic rays 45
Terrestrial radiation
External 60
Internal 25
TOTAL 130
Table II-5
Estimated Total Annual Whole-body Man-rem from Natural Radiation
in the United States
Year
1960
1970
1980
1990
2000
Population
(millions)
183
205
237
277
321
Annual Man-rem
(millions)
23.8
26.6
30.8
36.0
41.7
B. Global Fallout from Nuclear Tests
Fallout from nuclear weapons tests is another source of environ-
mental radioactive material. Large-scale, high-yield atmospheric test
series in the past (e.g., United States and Soviet tests, 1961 to 1962)
introduced radioactive material into the stratosphere which was later
deposited worldwide. The last such test series was conducted in 1962. A
portion of the small amount of material remaining in the stratosphere
continues to be deposited annually. During the past several years, a few
atmospheric tests by the French and Chinese have been conducted which
have been sufficient to maintain a relatively constant annual fallout
23
deposition. Past and current tests have also injected material into
13
-------
the troposphere which is deposited relatively quickly within a few
degrees of the latitude of the tests. (Local fallout from Nevada
3 85
Test Site tests is discussed in II. E; and worldwide H and Kr
doses are discussed in II. D.)
Both current fallout and that deposited from past tests contribute
to internal and external population doses. For this study, it was as-
sumed that the rate and type of testing from 1965 to 1970 will continue
through 2000. Estimates were made for 1963, 1965, 1969, and subse-
quent decades to 2000. In 1963 the highest fallout deposition occurred
The year 1969 was chosen as an example of the current situation.
1 . External Gamma Radiation
137
The accumulation of Cs deposited from past nuclear tests is the
major source of long-lived external gamma radiation from fallout. A
number of short-lived radionuclldes contribute significantly to doses
within a few years of their production. Estimates of external gamma
doses from fallout in the New York City area have been made which were
24 25 26
verified by measurements. ' ' Those values are the basis for the
1963 estimates in this study and an extension was used to esti-
mate doses from short-lived nuclides in other years. Estimates of
137 90
doses from Cs for 1965 and 1969 were based on Sr deposition data
23
for New York City. Two population areas were used for this purpose —
27 ?8 on
"wet" and "dry" areas. ' The average annual deposition of Sr in
MI! 2 S *? fi
wet areas is estimated to be 0.74 times that for New York City.
Based on measurements in 1963, deposition in "dry" areas was estimated
to be 55% of that in "wet" areas (or 41% of that for New York City) .
The population in "dry" areas was calculated to be 15% of the United
States population.
It is assumed that Cs deposition is 1.6 times29 that of
Sr, and that the factor for conversion of Cs deposition values
to open-field exposure rate is 1.7 x 10~3 (^H/hr.)/(mCi/mi?). Exposure
rates (|_iR/hr.) are then converted to air dose rates (p.rad/hr.). A
30
shielding factor of 0.4 due to buildings and other structures and a
31
screening factor of 0.8 caused by body shielding were assumed for
conversion of open-field air doses to whole-body doses.
14
-------
Similarly, average dose estimates were made for short-lived radio-
24
nuclides based on the study mentioned above. There was no significant
contribution from these nuclides in 1969.
The calculated total annual average external gamma radiation doses
to the United States population for 1963, 1965, and 1969 were 5.9, 1.8,
and 0.9 mrem/person, respectively. Annual doses from 1970 to 2000 are
estimated to be about the same as those for 1969.
2. Internal Radiation
Whole-body and individual organ doses have been estimated for in-
halation and ingestion of fallout radionuclides.
a. Inhalation
32 33
Radionuclide air concentration data ' were used to determine doses
to the lungs, bone, respiratory lymph nodes, and whole body due to in-
halation. The average air concentration from the United States data was
applied to the country as a whole. Dose values for individual radio-
nuclides were obtained by comparison with recommended maximum air con-
34
centrations or by using values of dose to be received by the individual
per unit of activity inhaled. ' The results are given in Table II-6.
Most doses are received within 1 year after exposure. However, the
90
doses from Sr and plutonium will be received over the 50 years follow-
ing inhalation because of their long physical and biological half-lives.
The fraction of the respiratory lymph node dose from plutonium delivered
by a certain time after a 1-year exposure can be estimated from Figure II-l
No attempt has been made to determine the total accumulated dose from
the inhalation of plutonium since air concentration data are not avail-
90
able for many years during the fallout period. The accumulation of Sr
doses is discussed further in the next section.
b. Ingestion
OQ OQ -I O-l -I o*7
Doses due to ingestion of Sr, Sr, I, and Cs have been esti-
37 38
mated using diet radionuclide concentration data from 12 cities. '
131
(Tritium is discussed in section D.3) Strontium-89 and I doses are
assumed to result entirely from a milk intake of 1.2 liters/day. (The
slightly higher-than-average milk intake will account for doses from
other food sources.) The United States was divided into 12 regions with
15
-------
Table I1-6
Estimated per Capita Organ Doses from Inhalation of Radioactive Fallout
(mrem accrued/yr . )
Lung Dosea Bone Dose
Nuclide 1963 1965 1969 1963
54MnC 0.96 0.16 b
55 c
Fe 0.02 0.01
ao <-.
Sr 0.60 0.01 0.08
qn p rl f
Sr ' 0.43 0.09 0.01 0.28
95Zr° 1.9 0.02 0.05 0.62
109CdC _ 0.01 _ __
137Cs° 0.23 0.06 0.01 0.03
1 44 c-
Ce 8.2 0.38 0.31 10.6
238Pud 0.35g 0.06 0.08 0.14f
239Pu6 4.5g 0.78 0.16 1.9f
TOTALS 17.0 1.6 0.6 14.0
a
Does not include whole-body dose .
Dose <0.01 mrem/yr. «.
From comparison with recommended MPC limits.
From dose values in Reference 35.
From dose values in Reference 36.
50-year dose for a 1-year intake (see text);
25% Sr dose given in 1st 5 years,
9% Pu dose given in 1st 5 years .
50-year dose for a 1-year intake (see text);
1965 1969
0.06 0.01
0.02
__
0.49 0.40
0.03 0.03
0.35 0.07
0.9 0,5
Whole-body Dose
1963
0.01
0.03
f
0.40
0.16
0.02
0.55
o.oif
0.19f
1.4
1965
0.09
_,_
0.02
0.04
0.2
Respiratory
Nucl ide
o o o j
238Pud
239^ e
Pu
TOTALS
Node Dose
1963
79f
i,ooof
1,080
1965
14
175
190
1969
0.01
:
0.02
0.01
0.04
Lymph
1969
19
36
55
-------
(9£ aoua-isjan tnoaj
oq. avtnsodxg
!a.insodxg
raojj asoa apo>i
• SA
"I-II
TJ
Q)
100
80
Q)
Q
0
(/)
o
Q
6O
c
0
o
l_
Q)
Q.
40
20
0
0
10 20 30
Years After Exposure
40
50
-------
delivered in 1 year except the Sr doses which are delivered over the
one designated city considered representative of each region. Using
35
values of dose per unit activity ingested, an average dose for the
14
United States was obtained. Doses from C were estimated using a
percent of C above natural levels in the body of 30% for 1963, 70%
39
for 1965, and 60% for 1969 with the natural dose levels as given in
Table II-3. The results are given in Table I1-7. All the doses are
delivered in 1 year except th<
50 years following ingestion.
90
Because of the long delivery time of Sr doses, Figure II-2 has
been prepared so that the accumulated dose to a cohort population of a
certain age in any given year can be determined. The method and values
used in constructing this figure are presented in Appendix II-A. The
90
shapes of the curves are affected by the amount of Sr intake and its
long-term retention in bone. The average accumulated dose to an indi-
vidual in the cohort population can be read from the chart by using the
year in which the given age is attained and the graph for that age. For
example, in 1970 the average 20-year-old person would have accumulated
90
a bone dose of about 260 mrem from Sr. Repeating this at 10-year
intervals gives the average individual accumulated dose as a function of
age. Figure II-3 shows this for several cohort populations. These
values represent a United States average and any one individual's actual
dose may vary by more than a factor of two because of variation in fall-
out and in diet.
3. Summary
3
The aggregate doses (except for H) are summarized in Table II-8.
C. Peaceful Applications of Nuclear Explosives
A number of possible uses of nuclear explosives have been suggested
for industrial applications. These include excavation, gas stimulation,
recovery of oil from oil shale, mineral recovery, underground storage,
waste and water management, and use of geothermal energy. ~ Experi-
mental programs in these areas have progressed to some extent. This is
especially true with regard to excavation and gas stimulation which lack
relatively little additional experimentation for complete development of
capabilities and proven economic advantage. However, development has not
18
-------
Table I1-7
Estimated Dose from Ingestion of Radioactive Fallout
(mrem accrued/yr ./person) *
Year
1963
1965
1969
1980
1990
2000
*The
bone
14c
Whole-body
0.3
0.7
0.6
0.6
0.6
0.6
90
,..Sr doses are
Yearly yuSr
Bone
0.5
1.1
1.0
1.0
1.0
1.0
137
Cs
Whole-body
4.3
2.3
0.4
0.4
0.4
0.4
delivered over 50 years
whole-body
dose rates
89
Sr
Bone
1.3
0.2
0.2
0.2
0.2
0.2
9°Sr I
Whole-body
7.3
7.2
3.2
3.2
3.2
3.2
The whole-body dose = 0,
estimated
from Figure I 1-3
Bone
73
72
32
32
32
32
. 1 times
for the
Thyroid
25
4
3
3
3
3
the dose to
years conside
are:
1963 =0.9 mrem/yr.
1965 =1.9 mrem/yr.
1969 =2.1 mrem/yr.
1980 =2.5 mrem/yr.
1990 =2.7 mrem/yr.
2000 =3.0 mrem/yr.
-------
1600
1400
1200
(S)
i_
0)
Q_
0) 1000
i—
£
(f)
0
Q 800
0)
c
o
CD
"5 6°°
3
E
D
400
200
Whole-Body Dose-.1/10 Bone Dose
Age 60.
Age 50
196O 1970 198O 199O 2OOO 2010
Year in Which Given Age is Attained
90
Figure II-2. Accumulated Bone Dose from Sr for Various Ages
(U.S. Average).
20
-------
'S'Q) suoiq.-B-[ndO(j
A"q esoQ auog jg
06
'£-11
1200
s-~\
O
0)
i_
d)
Q. 1000
\
E
0)
£
0)
0
Q
Q)
C
O
CO
I!
E
D
o
O
800
600
400
200
o
1955
Whole - Body Dose -. //10 Bone Dose
1960 1965 1970 1975 198O 1985 1990
Year
1995 2000
-------
Table I1-8
Year
1963
1965
1969
1980
1990
2000
Total Annual Whole-body
U.S.
Population
(millions)
190
194
204
237
277
321
Doses from Global
Per Capita
Dose
(mrem)
13
6.9
4.0
4.4
4.6
4.9
Fallout*
Man-rem for
U.S. Population
(millions)
2.4!
1.3
0.82
1.1
1.3
1.6
*Internal whole-body dose rate values for Sr are taken from the
footnote of Table II-7. Tritium is excluded here and is considered
in II.D.3.
advanced to the stage where reasonably accurate estimates of the radio-
logical impact of future usage can be made. Also, in general, appli-
cations of nuclear explosives would not be amenable to routine assess-
ment and would require assessment on an individual project basis. Be-
cause of this and the absence of experience as a basis, no attempt was
made to assess these potential sources of environmental radioactivity.
They should be included in future reviews and projections as sufficient
information becomes available.
Experimental activities in this area are included in II. E below,
since they are mostly Government activities with joint industrial
participation in gas stimulation experiments.
D. Nuclear Electric Power
The nuclear electric power industry has grown rapidly during the
last decade and is expected to grow considerably by the year 2000. The
various facilities involved in the production of nuclear power are
potential sources of environmental radioactivity. These facilities will
be discussed along with estimates of radiation doses. Also included
3 85
is a discussion of worldwide H and Kr accumulation from all sources.
1. Nuclear Electric Power Supply Requirements
Estimates have been made of worldwide nuclear electric power re-
quirements. These were used as a basis for estimates of worldwide radi-
22
-------
ation doses from the nuclear power industry. A special government study
43
was made for the United States requirements up to 1990. That study
was used as a basis for the current study and projected to 2000 at the
same rate as before 1990 based on recent estimates of power require-
44
ments. These are summarized below.
The world nuclear generating capacity was predicted to increase
45
from about 20 to 2,000 billion watts electric (OWE) between 1970 and
2000 (see Figure II-4). The generation of this power will give rise to
radioactive effluents which will be spread worldwide. These must be
considered in addition to local radiation doses in the vicinity of nuclear
power plants.
The projections for the United States were made for each of the six
National Power Survey Regions (see Figure II-5). These provide a basis
for projecting results from past and current experience on a realistic
basis. These projections are shown in Table II-9 and Figure II-4. The
predictions indicated that no plants in the future would have generating
capacities under 500 million watts electric (MWE) and the largest would
approach 10 GWE. It should be noted that plants generally will be mul-
tiple-reactor units rather than a single reactor.
As of December 31, 1970, there were 20 operable power reactors; 51
under construction and 36 planned (reactors ordered), all of which would
Table II-9
43
Estimated Nuclear Generating Plant Sites - 1990
1 Nuclear Plants by Capacity (megawatts electric)
Region*
Northeast
Southeast
East Central
South Central
West Central
West
TOTAL
500-1000
7
10
1
3
3
4
28
1000-2000
19
22
10
9
6
7
73
2000-4000
17
21
8
9
9
9
73
>4000
2
7
2
1
1
13
26
Total
45
60
21
22
19
33
200
*See Figure I1-5.
23
-------
pne
PUB
pap.o-cps.id
3000
C
0)
E
Q)
i_
'5
cr
0)
o:
0)
o
_Q)
UJ
T3
-------
to
01
WEST CENTRAL
: ; FEDERAL POWER COMMISSION
.."'": POWER SUPPLY AREA
REGIONS SELECTED FOR UPDATING
THE NATIONAL POWER SURVEY
Fig-are II-5. National Electric Power Survey RegionsT
43
-------
40
begin operation by 1979. These would have a total capacity of about
95 OWE and would be located at 72 plant sites. The reactors planned
to be in operation in 1975 were assumed to meet power requirements up
to that time. Additional reactors were projected for these sites or
additional sites in increments from 1980 to 1990 to meet predictions
shown in Table II-9 for the current study. These are summarized in
Table 11-10.
Table 11-10
Estimated
Number of
Operating
Reactor
Plant
Sites by
Year
and Region
Year
1960
1965
1970*
1975
1980
1985
1990
NE
1
3
9(8)
20
24
33
45
SE
0
0
KD
13
16
38
60
EC
0
2
3(3)
8
9
15
21
Region
SC
0
0
0
1
3
13
22
we
1
1
5(4)
13
13
18
19
W
0
1
3(3)
8
15
24
33
Total
2
5
21(19)
63
73
141
200 ,
*In parentheses are numbers of sites actually in or beginning operation;
delays prevented operation of other plants.
Estimates of requirements for uranium oxide indicate that uranium,
mining and milling would increase by a factor of about 25 between 1970
46 47
and 2000. ' In 1960 there were 703 operating underground uranium mines
48
and 166 open pit mines. The numbers decreased in 1961 to 497 and 122.,
respectively. In 1966, there were 533 and 88. By 1972 there will be
40
21 uranium mills in operation. In 1970 there were 10 fuel fabrication
facilities. These facilities or additional ones are expected to increase
production by a factor of about 15 by the year 2000. bne commercial
fuel reprocessing plant began operation in 1966. Two additional plants
are planned to begin operation in 1971 and 1974, respectively?0 There
47
are expected to be about 15 plants in operation by 2000.
2. Estimated Radiation Doses
Estimated radiation doses for the various types of facilities, in-
volved in the production of nuclear power are discussed below.
26
-------
a. Uranium Mines
It does not appear that uranium mining activities result in sig-
nificant increases in environmental radioactivity outside the immediate
vicinity of mines. Measurements in mining communities and areas are
14 15
in the same general range as non-mining areas. ' While mining activ-
ities undoubtedly increase surface uranium and its decay products, espe-
cially radon, they are not widespread and are accounted for in general
natural radioactivity measurements and estimates (see II. A above).
Therefore, no additional population dose estimates were made for this
activity except for occupational doses.
b. Uranium Mills
In the processing of uranium ore to extract uranium, the byproducts
or tailings and waste constitute a source of radioactivity in the en-
vironment. The general practice is to pile tailings in the vicinity of
226
the mill. The radioactive materials of significance are primarily Ra,
222
and its decay products, principally Rn. Except for the possible
222
transport of Rn, it would be expected that, in general, no signif-
icant radioactive material would reach populated areas. Studies have
been made at active and inactive mill sites with covered and uncovered
49
tailings. These studies'indicated that there was no significant radi-
ation exposure to the public from these sources. Except for stations
directly over the tailings piles, radon concentrations and external gamma
radiation exposures were at normal background (see II.A above).
Population doses attributable to the uranium milling industry are
expected to be relatively low. The location of mills in very remote and
sparsely populated areas and liquid waste treatment programs, as well as
the discharge of liquid wastes to receiving waters that are not usually
used for recreation or public water supplies, would support this expec-
tation.
Instances have been reported of contamination of streams near mills
50
through seepage from solution storage ponds and discharge of effluents
into streams. ' In the former, dissolved radioactivity was found to
be at background concentrations 1.5 mi. downstream from the mill and
the water was not used for substantial distances farther downstream. In
27
-------
the second instance, the study resulted in a change of procedures by
1960 which reduced the discharge. These examples are typical of such
situations .
While uranium milling activities contribute to the content of
radioactive material in the environment, it appears from available
measurements that population doses from this source cannot be distin-
guished from background. Therefore, no additional doses were included
for uranium milling except for occupational doses.
c . Fabrication Plants
For economic as well as safety reasons, fuel fabrication plants
are designed in such a manner that reactor fuel is conserved to a very
high degree. It is unlikely that this activity would increase levels
of exposure in the general environment. Similar activities at govern-
ment facilities discussed below contribute no significant population
doses. Therefore, only occupational doses are considered for fuel fabri-
cation.
d. Nuclear Power Plants
As part of studies of the long-range requirements and impacts of
the nuclear power industry, computer models were developed to assess
52 53
radiation doses from reactor effluents. ' These models were tested
with measurements made at 13 operating reactor sites. They were used
to calculate radiation doses in the current study along with the basic1
previously discussed.
O CO fiO
The principal radionuclides in reactor effluents are H, Co, Co,
85^ 890 90C 131 131 133V 134 137^ ^ 14()
Kr, Sr, Sr, I, Xe , Xe , Cs , Cs , and Ba. The
amounts released as gaseous or liquid effluents depend on the type of
reactor, and for a given type of reactor, the effluents vary widely be-
Q e "1*31
cause of the individual designs. Except for Kr, Xe , and Xe ,
these radionuclides give rise to environmental contamination leading to
131 133
potential internal doses. Krypton-85, Xe , and Xe emitted in
gaseous effluents are the major contributors to external gamma doses as
a result of immersion rather than surface deposition.
(1) External Radiation
The external radiation dose model was designed to predict doses with-
in several radii of a reactor site. It provides the average dose within
28
-------
each chosen radius, the total man-rem, and the average dose to the total
exposed population.
The model involves the use of average wind data by 22.5 sectors
around the reactor and the estimated population within each sector.
Based on experience at 13 reactors, it was assumed that whole-body
external gamma doses from atmospheric effluents were 5 mrem/yr. at
site boundaries for each reactor unit. In general, actual levels were
much less than this, so that dose estimates are quite conservative.
Doses were calculated for populations between several radii, usually
up to 50 mi., since at this distance or less, radiation doses were
found to be at levels not distinguishable from background. Population
estimates within each sector and radius were made for at least 2
years (e.g., 1960 and 1985) and computer calculations of doses were
52
made. From these, estimates were made for the years considered in
this study by interpolation or extrapolation. This was done for each
reactor site in operation or currently planned. As additional reactor
units at a site became operable, simple multiples of the calculations
provided estimates for each site in subsequent years.
After 1975 when currently unplanned reactors would become operable
(predictions, see Table 11-10), the calculated doses for the operable
and planned reactors were averaged by capacity and National Power Survey
Region to provide estimates up to 1990. This,in effect, assumes that the
average dose, exposed population, and types o£ reactors in each region
will be the same as that for existing or planned reactors. The pre-
diction for 2000 was made by extrapolating from the i960 to 1990 esti-
mates which increased in a regular manner.
It is not expected that a significant number of liquid-metal fast-
breeder reactors will be in operation by 1990, although there may be
by the year 2000, Since these reactors operate with significantly lower
54
effluents than current light water reactors, the dose estimates for
1990 to 2000 may be too high. Also, other technological improvements
in reactor subsystems would reduce doses below those estimated. Be-
cause of the uncertainties in the availability of advanced reactor or
component designs, no attempt was made to assess their effect on dose
estimates,
29
-------
55
The numerical guides proposed by the Atomic Energy Commission
would require employment of radiological waste systems which would
reduce radiation doses. However, the assumptions used in calcula-
tions for this report are quite similar to those which would be used
based on the proposed guides, as application of new guides will prob-
ably have little effect on doses.
The estimated external gamma whole-body doses are shown in Table
11-11. Skin doses are estimated to be about 10 times the whole-body
dose (see e below).
(2) Internal Radiation
Because of the very low levels of radionuclides in power reactor
effluents even at the boundaries of plant sites, no definitive data are
available to base estimates of internal doses. From limited data at a
boiling water reactor, an attempt was made to obtain order-of-magnitude
57
estimates. These estimates are quite conservative and maximize doses
131
from all exposure pathways. The highest calculated dose was from I
131
to the thyroid from milk and drinking water. No .1 was detected in
milk since levels were below detection limits. Estimates based on
calculations from stack release rates indicated that the highest expected
levels at the nearest farm would be about tenfold less than could be
131
measured during the study. Estimated doses from I in drinking water
were based on estimated dilution factors from a measured point to the
nearest point of consumption. These were conservative as consideration
was not given to decay, uptake by aquatic organisms, or adsorption. How-
ever, using these data, gross conservative estimates of time-averaged
doses 360 around the reactor site indicated that they would be orders of
magnitude lower than those in Table 11-11. When applied to all reactors,
the total man-rem would be too low to affect totals of average radiation
doses.
e. Fuel Reprocessing Plants
Nuclear fuel reprocessing is another part of the nuclear electric
power generating process which is a source of environmental radio-
activity. In this section, estimates are made of doses accrued per year
to the whole body, skin, lung, bone, thyroid, and respiratory lymph nodes
30
-------
Table 11-11
Estimated External Gamma Whole-body Doses from Reactor Gaseous Effluents
Year
1960
1970
1980
1990
2000
Man-years*
at Risk
(millions)
1.9
47.6
275
367
670
Total U.S.
Population
(millions)
183
205
237
277
321
Percent of
U.S. Pop-
ulation at
Risk
1.5
22.3
100
100
100
Annual
Man-rem
16.4
430
6,080
22,780
56,000
Annual Average
Dose to Pop-
ulation at
Risk (mrem/person)
0.0085
0.0091
0.026
0.082
0.17
Annual Average
Dose to U.S.
Population
(mrem/person)
0.0001
0.002
0.026
0.082
0.17
*By 1980, a significant population would reside within 50 miles of more than one reactor site,
indicated by the man-years/total U.S. population.
-------
due to exposure to radioactive material in the environment resulting
from fuel reprocessing operations. Local effects to a radius of 100 km
(62 mi.) around a plant are considered. Dose estimates from the nation-
3 85
wide buildup of H and Kr are considered in Section II.D.3. Since
there is only one commercial fuel reprocessing plant (Nuclear Fuel
Services in New York State) in operation at the present time and since
44
its operation is not considered typical of future plants, the dose
values are calculated estimates and are not based on measurements.
The calculated values depend on certain assumptions made and on
values selected for various factors in the dose estimations. There-
fore, they depend on the validity of these assumptions and selected
values. The calculated dose values will vary by as much as factors
of 10 to 100 by changing the assumptions and selected values. There-
fore, the methods of arriving at the dose values will be presented so
that future changes can be made as more accurate information becomes
available.
Only exposure to radiation from radioactive material released from
the stack of a fuel reprocessing plant is considered since future plants
44
are expected to have little radioactivity, if any, in liquid effluent.
Exposure pathways considered are external gamma exposures from the plume
and from ground surface deposition, inhalation and skin exposure from
the plume, and exposure through ingestion after surface deposition. All
doses at a point a given distance from the reprocessing plant are
assumed proportional to the air concentration of radioactive material
at that point. Therefore, air concentrations of radionuclides are cal-
culated and from these, dose estimates are made.
(1) Air Concentration
The air concentration at a certain location depends on the amount
of fuel processed per unit time, the amount of radioactivity of the
various nuclldes in the fuel, the release rates of the various radio-
nuclides, and the dilution from the stack outlet to the location. (Ref-
erence 44 was heavily relied upon to supply many of the factors needed.)
Two types of fuel are considered in the calculations - light water
reactor (LWR) fuel and fast breeder reactor (FBR) fuel. Light water
32
-------
reactor fuel consists of uranium or plutonium while FBR fuel contains
only plutonium. For this study the LWR-Pu fuel has been added with
the FBR fuel since the amount of radioactivity produced per equal burn-
up is about the same. Table 11-12 gives a projection of the amount of
each type of fuel to be processed up to the year 2000.
Table 11-12
Projected
Quantity
(metric
of Reprocessed
tons/yr .)
Reactor Fuel
Lightwater
Year
1970
1980
1990
2000
Total
200
3,500
10,000
20,000
Ub
200
2,800
3,000
3,000
Puc
700
4,000
3,000
Fueia
Type
Fast Breeder
Puc
3,000
14,000
a
Based on:
33,000 MWd burnup/metric ton,
0.30 thermal efficiency,
0.85 load factor,
MWE capacity 2 years before processing, and
fuel mixtures from Reference 44.
Treated as LWR fuel.
Treated as FBR fuel.
All fuel is assumed to be irradiated to a burnup of 33,000 MW-
days/metric ton with a thermal efficiency of 0.30. The LWR fuel is
allowed to decay for 150 days before processing, and the FBR fuel is
allowed to decay only 30 days because of the economics involved in plu-
44
tonium recovery. This difference in decay time causes a large differ-
ence in the amount of radioactivity present at fuel reprocessing time.
Table 11-13 gives the radionuclide content of the fuel at the start of
reprocessing.
Most of the radioactive material will go to waste storage but there
will always be some fraction released depending on the element and pro-
cess involved. In Table 11-14 are shown the assumed fractional re-
3 85
leases used in this study. All H and Kr is released through the
33
-------
Table 11-13
Radionuclide Content of LWR Fuel Decayed
and FBR Fuel Decayed
30 Days*
Concentration
Nuclide
3
H
85
Kr
89
Sr
90
Sr
90
Y
91
Y
95Zr
95Nb
99
Mo
99m
Tc
99
Tc
103D
Ru
106Ru
103mRh
111A
Ag
115m
Cd
124
b,D
125
Sn
125
Sb
125m
Te
Tf3
T O 1
127Te
129mTe
129Te
TOO
132Te
-\ o Q
129Z
131
I
*Ref erenop
(C
In LWR
692
11,200
96,000
76,600
76,600
159,000
276,000
518,000
—
—
14
89,100
410,000
89,100
—
44
86
20
8,130
3,280
6,180
6,110
6,690
4,290
—
0.
2.
44 n a
i/metric ton)
Fuel In FBR Fuel
932
10,200
637,000
43,400
43,500
921,000
2,100,000
2,660,000
1, 810
1,730
.2 14.9
1,760,000
1,290,000
1,760,000
12,600
.3 269
.3 76.7
. 0 6,720
19,600
6,860
61,100
61 , 800
181,000
116,000
4,170
038 0.053
17 139,000
_1 A
Nuclide
132
133
Xe
134
Cs
136
Cs
137
Cs
140
UBa
14°La
141Ce
144
Ce
143
Pr
1 44
•*- " * ,_
Pr
147Nd
147
Pm
149
Pm
i ^i
Sm
- co
Eu
155Eu
16°Tb
23%
238
Pu
239
Pu
240^
Pu
241
Pu
241
Am
242
Cm
244
Cm
150 Days
Concentration
(Ci/metric
ton)
In LWR Fuel In FBR Fuel
—
—
213,000
20.8
106,000
430
495
56,700 1
770,000 1
694
770,000 1
51.0
99,400
1,150
11.5
6,370
300
17.4
2,810
330
478
115,000
200
15,000
2,490
4,300
74,400
29,000
28, 800
109,000
523,000
601,000
,480,000
,280,000
644,000
,280,000
185,000
353,000
61.5
4,690
10.5
79,400
9,460
7,220
11,200
3,530
4,260
600,000
1,570
65,500
1,240
34
-------
133
stack while Xe decays considerably because of holdup in the process.
The halogen and particulate release rates are values that are assumed
can be attained with advanced technology. The particulate release rate
depends on the off-gas flow rate and on plant size, but the values given
are used for all plants in this study.
Table 11-14
Estimated Fractional Release of
Present
Radionucl ides
at Time of Reprocessing*
Radionucl ides
85Kr
133Xe
Tritium
Halogens
Particulates
LWR Fuel
Reprocessing
Plant
1.0
0.1
1.0
0.001
1.2 x 10~8
FBR Fuel
Reprocessing
Plant
1.0
0.1
1.0
io~7
8.5 x 10~10
*Adapted from Reference 44, p. 8-12.
—7 3
A concentration factor of 5 x 10 ((aCi/cm )/(Ci/sec. released) was
applied at a distance of 3,000 m from the plant stack. This value was
selected after comparison of values given for several Atomic Energy Com-
44 58
mission laboratories. ' The ratios of the concentration factor at
other distances to that at 3,000 m are given in Table 11-15.
The average annual air concentration for individual or groups of
radionuclides was then calculated by using the product of the radio-
activity per metric ton (Table 11-13), the release fraction (Table 11-14),
the concentration factor (5 x 10 ), and a time factor assuming 1 metric
ton per day plant capacity is equivalent to 300 metric tons processed
per year.
(2) Dose Calculations at 3,000 Meters
Doses at 3,000 m from a fuel reprocessing plant to the whole body,
skin, lung, bone, thyroid, and respiratory lymph nodes were calculated
from the air concentrations. Whole-body gamma dose rates from most
35
-------
radionuclides in the plume were calculated using the following equation:
r c
D(nuclide i) _ i i
D(13?Cs) rCsCCs
2
where C is the air radionuclide concentration in |_iCi/cm and F is the
gamma exposure rate constant for the radionuclides being considered.
Its units are (R-cm2)/(hr.-mCi). (See Appendix II-B for greater detail.)
Values of F were calculated for each radionuclide using F values for a
specific gamma ray energy59 and the number of gamma rays emitted per
decay*?0 The 13?Cs dose was taken from a detailed calculation made for
{- o
the Hanford, Washington, area. Krypton-85 dose values were taken from
an extensive calculation that gives a whole-body dose (from gamma
—7 3
energy) of 7 mrem/yr. for an air concentration of 3 x 10 |iCi/cm.
Results of these calculations are shown in Table 11-16.
Table 11-15
a
Air Concentration Distance Correction Factors
Air Concentration
Distance (m) _ Correction Factor*3
1,000 10.0
3,000 1.0
5,000 0.50
10,000 0.20
50,000 0.026
100,000 0.010
aAdapted from References 44 and 58.
b Air concentration at selected distance
Factor = - - - • -
Air concentration at 3,000 m
Whole-body gamma dose rates from radioactive material deposited on
the ground were determined by two methods. For the noble gases, calcu-
44 85 1*3*3 R'S
lations of others were used for Kr, and Xe was compared to Kr
by the use of the F factor. All other nuclides were compared to cal-
~\ T7 t-\ ft
culated values for I and Cs using calculations for Hanford. The
nuclides were divided into two groups according to half-life since the
half-life affects the maximum buildup on the ground. Those with a half-
36
-------
Table 11-16
Estimated Annual Dose Accrued at 3,000 Meters from a Fuel
Reprocessing Plant per
300 Metric Tons
of Fuel Reprocessed
per Year
Exposure
Pathway
A. External gamma
from
plume passage
85
1. Kr
133
2. Xe
3. All other
nuclides
B. External gamma
from
surface deposition
i 85tr
1 . Kr
133
2. Xe
3. All other
nuclides
C. Inhalation and
skin dose
from
plume passage
1. 3H
2. 85Kr
3. 133Xe
4. 144Ce
5. 131I
6. 129I
7. 9°Sr
8. Pu
a
Body Organ
Whole body
Whole body
Whole body
Whole body
Whole body
Whole body
Whole body
Skin
Lung
Skin
Lung
Skin
Lung
Bone
Thyroid
Thyroid
c
Bone
c
Bone
Lung
Annual Dose Accrued
(mrem/person at 3,000 m)
LWR Fuel
1.2
—
-3
0.09
—
~0.04
5.0
0.2
0.9
53
-
-
0.3
0.4
0.1
0.01
0.02
0.6
0.9
FBR Fuel
1 .1
9.1
-3
0.08
0.6
~0.02
6.7
0.2
0.8
48
0.3
5.7
0.04
0.05
0.7
-------
Table 11-16 - continued
Exposure a
Pathway Body Organ
9. Other actinides
,241. 242,,
( Am, Cm,
Cm)
10. All others
D. Ingest ion
from
surface deposition
1. 89Sr
2. 9°Sr
3. 129I
131
4. I
137
i- •*•"-** ^i
5. Cs
c
Bone
Lung
RLN
Lung
„ c
Bone
c
Bone
Thyroid
Thyroid
Whole body
Annual Dose Accrued
(mrem/person at 3,000 m)
LWR
0
0
100
~0
0
0
11
13
0
i
Fuel
.2
.8
.2
.008
.14
.2
.0
.02
FBR Fuel
0.03
0.2
20
-0.1
i
0.004
0.006
0.002
82
0.001
Doses to organs other than the whole body are in addition to
whole-body doses.
At 0.07 mm depth.
/•>
These doses received over 50 years following exposure
(see Section II.B.2). All other doses received within
1 year of exposure.
131
life less than 1 year were com'pared with I and those with a half-life
137 137
greater than 1 year were compared with Cs. A Cs buildup for 1 year
was used. Assuming that ground deposition is proportional to air con-
centration, the dose rates were calculated using the T values and the
I and Cs data from Hanford. A body shielding factor of 0.82
30
and a structural shielding factor of 0.4 were applied to correct air
dose rates to body dose rates. The results are presented in Table 11-16,
Part B.
Skin doses and doses caused by inhalation of radioactive material
from the plume are given in Table 11-16, Part C. The equations used in
calculating these doses are given in Appendix II-B.
Estimated doses from ingestion of radioniiclides due to surface de-
position were based on calculations made for the Dresden Nuclear Power
38
-------
Station. The Dresden dose values (see Appendix II-B) were corrected
to correspond to the assumed release rates from a fuel reprocessing
plant. Exposure pathways considered were:
(a) atmospheric discharge »deposition on grass ..cattle »
milk > man,
(b) atmospheric discharge »deposition on leafy vegetables »
man, and
(c) atmospheric discharge »• deposition on grass »• cattle
beef »man.
The results are presented in Table 11-16, Part D.
A summary of Table 11-16 is given in Table 11-17 showing annual
accrued doses to the whole body, skin, lung, bone, thyroid, and res-
piratory lymph nodes at 3,000 m from a plant processing 300 metric tons
of fuel per year. Each of the individual organ doses also contains the
whole body dose. Dose values at other distances can be obtained by using
the correction factors in Table 11-15.
Table 11-17
Summary of Table 11-16
Estimated Annual Dose Accrued at 3,000 Meters
from 300 'Metric Tons
of Fuel Reprocessed per
Year
Body Organ
Whole body
Skina'b
b,c
Lung
t>,c
Bone
Thyroid
b,c
Respiratory lymph nodes
mrem/person at 3,
LWR Fuel
6.3
60
9.4
7.7
31
420
000 m
FBR Fuel
18
72
20
18
100
150
3At 0.07 mm depth.
Includes whole-body dose.
Q
Respiratory lymph node dose and a small portion of the bone and
lung dose are received over the 50 years following exposure. Other
doses are received within 1 year of exposure.
39
-------
(3) Average Population Dose
The average annual dose accrued per person for the population around
a reprocessing plant (out to a distance of 100 km) was determined using an
,. 62
average value of dose calculated for a specified population distribution.
If the population density is uniform to a radius of 100 km around the
plant, the average per capita dose for a specified dose at 3,000 m is
0.027 times the dose at 3,000 m. If the population density increases at
a constant rate as the distance from the plant increases, the average
dose factor is 0.015. The first value was chosen for this study. Ap-
plying it to the values in Table 11-17, Table 11-18 was obtained which
gives annually accrued per capita dose within 100 km per 300 metric tons
of fuel processed per year.
Table 11-18
Average Annual Dose Accrued to the Population
Within 100 Kilometers of a Fuel Reprocessing Plant
(per 300
Body Organ
Whole body
Skin
Lung
b
Bone
Thyroid
Respiratory lymph nodes
metric tons processed per yr.)
Accrued Dose
LWR Fuel
0.17
1.6
0.25
0,21
0.84
11
(mrem/person/yr . )
FBR Fuel
0.49
1.9
0,54
0.49
2.7
4.0
a
Individual organ doses include whole-body doses.
Respiratory lymph node and part of bone doses received
over the 50 years following exposure.
Total man-rem was calculated by assuming a number for the popula-
tion living within 100 km of the processing plant; 1.5 x 106 was chosen
as the population value for 1970 and a 16% increase per decade was used.
This value is reasonably representative of currently operating reactors,
and the rate of population increase is the same as for the United States
40
-------
population (Table 11-11). From these population values and the projected
annual quantity of reprocessed fuel in Table 11-12 the annual per capita
dose was calculated for the various body organs. The results are given
in Table 11-19.
The 1970 dose estimates were based on assumptions used in this
study. However, Nuclear Fuel Services' (NFS) operations are different
than assumed operations 'of the future. ' A major difference is that
much of the waste effluent is through water media rather than entirely
through the air. Data from around NFS are not conclusive as far as pop-
63
ulation doses are concerned. Calculated doses to a "typical individual"
based on these data are so close to fallout background that it cannot
be determined what portion of the dose is from fuel reprocessing. The
most significant doses are those resulting from activities involving the
stream containing liquid effluent waste. The ingestion of fish and game
from sport fishing and hunting provides the largest potential exposure.
The measured and calculated air concentration factor at 3,000 m is
about 200 times less than the value used in this study. Therefore, air
pathway doses are expected to be much less than those given in Tables II-
16 to 11-19. The additional doses from the water pathways will keep the
total man-rem in the range of 100 to 200, however.
(4) Discussion
It must be recognized that modification of these calculations is
possible. Release rates will depend on the technology used at each
plant, concentration factors will vary from location to location, pop-
ulation distributions will vary, and methods of dose calculation will
change as new data are obtained. Therefore, the values in Table 11-19
may vary by as much as a factor of 10 or more. The values in this
section do show, however, which radionuclides result in the greatest
dose.
3. Worldwide Radioactivity
Two radionuclides are of concern on a worldwide scale. Because
of their chemical and physical properties, many separate sources of
these radionuclides may cause a general buildup of their concentration
in the biosphere. Tritium is distributed throughout the surface waters
41
-------
Table 11-19
Estimated
Annual Dose Accrued to the United
States Population
from Fuel Reprocessing
Other Body
Year
1970
1980
1990
2000
Whole-body Dose
(mrem/person)
0.0008
0.02
0.09
0.2
Man-rem
to U.S.
Population
170
5,000
25,000
65,000
Skin
0.008
0.1
0.4
0.8
Lung
0.001
0.03
0.1
0.2
Organ Doses (mrem/person)
Respiratory
Lymph
Nodes*
0.05
0.8
1.4
2.3
Bone*
0.001
0.02
0.09
0.2
Thyroid
0.001
0.1
0.5
1.1
*Dose received over 50 years following exposure.
-------
of the world and is of concern to man through any exposure pathway in-
volving water. Krypton-85, a noble gas, is distributed throughout the
atmosphere and is a source of exposure to man, both externally and
through inhalation. All sources of these radionuclides will be con-
sidered in this section.
a. Tritium
Tritium is produced naturally by cosmic rays and artificially by
thermonuclear detonations and in nuclear electric power production. It
contributes only to internal doses because of its low beta decay energy.
3
The worldwide content of H from all sources is projected and from this
the dose is estimated.
(1) Natural 3H
3
The sources of natural H are cosmic ray bombardment of oxygen and
2
nitrogen in the upper atmosphere and direct intrusion from outer space.
3
Estimates of the worldwide inventory of naturally produced H have been
graphically summarized. The range of most probable values is shown in
Figure II-6 and varies from 25 to 80 MCi.
(2) Nuclear Explosives
Both the fission and fusion processes of nuclear explosives produce
3
H. The fission process produces 1,000 to 2,000 Ci of tritium per mega-
ton (MT) of fission energy which is negligible compared to the 6 to 10
fifi fi7 o
MCi produced per megaton of fusion energy. ' The H produced by weapon
detonations and corrected for decay through 1962 was calculated using
the 6 to 10 MCi/MT of fusion energy and the atmospheric fusion yield
27
detonated over certain time periods. Tritium from underground det-
onations is assumed to be contained near the detonation site and is of
3
no worldwide consequence. The H accumulated to 1962 was corrected for
decay to the year 2000 as shown in Figure II-6. Figure II-6 also shows
the world inventory if 20 MCi per year or 100 MCi/yr. is added by nuclear
Q £> O
detonations. Since 1965, less than 20 MCi of H per year have probably
been added by French and Chinese tests.
(3) Reactors
Tritium is produced in reactors by several methods. The most impor-
tant of these methods are in the fission process itself and by neutron
43
-------
aoBjjng UT PUB a-iaqdsout:)^
jo
'9-II
10,000
Ma_xjmu_mjptal if; 100 MCi
20_MC/_Added_per year from weapons
Weapon Produced
(6-10 MCi/MT)
Total of all ranges
Naturally Produced
(range of probable va
Reactor Produced
(0.70-0.85 load factor)
1960 1965 197O 1975 198O 1985 199O 1995 20OO
-------
interactions with boron in reactor control rods, with boron and lith-
ium in the primary reactor coolant, and with deuterium in heavy water
(D20) reactors. ' For this study, it was assumed that (a) all 3R
produced by the fission process corrected for 1 year of decay will be
lost to the environment either at the reactor site or during fuel re-
3
processing, (b) that H produced in control rods will not be released
to the environment, (c) that technological changes will reduce 3H pro-
duction in the coolant to a negligible level, and (d) that 5% of the
world's production of nuclear power will be by DO reactors. ADO reac-
o 2
tor is assumed to contain 430 kg of DO coolant per MWE with a H concen-
/j
tration of 11 Ci/kg with 2.5% being lost per year to the environment?9
Table 11-20
Projected World Reactor
Year
1970
1980
1990
2000
Total World*
Reactor Power
20
250
800
2,000
(OWE)
D20
Reactors
1
12
40
100
Power Capacity
U-fueled
Reactors
19
200
240
240
Pu-fueled
Reactors
0
38
520
1,660
*Total world power values are taken from Reference 45, as
reasonable values when compared to the projected power
capacity of the United States.
Total world nuclear power capacity is projected in Table 11-20.
Five percent is allotted to DO reactors with uranium fuel and the remain-
£
der is divided between uranium- and plutonium-fueled reactors in the same
ratios as used in Table 11-12. The fuel types are separated because ura-
3
nium fuel produces 19 Ci H/MWE/yr. and plutonium fuel produces 36
fifi
Ci/MWE/yr.
3
Estimated reactor H production is shown in Figure II-6. The range
of values is caused by varying the power load factor from 0.70 to 0.85.
The upper value can be increased by 13% in the year 2000 if the fraction
of DO reactors is doubled, or the lower value can be decreased by about
£i
10% if the amount of uranium-fueled reactors is doubled and the pluto-
45
-------
nium-fueled reactors are decreased. The upper value of the range
3
could also be increased by considering some H being formed in the
coolant of light water reactors. These changes would about triple
the reactor range shown on the graph.
(4) Total 3H
The maximum and minimum ranges of the three individual components
Q
of H inventory have been added with the results shown in Figure II-6.
This shows that if no more thermonuclear explosives are detonated above
3
ground, the environmental H level in the year 2000 will be less than
3
half the 1970 level. Explosive-produced H is predominant at the pres-
ent time and will continue to be if up to 100 MCi (equivalent to 10 to
15 MT of fusion energy) are released to the environment per year.
3
Reactor-produced H will not become important on a worldwide basis
until after 1990.
(5) Dose
3 3
The dose from worldwide H depends on the H content in food and
3
water which will depend on the worldwide inventory. The whole-body H
dose rate, D, is calculated from:
D = 0.089X mrem/yr.
3
where X is the average H equilibrium concentration in water and diet
(nCi/liter). The factor 0.089 was determined using a body tissue con-
tent of 60% water, a quality factor of 1.0, and a factor of 1.4 increase
in dose due to organic labeling through chronic exposure.
The X can be estimated in several ways. One is to divide the total
3
world H inventory by the volume of circulating surface waters. Surface
44 69 16 3
water volume estimates ' range from 1.4 to 2.7 x 10 m (depending
on the depth of ocean waters used) with the volume between 30° and 50° N.
3
equal to 0.1 of the total volume. Since most H is released in the mid-
latitudes of the Northern Hemisphere, it is assumed that 50% is distrib-
uted from 30 to 50 N. and 50% in the rest of the world. For the range
3
of H world inventory values in 1970, this gives a range of X of 0.2 to
w
0.7 nCi/liter.
The Xw can also be determined by direct measurement. It is found
that Xw varies considerably from one location to another. Most surface
46
-------
and groundwater values in the United States vary from 0.2 to 1.5
„. ,-. . ^ 71,72
nCi/liter. '
A third method of determining X for dose calculations is from
W 3
diet studies. These show that from 1967 to 1969 the average H level
73
in the United States diet was about 0.5 nCi/kg.
3
Therefore, 0.5 nCi/liter is considered indicative of present H
levels in the environment and in the diet, and future levels are pre-
3
dieted by the trend shown in Figure I1-6 using 20 MCi/yr. of added H
from nuclear explosives tests. The resulting doses for the United
States population are given in Table 11-21.
Table 11-21
Estimated Annual Whole-body Dose
3
from Worldwide H
Year
1960
1970
1980
1990
2000
b.
Dose
(mr em/per son)
0.02
0.04
0.03
0.02
0.03
Krypton-85
Man-rem for U.S.
Population
3,100
9,200
7,100
6,700
8,400
Krypton-85 is produced artificially by nuclear explosive detonations
and by nuclear electric power production. Nuclear explosive production
rates are very low compared to reactor production. The world inventory
from nuclear explosives is calculated to be about 3 MCi. However,, reac-
tors are already producing greater than 10 MCi/yr. Therefore, only re-
actor production will be considered for the future. Dose estimates will
be determined from air concentration values.
(1) Air Concentration
The Kr air concentrations in 1960, 1965, and 1970 were about 5,
3
10, and 15 pCi/m , respectively. Future values of concentration are cal-
Q C
culated from reactor production rates assuming all Kr (corrected for
1 year of decay) will be released to the atmosphere. Krypton-85 yield
47
-------
235
corrected for decay is 410 Ci/MWE/yr. for U thermal neutron fission
239 44
and 380 Ci/MWE/yr. for Pu fast neutron fission. Using fuel mix-
3 85
tures as used for H in Table 11-20 and a load factor of 0.85, the Kr
concentration as shown in Figure I1-7 was obtained. For the lower
85
it was assumed that the total Kr is distributed uniformly in
,21
curve
the total atmosphere75 of 5.1 x 10^ g (air density is 0.0013 g/cm" at
mean sea level). For the upper curve it was assumed that 75% of the
85Kr is distributed in the Northern Hemisphere since this is where
most of it is produced.
(2) Dose
Annual doses were calculated from air concentrations. A concen-
c o
tration of 3 x 10 pCi/m was considered to give 7 mrem/yr. to the whole
body, 310 mrem/yr. to the skin at 0.07 mm depth, and 12 mrem/yr. to the
lungs. ' Using these values and the upper range of air concentrations
in Figure I1-7, the dose values in Table 11-22 were calculated. (It
Table 11-22
Estimated Annual Doses to the United States Population
85
from Worldwide Distribution of Kr
Dose
Whole-body
Year
1960
1970
1980
1990
2000
(mrem/person)
0.0001
0.0004
0.003
0.01
0.04
(man-rem)
20
80
700
4,000
12,000
Skin
(mrem/person)
0.005
0.02
0.1
0.6
1.6
Lung
(mrem/person)
0.0002
0.0006
0.005
0.02
0.06
should be noted that in the literature, skin dose is quite often refer-
red to as whole-body dose.)
E. Government Facilities
The government facilities which are potential sources of environ-
mental radiation include many types. Those concerned with somewhat non-
routine intermittent activities are discussed separately. The Nevada
Test Site (northwest of Las Vegas, Nevada) is considered as a single
48
-------
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facility although several government agencies are sponsors of some
activities; both weapons and peaceful nuclear explosives tests are
carried out there. Also, the Amchitka Island tests are considered
as part of that facility. Peaceful nuclear explosives tests conduct-
ed off the Nevada Test Site are considered separately as are activ-
ities of the Nuclear Rocket Development Station (adjacent to the Nevada
Test Site) .
1. Nevada Test Site
For estimating radiation doses from activities at the Nevada Test
Site for the early part of the last decade, the period from September 15,
1961 to September 15, 1962 was selected. (A similar period in 1969 and
1970 was considered.) This was the period of resumption of atmospheric
nuclear explosives testing following the moratorium of 1958. During
this period, attempts were made to collect more useful data for asses-
sing radiation doses to the population in the vicinity of the Nevada
Test Site than had been obtained previously. Included was a relatively
extensive personnel film badge program giving measurements of actual
external gamma radiation exposures to members of the potentially exposed
75
offsite population. Also, measurements were obtained providing a basis
for estimating internal doses. These were in addition to ground monitor-
ing and station personnel film badge data. The estimates made were based
primarily on the latter and extended with supplemental data where necessary
Calculations were made for distances where doses appeared to be in-
distinguishable from worldwide fallout.
Two underground nuclear tests have been conducted at the test
site on Amchitka Island, Alaska. No radioactivity was detected off
72
the site following these tests. Similar results are expected for
future tests at that site.
7 C fj Q
Based on the available data, ' arithmetic average doses were cal-
culated for each community. Then, estimates of average external gamma
doses were made for each of the smallest census divisions in the region
of interest. From these, the total man-rem were calculated. During the
period from September 15, 1961 to September 15, 1962, the calculated
average whole-body dose was 47 mrem to the exposed population of 18,000
50
-------
persons, or 860 man-rem. Since the calculations were based on personnel
film badge measurements and the sources were primarily atmospheric
volume sources, the shielding and screening factors for conversion to
doses were assumed to be unity.
During a similar period 1969 to 1970, there were no Nevada Test
Site activities which caused doses to the population in the vicinity
of the installation. Future doses from this source are unpredictable.
Sufficient data are not available on possible peaceful nuclear exca-
vation tests to provide a basis for predictions and each would require
separate predictions based on specific characteristics. Other nuclear
tests' radioactivities would be completely contained underground except
for unforeseeable conditions,
n c 7 Q or>
Using levels of radionuclides in milk, ' ' estimates of internal
doses were made using the methods described in II. B. The data were
adjusted so that the doses were contributed by only local fallout from
the Nevada Test Site. However, the calculated doses here are prob-
ably overestimates, while those from worldwide fallout are probably under-
estimates. The region of concern generally had higher levels of world-
wide fallout than the average for that section of the nation. Worldwide
fal]
137
131
fallout dose calculations were considered in II. B. Only I and
Cs appeared in milk in significant amounts over those from worldwide
fallout in the same region to contribute to the estimates.
137
The calculated average whole-body dose from Cs to a population
of about 792,000 was 10 mrem during the period considered, or 7,920 man-
rem. The average dose to the thyroid to the same population was esti-
mated to be 9 mrem.
The total estimated whole-body dose of 8,780 man-rem to a popula-
tion of 810,000 (an average of 11 mrem to the population at risk) gives
0.05 mrem/person to the total United States population for the period
cons idered.
2. Nuclear Rocket Development Station
From 1959 through 1969, 31 nuclear reactor rocket engine tests were
conducted at the Nuclear Rocket Development Station. During each of
these tests, data were collected and reported for purposes of radiological
51
-------
assessments (e.g., References 81 to 83). Based on these data, calcula-
tions of external whole-body doses and organ doses were made and report-
ed?4 These were used as a basis for estimates made during this study.
For this facility, doses were calculated for the entire 10-year period.
To date, external gamma doses were too low to be significant for
131
all tests. The principle effluent radionuclides from these tests are I
133
and I and concentrations were too low to give significant ex-
ternal gamma exposures during cloud passage or after deposition.
Levels of these nuclides were detected in milk and led to thyroid
dose estimates. The average thyroid dose to a population (1960) of about
740,000 was calculated to be about 3 mrem, or 2,100 man-rem during the
10-year period.
It is not possible to predict the dates of future tests of nuclear
rocket engines or possible levels of effluents. During the period con-
sidered above, the technology program was completed. The development
of a flight-rated rocket engine has been initiated and some tests are
40
required during this phase. Adequate estimates of potential doses
to populations in the vicinity of the test facility require individual
treatment.
3. Peaceful Nuclear Explosive Tests
Peaceful nuclear explosives tests conducted at places other than the
Nevada Test Site are discussed. To date, the following have been con-
ducted:
Date Project Location
December 10, 1961 Gnome near Carlsbad, New Mexico
December 10, 1967 Gasbuggy near Farmington, New Mexico
September 10, 1969 Rulison near Grand Valley, Colorado
All of these were underground tests. During the Gnome test, radioactiv-
ity escaped from the cavity to the environment. The other two were gas
stimulation tests, and no radioactivity was found off the test sites
QC 07
during the detonation phase. ' Radioactivity was released to the en-
vironment after gas wells were drilled into the cavities to obtain ex-
perimental data. The gas was deliberately flared, thus releasing small
amounts of radioactivity to the atmosphere. Because of the similarities
52
-------
of the Gasbuggy and Rulison events, only the former is discusser! (see
Reference 87). As with the above facilities and the applications
discussed in C, future tests are too uncertain with respect to time,
place, and type to permit adequate predictions of potential doses.
a. Project Gnome
For several hours, some venting occurred sporadically during Project
o c,
Gnome shortly after the detonation. The effluent was mostly gaseous
and deposition was only detected about 10 mi. off the test site.
Doses in populated areas were due to passage of the cloud. Calculations
of external gamma doses were made from instrument readings at populated
locations along the path of the cloud. These gave a total of 30 man-
rem for a population of about 45,000 persons, or an average dose of 0.7
mrem. Shielding and screening factors for conversion of measurements to
doses were assumed to be unity. Analyses of environmental samples indi-
cated levels of radionuclides about the same as or lower than those for
the general region. Therefore, no significant internal radiation doses
resulted from this event.
b. Project Gasbuggy
During the gas production phase of this test, radioactivity was
3 T 4 S S
released from the well. Only H, C, and Kr were detected in the ef-
Of:
fluent. No radioactivity was detected beyond 10 mi. of the gas well
and there are no populated sites within that distance of the well. Cal-
culational estimates of doses for areas beyond 10 mi. of the well were
not significant.
4. Other Atomic Energy Commission Facilities
Other Atomic Energy Commission facilities involve a wide variety
of activities in the Atomic Energy Program and a large number of con-
tractor activities. ' Most of the major facilities operated by and
for the Atomic Energy Commission involve multiple-purpose activities,
although a few are concerned with only certain phases of nuclear materials
production or manufacturing. Most are concerned with research in one or
more areas. The majority of facilities are those of research contractors
at universities, and private, commercial, and government installations.
Most of the facilities involve the use of radioactivity and con-
stitute a source of environmental radioactivity through airborne or
liquid releases of wastes. A few emit radiation inside the facility
53
-------
which is measurable outside the facility. The nature of the facility
and its potential for contamination of the general environment deter-
mine the degree to which data are obtained to assess the impact of the
facility on the environment. Facilities such as the National labora-
tories and similar installations generally have extensive programs of
environmental surveillance of radioactivity. Those using only relative-
ly small quantities of tracer radionuclides in research usually have a
minimal surveillance program, often simply monitoring effluents before
release to insure compliance with regulations.
Estimates were made for populations at risk in the vicinity of the
facilities as well as for the total United States population. The years
considered were those typical of the early (indicated as "i960") and
latter (indicated as "1970") parts of the decade 1960 to 1970. The Na-
tional Accelerator Laboratory, expected to begin operation in 1971 was
also included in the "1970" estimates. It was assumed that the situation
in the period 1970 to 2000 would be similar to that in "1970" although
different facilities may be involved. The facilities (not considered
elsewhere in this report) contributing to significant doses are among
those listed in Table 11-23. Included in the list are some in operation
in 1960 but not in 1970 and some beginning operation after 1960. In
many cases,the activities at facilities have changed considerably either
by reduction or cessation of some activities or beginning or increasing
others.
A large number of reports were used as a basis for the estimates
on_"i Q-i
made for this section. Only the major ones contributing signifi-
cantly to doses are listed in the references. The distances from facil-
ities to which estimates were made were sufficient to include doses
above about 0.01 mrem/yr. Data were extrapolated to farther distances
than reported and dose calculations were made in some cases by methods
described elsewhere in this report (see II. D). Where reported data
probably included natural and fallout radioactivity, estimates of these
were considered by methods discussed in II. A and B.
The estimated whole-body (internal and external) doses are shown
in Table 11-24. In most cases, external gamma radiation doses were based
54
-------
Table 11-23
Major Atomic Energy Commission Installations
Aircraft Nuclear Propulsion Department, Cincinnati, Ohio
Argonne National Laboratory, Argonne, 111.
Atomics International, Canoga Park, Calif.
Bettis Atomic Power Laboratory, Pittsburgh, Pa.
Brookhaven National Laboratory, Upton, N.Y.
Cambridge Electron Accelerator, Cambridge, Mass.
Connecticut Aircraft Nuclear Engine Laboratory, Middletown, Conn.
Feed Materials Production Center, Fernald, Ohio
Feed Materials Production Facility, Weldon Spring, Mo.
Hanford Facilities, Richland, Wash
Knolls Atomic Power Laboratory, Schenectady, N.Y.
Lawrence Laboratories, Berkeley and Livermore, Calif.
Los Alamos Scientific Laboratory, Los Alamos, New Mex.
Mound Laboratory, Miamisburg, Ohio
National Accelerator Laboratory, Batavia, 111.
National Reactor Testing Station, Idaho Falls, Idaho
Neutron Devices Department (Pinellas), St. Petersburg, Fla.
Oak Ridge Research and Development and Production Facilities, Oak Ridge, Tenn.
Paducah Plant, Paducah, Ky.
Portsmouth Gaseous Diffusion Plant, Piketon, Ohio
Princeton-Pennsylvania Accelerator, Princeton, N.J.
Rocky Flats Plant, Rocky Flats, Colo.
Sandia Laboratories, Albuquerque, New Mex.
Savannah River Facilities, Aiken, S. C.
Stanford Linear Accelerator Center, Palo Alto, Calif.
55
-------
Table 11-24
Estimated Total Annual Whole-body Doses from
Year
"1960"
"1970"
1980
1990
2000
Population
at Risk
(millions)
2.4
1.6
1.8
2.2
2.5
Other Atomic Energy
Percent of U.S.
Population
at Risk
1.3
0.8
0.8
0.8
0.8
Commission
Annual
Man -r em
2,600
2,500
2,700
3,300
3,800
Installations
Average Dose to
Population
at Risk (mrem)
1.1
1.5
1.5
1.5
1.5
Average Dose to
U.S. Population
(mrem)
0.01
0.01
0.01
0.01
0.01
-------
30
on open field measurements. Therefore, a shielding factor of 0.4 and
31
a screening factor of 0.8 were used in those cases. Internal doses
to the lung, thyroid, and bone are shown in Table 11-25.
Table 11-25
Q
Estimated Internal Doses from Other Atomic Energy
Commission Facilities
Year
Lung
"1960"
"1970
Thyroid
"1960"
"1970"
Bone
"1960"
"1970"
Population at Risk
(millions)
4.9
5.5
0.26
0.1
0.26
0.1
Annual Average
Dose
(mrem)
0.6
0.6
45
1.3
4.3
4.8
a
Do not include whole-body doses.
Probably includes some fallout although an estimated fallout
component was excluded from these estimates.
5. Other Government Facilities
Several other government agencies maintain facilities involving radi-
ation and radioactivity. Included are the Department of Agriculture; De-
partment of Defense; Department of Health, Education, and Welfare; Nation-
al Bureau of Standards; Geological Survey; Environmental Protection Agency;
National Aeronautics and Space Administration; and Veterans Administra-
tion. The NS Savannah began operation in 1965 by the Maritime Adminis-
tration, Operation of the ship was terminated in 1971. Nuclear power
stations operated by the Tennessee Valley Authority, Department of Defense
and Panama Canal Company are considered in II, D. Nuclear testing
activities by several government agencies are considered as part of the
Atomic Energy Commission's activity in Paragraph 1 above,
57
-------
A large number of government research and medical facilities uti-
lize radionuclides and radiation sources in their activities, similar
in general to such facilities operated by the Atomic Energy Commission.
Several of these include research, experimental, and test reactors. In
1960 there were four of these operating at a total of about 6 MW and in
1970,there were six operating at about 2 MW. A large number of radia-
tion sources are used for industrial-type purposes; e.g., well-logging,
radiography, and luminescence.
Most of these facilities discharge some radioactivity to the en-
vironment as liquid and gaseous wastes, or use radiation sources which
are potential sources of environmental radiation. None of these dis-
charge radioactivity at levels comparable to those discussed in Section
II.E.4 which contributed significant population doses. Based on esti-
mates for some facilities and comparisons of these facilities with
similar types as those above (where effluents have higher levels of radio-
activity) , it was concluded that these other government facilities con-
tributed no significant doses to populations in the United States in the
vicinity of these facilities,except occupational doses. Comparisons of
occupational doses suggest similar conclusions as do negative environ-
mental monitoring data (e.g., References 102 and 103).
F. Private Facilities l
Many of the major private facilities utilizing radioactivity or
radiation sources are involved in the nuclear electric power industry
and were included in II. D above. Some others are operated under con-
tract with Government agencies and were included in II. E above. The
remainder of private facilities include research and medical organiza-
tions and those concerned with commercial applications similar to those
discussed above. Others are concerned with radionuclide preparation as
sources, tracers, Pharmaceuticals, or radiation source' devices.
The effluents from these facilities are generally of the order of
magnitude or less than the government facilities discussed in II. E
58
-------
Therefore, these facilities contribute no significant doses except from
occupational exposures.
G. Summary
Estimated whole-body doses from environmental radiation are summa-
rized in Table 11-26. Total man-rem will increase because the population
will increase as shown by the man-rem per million people remaining con-
stant. Environmental radiation caused by the nuclear electric power
production process will increase faster than the population but it is
estimated to be less than 1% of natural radiation by the year 2000. En-
vironmental radiation doses to the whole body are compared to radiation
doses from other sources in Section V.
Doses to other organs of the body are given in several sections in
the report. Natural internal radiation dose estimates for the bone mar-
row and the lung are given in Table II-3; fallout radiation doses to the
lung, skin, thyroid, bone, and respiratory lymph nodes in Tables II-6
and II-7; doses to the same organs from fuel reprocessing activities in
Tables 11-16 to 11-19; lung and skin doses from the worldwide distribution
Q C
of "Kr in Table 11-22; thyroid doses frorr activities at the Nevada Test
Site and the Nuclear Rocket Development Station; and lung, bone, and
thyroid doses around several Atomic Energy Commission facilities in
Table 11-25.
59
-------
Table 11-26
Summary of Estimates of Whole-body Environmental
Rad:
Source
Natural
Cosmic
External gamma
Internal
Subtotal
Fallout
External gamma
Inhalation
Ingestion
Subtotal
Other
Reactors
.ation Doses
1960
8.2
11.0
4.6
23.8
l.ia
0.27a
1.0a
2.4E
0.000016
Fuel reprocessing
Worldwide 3H 0.0031
Worldwide 85Kr 0.00002
PNE tests 0.00003b
Nevada Test Site
Other AEC
installations
Subtotal
TOTAL
Population
(millions)
/?
Man-rem/10
people
0.0088C
0.0026
0.015
24.8
183
136,000
to the United
Annual Man-rem
1970
9.2
12.3
5.1
26.6
0.18
0.008
0.63
0.82
0.00043
0.00017
0.0092
0.00008
-
0.0025
0.012
27.4
205
134,000
States
Population
(millions) for Years
1980
10.7
14.2
5.9
30.8
0.21
0.009
0.83
1.1
0.0061
0.0050
0.0071
0.0007
-
0.0027
0.022
31.9
237
135,000
1990
12.5
16,6
6.9
36.0
0.25
0.11
1.0
1.3
0.023
0.025
0.0067
0.004
_
0.0033
0.062
37.4
277
135,000
2000
14.4
19.3
8.0
41.7
0.29
0.013
1.3
1.6
0.056
0.065
0.0084
0.012
__
0.0038
0.15
43.4
321
135,000
d!963 value. A 1960 total fallout value of 1.0 was used in the TOTAL
o:C all environmental radiation.
b
1962 dose; not used in totals. PNE is peaceful nuclear explosives.
Sept. 15, 1961 to Sept. 15, 1962 dose. This value was used in the
1960 totals.
60
-------
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of the United Nations Scientific Committee on the Effects of Atomic
Radiation. General Assembly, 21st Session, Supplement No. 14.
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2. Korff, S.A. 1964. Production of neutrons by cosmic radiation.
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and W.M. Lowder, eds. Rice University, University of Chicago Press,
Chicago.
3. Kastner, J., B.J. Oltman and L.D. Marinelli. 1964. Progress report
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4. Hill, C.R. and D.S. Woodhead. 1964. Tissue dose due to the neutrons
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5. May, H. and L.D. Marinelli. 1964. Cosmic ray contribution to the
background of low-level scintillation spectrometers. pp. 463-480.
Ibid.
6. Lowder, W.M., P.D. Raft and H.L. Beck. 1971. Experimental deter-
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7. O'Brien, K. and J.E. McLaughlin. 1970. Calculation of dose and dose-
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8. Oakley, D.T., D.W. Moeller and A.S. Goldin. 1971. Personal commu-
nication. School of Public Health, Harvard University.
9. Harley, J.H. 1971. Personal communications. Health and Safety Lab-
oratory, U.S. Atomic Energy Commission, New York.
10. KLement, A.W., Jr. 1965. Natural radionuclides in foods and food
source materials. pp. 113-155. In: Radioactive Fallout, Soils,
Plants, Foods, Man. E.B. Fowler, ed. Elsevier, Amsterdam.
11. KLement, A.W., Jr. 1965, 1970. Natural environmental radioactivity
(a selected bibliography). U.S. AEC report WASH-1061. 125 pp. Ibid.
(Supplement). WASH-1061 (Suppl.). 72 pp.
12. Eisenbud, M. 1963. pp. 135-170. In: Environmental Radioactivity.
McGraw-Hill, New York.
13. Lowder, W.M. and L.R. Solon. 1956. Background radiation, a literature
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61
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14. Beck, H.L., W.M. Lowder, E.G. Bennett and W.J. Condon. 1966. Further
studies of external environmental radiation. Health and Safety Lab-
oratory, U.S. AEC report HASL-170. 53 pp.
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investigations of natural environmental radiation. Health and
Safety Laboratory, U.S. AEC report HASL-73. 32 pp.
16. McLaughlin, J.E. 1970. Unpublished data. Health and Safety Lab-
oratory, U.S. Atomic Energy Commission, New York.
17. Harley, J.H. and W.M. Lowder. 1971. Natural radioactivity and
radiation, pp. 1-2 - 1-23. In: Fallout program quarterly summary
report. E.P. Hardy, Jr., prep. U.S. AEC report HASL-242.
18. Human Studies Branch. 1972. Personal communication. Twinbrook
Research Laboratory, Office of Research and Monitoring, Environ-
mental Protection Agency, Rockville, Maryland.
19. Shleien, B. 1969. Evaluation of radium-226 in total diet samples,
1964 to June 1967. Radiological Health Data 10(12): 547-549.
20. Lockhart, L.B., Jr. 1964. Radioactivity of the radon-222 and radon-
220 series in the air at ground level, pp. 331-334. In: The Natural
Radiation Environment. J.A.S. Adams and W.M. Lowder, eds. Rice
University, University of Chicago Press, Chicago.
21. Gold, S., H.W. Barkhau, B. Shleien and B. Kahn. 1964. Measurement
of naturally occurring radionuclides in air. pp. 369-382. Ibid.
22. Struxness, E.D. 1971. Personal communication. Oak Ridge National
Laboratory, Oak Ridge, Tennessee.
90 89
23. Hardy, E.P., Jr. (prep.). 1971. Sr and Sr in monthly deposi-
tion at world land sites. App., pp. A1-A292. In: Fallout program
quarterly summary report. Health and Safety Laboratory, U.S. AEC
report HASL-242.
24. Beck, H.L. 1966. Environmental gamma radiation from deposited fission
products, 1960-1964. Health Physics 12(3): 313-322.
25. Beck, H.L., W.M. Lowder, E.G. Bennett and W.J. Condon. 1966. Further
studies of external environmental radiation. Health and Safety Lab-
oratory, U.S. AEC report HASL-170. 53 pp.
26. Lowder, W.M., H.L. Beck and W.J. Condon. 1965. Dosimetric investi-
gations of environmental gamma radiation from deposited fission pro-
ducts, pp. 233-244. In: Radioactive Fallout from Nuclear Weapons
Tests. A.W. Element, Jrr, ed.U.S. AEC Symposium Ser. 5, report
CONF-765.
62
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27. Federal Radiation Council. 1963. Estimates and evaluation of fall-
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28. Federal Radiation Council. 1964. Revised fallout estimates for
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38. Rivera, J. 1970. HASL diet studies: fourth quarter 1969. p. II-4,.
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63
-------
39. United Nations. 1969. Report of the United Nations Scientific
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40. Atomic Energy Commission. 1971. Annual report to the Congress of
the Atomic Energy Commission for 1970. Washington. xiv, 343 pp.
41. Atlantic-Pacific Interoceanic Canal Study Commission. 1970. Inter-
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42. Atomic Energy Commission. 1970. Symposium on Engineering with
Nuclear Explosives (January 14-16, 1970, Las Vegas). U.S. AEC
report CONF-700101. 2 vols., x, 1,785 pp.
43. Office of Science and Technology. 1968. Considerations affecting
steam power plant site selections. A report sponsored by the Energy
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44. Oak Ridge National Laboratory. 1970. Siting of fuel reprocessing
plants and waste management facilities. U.S. AEC report ORNL-4451.
var. pp.
45. Pannetier, R. 1968. Distribution, transfert atmospherique et bilan
du krypton-85. France Commisariat a 1'Energie Atomique report
CEA-R-3591. 180 pp.
46. Patterson, J.A. 1971. Uranium supply and nuclear power. Paper pre-
sented before the 40th Annual Conference of the Public Utility Buyer's
Group, Atlanta, Georgia, March 8, 1971. Division of Raw Materials,
U.S. Atomic Energy Commission, Washington. 20 pp.
47. Cool, W.S. 1971. Personal communication. Division of Radiological
and Environmental Protection, U.S. Atomic Energy Commission, Washing-
ton.
48. Federal Radiation Council. 1967. Guidance for the control of radi-
ation hazards in uranium mining. Washington, Report No. 8 (Revised).
iv, 60 pp.
49. Public Health Service. 1969. Evaluation of radon 222 near uranium
tailings piles. Bureau of Radiological Health report DER 69-1.
viii, 67 pp.
50. Federal Water Pollution Control Administration. 1967. Evaluation
of the radioactivity level in the vicinity of the Mines Development,
Inc., uranium mill at Edgemont, South Dakota, September 1966. 28 pp.
51. Tsivoglou, E.D., S.D. Shearer, J.D. Jones, C.E. Spomagle, H.R. Paren,
J.B. Anderson and D.A. Clark. 1960. Survey of interstate pollution
of the Animas River (Colorado-New Mexico). II. 1959 surveys. U.S.
Public Health Service, Robert A. Taft Sanitary Engineering Center.
53 pp.
64
-------
52. Waterfield, R.L. 1971. Personal communication. Division of Radio-
logical and Environmental Protection, U.S. Atomic Energy Commission,
Washington.
53. Rogers, L. and C.C. Gamertsfelder. 1970. USA regulations for the
control of releases of radioactivity into the environment in effluents
from nuclear facilities. pp. 127-145. In: Environmental Aspects
of Nuclear Power Stations. (Proc. Symposium, New York, 10-14 August
1970.) International Atomic Energy Agency, Vienna. (STI/PUB/261)
(CONF-700810.)
54. Shaw, M. 1969. p. 48. In: Selected Materials on the Environmental
Effects o_f Producing Electric Power. Joint Committee on Atomic
Energy, Congress of the U.S. Washington.
55. Atomic Energy Commission. 1971. Light-water-cooled nuclear power
reactors. Licensing of production and utilization facilities.
(10 CFR Part 50). Federal Register 36(111): 11113-11117.
56. Kahn, B., et al. 1970. Radiological surveillance studies at a boil-
ing water nuclear power reactor. Bureau of Radiological Health, U.S.
Public Health Service report BRH/DER 70-1. xiii, 116 pp.
57. Blanchard, R.L., H.L. Krieger, H.E. Kolde and B. Kahn. 1970. Radio-
logical surveillance studies at a BWR nuclear power station - esti-
mated dose rates. Vol. II, pp. 372-384. In: Proceedings of the
Health Physics Society Mid-year Symposium, November 3-6, 1970,
Idaho Falls, Idaho.
58. Slade, D.H. (ed.). 1968. Meteorology and Atomic Energy - 1968.
U.S. AEC report TID-24190. 445 pp.
59. Hine, G.J. and G.L. Brownell. 1956. Radiation Dosimetry. Academic
Press, New York. 932 pp.
60. Public Health Service. 1970. Radiological health handbook. vi, 450 pp
85
61. Hendrickson, M.M. 1970. The dose from Kr released to the earth's
atmosphere. Battelle Northwest Laboratory, U.S. AEC report BNWL-
SA-3233A. 15 pp.
62. Knox, J.B. 1971. Airborne radiation from the nuclear power industry.
Nuclear News 14(2). 27-32.
63. Shleien, B. 1970. An estimate of radiation doses received by indi-
viduals living in the vicinity of a nuclear fuel reprocessing plant
in 1968. U.S. Public Health Service, Northeastern Radiological Health
Laboratory, report BRH/NERHL 70-1. x, 19 pp.
64. Cochran, J.A., D.G. Smith, P.J. Magno and B. Shleien. 1970. An
investigation of airborne radioactive effluent from an operating nuclear
fuel reprocessing plant. U.S. Public Health Service, Northeastern
65
-------
Radiological Health Laboratory, report BRH/NERHL 70-3. x, 39 pp.
65. Magno, P.J. 1971. Personal communication. Northeastern Radio-
logical Health Laboratory, U.S. Public Health Service.
66. Peterson, H.T., Jr., J.E. Martin, C.L. Weaver and E.D. Harward.
1969. Environmental tritium contamination from increasing utili-
zation of nuclear energy sources. pp. 35-59. In: Environmental
Contamination by Radioactive Materials. (Proc. Seminar, Vienna,
24-28 March 196?)~ International Atomic Energy Agency, Vienna.
(STI/PUB/226.)
67. Kartell, E.A. 1963. On the inventory of artificial tritium and
its occurrence in atmospheric methane. J. Geophys. Res. 68(13):
3759-3769.
68. Bennett, E.G. 1971. Global Sr-90 fallout and its occurrence in
diet and man. Paper presented at the meeting on Biomedical Impli-
cations of Radiostrontium Exposure, University of California, Davis,
February, 1971.
69. Jacobs, D.G. 1968. Source of tritium and its behavior upon release
to the environment. U.S. AEC, Critical Review Series, report TID-
24635. 90 pp.
70. Evans, A.G. 1969. New dose estimates from chronic tritium ex-
posures. Health Physics 16: 57-63.
71. Public Health Service. 1970. Tritium in surface water network,
July-December 1969. Radiological Health Data 11: 347-348.
72. Public Health Service. 1970. Tritium in community water supplies,
1969. Radiological Health Data 11: 692-94.
73. Public Health Service. 1971. Carbon-14 and tritium in total diet
and milk January 1969 - June 1970. Radiological Health Data 12:
42-44.
74. Shuping, R.E., C.R. Phillips and A.A. Moghissi. 1970. Krypton-85
levels in the environment determined from dated krypton gas samples.
Radiological Health Data 11(12): 671-672.
75. Coleman, J.R. and R. Liberace. 1966. Nuclear power production and
estimated krypton-85 levels. Radiological Health Data 7: 615-621.
76. Atomic Energy Commission. 1962. Off-site environmental contamina-
tion from nuclear explosives at the Nevada Test Site, September 15,
1961 - September 15, 1962. Nuclear Explosives Environmental Safety
Branch, Division of Operational Safety, report TID-18892. iii(
62 pp.
66
-------
77. Public Health Service. 1970. Final report of off-site surveil-
lance for the Milrow event, October 2, 1969. Southwestern Radio-
logical Health Laboratory, Las Vegas, U.S. AEC report SWRHL-95r.
22 pp.
78. Placak, O.K. 1963. Final off-site report Project Sedan, Nevada
Test Site/July 6, 1962. U.S. Public Health Service, U.S. AEC
report PNE-200F. vii, 85 pp.
79. Knapp, H.A. 1963. Iodine-131 in fresh milk and human thyroids
following a single deposition of nuclear test site fallout. pp.
1034-1040. In: Fallout Radiation Standards and Countermeasures.
Hearing before the Special Subcommittee on Radiation, Joint
Committee on Atomic Energy, U.S. Congress, August 20, 21, 22, and
27, 1963. Washington.
80. Public Health Service. 1963. Pasteurized milk network, September
1962. Radiological Health Data 4(1): 23-26.
81. Public Health Service. 1965. Final report of off-site surveil-
lance for the KIWI B4E experiment. Southwestern Radiological Health
Laboratory, Las Vegas, U.S. AEC report SWRHL-15r. 22 pp.
82. Public Health Service. 1964. Ibid. KIWI B4D. Report SWRHL-7r.
17 pp.
83. Public Health Service. 1966. Ibid. PHOEBUS 1-A. Report SWRHL-
19r. 20 pp.
84. Grossman, R.F. 1970. Summary of hypothetical whole-body exposures
and infant thyroid doses resulting off-site from project Rover
nuclear reactor/engine tests at the Nuclear Rocket Development
Station. U.S. Public Health Service, Southwestern Radiological
Health Laboratory, Las Vegas, U.S. AEC report SWRHL-92-r. 19 pp.
85. Placak, O.R. 1962. Off-site radiological safety report, Project
Gnome, Carlsbad, New Mexico, December 10, 1961. U.S. Public Health
Service, Las Vegas, U.S. AEC report PNE-132F. iv, 102 pp.
86. Public Health Service. 1970. Environmental surveillance for Project
Gasbuggy production test phase. Southwestern Radiological Health
Laboratory, Las Vegas, U.S. AEC report SWRHL-lOOr. iii, 39 pp.
87. Evans, R.B. and D.E. Bernhardt. 1970. Public health evaluation,
Project Rulison (production testing). U.S. Public Health Service,
Southwestern Radiological Health Laboratory, Las Vegas, report SWRHL-
96 (PHEP-1). 29 pp., w/Apps.
88. Atomic Energy Commission. 1971. Fundamental nuclear energy research
1970. (A supplemental report to the Annual Report to Congress for
67
-------
1970 of the United States Atomic Energy Commission.) Washington.
xix, 210 pp.
89. Atomic Energy Commission. 1960-1971. Environmental levels of
radioactivity at Atomic Energy Commission installations. Radio-
logical Health Data 1-12(1-12): var. pp. (Each issue includes
data on these installations.)
90. Brown, E.G. and R.C. Baker. 1961. Environmental monitoring summary
for the Paducah Plant for 1960. Union Carbide Nuclear Co., Paducah
Plant, U.S. AEC report KY-371. 15 pp.
91. Davis, K.A. and E.G. Brown. 1969. Ibid. 1968 and 1969. U.S. AEC
report KY-582. 14 pp.
92. E.I. Dupont de Nemours. 1969. Effect of the Savannah River Plant
on environmental radioactivity, semiannual report July through
December 1968. Savannah River Plant, U.S. AEC report DPST-60-30-1.
19 pp.
93. Honstead, J.E. 1970. Quantitative evaluation of environmental
factors affecting population exposure near Hanford. Battelle North-
west Laboratory, U.S. AEC report BNWL-SA-3203. 13 pp.
94. Adams, P.C. 1964. Environmental monitoring semiannual report:
January-June 1964. Monsanto Research Corp., Mound Laboratory, U.S.
AEC report MLM-1210. 16 pp.
95. Monsanto Research Corp. 1971. Ibid. 1970. U.S. AEC report MLM-
1784. 36 pp.
96. Hart, J.C. (ed.). 1963. Health Physics Division applied health
physics annual report for 1962. Oak Ridge National Laboratory, U.S.
AEC report ORNL-3490. iv, 76 pp.
97. Oak Ridge National Laboratory. 1970. Ibid. 1969. U.S. AEC report
ORNL-4563. viii, 68 pp.
98. Cowser, K.E. 1964. Current practices in the release and monitoring
of 131I at NRTS, Hanford, Savannah River, and ORNL. Oak Ridge Na-
tional Laboratory, U.S. AEC report ORNL-NISC-3. vii, 107 pp.
99. Dodd, A.O. (ed.). 1964. Health and Safety Division annual progress
report, 1963. Idaho Operations Office, U.S. AEC report ID-12037.
pp. 36-40, 69-73.
100. Atomic Energy Commission. 1971. Environmental statement for the
National Accelerator Laboratory, Batavia, Illinois. Washington.
ii, 21 pp.
68
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101. Copp, J..J. 1971. Summary of environmental monitoring at Ames
Laboratory. 1962-1969. Radiological Health Data 12(3): 119-128.
102. Miles, M.E., J.J. Mangeno and R.D. Burke. 1971. Disposal of radio-
active wastes from U.S. Naval nuclear-powered ships and their support
facilities, 1970. Radiological Health Data 12(5): 235-244.
103. Bouvier, J.A. 1970. Summary of environmental radiation levels for
the year 1969. WRAMC ENRADMON Plan, Environmental Radiological
Monitoring Plan. Walter Reed Army Medical Center. Washington.
Appendix H-3.
104. Hardy, E.P., Jr. and J. Rivera. (preps.). 1970. Radiostrontium
in milk and tap water. App. E. In: Fallout program quarterly
summary report. Health and Safety Laboratory, U.S. AEC report
HASL-217.
105. Bureau of the Census. 1970. Projections of the population of the
United States, by age and sex (interim revisions): 1970-2020.
Washington, Series I, P-25, No. 448. 50 pp.
90 89
106. Mays, C.W. and R.D. Lloyd. 1966. Sr and Sr dose estimates for
the fetus and infant. Health Physics 12: 1225-1236.
107. Butler, G.C. and A. Veld. 1967. Evaluation of radiation exposure
from internal deposition of three bone-seeking radionuclides. Health
Physics 13: 916-918.
69
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APPENDICES
TO
ENVIRONMENTAL RADIATION SECTION
71
-------
APPENDIX II-A
90
Accumulated Bone Dose from Sr vs. Age
(Determination of Figure II-2)
The bone dose values in Figure II-2 were calculated using different
90
Sr diet data and values of dose per \j.C± intake for different age
90
groups. The intake of Sr varies for different age groups depending
38
primarily on the quantity of milk consumed in the diet. Adult diets
OC
are used for people over 20 years old, teenage diets for ages 2 to
37
20, and infant diets (half the adult intake) for up to 2 years old.
These age groupings were selected to correspond to the available data.
90
The United States average Sr intake used for each of the three
38
age groups is given in Table IIA-1. Adult diet data were available
37
for 1960 to 1970 for three cities and teenage diet data were available
for 1963 to 1969 for 10 cities. Chicago was in both groups and provided
a means of comparison between teenage and adult diets. For 1954 to 1959
90 104
the ratio Sr/Ca in milk was available for adults. For years when no
data were available, various ratios given at the end of the table were
used to convert from one age group to another. The average was deter-
mined for 1963, 1965, and 1969 for 12 regions of the United States, each
represented by one of the cities for which diet data were available. A
national average was then determined using the populations of the 12
regions and the data from the 12 cities. The 1970 fraction of the pop-
ulation in each age group was used for all years. The national aver-
age was approximately a factor of 1.2 times the average of New York City
and San Francisco. This factor was used for other years.
Each yearly dietary intake was considered taken at midyear for cal-
culational purposes. For the year of birth, an intake of half that for
adults (to account for fetal dose) plus half that for infants was assumed
Changes in this assumption would not change the accumulated dose signif-
icantly .
Values of dose imparted to bone per unit of activity intake used in
the calculations were:
-1 f\C
Infant : 1st year dose: 1.24 rem/^Ci intake 1st year
2nd year dose: 1.52 rem/|iCi intake 1st year + 2.02
rem/p.Ci intake 2nd year
73
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Table 11A-1
Strontium-90 Intake
(pCi/yr.)
Year
Pre-1954
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
Post-1970
Notes :
Adult data:
Infant
Teen
(ages 0 to 2) (ages 2
0
193
560
900
900
1,520
2,200
1 , 675
1 ,434
1 , 993
4,698
4,687
3, 690
2,617
2,420
2,037
1,818
1,785
1, 785
1954-1959
1,
2,
2,
4,
6,
5,
4,
5,
17,
16,
10,
7,
6,
5,
4,
4,
4,
90
ratio Sr/Ca
to 20)
0
580
680
700
700
560
600
020
300
980
700
400
840
960
263
970
818
640
640
•-,, 104
in milk
Adult
(>age 20)
1,
1,
1,
3,
4,
3,
2,
3,
9,
9,
7,
5,
4,
4,
3,
3,
3,
(pCi/g
0
386
120
800
800
040
400
351
869
986
395
373
380
234
840
073
635
570
570
Ca) x 400 =
pCi/yr. ("400" varies from 330 to 480 for
1960-1968).
. „„„ ^ r „ 37 New York + San Francisco , „
1960-1970 U.S. Average = x 1.2.
37
Infant data: 0.5 of adult data.
Teen data: 1963-1969 (from Reference 37)
1954-1962, 1.5 times adult data for same years
1970 and after, 1.3 times adult values (less because of less
deposition resulting in less influence of milk
on total intake).
74
-------
37 105
Teen and adult ' : 50-year dose (after age 2)
= 9.1 rem/)j.Ci intake during
1st two years
+ 8.4 rem/p.Ci intake after age 2.
The fraction of the 9.1 rem or 8.4 rem accumulated each year after intake
is given in Table IIA-2. Several of these values had been calculated
based on a decline of Sr in the body according to the equation t "e
90
where t is time after intake in days, n is 0.20 for Sr, and X is the
Sr decay constant. These values were plotted, a curve drawn, and
then the values of fractional accumulated dose for each year after in-
take were taken from the curve.
The accumulated dose at various ages was determined by summing the
dietary intakes times the accumulated dose per unit activity intake for
the number of years after intake being considered. These dose values
are presented in Figure II-2.
75
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Table IIA-2
Fraction
90
of 50-year Sr Bone
Dose Delivered
107
after Intake
Years after
Intake
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Fraction of Dose
Delivered
0.072
0.121
0.169
0.210
0.246
0.274
0.313
0.344
0.373
0.402
0.428
0.456
0.484
0.510
0.534
0.555
0.577
0.600
0.619
0.636
0.655
0.675
0.693
0.708
0.726
Years after
Intake
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Fraction of Dose
Delivered
0.741
0.757
0.770
0.783
0.798
0.810
0.821
0.834
0.846
0.857
0.867
0.878
0.888
0.898
0.909
0.919
0.929
0.937
0.946
0.956
0.965
0.975
0.985
0.993
1.000
76
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APPENDIX II-B
Dose Calculational Methods for Fuel Reprocessing
1. Whole-body Gamma Doses
Whole-body gamma dose rate from a single radionuclide, due to im-
mersion in a cloud of radioactivity can be determined from the equation:
r c
2 TT i i
D = —- • rem/hr.
103 "i
where |j. is the linear attenuation coefficient for air, C is the average
3
air radionuclide concentration in (j.Ci/cm , and F is the gamma exposure
2
rate constant in (R-cm )/(hr.-mCi) for the radionuclide being considered.
The above equation is obtained by taking half of an integration over an
infinite sphere of radioactivity. Assuming \i is constant over the range
of gamma energies of in'
by the following ratio:
137
of gamma energies of interest, each radionuclide can be related to Cs
D(nuclide i)
T"1 C
D( Cs) Cs Cs
137
The Cs dose rate was taken from a detailed calculation for the Hanford
CO
Washington, area and multiplied by six since the dilution factor for
Hanford is six times lower than the dilution factor used in this study.
2 . Skin Doses and Doses Due to Inhalation
3 ~~~~ ' 4~
H Whole-body dose rate =3.6«10X»1.4 rems/week
44 3
where X is the air concentration in ^Ci/cm and
the factor 1.4 takes into account an increase in dose
70
due to organic labelling from chronic exposure.
3 44
Skin dose rate = 1.7 • 10 X rems/week. (All organ
doses are in addition to whole-body doses.)
85 300X . 59,61
Kr Skin dose rate (0.07 mm depth) = 7 mrem/yr.
5X 61
Lung dose rate = — - — '7 mrem/yr.
TOO _
Xe Skin dose rate (surface) = 0.23EXAt (Reference 58)
— 133
where E = 0.112 Mev (the average beta energy of Xe)
7
and At = 3.15 • 10 sec./yr.
77
-------
133 58
Xe Skin dose (0.07 mm depth) = 0.20 • surface dose.
2 3X
Lung dose rate = t '10-y mrem/yr.
85
from a comparison with Kr lung doses.
144 3 » 10 X 34
Ce Bone dose rate = ' . 10_9 mrem/yr.
1.5 • 104X . 34
Lung dose rate = -^- mrem/yr.
129 3 • 104X , 34
I Thyroid dose rate = — ^Q mrem/yr.
131 3 • 104X , 34
I Thyroid dose rate = mrem/yr.
y 3 • 10-9
Sr Bone dose rate = X • 20 • 10 cm /day air intake • 365
3 35
days/yr. • 0.7 « 10 mrem/50 yr./|j.Ci intake.
Pu Isotopes and Other Actinides
239
For Pu:
3
bone dose rate = 226 • 10 mrem/50 yr./|j.Ci intake,
3
lung dose rate = 588 • 10 mrem/50 yr./|j.Ci intake, and
respiratory lymph node dose rate = 132 • 10 (mrem/50 yr.)/|_iCi intake.
240 239
Plutonium-238 and Pu were considered equivalent to Pu because
34 241 241 242 244
their MPC 's are the same. Other nuclides ( Pu, Am, Cm, Cm)
239
were compared to Pu by using ratios of their MPC 's for different body
organs. Whole-body MPC ratios were used for bone and respiratory lymph
a
node doses and lung MPC ratios were used for lung doses.
3.
Other Nuclides
"~^ 15 • 10 X .
Lung dose rate = n— mrem/yr.
10~H
_ Q O
since the MPC of most radionuclides is greater than 10 u.Ci/cm. Those
a
with lower MPC 's were individually checked to determine their significance.
a
78
-------
3. Doses Due to Ingestion o£ Surface Deposition
57
Dose values from Dresden calculation:
Nuclide
89Sr
9°Sr
137Cs
129
Critical
Organ
Bone
Bone
Thyroid
Whole-body
thvrniH rln .<=; p^ -
Release Rate Dose at 3,000 m
(pCi/sec.) (mrem/yr.)
7,300
5
550
123
, R.R. (129D
= fS a •
5
8
3
1
131T ^
• T nrtcip •
.4 •
.2 •
.4 •
.8 •
i n
io-3
io-5
io-4
R.R. (I)
-] o Q -I Q I
where R.R. is the release rate of the I or I, the 5 takes into
34
account the difference in thyroid dose for the same concentrations,
and the factor 10 (a gross estimate) takes into account the buildup of
129 44
I in the environment because of its long half-life.
79
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III. MEDICAL RADIATION
-------
III. MEDICAL RADIATION
In this section, doses to the United States population resulting from
radiation exposures in the healing arts are discussed under the following
headings: Medical and Dental Radiology, Diagnostic Use of Radiopharma-
ceuticals, Radiation Therapy, and Medical Occupational Exposure.
A. Dose Estimates
At present, the use of radiation in the healing arts is recognized
as the largest manmade component of radiation dose to the United States
population. This includes medical diagnostic radiology, clinical nuclear
medicine, radiation therapy, and occupational exposure of medical and
paramedical personnel. Drawing comparisons between radiation doses to
the population from medical x-rays and other sources of exposure is
difficult. First, the radiation is delivered to an individual largely
on the basis of the professional judgement of an individual practitioner.
Second, a limited portion of the body is normally exposed during X-ray
examinations as contrasted with the whole-body exposure received from
many other sources, and this exposure is intermittent and delivered at
high dose rates, as opposed to the constant low-level exposure from most
other sources. This dissertation is presented to estimate doses accrued
to specific exposed populations and to the United States population as
a whole from the medical uses of radiation; in addition, trends in the
use of radiation in the healing arts and their effect on radiation dose
will be explored. Extrapolations and projections made in this study
concerning specific organ doses and future population doses are, in all
cases, based on presently available data and assume a continuity of para-
meters cited in the original base line information,
1. Medical and Dental Radiology
The potential mutagenic effect of x radiation received from medical
exposure led early to a dosimetric designation that would adequately ex-
press genetic significance. Genetically significant dose (GSD) is one
index of radiation received by the genetic pool. This index permits
comparisons between diverse national surveys and serves as an important
83
-------
measure of x-ray exposure. Estimates of the components of this index
have permitted the identification of those medical x-ray procedures
which contribute most to the genetic effect of radiation and thus
focuses corrective action on them. Mathematically, the GSD is expressed
A
ED N P
i i i
GSD = --
where D = the average gonad dose to persons age i who receive
i
x-ray examinations,
N = the number of persons in the population of age i who
i
receive x-ray examinations,
P = the expected future number of children for a person
i
age if and
N. = the number of persons in the population of age i.
Ihe magnitude of x-ray dose to segments of the United States popu-
lation has been reported in numerous studies (Appendix III-A). These
studies have been limited to estimations of GSD or, in some cases, to
gonad dose. Population studies of x-ray dose resulting from diagnostic
radiology vary as to time of inception (beginning in 1953), scope (local
or national), population size and characteristics, survey methods, and
dosimetry. One of the objectives of this review is to estimate some
doses of somatic significance from available published and unpublished
information.
a. Methodology and Results of United States Studies;
Genetically Significant Dose
Calculation of GSD for a population group is subject to broad vari-
ations. National and local population studies most often obtain the
annual GSD by weighting the individual gonad doses received during x-ray
examinations by the number of individuals examined and by the relative
*Assumes an equal fertility rate in the x-rayed population being studied
and the total population.
84
-------
contribution of these persons to the expected number of future children
produced by the population. An alternative procedure is to estimate the
mean annual gonad dose to that segment of the population below the age
of 30 and consider it equivalent to the GSD. The equivalence of
the two methods is based on the preponderance of potential child-bearing
and child-fathering individuals in the age group below 30.
Changes in diagnostic radiographic techniques and their relative
rate of use (influenced by the year the study was conducted and the loca-
tion where it was performed) have a great effect upon the results obtained.
In addition, parameters such as the health characteristics and the fraction
of the population exposed, the accuracy of gonadal dose determination,
and the method by which x-ray machine output is measured; all these influence
the estimates made from a survey and limits comparisons between surveys.
Estimates of United States population GSD range from 18 to 136 mrem
according to different reports. This variation is influenced by
relative child expectancy, age and sex distribution of the subjects,
usage distribution of specific examinations, and gonad dose per examina-
tion. While no one variable can account for the differences in the
results obtained, the incidence of obstetrical examinations and the
weight given to doses from these examinations appear to explain, to some
extent, some of the differences in the range of values reported. For
example, examinations of pregnant women provided approximately 30% of
3
the total GSD in New Orleans (1962), while the contribution of pregnant
women in the Public Health Service 1964 study was very small.
Published information from the Public Health Service survey of
x-ray exposure in the United States indicates a GSD of 54.6 mrem in
1964. Preliminary information from a repeat study in 1970 yields a GSD
of 35.5 mrem. At this time, the significance of this difference cannot
be clearly evaluated because information as to the magnitude of the
uncertainty surrounding these results has not as yet been published.
Although the error in the representativeness of the entire population
12
sample is small, the representativeness of dose estimates in any specific
examination-age-sex group can significantly influence the result. For
example, in 1964 lumbo-sacral and lumbar-spine examinations of 15- to
85
-------
29-year old males accounted for 30% of the entire GSD (16.5 mrem).
Furthermore, approximately 70%* of the difference between the 1964 and
1970 results are attributable to this examination-age-sex group.
Testicular exposure of individuals in this examination-age-sex
group is relatively infrequent, but because of the magnitude of the
potential testicular dose from this examination and the child expectan-
cy of this age group, these doses have a large influence on the resultant
population GSD. The magnitude of the testicular dose appears to depend
on whether or not the testes are in the direct x-ray beam. Accordingly,
when the testicular doses from the PHS 1964 survey are plotted,they tend
13
to follow a bimodal distribution, the lower dose peak corresponding to
examinations in which the testes are out of the direct beam and the upper
dose peak corresponding to examinations in which the testes are in the
direct beam. The degree of certainty surrounding the determination of
testicular dose in this examination-age-sex group is dependent upon the
number of measurements made. The data indicate that the number of measure-
ments in the 1964 and 1970 surveys of this examination-age-sex group were
13
limited. The small number of examinations in which testicular doses were
measured and the nature of the distribution introduce uncertainty into
the available GSD information.
b, Extrapolation of Other Doses
(1) Abdominal Dose
In order to evaluate somatic implications of the radiation doses
received by the population from diagnostic x-ray usage, dose estimates
for specific organs are needed. Such estimates are generally not yet avail-
able for the U.S. As a first step in estimating an approximate relative
somatic dose, one might determine the mean dose in the center of the
abdomen. (It must be remembered that the true specific organ doses depend
on many parameters such as field size, type of projection, etc.) An index
of the abdominal dose is provided by the PHS studies of 1964 - 1970, which
*[T6.5 mrem (1964 GSD contribution from male lumbo-sacral lumbar-spine
15-29-year age group) minus at least 3.2 mrem (maximum estimate 1970
GSD contribution from male lumbo-sacral lumbar-spine 15-29-year age
group)] 4- [54.6 (1964 GSD) minus 35.5 (1970 GSD)] .
86
-------
produced ovarian dose estimates for each procedure completely reported
in the surveys, regardless of patient sex. This information has not
been previously published. The ovarian and "simulated ovarian doses"
were computed as the mean of the estimated left and right ovarian doses
generated for each examination for which dose could be calculated in the
14
PHS study files. The per capita ovarian* and simulated ovarian doses"
weighted for representation in the United States population will, for
the sake of simplicity and to differentiate them from the true gonad
doses=f* be referred to as the "abdominal dose." Because the entire pop-
ulation regardless of age was employed, the data were not weighted for
future child-bearing potential, and the dose estimates were not as
sensitive to small variations in beam size and position, the diffi-
culties encountered in determination of GSD were reduced. The "abdominal
dose" values are presented as an index of somatic dose in an effort
to provide an alternate to the GSD estimates and to establish a basis
for analyzing contributing factors and evaluating future trends. The
biological significance of the "abdominal dose" is not evaluated in this
report, nor have these estimates been used to develop values for other
i
organs. The unequal distribution of body areas exposed, the non-homo-
geneity of human tissue, and variations of dose with age, all preclude
such application.
The estimated abdominal doses for 1964 and 1970 (based on prelim-
inary data) are presented in table III-l. Results are not presently
available for fluoroscopy during 1970, and these doses have been esti-
mated from the ratio of radiography to fluoroscopy doses in 1964. An
estimate of the abdominal dose from dental examinations was not made,
but this would be less than 0.3 rarem annual per capita dose since no
dental film in the Public Health Service survey produced an estimated
gonad dose higher than 0.2 mrem. Considering only the exposed popula-
tion (i.e., only persons receiving x-ray examinations), the abdominal
*Estimates made using the dose model yield ovarian and "simulated ovarian
doses" at a depth of 10 cm.
**The true gonad doses being the ovarian dose for females and testicular
dose for males.
87
-------
dose for males remained the same in 1970 as it had been in 1964 while
that for females appears to have risen. The reason for the rise in
female dose needs to be elucidated. The annual per capita abdominal
dose to the whole United States population appears to have increased by
about 20%, the entire increase being due to the rise in the female dose.
Table III-l
Estimated Abdominal Dose from Diagnostic Radiology
(Simulated Ovarian Dose - Male; Ovarian - Female)
Annual per Capita
Dose for the Size of
Exposed Population Exposed
(mrem) Population
Annual per
| Capita Dose for
Fraction of tne Whole U.S.
Whole U.S. Population
Year
Male Female Both (thousands) Population
(mrem)
1964
Radiography 150 126 138 66,086 0.354
Fluoroscopy 273 318 296 7,779 0.042
Total
1970*
Radiography 148 156 153 75,400 0.377
Fluoroscopy** 269 394 328 8,600 0.043
Total
49
12
61
58
14
72
*Preliminary results.
**Estimate based on ratio Radiography/Fluoroscopy for 1964.
(2) Thyroid Dose
Because of their proximity to the thyroid gland, examinations of the
head and neck, chest, and mouth are most likely to contribute to the thyroid
dose. Estimates of thyroid dose (Appendix III-B) indicate that for the
exposed population in 1964,the per capita thyroid dose was 172 mrem from
examinations of the head and neck. For the population as a whole the
annual per capita dose was about 7 mrem. This large difference is due
to the relatively small size of the population experiencing this type of
examination in 1 year. If one were to assume that the ratios of doses
to the lens of the eye and to the thyroid gland for head and neck exam-
inations and for dental examinations are the same, the estimates above
88
-------
may be made. Such a procedure does not take into account differences
in X-ray beam projections and in beam geometry. With the same reser-
vations, assuming that the ratio of the skin dose to the male gonad
dose for abdominal examinations has the same ratio as the skin dose
to the thyroid dose for chest examinations, one is able to estimate
thyroid doses of 171 mrem from a photofluorographic chest examination
and 15 mrem from a radiographic chest examination. Thus, in 1964, the
per capita thyroid dose for the exposed population from chest examina-
tions was 69 mrem while the corresponding dose for the whole population
was 19 mrem. -No estimates have been made of the contributions of exam-
inations of the abdomen and extremeties to thyroid dose due to virtually
a complete lack of information.
During 1964, 226,700,000 dental films were taken!2 According to the
distribution of film types used and estimates of thyroid dose per
film for each film type, ' the per capita thyroid dose in 1964 was 57
and 14 mrem in the exposed and whole populations, respectively. A summary
of annual per capita thyroid doses from medical and dental diagnostic
radiography is presented in Table III-2.
Table II1-2
Estimated Thyroid Doses from Diagnostic Radiology
Annual per
Capita Dose
for the Exposed
Population
Source (mrem)
Size of
Exposed
Population
(thousands)
Fraction of
Whole U.S.
Population
Annual
per Capita
Dose for the
Whole U.S.
Population
(•nrem)
Examinations of
head and neck (1964)
Examinations of
chest and thorax (1964)
Dental examinations
(1964)
172
69
57
7,500
51,100
45,900
0.04
0.27
0.25
19
14
89
-------
2. Diagnostic Use of Radiopharmaceuticals
Other sources of radiation doses in the healing arts, more recent
in terms of use than x-ray machines, are radiopharmaceuticals. These
materials find use in the diagnosis, and in a few specific cases in the
treatment of disease. Because of their newness, exposed populations are
still limited in size. However, there is strong evidence of the in-
creased use of these radiation sources.
a. Genetically Significant Dose
An early estimate (1956) of genetically significant dose from the
medical uses of radionuclides indicated a dose of 8 mrem per person per
18 131 32
year. This analysis was based on the total quantity of I and P
shipped during the year, including both diagnostic and therapeutic uses,
and did not include age selection and procreative potential. A sub-
19
sequent analysis (1957), assuming a diagnostic examination rate of
150,000 to 200,000 per year, of which probably not more than 25,000 exam-
inations were performed per year on patients below age 3'0, indicated that
the total accumulated patient gonad dose accrued from the diagnostic use
131
of I would be 375 rem (sum of doses to all'exposed individuals) to '
this younger age group. The genetically significant dose would be
equivalent to 0.004 mrem, assuming that 50% of the noninstitutional '
civilian population was below age 30. An equal gehetic'ally significant
dose was alleged to be accrued through other diagnostic radionuclide pro-
cedures for a total annual GSD of 0.008 mrem.
20
More recent information (1966) on radiopharmaceutical usage patterns
provided a basis for evaluating an estimated total accumulated gonad dose
of 195,000 rem (sum of doses to all exposed individuals) from all diag-
nostic radiopharmaceutical procedures to all age groups. Again, if one
assumes that 12.5% of the individuals receiving these 'procedures are
below age 30, and that 50% of the total population is also below age 30,
then the 1966 estimated annual GSD is 0.26 mrem from the diagnostic use'
of radiopharmaceuticals.
b. Extrapolations of Other Doses
Calculation of radiation doses to specific organs from radiophar-
maceuticals requires a knowledge of three parameters: (a) radiopha'r-
90
-------
maceutical usage rates, (b) activity per patient administration, and
(c) the dose delivered to a specific organ per unit activity adminis-
90
tered. During a 1966 Public Health Service study7 questions were asked
of 7,204 physicians licensed to use radionuclides in medical practice.
The reported number of patient administrations of various pharmaceuti-
cals in specific procedures was based on the response of 54% of those
queried. In some cases, this study also documented the average activity
administered per procedure for a 70 kg-male. For those procedures where
these latter data were missing, the recommended activity administered per
21
procedure was obtained from a current text and/or the manufacturer's
literature. The organ specific doses per unit activity administered
22
represent the median values from a range of values recently published.
However, the authors acknowledge that reliable biological data necessary
for absorbed-dose calculations is unavailable for many nuclear medicine
procedures. Thus, only limited information on all of the required para-
meters is available. Based on this information, the cumulative radiation
dose to a specific organ from a specific radionuclide was calculated
(Appendix III-C). The estimated annual ptr capita doses for the exposed
population and for the whole United States population from the diagnostic
use of radiopharmaceuticals in 1966 are presented in Table III-3.
The most significant dose was that accrued to the thyroid from admin-
istration of I. Most of this dose was due to the performance of I
thyroid function tests and scans. If the recommended dose* had been admin-
istered, the estimated thyroid dose per procedure would have been 5 to 15
rem (depending on dose administered and thyroid size) for a function test
21
and 50 to 150 rem for a thyroid scan. Based on meager reports on actual
131
practice in 1966, the average activity of I administered per thyroid
function test was reported to be 27 u.Ci and the average activity admin-
20
istered per thyroid scan was 46 (iCi. Unfortunately, the data on the
average activity administered are from a very limited number of responses
( 30). In the case of thyroid function tests, the data on the average
activity administered from the Public Health Service survey exceeded the
21
quantities recommended in current practice. Using the reported data,
*5-10|iCi for uptake and 50-100|aCi for scan.
91
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Table III-3
Estimated Doses from the Diagnostic
Uses of Radiopharmaceuticals - 1966
Specific Organ Dose
Thyroid
131
I thyroid function
/131
\ I thyroid function
131
I thyroid scanning
131
I other
99m
Tc brain scans
125
I thyroid scans
Other radionucl ides
TOTAL
Gonads
131
I thyroid function
131
I thyroid scanning
131
I other
203
Hg
Other radionuclides
TOTAL
Whole body
131
I thyroid function
131
I thyroid scanning
131
I other
Other radionuclides
TOTAL
Annual
per Capita Dose
for the Exposed
Population
(mrem)
3
5 to 15 x 10
47 x 103
3
78 x 10
3
1.6 x 10
3
2.4 x 10
3
67 x 10
-
69
114
86
630
134
55
91
44
279
Size of
Exposed
Population
(thousands)
481
481
252
320
104
2
339
481
252
320
89
356
481
252
320
445
Fraction of
Whole U.S.
Population
0.0025
0.0025
0.0013
0.0017
0.0005
-5
10
0.0018
0,0025
0.0013
0.0017
0.0004
0.0019
0.0025
0.0013
0.0017
0.0023
Annual
per Capita
Dose for the
Whole U.S.
Population
(mrem)
37*
117J**
101
2.7
1.2
0.7
-
143*
(220)**
0.17
0.15
0.15
0.25
0.25
1.0
0.14
0.12
0.07
0.64
1.0
**Based on small survey sample.
92
-------
the estimated annual per capita thyroid dose to the whole population was
220 mrem. If the recommended dose for thyroid function tests was admin-
istered, the annual per capita whole population thyroid dose would have
been 143 mrem. Despite the relatively small size of the exposed popula-
tion, administration of radiopharmaceuticals for thyroid tests contributes
the major radiation dose to the thyroid gland. It is interesting to note
125
that the dose from an I thyroid scan is only moderately lower than
that of an I scan. The dosimetric advantages of I over I are
partially negated because more is administered per procedure. The radio-
pharmaceutical Tc, available from ™Tc- Mo generators, has been
131
found a useful substitute for I in certain scanning procedures. The
131
thyroid dose from this nuclide is low relative to I.
131
Other than I, radiopharmaceuticals which deliver relatively high
203
doses to an individual experiencing a diagnostic procedure are Hg and
198
Au. The annual per capita dose to the whole body when considered for
the population as a whole, is approximately 1 mrem.
3. Radiation Therapy
The treatment of cancer with radiation is an established medical
modality, the object of which is the delivery of large quantities of radi-
ation to the diseased tissue. With this purpose in mind, and because radi-
ation exposure is not considered an undesirable side effect in therapy
procedures as it is in diagnostic radiography, it appears judicious to
estimate population dose from radiation used in treating cancer only in
terms of the genetically significant dose for the whole United States pop-
ulation. In the use of radiation in nonmalignant diseases, where other
modalities of treatment may be available and the use of radiation may be
more open to question, population dose could be calculated both in terms
of GSD and specific organ doses. Unfortunately, information relative to
the use of radiation for the treatment of nonmalignant disease is sparse.
a. Radiation Treatment of Cancer
In order to obtain an estimate of the population GSD from radiotherapy
of cancer, several informational items are required:
93
-------
(1) the number of individuals less than 30 years of
age having a particular malignant disease first diagnosed in any one year,
(2) the proportion of the above individuals receiving
radiation therapy,
(3) the proportion of individuals receiving radiation
therapy and surviving,
(4) the gonad dose per treatment, and
(5) the reduction in fertility due to the disease
itself*
Information on and estimates of these parameters, albeit in differ-
ent time periods, are presented in Appendix III-D. Using the incidence
23
of cancer in Connecticut in 1966, the occurrence, by age distribution
and by type and site of the malignancy, can be approximated for the entire
24
United States. Unpublished data were made available that provided in-
formation on the proportion of persons treated with radiation and the
5-year survival rates in the under-30 age group for the years 1955 through
1964. It is estimated that malignant diseases occurred in 93,000 indi-
viduals under the age of 30 in the United States during 1966, and that
approximately 25,000 were treated with radiation (X' ray, teletherapy, and
brachytherapy not differentiated).
Having established occurrence, treatment, and survival rates, esti-
mates of gonad dose and appropriate fertility rates are required. No
comprehensive United States information on this subject appears to exist
25
and British data for 1957 seem to provide the best approximation of
United States practice, in some cases, the data used for gonad doses are
maximum estimates, since for treatment of cancers of unspecified sites
(lymphomas, leukemia, endocrine tissue, and melanomas), doses found
during treatment of the lower abdomen, pelvis, and upper thigh were em-
ployed. In these cases, a correspondingly lower fertility rate was also
used in the calculations.
Assuming that the gonad dose to the population under age 30 is a
measure of the population GSD and that the size of this population is
*For example, females receiving radiation therapy to the pelvic region
were assumed to have no future childbearing potential. For the reduced
fertility factors employed see Appendix III-D, Table III-D-5.
94
-------
50% of the total noninstitutional civilian population, then the esti-
mated annual GSD from radiation therapy of malignant disease is approx-
imately 5 mrem.
No estimate of the GSD from use of radiopharmaceuticals and radium
in the treatment of malignant diseases is made since there is little
likelihood that the number of persons under age 30 treated in such a
19
manner would be large.
b. Radiation Treatment of Nonmalignant Diseases
Radiation therapy has been used for the treatment of nonmalignant
conditions of the skin such as acne and eczema, inflammatory processes
such as bursitis and spondylitis, and other conditions. There is no
significant information concerning the usage and doses accrued to the
United States population from this application of radiation.
Unpublished information from the 1964 study (which was not published
because its relative standard sampling error was 25%) indicated that approx-
imately 597,000 persons received 3,445,000 radiation therapy procedures
in 1964, of which 1,700,000 procedures were directed to the skin of the
head. It is estimated that 525,000 procedures (relative standard error
of approximately 50%) were to the skin of the head to the age group
below 30 years. Based on the age of the population involved and the
fact that approximately 70% of these procedures were administered by
dermatologists, it is likely that the majority of these procedures were
for nonmalignant skin conditions. These same data indicate that the
approximate average number of exposures per patient is four. Given the
large sampling error,one might estimate that the population at risk under
age 30 experiencing radiation therapy to the head was 131,500.
If a commonly suggested technique is employed (75 R per treatment to
each side of the face, 50 to 100 kVp), then the estimated gonad dose is
1.5 mrem. ' The annual per capita GSD from dermatological therapy to
the head is thus relatively low and is estimated to be 0.008 mrem. In-
formation on doses to other organs, specifically for the lens of the eye
and thyroid gland, is not available. Although the contribution of these
types of examinations to the gonad dose and GSD is minimal, it should be
mentioned that somatic doses to a sizable group of individuals may be high.
95
-------
For the most part, administration of radiopharmaceuticals for therapy
of nonmalignant illnesses in the under-30 age group is limited to the
treatment of hyperthyroidism. This procedure accounted for 61.4 percent
20
of radiopharmaceutical therapy procedures for all ages in 1966.
The estimates of the extent of use of radiation in the United States
for treatment of nonmalignant conditions are based on tenuous data. Un-
fortunately, suitable data are not available. Neither is information
available on specific organ doses. From studies in other countries prior
to 1962, it was reported that GSD's were as high as 4.5 rem from the use
28
of radiation in nonmalignant diseases,
4. Medical Occupational Exposure
Estimation of dose accrued to the population because of occupational
associations with the delivery of medical radiation is constrained, in that
only film badge data are available and various agencies and facilities
define an occupationally exposed individual differently. Unpublished data
on occupational radiation exposure from medical sources present informa-
29
tion gathered in several States. Film badge data serve as the only
available index of whole-body dose.
An independent analysis of this information, presented in detail else-
where in this report, indicates the following mean annual doses: medical
x-ray workers 320 mrem, dental x-ray workers 125 mrem, radioisotope work-
ers 262 mrem, and radium workers 540 mrem.
A population at risk of 195,000 and 171,000 persons in 1968 has been
reported for the medical and dental occupational exposure groups, respec-
30
tively. Counting radium and radioisotope workers, the total exposed
population is estimated to be approximately 454,000 persons so that the
annual per capita dose to the United States population as a whole is
0.56 mrem (see IV below).
B. Projected Doses
1. Medical and Dental Radiology
Projections of doses from diagnostic medical radiography must take
into consideration a variety of variables, These include changes in the
rate of delivery of radiographic examinations, in the age and sex distri-
bution of the patients, in the distribution of examinations by type, and
96
-------
in the dose per examination. In the case of GSD, the projected fertility
rate per age group also may influence the resultant estimate. Further-
more, future doses will be influenced by technical, educational, and
regulatory actions which could modify patient doje. These variables
are difficult to evaluate, and projections of radiation dose from medical
radiation must be evaluated with consideration for the uncertainties
involved.
Film sales provided an early estimate of increased usage of radio-
logical services. Between 1945 and 1965,film sales increased at the rate
31
of 5.4% per annum. More recent preliminary evidence indicates that film
32
usage has increased at the rate of 4.7% per annum. Information relative
to changes in patient usage rates is probably more pertinent to changes
in radiation dose than are increases in film sales or use. A study in
selected hospitals indicates that between 1963 and 1968 the annual rate
of discharges of patients in any diagnostic radiation category and in
total diagnostic radiation categories increased by 3.6 and 6.6%, respec-
33
tively. Preliminary information from the 1970 Public Health Service
study yields a somewhat lower indicator of the rate of delivery of radio-
graphic medical examinations. Based on the 1964 and 1970 studies, the
examination rate for medical diagnostic radiography increased from 61.8
examinations per 100 persons in 1964 to 68.5 examinations per 100 persons
32
in 1970 or a 1.6% increase per annum. Thus, the information presented
above leads to an estimate of between 1 and 4% increase per annum in the
rate of delivery of radiographic procedures. At least some of this in-
crease appears to be due to the expansion of radiology services to persons
who previously did not have such care available (i.e., persons with low
32
family income and in the age group over 65).
Other available information relevant to projected dose pertains to
potential reduction in patient dose due to improved collimation and
technique. Experience in a large teaching hospital showed that about
30% of radiation dose delivered pursuant to x-ray examinations could
(2
be reduced by optimization of technique. This is inclusive of 10%
unnecessary radiation due to repetitive examinations. In particular,
optimization of technique could reduce the amount of radiation dose
97
-------
delivered in a gastrointestinal tract examination by 20% and in other
abdominal examinations by 27%. The effect of collimation in dose re-
duction is dependent upon the procedure, position, and film size. Re-
ductions in bone marrow dose due to collimation appear to vary from 17
to 80%; while for gonad dose, exclusion of the gonadal regions from the
34
direct beam can reduce the dose by a factor of 5. Gonadal shielding
is particularly important in reduction of male gonad doses, and, report-
edly, reduces this dose by about 92% for a shield acceptable to most
35
patients. An optimistic evaluation of the reduction of genetically
significant dose by collimation indicates that a large reduction is
possible through simple restriction of beam size to film size. In
practice, this is not accomplished easily or carried out routinely,
since it requires care in positioning the patient and x-ray tube, as
well as selection of proper cone or x-ray field size adjustment. From
the above discussion it appears reasonable that as much as a 50% re-
duction in dose might be possible due to technical and educational meth-
ods .
In fact, there is some evidence that technical improvements are
occurring. While a survey of x -ray facilities between 1963 and 1968
indicated that at least 28% of medical x -ray machines were improperly
collimated. A comparison of the 1964 and 1970 Public Health Service
studies shows that collimation improved in all types of x-ray facilities
32
during this period.
The information presented in this report comparing the estimates
of GSD and annual per capita abdominal dose for 1964 and 1970 is such
that no firm conclusions can be drawn at this time as to changes. In
view of the possible decrease in the GSD and increase in the abdominal
dose estimates shown by the Public Health Service 1964 and 1970 studies,
and the fact that the magnitude of the uncertainty surrounding these
figures has not, as yet, been determined, no firm conclusion can be drawn
at this time as to future radiation doses. _Lf one assumes that there is
no change with time in the mean abdominal dose to the whole population,
i.e., if technical improvements keep pace with increased usage, then the
man-rem received by the population depends only upon population size.
93
-------
Using an annual per capita abdominal dose of 72 mrem would yield the
projected man-rem listed in Table III-4.
Table III-4
Estimated Total Man-rem to the United States Population
from Medical Diagnostic Radiology - 1960 to 2000
Year
1960
1970
1980
1990
2000
Population
(millions)
183
205
237
277
321
Estimated Total
Man-rem
(millions)
13.2
14.8
17.1
19.9
23.1
Dental x-ray visit rates during 1961 and 1964 are similar, with a
slight decrease during the latter year being attributable to sampling
differences.' Between 1964 and 1970, a gradual rise of about 4% per
year in the rate of dental x-ray visits is evident. Using a per capita
dental x-ray visit rate of 0.27 and an average of five films per visit,
the predicted whole-body man-rem to the United States population from
dental x-rays in the year 2000 is less than 200,000.
2. Radiation Therapy
The purposeful delivery of radiation in the case of radiation therapy
is an argument against the inclusion of this source of radiation in esti-
mates of accumulated man-rem doses to the population. There is no sig-
nificant information to indicate the direction that the doses from radi-
ation therapy will take in the future even though its use might increase.
3. Diagnostic Radiopharmaceuticals
Studies of radiopharmaceuticals indicate increases in the rate of
31 37
administrations of between 15 and 20% per year in the mid-1960's.
More recent information based on sales of radiopharmaceuticals indicates
38
an annual increase of 25% per year. It appears judicious to estimate
that in the 1960's the use of radiopharmaceuticals increased fivefold
99
-------
during the 10-year period and that an increase of sevenfold may be ex-
perienced in the next 10 years. Thereafter,it is difficult to make pre-
dictions, especially in terms of dose since technical changes are likely
to play a large role in dose reduction in a rapidly changing field.
Assuming no technical changes, and the growth pattern indicated above,
it is expected that the whole-body man-rem to the United States popu-
lation in 1980 from diagnostic use of radiopharmaceuticals will be 3.3
million man-rem. Even with a slowing of the rate of increased use of
radiopharmaceuticals the accrued whole-body man-rem could easily reach
approximately 15% of the total dose from medical uses by the year 2000.
Improvements in equipment have led to decreased dosage require-
ments in thyroid function tests and kidney scans, and the substitution
of radionuclides yielding lower patient exposure have already reduced
total body and kidney doses per procedure. Even with these improvements,
in the 4-year period, 1964 to 1968, one institution reports that the aver-
age whole-body dose per patient increased from 100 mrem to 160 mrem due
37
to the increased use of radiopharmaceuticals.
4. Medical Occupational Exposure
Projections of future occupational dose are based on the growth ex-
pectation for medical and dental personnel. This projection assumes that
the manpower requirements for the radiological sciences are growing at
31
the composite compounded rate of 7.1% per year. For dental personnel
projected doses are based on approximately 0.87 dental workers per 1,000
population and it is assumed that this ratio (which has remained fairly
39
constant) will continue. Using the dose estimates previously presented,
the projected accrued annual whole-body man-rem dose to the United States
population by the year 2000 is less than 0.2 million man-rem.
C. Summary
A summary of estimated doses from medical and dental radiation is
presented in Table III-5.
The genetically significant dose provides one index of the magnitude
of radiation dose to the population from the use of radiation in the heal-
ing arts. The main contributor to the GSD in 1964, reported to be 55
mrem, was diagnostic medical radiography. The genetically significant
100
-------
Table III-5
o
Summary of Estimated Doses
from Medical and Dental Radiation
Dose Category
or Organ
Genetically
significant dose^
(1964)
(1970)
(1966)
(1966)
"Abdominal dose"
(1964)
(1970)
Whole-body
dose (1966)
Source
Medical and dental
diagnostic radiography
Same
Radiation therapy
Radiopharmaceuticals
Medical radiography
Radiography
Flouroscopy
Radiography
Flouroscopy
Diagnostic uses of
radiopharm.
Annual per
Capita Dose
for Exposed
Population
(mrem)
138
296
153
328
Depends on
radiopharm.
Size of
Exposed
Population
(thousands)
66,900)
7 780 /
75, 400 )
8,600 f
1, 500
Annual per
Capita Dose
Fraction of for Whole U.S.
Whole U.S. Population
Population (mrem)
55
36C
5
0.3
0.40 61
0.42 72°
0.008 1
(continued)
-------
Table 1II-5 (continued)
o
to
Dose Category
or Organ
Whole-body dose
occupational (1968)
Source
Medical workers
Dental workers
Radiopharm. and
radium workers
Annual per
Capita Dose
for Exposed
Population
(mrem)
320 1
125 |
262-540!
Size of
Exposed
Population
(thousands)
454
Fraction of
Whole U.S.
a
Population
0.002
Annual per
Capita Dose
for Whole U.S.
Population
(mrem)
0.6
Organ
Thyroid (1964)
Thyroid (1966)
Medical radiography
Examinations of
head and neck
Examinations of
chest and thorax
Dental radiography
Diagnostic uses
of radiopharm.
131
I thyroid function
172
69
57
7,500
51,100
45,900
0.31
0.25
26
14
3e)
function
I thyroid scan
Other
5t°15Xf 1,500 0.008
78x10 >
Depends on
radiopharm.
143
Based on civilian non-institutionalized population only.
GSD applicable to whole United States population.
"Preliminary information.
Ovarian and "simulated ovarian" doses.
^Based on recommended activity per administration.
-------
doses from dentistry and radiopharmaceuticals were small; less than 1
mrem for dentistry (1964) and 0.3 mrem for radiopharmaceuticals (1966).
The GSD (1966) from radiotherapy was estimated to be 5 mrem. Preliminary
reports have stated that the GSD has decreased from the 1964 level to
35.5 mrem in 1970. A large portion (30%) of the GSD in 1964 was due
to lumbo-sacral and lumbar-spine examinations of males in the 15- to 29-
year age group. This examination-age-sex group also accounts for approx-
imately 70% of the difference in the GSD between 1964 and 1970. The
small number of examinations in this category for which testicular doses
were actually measured, and the nature of the distribution of the data,
has introduced reservations concerning the conclusiveness of the results.
Another index of medical radiation dose used in this report is the
per capita abdominal dose. This index is calculated from dose estimates,
ovarian (for females) and "simulated ovarian" (for males), weighted for
their representation in the United States population. Because the entire
population regardless of age is employed, the data are not weighted for
future child-bearing potential, and the dose estimates are not sensitive
to small variations in beam size and position; the difficulties encountered
in determination of GSD are reduced. Furthermore, one is able to calculate
dose estimates for the exposed population (i.e., considering only persons
receiving x-ray examinations). The annual per capita abdominal depth dose
for the exposed population in 1964 was 138 and 296 mrem from medical radio-
graphy and fluoroscopy. respectively. In 1970, based on preliminary in-
formation, the abdominal dose due to medical radiography appears to have
risen. This increase, due entirely to an elevation of the female per
capita abdominal dose, requires elucidation. For the whole United States
population, the annual per capita abdominal doses for 1964 and 1970 are
estimated to have been 61 and 72 mrem, respectively. Errors in the survey
and the measurements from which these estimates were derived have not, as
yet, been fully evaluated. Accordingly, it appears that the most prudent
conclusion is that this index has remained relatively stable during the
two study years.
Estimates of whole-body dose may also serve as an index of somatic
dose. Whole-body doses from radiopharmaceuticals may be relatively high
103
-------
(approximately 1 rem) to individuals experiencing a particular procedure;
however, because the number of persons so treated is still relatively
small, the accrued dose to the whole population is small.
Among specific organs which may be exposed in the course of medical
treatment, present information permits estimates of thyroid dose. The
131
highest thyroid doses are delivered to individuals experiencing I
thyroid function and scan tests who receive an estimated per capita dose
of 5 to 15 rem to this organ during a thyroid function test and 78 rem
during a thyroid scan. The introduction of in vitro thyroid function
tests and new radiopharmaceuticals will significantly lower these doses.
Although the population receiving such procedures is small, the annual
per capita thyroid dose to the whole United States population (1966) from
radiopharmaceuticals is estimated at 143 mrem. This is greater than the
corresponding estimated annual per capita doses to the whole population
(1964) of 26 mrem from medical x-ray examinations of the head, neck, chest,
and thorax and 14 mrem from dental radiography.
A word should be said about occupational doses associated with the
delivery of medical x-rays and therapy. Estimated annual per capita doses
(1968) to exposed groups of workers range from 125 mrem for occupational
dental exposure to 540 mrem for persons employed in administration of
radium therapy. As a group, medical workers contribute a greater portion
to overall population dose than any other occupational group, and experience
a higher annual per capita dose than any other occupational group.
Among pertinent information required for a more complete evaluation of
radiation doses to the United States population from the healing arts, but
as yet, still lacking are bone marrow doses from the medical radiation
sources. Also, doses from the treatment of nonmalignant diseases with radia-
tion, and doses to particular populations at maximum risk due to specific
chronic illnesses are also not available.
Projection of doses from diagnostic medical radiography must take
into consideration changes in the rate of delivery of radiographic exam-
inations, in the age and sex distribution of the patients, in the distri-
bution of examinations by type, and in dose per examination. Review of
several reports on the rate of increase of radiographic examinations, each
104
-------
using different measurement parameters, leads to the conclusion that in
the past decade the rate of radiological examinations increased between
1 and 4% per year. At least some of this increase appears to be due to
the expansion of radiographic services to persons who previously did not
have such care available. Furthermore, there is some evidence of tech-
nical improvements, and it is reasonable that as much as a 50% reduction
in dose might be possible due to technical and educational methods. Thus,
it appears that the potential for technical improvement could keep pace
with increased usage. Based on the evaluations presented in this report
of the Public Health Service surveys of 1964 and 1970, it appears that
the reported changes in the GSD are, at present, uncertain and require
further elucidation. An evaluation of abdominal dose, based on these
same surveys, leads to the conclusion that the level of population dose
between 1964 and 1970 from diagnostic medical radiology has not changed
greatly. Considering the above factors, the man-rem dose from diagnostic
medical radiation would increase only through population increase. An
annual per capita abdominal depth dose (an index of somatic dose) of 72
mrem in 1970 would yield an estimated 14.8 million man-rem to the whole
United States population. Increasing population alone would raise this
to 23.1 million man-rem by the year 2000.
Compared to diagnostic medical radiography, estimated future accrued
man-rem doses to the United States population from other medical uses of
radiation are small. Only the diagnostic uses of radiopharmaceuticals,
which by the year 2000 could accrue a whole-body man-rem dose of greater
than 3.3 million man-rem to the population, is significant. The corres-
ponding accrued man-rem doses from dentistry and medical occupational
exposure in the year 2000 are 200,000 man-rem each.
Extrapolations and projections made in this study must be considered
in light of the uncertainties surrounding the base measurement, the assump-
tions employed, and the changing state of medical technology. Despite
these reservations, medical radiation is the largest manmade component of
radiation dose to the United States population. It accounts at present,
on the basis of the indices employed in this study for at least 90% of
the total manmade radiation dose and at least 35% of the total radiation
105
-------
dose (including natural background) to which the United States population
is exposed. Conclusive evidence that doses from diagnostic medical radio-
graphy has either increased or decreased in the past decade is lacking.
Based on the information presently available and discussed in this re-
port, it is logical to conclude that the annual per capita population
dose from diagnostic medical radiography could remain stable if tech-
nical improvements keep pace with increased usage rates.
106
-------
REFERENCES
1. Public Health Service. 1969. Population dose from X-rays, U.S.
1964. Washington, Publ. No. 2001. xiv, 143 pp.
2. Gileadi, M. 1969, Evaluation of health hazards due to unintentional
irradiation of the gonads during routine abdominal X-ray examinations
of male and female patients in Puerto Rico, Report I-Western Region.
Puerto Rico Nuclear Center, U.S. AEC report PRNC-132 105 pp.
3. Izenstark, J.L. and W. Lafferty. 1968. Medical radiological practice
in New Orleans; estimates and characteristic? of visits, examinations,
and genetically significant dose. Radiology 90: 229-242.
4. Pasternak, B.S. and M.B. Heller. 1968. Genetically significant dose
to the population for New York City from diagnostic medic;?! radiology.
Radiology 90: 217-228.
5. Cooley, R.N. and L.B. Beentjes. 1964. Weighted gonadal diagnostic
roentgen-ray doses in a teaching hospital with comments on X-ray
dosages to the general population of the United States. Am, J.
Roentgenol., Had. Therapy Nucl. Med. 90: 404-417.
6. Morgan, R.H. and J.C. Genret. 1966. The radiant energy received by
patients in diagnostic X-ray practice. Am. J, Roentgenol,, Rad,
Therapy Nucl. Med. 97; 793-810.
7. Billings, M.S., A, Norman and M.A. Greenfield. 1957, Gonad dose during
routine roentgenography. Radiology 69: 37-41.
8. Laughlin, J.S. and I. Pullman. 1957. Gonadal dose produced by the
medical use of X-rays, preliminary edition of section III. National
Academy of Sciences-National Research Council, Washington. 105 pp.
9. Brown, F.R., J. Heslep and W. Eads. 1960. Number and distribution
of roentgenologic examinations of 100,000 people. Radiology 74: 353-
362.
10. Norwood, W.D., J.W. Healy, E.E. Donaldson, W.C. Roesch and C.W. Kirklin.
1959. The gonadal radiation dose received by the people of a small
American city due to the diagnostic use of roentgen rays. Am. J.
Roentgenol., Rad. Therapy Nucl. Med. 82; 1081-1097.
11. Gitlin, J.N. 1972, Preliminary dose estimates from the U.S. Public
Health Service 1970 X-ray exposure study. Paper presented at the 49th
Annual Meeting of the American College of Radiology, Miami Beach,
Florida, April 6, 1972.
107
-------
12. Gitlin, J.N. and P.S. Lawrence. 1968. Population exposure to X-rays.
U.S. 1964. U.S. Public Health Service, Washington, Publ. No. 1519.
x, 218 pp.
13. Roney, P.L. 1972. Personal communication, April 24, 1972. Bureau
of Radiological Health, Food and Drug Administration, Department of
Health, Education, and Welfare.
14. Goldstein, N. and J. Gaskill. 1972. Personal communications,
February 11, 1972 and April 17, 1972. Bureau of Radiological Health,
Food and Drug Administration, Department of Health, Education, and
Welfare.
15. Fess, L.R., R.B. McDowell, W.R. Jameson and R.W. Alcox. 1970.
Results of 33,911 X-ray protection surveys of facilities with
medical or dental diagnostic X-ray equipment, fiscal years 1961-
1968. Radiological Health Data 11(11): 581-612.
16. Richards, A.G. and R.L. Webber. 1964. Dental X-ray exposure of
sites within the head and neck. Oral Surg. 18: 752-756.
17. Public Health Service. 1970. Diagnostic dental X-rays and the
patient - an overview. Radiological Health Data 11(1): 1-5.
18. Clark, S.H, 1956. Genetic exposure in the field of medicine. Bull.
Atomic Scientists 13: 14.
19. Chamberlain, R.H. 1957. p. 885. In: Radioactive Fallout and Its
Effects on Man. Hearings before the Special Subcommittee on Radia-
tion, Joint Committee on Atomic Energy, U.S. Congress, May 27, 28,
29, and June 3, 1957. Washington.
20. Public Health Service, 1970. Survey of the use of radionuclides in
medicine. (Prepared by Stanford Research Institute). Bureau of
Radiological Health report BRH/DMRE 70-1. xxii, 132 pp.
21. Maynard, C.D. 1969. Clinical Nuclear Medicine. Lea and Febiger,
Philadelphia. xiii, 280 pp.
22. Hine, G.H. and R.E. Johnson. 1970. Technical communication. J. Nucl,
Med. 11: 468.
23. Christine, B.W., P.O. Sullivan and R.R. Connelly. 1970. Cancer in
Connecticut 1966. Connecticut State Department of Health, Health
Bull. 84.
24. National Institutes of Health, National Cancer Institute. 1971.
Unpublished information provided through the courtesy of Dr. S. Cutler
and Mrs. Axtell, End Results Group, End Results Section. Washington.
108
-------
25. Ministry of Health. 1960. Radiological hazards to patients,
second report of the Committee. Department of Health for Scotland,
London. 114 pp.
26. Cipollaro, A.C. and P.M. Crossland. 1967. X-rays and Radium in the
Treatment
-------
37. LeBlanc, A. and P.C. Johnson. 1970. Medical radiation exposure
survey in a hospital with a nuclear medicine laboratory. Health
Physics 19: 433-437.
38. Atomic Energy Commission. 1971. The nuclear industry.1971.
Washington. vii, 199 pp.
39. Public Health Service. 1970. Health resources statistics, 1969.
National Center for Health Statistics, Washington, Publ. No. 1509
vi, 286 pp.
110
-------
APPENDICES
TO
MEDICAL RADIATION SECTION
111
-------
APPENDIX III-A
Summary of Information Relating
to United States Studies for
Determination of GSD
113
-------
Table IIIA-1
Summary of
Study and Location
Public Health
Service/National
Izenstark & Lafferty/
New Orleans , La?
Pasternak & Heller/
New York, N.Y^
Cooley & Beentjes/
Galveston, Tex.
Morgan & Gehret/
Baltimore, Md?
Billings, Norman, &
Greenfield/
Los Angeles, Calif.
Laughlin & Pullman®
Information Relating
Year
1964
1962-
1963
1962
1964
1963-
1964
Prior
to
1957
1957
Approx . No .
Persons
x rayed or
Exams .
4,500
8,000
persons
Not
reported
220,000
exami-
nations
36,000
persons
900
persons
_
to United States Studies
Site or
Sampling See
Source Footnotes
Household a,b,c
interview
Hospitals & c
offices
Gen . , TB & a,c
mental hosp . ,
clins . , of f s .
University a,b,c
hospital
Teaching a,c
hospital
Large private & d
general hosp . ,
childrens clin.
Based on a,b,d
published
literature
for Determination of
Source of Popu-
lation Age Dis-
tribution Data
Study
itself
Study
itself
NYC
Census-
1960
U.S.
Census-
1960
U.S.
Census-
1960
Study
itself
_
GSD
Source of Age-
Specific Child
Expectancy Data
National Center
for Health Sta-
tistics, 1963
National Center
for Health Sta-
tistics, 1963
Not reported
U.S. Vital
Statist ics -
1960
National Center
for Health Sta-
tistics, 1963
"
American Medi-
cal Directory,
1950, 1956
(continued)
-------
Table IIIA-1 - continued
Study and Location
Brown, Heslep, & Eads/
San Francisco, Calif.
Norwood, Healy,
Donaldson, Roesch, &
Kirklin/
Richland, Wash.
Year
1956-
1957
1953-
1956
Approx . No
Persons
x rayed or
Exams .
110,000
exami-
nations
85,000
exami-
nations
Site or
Sampling
Source
Medical ins.
hospital
Hospital &
offices
Source of Popu-
See lation Age Dis-
Footnotes tribution Data
a,d Study
itself
a,b,c,d Study
itself
Source of Age-
Specific Child
Expectancy Data
-
Study itself
Flouroscopy included.
Dentistry included.
Q
GSD based on age distribution anr" child expectancy.
GSD equivalent to 30-yr. gonad dose.
-------
Table IIIA-2
Summary of Information Relating to United States Studies for Determination of GSD
Study and Location
Public Health
Service/National
Izenstark & Lafferty/
New Orleans, La.
Pasternak & Heller/
New York, N.Yi
Cooley & Beentjes/
Galveston, Tex~
Morgan & Gehret/
Baltimore, Md?
Billings, Norman, &
Greenfield/Los Angeles,
Calif?
8
Laughlin & Pullman
Brown, Heslep, & Eads/
San Francisco, Calif?
Norwood, Healy, Donald-
son, Roesch, & Kirklin/
Richland, Wash*0
Actual Measure-
ment of X-ray Method of Measure-
Machines Made ment of X-ray
Dose Model During Study Machines During;
Employed Yes No Study
Phantom & human x - Various film packs
subjects depending on procedure
Phantom X
Model based on - X
phantom
Phantom, human X - Assortment of ioniza-
subjects & tion chambers and/or
published lit, monitoring films
Calculational (rela- X - Differential-type
tionship between ionization chambers
abdominal & gonad
dose)
Phantom & human X
subjects
Based on published X
literature
Based on published X
literature
Phantom & Partial - Ionization chambers
published
literature
GSDa
(mrem)
55
(New 75
Orleans)
(New York 50
City)
18
23
(L.A. 61
hospi tal )
(probable) 136
(minimum) 50
40
(Richland) 46
For U.S. population unless otherwise stated. Not differentiated between estimates to population
less than 30 and whole population.
-------
APPENDIX III-B
Estimated Thyroid Dose - 1964
A. Head and Neck Examinations
12
1. 27,069,000 films or 7,519,166 examinations assuming 3.6 films per
examination.
2. Mean skin exposure (skull, mastoid, optic, mandible, and sinuses) = 279
mR per examination^2
3. Assume that the skin dose and dose to the lens of the eye are equiv-
alent .
4. Ratio of lens of eye to thyroid exposure:
16
14 periapical films
@ 65 kVp 2.1:1.3 = 1.61
@ 90 kVp 79:48 = 1.64.
279 mR lens of eye/examination ^ _„ , . , . ......
5. 1—~ — = 172 mrad thyroid dose/examination*
1.62
9
6. 7,519,000 examinations x 172 mrad/examination _ 1,293 x 10
_. _ — _ . mra
187 x 10 whole population 187 x 10 annual
per capita
thyroid dose.
B. Chest Examinations
1. Assume ratio of skin to thyroid dose from chest examinations same
ratio as skin to male gonad doses from abdominal examinations.
Abdominal mean male gonad dose/film _ 273 mrad _ abdominal gonad
... . n i • j /j. • -, 12 790 mrad ' abdominal skin
Abdominal mean skin dose/film
2. Mean skin dose - chest x rays:
12
Chest (photofluorographic)/film = 500 mrad.
Estimated thyroid dose = 170 mrad.
12
Chest (radiographic)/film = 45 mrad.
Estimated thyroid dose = 15 mrad.
3. Dose 1963:
12
No. chest films (photofluorographic) (1964) = 16,800,000 x 170 mrad
= 2,900,000 rad.
Assumes mR and mrad to be equivalent.
118
-------
12
No. chest films (radiographic) (1964) = 46,800,000 x 15 mrad
= 702,000 rad
Total = 3,600,000 rad.
3,567,730 patient-rad (1964)
51,100,000 persons at risk = °'069 rad = 69 mrem to person in
exposed population.
51,100,000 exposed population x 69 mrem
= 0.27 x 69 = 19 mrem mean
187 x 10 total population annual per capita
dose to whole
population.
C. Dental Examinations
1. 226.7 x 106 films/yrl7
2. Distribution by film use (percent).
Film type Bite wing Periapical
A
B
C
D
3
48
17
32
3
47
18
32
3. Distribution of film use by type of film (percent)
Periapical 67
Bite wing 33
4. Thyroid dose per film (mrem).
Bite wing Periapical
Film SpeedDose Film Speed Dose
A 44 A 27.2
B 22 B 13.6
C 11 C 6.817
D 5.5 D 3.4
5. Dose (1964):
JJ J- L-C: W J-IIg,
226,7 x 106 x 0.33 (0.03 x 44) + (0.48 x 22) + (0.17 x 11) + (0.32 x 5.5)
6 — —
45.9 x 100
= 25.279 mrem mean annual dose to person in population at risk.
119
-------
Periapical
226.7 x 106 x 0.67 (0.03 x 27.2) + (0.47 x 13.6) + (0.18 x 6.8) + (0.32 x 3.4)
D _ _....... ~45.9 x 10b '
= 31.502 mrem mean annual dose to person in population at risk.
6
45.9 x 10 exposed persons .._ __
—— r :;—— x 56.78 mrem = 13.93 mrem per capita to population
187 x 106 total population ,
as a whole.
120
-------
APPENDIX III-C
Radiopharmaceut icals
Table IIIC-1
)
Patient
Administration and Dose Administered - 1966
Radionuclide and Form
131T
I
Nal
Nal
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin (MAA)
Sodium lodohippurate
Sodium lodohippurate
Labelled fats
Rose Bengal
Rose Bengal
125
I
Nal
Other radionucl ides
57
Co Labelled Vita-
min B-^2
60
Co Labelled Vita-
min B-^2
51
Cr Sodium chromate
51
Cr Sodium chromate
Estimated number
of patient
administrations
Procedure (1966)
Thyroid uptake
Thyroid scanning
Blood volume
Cardiac output
Placental scanning
Brain scanning
Heart scanning
Liver scanning
Lung scanning
Renal function
Kidney scanning
Fat malabsorption
Hepatic function
Liver scanning
Thyroid scanning
Vitamin B absorption
Vitamin B12 absorption
Blood volume
Red blood cell survival
481,
252,
163,
2,
6,
6,
37,
53,
3,
12,
1,
32,
2,
39,
26,
36,
10,
830
567
418
527
753
077
675
337
817
069
376
635
685
415
026
591
113
221
108
Dose
administered
(nCi/70-kg
adult)
27.5
45.7
5.5
20
7.1
400
300
157.7
260.4
45.0
200
44.4
10
150
75
0.50
0.50
27.3
100
51
59
Cr Heat-treated red
blood cells
Fe chloride or
citrate
Spleen scanning
Iron turnover
2,701
5,054
225
7.5
(continued)
321
-------
Table IIIC-1 - continued
Radionuclide and Form
99m
Tc pertectnetate
99m
Tc pertectnetate
99m
Tc sulfur colloid
99m
Tc labelled albumin
99m
Tc labelled albumin
198 :
Au colloidal gold
203
Hg labelled mer-
curials
203
Hg labelled mer-
curials
197
Hg labelled mer-
curials
197
Hg labelled mer-
curials
Mercurihydroxipropane
85
Sr nitrate or chlo-
ride
75
Se selenomethiodine
Procedure
Brain scanning
Thyroid s-canning
Liver scanning
Placental scanning
Lung scanning
Liver scanning
Brain scanning
Kidney scanning
Brain scanning
Kidney scanning
Spleen scanning
Bone scanning
Pancreas scanning
Estimated number
of patient
administrations
(1966)
103,998
337
4,911
205
205
68,881
62,128
27,012
30,389
11,480
675
675
2,701
Dose b
administered
(liCi/70-kg
adult)
7,936
2,000
2,971
1,000
1,000
175
700
116
1,000
144
300
2,000
125
.6
.6
.0
1
.6
.4
Represent returns"" from 54% of queried, corrected to estimate total patient
administrations. i
b
Values stated to one decimal place from Reference 20. Mean dose is average
representative of all physicians performing procedure. Assumes a 70-kg adult
131
patient, except for I, where weighted average was used. Other values
21,22
represent median dose recommended^
or values from manufacturer's literature.
122
-------
Table III-C-2
Dose per Administration
to
co
Dose (mrad) *
Radionuclide and form
131z
Nal
Nal
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin
Labelled albumin
Sodium iodohippurate
Sodium iodohippurate
Labelled fats
Rose Bengal
Rose Bengal
125
Nal
Other Radionuclides
Co labelled Vitamin ¥>
fin
Co labelled Vitamin B
51
Cr sodium chromatt
Procedure
Thyroid uptake
Thyroid scanning
Blood volume
Cardiac output
Placental scanning
Brain scanning
Heart scanning
Liver scanning
Lung scanning
Renal function
Kidney function
Fat malabsorption
Hepatic function
Liver scanning
Thyroid scanning
Vitamin B absorption
Vitamin B absorption
1 *j
Blood volume
Whole body
55
91
11
40
14
800
600
315
65
5
24
29
7
105
3
1.75
210
5.5
Gonad
69
114
30
110
39
2,200
1,650
867
208
25
-
-
-
50
280
6.8
Thyroid
46,750
77,690
193
800
248
14,000
10,500
5,519
9,110
1,575
7,000
-
-
67,500
-
(continued)
-------
Table IIIC-2 - continued
Dose (mrad)
Radionuclide and form
Cr sodium chromate
51
Cr heat-treated red
blood cells
59
Fe chloride or citrate
Tc pertectnetate
99mm
Tc pertectnetate
99m
Tc sulfur colloid
99m
Tc labelled albumin
99m
Tc labelled albumin
198
Au colloidal gold
203
Hg labelled mercurials
203
Hg labelled mercurials
197
Hg labelled mercurials
197
Hg labelled mercurials
Mercurihydroxipropane
85
Sr nitrate or chloride
87m
Sr nitrate or chloride
75
Se Selenomethiodine
Procedure
Red blood cell survival
Spleen scanning
Iron turnover
Brain scanning
Thyroid scanning
Liver scanning
Placental scanning
Lung scanning
Liver scanning
Brain scanning
Kidney scanning
Brain scanning
Kidney scanning
Spleen scanning
Bone scanning
Bone scanning
Pancreas scanning
Whole body
20
67
225
119
30
44
15
15
218
1,050
175
100
14
42
1,312
20
1,000
Gonad
25
450
1,125
198
198
297
40
40
87
630
630
80
11
36
-
-
625
Thyroid
-
-
-
2,831
600
-
-
-
-
-
-
-
-
-
-
-
750
9 o
^Product of activity per administration and dose to specific organ per unit activity.
-------
APPENDIX III-D
Radiation Therapy
Table III D-l
Exposed
Population
Radiat
ion Therapy (Malignancies) Age <30
ICS No.
140 - 149
151
153
154
155
157
160
162
163
170
171
172
174
175
177
178
180
181
181.7
190
192
193
193.1
194
195
197
199
Lymphatic
Leukemia
Rate/100
in Conn.23
,000
1966
Male Female
1
-
1
1
-
-
1
1
2
-
-
-
2
11
2
1
1
9
2
9
4
5
1
8
2
19
18
-
1
3
1
1
1
-
-
1
1
110
3
3
7
-
2
-
-
9
1
13
4
8
1
7
3
17
12
Expected number
of cases in U.S „*
Site
Buccal cavity & pharynx
Stomach
Large intestine
Re c t urn
Liver, bile duct
Other; digestive
Nose and nasal cavity
Lung bronchio-tracheal
Other, respiratory
Breast
Male
553.8
_
553.8
553.8
-
-
553.8
553.8
1,107.6
-
Female
538.3
1,615.0
538.3
538.3
-
538.3
538.3
Uterus (excluded from genetic dose)
Prostate
Other male genitals
Kidney
Bladder
Other urogenital
Malignant melanoma
Eye
Brain
Other central nervous
system
Thyroid
Other endocrine
Connective tissue (b'one)
Other
Lymph
Leukemia
1,107.2
553.8
553.8
4,984.2
1,107.6
4,984.6
2,215.2
2,769.0
553.8
4,430.4
1,107.6
10,522.2
9,968.4
1,077.2
-
-
4,845.0
538.6
6,997.9
2,153 .3
4,306.6
538.3
3,768.3
1,615.0
9,151.1
6,460.0
^Estimated Population to Age 30 (1970):
Male; 55,385,000
Female; 53,833,000.
125
-------
Table III -D-2
to
Treatment of Cancer (Diagnosed 1955-1964) with Radiation3 - Age <30
Treated with
Radiation
All Cases
Site
Lip
Tongue
Salivary gland
Floor of mouth
Mouth (other)
Oral mesopharynx
Nasopharynx
Hypopharynx
Pharynx , NOS
Esophagus
Stomach
Small intestine
Large intestine
Rectum
Liver/gallbladder
Pancreas
Peritoneum
Digestive, NOS
Nose, nasal cavity,
ear, etc.
Number
22
17
379
3
23
10
62
2
3
1
40
36
305
51
73
32
8
1
50
Percent
0.2
0.2
3.4
0.1
0.2
0.1
0.6
0.1
0.1
0.1
0.4
0.3
2.8
0.5
0.7
0.3
0.1
0.1
0.5
Number
3
8
19
3
6
9
53
2
2
1
9
14
7
3
14
6
5
1
33
Percent-
age of
Cases
14
47
5
100
26
90
85
100
67
100
22
39
2
6
19
19
62
100
66
Relative Survival Rate
(%)
All Cases Radiation Treated
3 yr.
95
-
97
-
-
-
(37)
-
-
-
(16)
(32)
76
(48)
15
(21)
-
-
(53)
5 yr. 3 yr. 5 yr.
95 -
_ _
94 (79) (79)
_ _
_
- -
(31) (35) (35)
- -
_
_
- -
(32)
71 - -
(42)
13 - -
(21)
- -
- -
(45) (50)
(continued)
-------
Table III D-2 (continued)
Treated with
Radiation
Site
Larynx
Bronchus , lung
Mediastinum
Breast
Cervix, uteri
Corpus, uteri
Ovary, fallopian
tubes , etc .
Vulva, vagina
Prostate
Testis
Penis, other
male genitals
Kidney
Bladder
Other, urinary
Lower GI, NOS
Melanoma
Other skin
Eye
Brain, other nervous
All
Number
15
89
89
195
351
37
186
19
12
327
12
278
88
7
0
369
264
381
1.600
Cases
Percent
0.1
0.8
0.8
1.8
3.2
0.3
1.7
0.2
0.1
3.0
0.1
2.5
0.8
0.1
-
3.3
2.4
3.5
14.5
Number
8
30
62
81
215
9
85
5
8
175
0
216
9
0
0
9
24
125
811
Percent-
age of
Cases
53
34
70
42
61
24
46
26
67
54
—
78
10
-
-
2
9
33
51
Relative Survival Rate
(%>
All Cases
3 yr.
(91)
(41)
(33)
53
72
(86)
68
-
-
52
-
41
84
-
-
70
95
86
38
5 yr .
-
(36)
(31)
44
67
(86)
64
-
-
51
-
40
84
-
-
64
92
84
33
l
Radiation Treated
3 yr.
-
(18)
(37)
(38)
57
-
(59)
-
-
52
-
38
-
-
-
-
(82)
82
34
5 yr .
-
(11)
(33)
(29)
53
-
(52)
-
-
50
-
38
-
-
-
-
(82)
81
28
system
(continued)
-------
Table III-D-2 (continued)
M
00
Treated with
Radiation
Site
Thyroid
Other endocrine
glands
Bone
Connective tissue
Ill-defined sites
Lympho/reticulo
sarcoma
Hodgkins disease
Other lymphoma
Multiple myeloma
Leukemia
Mycosis fungoides
ALL SITES COMBINED
All
Number
613
233
485
444
169
413
904
100
5
2,167
5
11,034
Cases
Percent
5.6
2.1
4.4
4.0
1.5
3.7
8.2
0.9
0.1
19.6
0.1
100
Number
143
143
252
137
37
260
678
34
2
165
1
3,976
Percent-
age of
Cases
23
61
52
31
51
63
75
34
40
8
20
36
Relative Survival Rate
(%)
All Cases
3 yr.
97
34
32
52
13
24
52
40
-
4
-
5 yr.
96
32
28
50
13
18
31
37
-
3
-
b
Radiation Treated
3 yr.
94
34
24
27
14
26
55
(43)
-
3
-
5 yr .
92
32
19
26
14
20
34
(43)
-
3
-
aRadiation alone or in combination with other therapy.
Rates in parentheses have standard error between 5 and 10%. Rates with standard errors
larger than 10% not shown.
-------
Table III D-3
25
Estimated Gonad Dose per Treatment
Site
Buccal cavity and pharnyx
Stomach
Large intestine
Rectum
Liver and bile duct
Nose and nasal cavity
Breast
Lung, bronchi and trachea
Other respiratory
Kidney
Bladder
Melanoma*
Eye
Brain
Other central nervous system
Thyroid
Other endocrine
Connective tissue*
Lymphoma*
Leukemia*
Dose
Male
0.22
9.07
212.09
385.2
5.38
0.51
-
2.05
2.05
44.74
262.59
88.37
0.2
0.4
0.4
0.45
44.74
141.39
123.72
123.72
(rem)
Female
0.25
16.94
-
-
10.04
0.57
7.79
5.94
5.94
-
71.71
150.0
0.22
0.44
0.44
1.0
405.0
240.0
210.0
210.0
— — A - r
abdomen, pelvis or upper thigh.
129
-------
Table III -D-4
oo
c
Gonad Dose
from Radiation
Therapy of Malignancies to the Less Than 30 Age Group
Site
Buccal cavity
and pharynx
Stomach
Large intestine
Rectum
Liver, bile duct
Nose and nasal
cavity
Breast
Lung, bronchi and
trachea
Other respiratory
Kidney
Bladder
Other urogenital
Melanoma
Eye
Brain
Other central
nervous system
Product of Percent-
age of Population <30
Treated by Radiation &
10-year Survival Rate
0.10
0.04
0.01
0.03
0.03
0.33
0.12
0.04
0.48
0.30
0.08
0.01
0.26
0.14
0.14
(0.145
(.22 x
(.02 x
(.06 x
(.19 x
(.66 x
(.42 x
(.34 x
(.53 x
(.78 x
(.10 x
(.02 x
(.33 x
(.51 x
(.51 x
x .70)
.16)
.70)
.50)
.14)
.50)
.29)
.11)
.91)
.38)
.84)
.64)
.81)
.28)
.28)
Estimated Population
<30 Having Malignancy
Receiving Radiation,
& Surviving >5 Years
Male
55
-
5
17
-
183
-
22
532
332
44
-
50
288
698
310
Female
-
21
16
16
16
—
66
-
258
323
-
-
48
140
980
301
j
Gonad
(patient-rem per year)
Male
12.1
-
1,060.4
6,548.4
-
93.3
-
45.1
1,090.6
14,840.4
11,554.4
-
4,420.0
57.6
279.2
124.0
Female
-
355.7
3,393.6
6,163.2
160.6
~
514.1
—
1,532.5
14,438.1
-
-
7,200.0
30.8
431.2
132.4
(continued)
-------
Table III D-4 (continued)
Estimated Population
Product of Percent- <30 Having Malignancy
age of Population <30 Receiving Radiation,
Treated by Radiation & & Surviving >5 Years
Site
Thyroid
Other endocrine
Connective tissue
Lymphoma
Leukemia
Other
TOTAL
10-vear Survival Rate
0
0
0
0
0
0
.21
.19
.08
.25
.02
.14
(.23 x
(.61 x
(.31 x
(.34 x
(.08 x
.92)
.32)
.26)
.75)
.03)
Male
581
105
353
2,631
199
155
6,560
Female
904
102
301
2,288
129
226
7,814
t
Gonad
(patient-rem per year)
Male
4,
49,
325,
24,
13,
448,
261
693
914
454
616
697
363
.4
.5
,2
.7
.3
.3
,9
41
72
480
27
33
690
Female
904.0
,310.0
,240,0
,480,0
,090,0
,900.0
,276.2
-------
Table III D-5
Estimated GSD from Radiation Therapy (Malignant Diseases)
Area of Body
Male genitals
Male pelvic region
Male - other
Female pelvis (bladder,
cervix, rectum, and
kidney)
Female pelvic region
Female - other
Fertility
Index Annual Cumulative
Relative or. Patient-rem
to Normal""' Male Female
0.02
0.40 490,670
1.0 1,936
0.0
0.4 - 681,184
1.0 - 3,545
Annual Cumula-
tive Patient-
rem Corrected
for Fertility
-
196,268
1,936
272,473
3,545
M , 474,249 patient-rem _ n
Note- 5 1 m-rom
93.5 x 10 population under 30
132
-------
IV. OCCUPATIONAL DOSES
-------
IV. OCCUPATIONAL RADIATION
The contribution of occupational exposure to the population dose
from ionizing radiation is poorly documented in the scientific litera-
ture. Despite the lack of published information, a vast quantity of data
has been accumulated in various personnel dosimetry programs throughout
the United States. Most of the information from these programs has been
made available for this study. The purpose of this section is to provide
mean dose estimates for various occupational specialities, an estimate of
the total number of radiation workers in the population, and an estimate
of the contribution of occupational exposures to the United States popu-
lation dose.
A. Assumptions and Limitations of Data
In general, the data collected by the various reporting agencies
were primarily for verification of the adequacy of radiation protection
practice and to preclude, where possible, overexposure of the worker. The
retention of the data by the employer is, in most instances, for medico-
legal purposes. There is no requirement for uniformity in collecting or
reporting of all occupational exposures to ionizing radiation nor are
there any required standards for accuracy.
In consideration of the foregoing, the data collated by major report-
ing agencies will be treated separately. In numerous instances,the major
reporting agency includes data from other agencies through joint agree-
ments to provide personnel dosimetry service. Where possible, these will
be shown.
Except where indicated, the doses are from external sources. Infor-
mation on dose from internal sources during occupational exposure is
limited and is reported only for special categories. The terminology
used by the reporting agencies is extremely varied. It has been assumed
that the value reported is the exposure of the dosimetry device and no
135
-------
attempt has been made to calculate a true absorbed dose. Additional
complications in assessing a true dose are variations in placement of
the dosimeter on the individual and variations in the terminology used
in reporting results; i.e., reports made in roentgens, rad, and rem.
For the purposes of this report, the value reported is considered to
be accurate; to be a whole-body dose and is assumed to be the dose equi-
valent in rem. It is intended that the use of dosimeter exposure results
as dose equivalent will result in an overestimate of the actual whole-
body dose .
With the exception of data obtained from the Army and Navy, all re-
sults were provided in dose ranges. For the purpose of calculating total
man-rem, the midpoint of the ranges were taken to be the mean for the
entire range. Since there is a tendency to badge for convenience, and
for legal purposes, it has been reported that in most cases those indi-
viduals who have no detectable exposure are included in the lowest dose
range. The arbitrary assignment of unexposed workers to the lower end
of the distribution skews the data and would underestimate the overall
mean dose of those exposed. To compensate for this bias, the midpoint
has been established as the mean.
In addition to the assumption that all reported exposures are accu-
rate, it has been assumed that all overexposures were true individual
doses. In only a limited number of cases was there any indication that
an investigation had been conducted following an overexposure or that any
adjustment in the individual's dose had been made.
B. Summary of Data from Reporting Agencies
Below are discussed the data reported by Federal agencies and other
organizations.
1. Federal Agencies
The reporting Federal Agencies include: the Army, Air Force, Navy,
Atomic Energy Commission, and Public Health Service.
a. Army
The Army employs approximately 22,790 individuals who may be exposed
to ionizing radiation as a result of their duties. Sources to which Army
personnel may be exposed are quite varied. Radiation protection practice
136
-------
and control of sources is established by regulation and strictly en-
forced. All exposure records are maintained at two processing centers
(Sacramento and Lexington Bluegrass Army Depots) which provided indi-
2
vidual annual doses for this study. For purposes of this evaluation,
individuals exposed as a result of employment to greater than 10 mrem/yr.
3
have been considered to be radiation workers. It has been suggested
that individuals receiving an annual dose of less than 10 mrem should
ii , 3
be considered as occasionally exposed individuals."
The method of reporting exposure data was such that the broad cat-
egories of occupational specialities could be identified as medical, in-
dustrial, and reactor fields.
As shown in Table IV-1 the average dose per worker (>10 mrem/yr.)
in the medical field is 95 mrem, industrial field 94 mrem, and the reactor
field, 245 mrem.
Table IV-1
Summary of Army Annual Occupational Doses - 1969 to 1970
Job Category
All
Medical
Industrial
Reactor
Percent of
Workers
100
49.6
46.5
3.8
Percent in Dose Range (rem) Mean
0-0.1 0.1-0.5 0.5-1.5 >1.5 (mrem)
96 3.2 0.68 0.02 100
95
94
- - - 245
Included in the data provided by the film badge processing facilities
is dose information from other Government agencies, such as the National
Bureau of Standards and from some National Aeronautics and Space Admin-
istration facilities.
b. Air Force
The Air Force monitors 34,975 individuals who may be exposed to ion-
izing radiation in the course of their work. The Radiological Health Lab-
oratory at Wright-Patterson AFB provides dosimetry service and serves as
a repository for exposure data for the Air Force. All doses for this
study were provided by that agency through the Surgeon General, Depart-
4
ment of the Air Force.
137
-------
The system developed by the Air Force not only records Individual
doses but categorizes them in terms of dose groups for a specific occu-
c c
pational specialty.' Table IV-2 shows the mean annual dose for selected
occupational areas. Through discussions with personnel at the Radiolog-
ical Health Laboratory, it was determined that anyone having a recorded
dose less than 10 mrem/yr. was included in the 10 to 49 mrem range. An
estimate of the number of these individuals was deducted from total mon-
itored personnel prior to determining the mean dose in each job cate-
gory. The calculated mean annual dose for Air Force occupational ex-
posure is 88 mrem.
Table IV-2
Summary of Air
Force Occupational Doses
- 1969 to 1970
Job Category
Medical X-ray
Dental X-ray
Veterinary X-ray
Medical nuclide
Industrial nuclide
Industrial X-ray
Radar
Special weapons
Reactors
Miscellaneous
TOTAL
0-0.049 .049-. 099 .1-
95.7 2.4 0
Percent of
Workers
23
19
1
3
19
12
8
4
1
10
100
Percent of Workers
Dose Range (rem/yr.)
.299 .3-. 499 .5-1.49 1
.9 0.6 0.3
Mean Annual Dose
(mrem)
101
77
67
100
68
79
67
89
461
98
88
.5-2.99 3-4.99 >5
0.05 0.02 0.02
c. Navy
Occupational exposure data for the Navy are maintained by the Naval
Medical Data Services Center, Bethesda, Maryland. Exposure data on 55,051
individuals was provided for this study through the Radiation Safety Office
National Naval Medical Center (see Table IV-3).
138
-------
Table IV-3
Summary of Navy Occupational Doses - 1969 to 1970
Job Category
Medical
Industrial
TOTAL
d. Atomic
Percent of Workers
10
90
100
Energy Commission
Mean Annual
(mrem)
83
211
198
Dose
The Atomic Energy Commission maintains dosimetry records for employ-
ees and contractors who routinely work with byproduct material and special
nuclear material. The 1969 data used for this study included exposures
to 102,918 employees. The format was in dose ranges of 1 rem from 0 to
12 rem?'9
To determine the total man-rem, the low range of 0 to 1 rem was
divided into smaller increments corresponding to those reported for Atomic
Energy Commission and agreement State licensees. The percentage of employ-
ees assigned to each range was assumed to be comparable to licensees. The
reported ranges and the estimated ranges are shown in Table IV-4. The
total man-rem was calculated to be 20,361. This results in an overall
mean annual dose of 198 mrem per worker.
e. Public Health Service
The Public Health Service provides dosimetry for all its activities,
as well as for the Bureau of Prisons and the Coast Guard. The sources
of exposure in these agencies are similar to those found in the practice
of medicine and dentistry throughout the United States.
A thorough analysis of the results of this dosimetry program was
furnished for this study. During fiscal year 1970, film badge records
were maintained for 2,750 individuals. Of this number, 508 exceed 10
mrem. For this group the mean annual dose was 129 mrem.
f, Other Federal Agencies
It has been estimated that approximately 2,000 Federal employees
may not have been included in the reports of other agencies. To account
for these employees, they have been assigned the mean dose for the Public
Health Service.
139
-------
Table IV-4
•y of Atomic Energy
Commission* Occupational Doses -
Dose Range
(rem/yr . )
0-1
(0-0.1)
(0.1-0.2)
(0.2-0.5)
(0.5-1.0)
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
>12
TOTAL
Number of Percent of
Persons Total
98,625 95.8
(73,372) (71.3)
(9,869) (9.6)
(10,059) (9.8)
(5,325) (5.2)
2,554 2.5
1,313 1.3
335 0.3
86 0.1
4
0
0
0
0
1
0
0
102,918 100
^Contractors and employees.
2. Nonfederal Activities
Nonfederal activities include Atomic Energy Commission licensees,
agreement State licensees, X-ray use in the healing arts, and medical
use of radium.
a. Atomic Energy Commission Licensees
Atomic Energy Commission regulations require that certain categories
of licensees report annually all doses in excess of 1.25 reins. Admin-
istratively, many licensees find it easier to report all doses. Data
are also obtained as part of an annual survey of exposure levels determined
by commercial film badge suppliers. The data provided by this survey
represent approximately 29% of the total number of Atomic Energy Com-
140
-------
mission licensees. Of the 62,090 individual records, 95.8% indicated
12
a dose of less than 1 rem. The employees for whom records were pro-
vided are estimated to be approximately 40% of all occupationally ex-
Q
posed personnel operating under an Atomic Energy Commission license.
All doses were reported in ranges as shown in Table IV-5. The
total man-rem and mean dose values were calculated as previously de-
scribed and are shown in Table IV-6. It is believed that they are over-
Table IV-5
Summary of Reporting Atomic Energy Commission (AEC) Licensee
and Agreement State Licensee Occupational Doses -
Dose Range
(rem/yr . )
0
0
0
0
.0-0.1
.1-0.2
.2-0.5
.5-1.0
1-2
2-3
3-4
4-5
5-6
>6
TOTAL
Numbe r
1969
(and %) of Persons
AEC Licensee
45,785
5,224
5,777
2,710
1,489
583
191
109
64
158
62,090
(73
(8
(9
(4
(2
(0
(0
(0
(0
(0
.7)
.4)
.3)
.4)
.4)
.9)
.3)
.2)
.1)
.2)
(100)
State Licensee
17,041
2,084
2,550
1,422
785
319
98
73
49
98
24,519
(69
(8
(10
(5
(3
(1
(0
(0
(0
(0
.5)
.5)
.4)
.8)
.2)
.3)
.4)
.3)
.2)
.4)
(100)
estimates of the actual individual dose to all employees because it is
assumed that the 60% not reported were below 1.25 rem/yr. Thus, approx-
imately 93,000 individuals are exposed to some level of radiation less
than the mean annual exposure of those who may be expected to exceed
1.25 rem. Since the opportunity for exposure of the higher group would
be up to 5 rem/yr., and the opportunity for exposure of the lower group
is 1.25 rem/yr., a simple ratio of opportunity to be exposed has been
used to calculate the mean of 54 mrem for the lower group. These doses
are shown as nonreported Atomic Energy Commission licensees in summary
tables below.
141
-------
Table IV-6
Mean Annual Doses for Reporting Atomic
Energy Commission Licensees - 1969
Activity
Medical
Major processor
Waste disposal
Radiography
Industrial
Academic
Reactors
Fuel processing
Packing and
transport
Not specified
TOTAL
b.
Employees
20,228
1,789
21
1,894
13,331
7,738
2,302
6,637
335
7,815
62,090
Agreement State
Man-rem
5,260
495
96
752
2,139
903
497
2,177
22
1,024
13,365
Licensees
Mean Dose
(mrem)
260
276
457
397
160
117
216
328
66
131
215
During 1969 there were 17 (22 at the end of 1970) States which had
assumed regulatory authority over byproduct, source, and limited quan-
tities of special nuclear materials. These agreement States continue to
cooperate with the Atomic Energy Commission to insure compatible regu-
latory programs.
Exposure data for 1970 comparable to that of Atomic Energy Commission
licensees were provided for this study through the Atomic Energy Commis-
Q
sion by 15 of the agreement States (see Table IV-5). Since only 15 of
the 17 agreement States were reported, an average of the reporting States
was used to add 3,000 employees for the two States which did not report.
The mean dose of the reporting States (Table IV-7) was used to determine
man-rem as shown under nonreporting States in summary tables below.
c. X-ray Use in the Healing Arts
The most tenuous estimate developed in this study is the mean annual
dose of nonfederal employees exposed during the use of radiation in
diagnostic and therapeutic medical and dental radiology. The data for
142
-------
Table IV-7
Mean Annual Occupational Doses for Agreement
State Licensees - 1970
Activity
Medical
Processor
Waste disposal
Radiography
Industrial
Academic
Not specified
TOTAL
Employees
11,867
32
256
1,174
6,479
3,980
731
24,519
Man-rem
3,403
37
766
294
1,490
499
226
6,715
Mean Dose
(mrem)
286
1,160
2,991
250
230
125
309
273
estimating this value has been obtained from a limited number of State
health organizations which maintain central files on occupational doses
and those which have conducted film badge surveys.
(1) Wisconsin
The State of Wisconsin has conducted film badge surveys on various
categories of radiation workers for limited periods of time to evaluate
the radiation protection procedures being followed by persons using x rays
in the healing arts.
The most recent survey conducted involved 4,175 dentists for 1 month.
13
The data obtained are shown in Table IV-8. The mean annual dose was
calculated to be 156 rarem.
Table IV-8
Wisconsin Dental Facility Survey - 1969 to 1970
Number Percentage in Dose Rate Range (mrem/week)
Surveyed 0 - 1Q 11 - 50 50 - 99 >100
4,175 93.6 5.8 0.6 0*
Assumed mean
Number
Total man-mrem/wk.
1
3,908
3,908
30
242
7,260
75
25
1,875
140
0
0
*Originally 4 individuals; review indicated improper handling of
badge. Resurvey of these placed them in a lower range.
143
-------
During 1969 a survey of 663 medical x-ray workers indicated an
14
average total dose rate of 4,150 man-mrem/week. Assuming that each
individual works for 50 weeks/yr. the mean annual dose would be 313
mrem.
(2) Illinois
The State of Illinois requires that reports of all occupational
exposure of employees who may receive a dose of greater than 0.312 rem/
quarter be submitted to the Department of Public Health. The data for
a portion of 1970 is shown in Table IV-9. Although this program has
been operating since 1964, it was not until 1970 that investigations of
Table IV-9
Summary of
Illinois Whole-body
Radiation Doses
- 1970
Category
Dentists
Physicians
Osteopaths
Chiropractor
Veterinarians
Podiatrists
Nursing institution
Hospitals
Clinics
Private laboratories
Number of
Reports
24
75
0
10
6
0
3
1,125
45
3
Mean Dose
(rem/quarter)
0.024
0.043
0
0.003
0.098
0
0.023
0.085
0.080
0.057
Man-rem/
Quarter
0.58
3.22
0
0.03
0.59
0
0.069
95.6
3.6
0.17
reported overexposures were required. It is believed that the reported
data for 1970 represent a more valid mean dose than that of previous years
when no attempt was made to determine if a badge exposure represented the
exposure of the worker.
The data in Table IV-9 yield a dose of 324 mrem to these medical
workers and 96 mrem to the dental workers.
(3) Maine
The State of Maine operated a statewide film badge service from 1956
to 1968. During the period 1956 to 1965, 580 individuals representing
144
-------
about 75% of all radiation workers in the State were monitored by this
program. During fiscal year 1965, the average dose per month for all
16
•s was 20 mrem.
(4) National Mean Dose
categories of workers was 20 mrem.
The data from the foregoing three States are the only readily avail-
able bases for establishing a national mean annual dose of 320 mrem per
nonfederal medical x-ray worker and 125 mrem per nonfederal dental x-ray
worker. These means are applied to the 194,541 medical x-ray worke-s
17
and 171,226 dental x-ray workers in the United States.
d. Medical Use of Radium
A survey of personnel occupationally exposed in radium therapy was
conducted by the State of Wisconsin. The results of this study provided
to the Public Health Service indicated that there may be as many as 185
medical radium workers per million population. Extending this to the
population of the United States would indicate that there may be up to
37,925 individuals occupationally exposed in radium treatment who are
not otherwise reported. The estimated number of radium treatments in
Wisconsin is 800 per year. From 37 treatments monitored, the average
total dose was 500 mrem per treatment or 400 man-rem per year from all
treatments. This results in a mean annual dose of 540 mrem for the 740
medical workers in Wisconsin. This mean has been applied as a national
mean dose from medical use of radium.
3. Summary
A summary of man-rem by reporting agency and occupation is shown in
Table IV-10.
C. Internal Doses Incident to Occupation
It has been reported that reactor and accelerator workers as well as
those involved with the manufacture and use of unsealed radioactive
material can accumulate detectable amounts of radioactive material in
18
the whole body and in various organs.
In two studies, 91 radiopharmaceutical production workers and medical
and paramedical personnel were subjected to whole-body counting over a
1 Q or\
period of 1 year. ' Of the individuals monitored, approximately 88%
145
-------
Table IV-10
Total Annual Whole-body Man-rem by Reporting Group and Occupation - 1969 to 1970
Activity
Healing arts
Medical x ray
Dental x ray
Radionuclides
Veterinary x- ray
Medical radium
Industrial practice
Radionuclides
Radiography
Reactors
Waste disposal
Fuel processing
Packaging & transport
Radar
Special weapons
Academic
Not specified
Major processing
Air
Force
736
(405)
(264)
(53)
(14)
394
(229)
(165)
100
96
65
164
State
Army Navy Licensee
366 477 3,403
269 10,402 1,784
(1,490)
(294)
73
766
499
226
37
AEC Non- Nonreporting Licensee
Licensee AEC PHS federal State AEC
5,260 65 104,136
(62,253)
(21,403)
(20,480)
2, 891
(2,139)
(752)
497
96
2,177
22
903
1,024 20,361 819 5,022
495
-------
had detectable body burdens although the average body burden was a
very small percentage of the maximum permissible body burden (1.3% for
radiopharmaceutical workers). None of the individuals in these studies
had more than 15% of a maximum permissible body burden. During the
study of radiopharmaceutical workers up to 19 nuclides were identified
while nine nuclides were found in the medical and paramedical personnel.
Because of the sparsity of data and difficulty in determining the
contribution of internal emitters to population dose it is not included
in estimates of population dose.
D. Population Dose from Occupational Exposure
Using reported numbers of workers and judicious estimates in non-
reported areas, a value for the number of workers in the population was
derived. As shown in Table IV-11, this number is 771,814 or 3.76 per
thousand population.
As shown in Table IV-11, the total man-rem from occupational ex-
posure is 163,922; mean annual dose is 210 mrem/worker. The percentage
of employees in dose ranges by agency are shown in Table IV-12. For
the population of the United States, assuming the dose indicated by
dosimetry to be a whole-body dose, the calculated whole-body dose is
0.8 mrem per capita.
E. Population Dose from Occupational Exposure,1960 to 1970
The evaluation of occupational dose during the period 1960 to 1970
is complicated by a lack of appropriate monitoring data. In many cases,
the personnel monitoring systems of various agencies were relatively new
or nonexistent in 1960. In addition, the reliability of dosimetry data
was more questionable than it currently is and the appropriate persons
to be monitored were doubtful.
For many agencies the early 1960's marked the beginning of active
radiation protection programs and serious efforts to reduce dose to the
lowest practicable level were introduced.
From the data available,it may be reasonably concluded that the
average dose per worker was reduced during this period. In general, the
percentage of workers in the range from 0 to 1 rem increased and the
total number of doses in excess of 5 rem/yr, decreased. In 1960,it was
147
-------
Table IV-11
Total Annual Occupational Whole-body Doses - 1969 to 1970
Agency
Army
Air Force
Navy
AEC
PHS
Other Federal
AEC licensees
Agreement State
Nonfederal
medical x ray
Nonfederal
dental x ray
Medical radium
Nonreporting
AEC licensees
Nonreport ing
agreement State
TOTAL
Number of
Workers
7,445
17,591
55,051
102,918
508
2,000
62,090
24,519
194,451
171,226
37,925
93,000
3,000
771,814
Man-rem
744
1,555
10,879
20,361
65
258
13,365
6,715
62,253
21,403
20,480
5,022
822
163,922
Mean Dose
per Worker
(mrem)
100
88
198
198
129
129
215
274
320
125
540
54
274
210
Average Dose to
U.S. Population
(mrem)
0.003
0.007
0.05
0.10
0.0003
0.001
0.07
0.03
0.30
0.10
0.10
0.02
0.004
0.8
reported that at two major Atomic Energy Commission facilities, Oak Ridge
National Laboratory and Hanford facilities, the annual average exposure of
21
radiation workers was 0.4 R and 0.2 R, respectively. For these reasons
an annual average dose of 300 mrem/worker has been used for 1960.
The numbers of workers in the population in 1960 are also obscured
by lack of reliable records. To determine the number of medical workers
(excluding dental) an annual rate of increase in demand for service of
22
7.1% has been used. Extrapolating from 1970 data, shown in Table IV-13,
the number of medical radiation workers per thousand population would be
0.88 or 161,000 workers.
For dental workers, although the ratio of dentists to the population
has decreased below the 1950 ratio, the ratio of allied workers has in-
148
-------
Table IV-12
Percent of Employees in Annual Dose Ranges - 1969 to 1970
Reporting
Agency
AEC
State
1 icensees
AEC
licensees
Army
Air Force
PHS
Navy
Number of Dose Ranges (rem)
Employees 0-1 1-2 2-3 3-4
102,918 95.8 2.5 1.3 0.3
24,519 96.2 3.2 1.3 0.4
62,090 95.8 2.3 0.9 0.3
22,790 99.0 - - 1.0
(7,445)°
34,975 99.0 - - 1.0
(17,591)°
508 99.0 - - 1.0
55,051 Not available
4-5 >5
0.1 0.0
0.2 0.6
0.1 0.3
-
-
-
a!5 of 17.
b~40%.
cNo. >10 mrem/yr.
Table IV-13
Job Category Data - 1969 to 1970
Category
Medical x ray
Dental x ray
Medical radio-
nuclides
Medical radium
Number
of Workers
(thousands)
203.6
178.6
33.5
38.0
Workers/
Thousand
0.99
0.87
0.16
0.18
Annual
Man -rem
(thousands)
63
22
8.8
20
Average Dose to
U.S. Population
(mrem/yr . )
0.3
0.1
0.04
0.1
Research and
industrial use
318.3
1 .55
49
0.2
149
-------
23
creased and the ratio of radiation'workers is believed to be relatively
constant from 1960 to 1970. For this reason the value of 0.87 workers
per thousand or 159,000 workers has been used for dental practice.
There was undoubtedly a significant change in the numbers of radi-
ation workers involved in industrial applications from 1960 to 1970.
The advent of a nuclear-powered naval force during this period increased
the number of workers by several thousand. It was also reported in 1960
that the Atomic Energy Commission classified 66,000 employees as radi-
21 '
ation workers. It has been assumed that the workers per thousand in
this area did not exceed 0.75, or 137,000 workers.
The total radiation workers as derived above is 457,000 and repre-
sents 0.25% of the 1960 population as opposed to 0.2% reported by the
21
Federal Radiation Council in that year. Using this number of workers
and a mean annual dose of 300 mrem/worker, the resulting population
dose is 0.8 mrem per capita (Table IV-14).
Table IV-14
Estimated Annual Whole-body Doses to the United
States
1 Population from Occupational Exposure
(mrem)
Practice
Medical
Dental
Industrial
TOTAL
1960
0.3
0.3
0.2
0.8
1970
0.4
0.1
0.3
0.8
Year
1980
0.4;
0.1
0.3
0.8
1 1990
0.4
0.1
0.4
0.9
2000
0.3
0.1
0.5
0.9
F. Population Dose from Occupational Exposure,1980 to 2000
To estimate the population dose through the year 2000,the following
assumptions have been used.
1. The number of workers in dental practice will remain constant
at 0.87 per thousand.
2. The demand for medical care will increase at a lesser rate until
it becomes constant at 1.5 per thousand in 1990. The value for 1980 has
been assumed to be 1.3 per thousand.
150
-------
3. The greatest increase will be from industrial usage, partic-
ularly from the increase in nuclear power facilities and the required
ancillary support activities. The number of workers in this category
will increase continually through the period under consideration. The
number of workers per thousand estimated for 1980, 1990, and 2000 are
1.7, 2.0, and 2.2, respectively.
4. Through legislation and education, the practice of good radi-
ation protection methods will become more widespread among the users of
ionizing radiation. Without consideration of development of new tech-
niques, the enforcement of currently recognized good practice will sub-
stantially reduce tr^e mean annual dose per worker. By the year 2000, the
mean for medical workers should approach the current mean for Federal em-
ployees. It is assumed that this will be for 1980, 1990, and 2000: 300
mrem, 250 mrem, and 200 mrem, respectively. A similar reduction in oc-
cupational exposure from dental practice is assumed to result in mean
annual doses of 110 mrem, 100 mrem, and 95 mrem, respectively.
5. In industrial and research activities the mean annual dose will
probably increase. Although the more widespread use of good protection
methods will lessen the impact, it is anticipated that the mean annual
doses from these sources will approach 225 mrem by the year 2000. For
1980 and 1990, 175 mrem and 200 mrem have been used as the mean.
The foregoing assumptions have been used to estimate the future pop-
ulation doses shown in Table IV-14.
151
-------
REFERENCES
1. United Nations. 1972. Report of the United Nations Scientific
Committee on the Effects of Atomic Radiation. New York. (In
preparation.)
2. Army. 1971. Summary of individual exposures to ionizing radiation,
1966-1970. Lexington Bluegrass Army Depot, Lexington, Kentucky.
(Unpublished data.)
3. National Council on Radiation Protection and Measurements. 1971.
Basic radiation protection criteria, report No. 39. Washington.
ix, 135 pp.
4. Air Force. 1971. Occupational radiation exposure history of United
States Air Force personnel. Radiological Healtii Laboratory, Wright-
Patterson AFB, Ohio. (Unpublished data.)
5. Air Force. 1968. Supplemental instructions for the film badge
dosimetry program. Radiological Health Laboratory, Wright-Patterson
AFB, Ohio.
6. Air Force. 1965. Film badge dosimetry program. Washington, AFR
161-11.
7. Navy. 1971. Summary of exposures to ionizing radiation in the U.S.
Navy. Naval Medical Data Services Center, Bethesda, Maryland.
(Unpublished data.)
8. Denton, L.D. 1971. Personal communication. Division of Compliance,
U.S. Atomic Energy Commission, Washington.
9. Atomic Energy Commission. 1961-1971. A summary of industrial
accidents in USAEC facilities. U.S. AEC report TID-5360. var. pp.
10. Pettigrew, G.L. 1971. A review of the Public Health Service film
badge program. (Unpublished.)
11. Atomic Energy Commission. 1971. Personal communication. Assistant
for Workmen's Compensation and Radiation Records, Office of the
Assistant General Manager for Operations, Washington.
12. Atomic Energy Commission. 1971. pp. 96-98. In: Annual report to
Congress of the Atomic Energy Commission for 1970. Washington.
13. Wisconsin Department of Health. 1971. Personal communication.
14. Pettigrew, G.L. 1970. Memorandum to the Director, Bureau of Radio-
logical Health, Public Health Service, Washington.
If) 2
-------
15• Illinois Department of Public Health. 1971. Summary of whole-body
exposure reports. Springfield, Illinois. (Unpublished data.)
16. Puller, J.W. 1966. Maine's experience with a State-operated
personnel monitoring program for radiation workers. Radiological
Health Data 7: 489-492.
17- Fess, L.R. 1969. Summary of diagnostic X-ray statistics relating
facilities, equipment and personnel by healing arts professions.
Radiological Health Data 10: 379-380.
18. Sill, C.W., J.I. Anderson and D.R. Percival. 1964. Comparison of
excretion analysis with whole-body counting for assessment of inter-
nal radioactive contaminants, pp. 217-228. In: Assessment of
Radioactivity ±n_ Man. International Atomic Energy Agency, Vienna.
Vol. I. (STI/PUB/84.)
19. Athey, T.W., C. Killian, M.A. Dugan and B. Shleien. 1970. Whole-
body counting of some radioactive isotope and radiopharmaceutical
production workers. Am. Industr. Hyg. Assoc. J. 31: 711-717.
20. Shleien, B. and E. LeCroy, Jr. 1971. Results of thyroid and whole-
body counting of some medical and paramedical personnel. J. Nucl.
Med. 12(7): 523-525.
21. Federal Radiation Council. 1960. Background material for the
development of radiation protection standards, staff report. Wash-
ington, report No. 1. iii, 39 pp.
22. Public Health Service. 1966. Protecting and improving health
through the radiological sciences. National Advisory Committee on
Radiation, Washington. vi, 27 pp.
23. Public Health Service. 1969. Health resources statistics, 1969.
Washington, Publ. No. 1509. vi, 286 pp.
153
-------
V. MISCELLANEOUS RADIATION
-------
V. MISCELLANEOUS RADIATION
There are several sources of exposure to ionizing radiation to which
the general public may be exposed that are not discussed in the previous
sections of this report.
A. Television Receivers
In 1968 a survey of 1,124 color television receivers was performed
in the metropolitan Washington, D.C., area. The average rate of emission
of ionizing radiation 5 cm from the front face of these receivers was
found to be 0.043 mR/hr. This survey also analyzed the viewing habits
of the family members in the households where receivers were surveyed.
Based on the 1968 survey, estimates of potential doses to various
organs were derived. For purposes of this report, the female gonadal dose
has been selected to represent the somatic dose for determination of total
man-rem from this source.
To determine the total man-rem and mean per capita dose as shown in
Table V-l, the following assumptions have been made.
1. The viewing habits of the population are essentially the
same as those in the 1968 survey and will not change.
2. The population exposed in 1970 is approximately 50% of the
total population. This is based on 24% of the households having color
3 2
television in 1968 and 39% in 1969, and a production rate of 500,000
color television receivers per month.
3. The population exposed in 1980 will approach 100%.
4. The trend in reduction of emission rate from television
receivers noted in 1968 and 1969 will continue with improved design and
O
new developments. A reduction of average emission rate to 0.025 mR/hr.
at 5 cm by 1980 is assumed. Since the estimates of dose mentioned above
are based on a linear function of exposure rate a proportional reduction
2
in dose is expected.
157
-------
The estimates are shown in Table V-l. These may be high by as much
2,3
as a factor of two because of instrument calibration in the 1968 survey.
Table V-l
Total Annual Average Whole-body Doses
from Television Receivers -
Year
Emission rate (mR/hr . at 5 cm)
Mean dose (mrem)
Age <1 5 yr .
Age >15 yr.
Population at risk (millions)
Age <15 yr.
Age >15 yr.
Man-rem 26
Total population (millions)
Mean per capita dose (mrem)
B. Consumer Products Containing
1970
0.043
0.4
0.2
28
75
,200
205
0.1
1970 to 2000
1980
0.025
0.2
0.1
63
174
30,000 35
237
0.1
1990
0.025
0.2
0.1
80
197
,700
277
0.1
2000
0.025
0.2
0.1
89
232
41,000
321
0.1
Radioactive Material
For many years,radium has been used in items readily available to
the general public. Some of these uses are: fire detection devices,
static eliminators, gauges, electronic tubes, and laboratory balances.
In many instances the user is unaware that radium is incorporated into
4 5
the product or that a potential radiation hazard exists.' In recent
147
years,tritium and Pm have also been used as radiation sources in
self-luminous devices. Luminous watches appear to be the greatest source
of population exposure from the devices mentioned above.
The number of watches containing radioactive materials is difficult
to estimate. In the case of watches containing radium, no United States
data are available. However, assuming usage similar to that in foreign
4
countries as much as 35 to 50% of the adult United States population may
have possessed a watch containing radium in the late 1960's. Tritium
compounds imported into the United States together with domestic manu-
facture indicate that 25 million watches containing 1 to 5 mCi of tritium
/?
were sold during the year June 1969 to June 1970. During this same period
158
-------
147
approximately 1 million watches with 30 to 50 (iCi of Pm were made
available to the public.
Doses from radium watches reported in 1963 appear to indicate whole-
7
body doses between 1.3 and 5,3 mrem/yr. Whole-body doses from 1 to 4
mrem/yr. have been estimated, using a quality factor of 1.7, in persons
using wrist watches containing tritium,' while watches containing Pm
g
give doses in the p,rem range.
Other luminescent items containing radioactivity, particularly self-
luminous military devices, make slight contributions to the total popu-
lation dose, the maximum estimated to be 0.01 mrem/person/yr. to the
United States population.
The estimated annual whole-body dose to the population of the United
States in 1960 is 1 mrem, and for 1970, 1.5 mrem. The projected average
for 1980 is 1 mrem and 0.01 mrem for 1990 and 2000. These estimates re-
flect increased use of radium and tritium in watches from 1960 to 1970
147
and increased use of Pm from 1970 to 2000.
C. Air Transport
Passengers and crew of aircraft are subjected to increased rates of
exposure during high altitude flight from galactic cosmic radiation. Pre-
9
liminary data show that the average increase in dose equivalent rate at
an altitude of 30,000 ft. (approximate conventional jet aircraft altitude)
may be 0.7 mrem/hr. and at 60,000 ft. (supersonic transport aircraft
altitude) 1.1 mrem/hr.
There were 125 billion passenger-miles flown by United States air-
lines during 1970. It is estimated that the average air speed during
this period was 400 mi./hr. (average in 1968 was 389 mi./hr.). Using
these values, 310 million passenger-hours were flown by United States
airlines during 1970. It is assumed that all flights were at conventional
jet altitude.
As a result of air transport, approximately 200,000 man-rem were
accumulated by passengers.
Air crew members are considered here as a special occupational group.
The number of air crew members has not been obtained. However, the total
number of aircraft owned and leased by air carriers in 1969 was 2,638,
159
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Assuming an average crew of five, there could be up to 13,000 air crew
members employed. To include military air crews, it is estimated that
there are approximately 15,000 individuals serving as air crew members
operating at conventional jet altitudes.
10
Using a value of 80 hr. flight time per month, the average crew
member receives a dose of 670 mrem/yr.
From high altitude flight, the population dose is estimated to be
210,000 man-rem during 1970 or a mean United States per capita dose of
1.0 mrem.
For projected doses from air transport, super-sonic altitudes must
be considered. It is indicated that the dose to passengers will be re-
duced because of the shorter time at altitude even though the dose rate
is increased. No assumptions on projected air crew dose have been made.
Because the conditions of air transport are in doubt, the projected doses
are proportional to population increase only.
The foregoing estimates are based on limited studies which should
be re-evaluated as more data become available.
D. Summary
The total estimated annual whole-body doses from miscellaneous sources
to the United States population are summarized in Table V-2.
Table V-2
Total Annual Average Whole-body
Doses
to the
United States Population
from Miscellaneous Sources
Doses
Television
Year
1960
1970
1980
1990
2000
mrein
0
0.1
0.1
0.1
0.1
man-rem
26,
30,
36,
41,
0
000
000
000
000
Consumer Products
mrem
1
1
1
0
0
.0
.5
.0
.01
.01
man-rem
180
310
240
3
3
,000
,000
,000
,000
,000
Air Transport
mrem
1
1
1
1
1
.0
.0
.0
.0
.0
man-rem
180
210
240
280
320
,000
,000
,000
,000
,000
Total
mrem
2.0
2.6
2.1
1.1
1.1
man-rem
360,000
550,000
510,000
320,000
360,000
160
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REFERENCES
1. Public Health Service. 1968. A survey of X-radiation from color
television sets in the Washington, D.C. metropolitan area. Bureau
of Radiological Health TSB report No. 3. 21 pp.
2. Neill, R.H., H.B. Youmans and J.L. Wyatt. 1971. Estimates of
potential doses to various organs from X-radiation emissions from
color television picture tubes. Radiological Health Data 12; 1-5.
3. Electronic Industries Association. 1971. Evaluation of television
contribution to the annual genetically significant radiation dose of
the population. Radiological Health Data 12: 363-369.
4. Robinson, E.G. 1968. The use of radium in consumer products. U.S.
Public Health Service report MORP 68-5. vii, 25 pp.
5. Department of the Army. 1966. Ionizing radiation facilities,
Annlston Army Depot. Radiation Protection Survey No. 4948R97-65/67.
U.S. Army Environmental Hygiene Agency, Edgewood Arsenal, Maryland.
23 pp.
6. Barker, R. 1971. Personal communication. Division of Radiological
and Environmental Protection, U.S. Atomic Energy Commission, Washing-
ton .
7. Schell, W.R. and B.R. Payne. A possible contamination source in low
level tritium laboratories. Intern. J. Appl. Radiation Isotopes
22(11): 653-656.
8. Moghissi, A.A. 1971. Personal communication. Western Environmental
Research Laboratory, Environmental Protection Agency, Las Vegas,
Nevada.
9. Federal Aviation Administration. 1970. Interim report on the radi-
ation biology aspects of the supersonic transport. Advisory Committee,
Washington. 35 pp.
10. Gerathewohl, S.J. 1971. Personal communication. Federal Aviation
Administration, Washington.
11. Federal Aviation Administration. 1970. Handbook of airline statistics
Civil Aeronautics Board, Washington. ix, 544 pp.
161
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VI . SUMMARY
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VI. SUMMARY
The study reported in this document is that part of the overall re-
view of the bases for radiation guidance that is concerned with estimates
and predictions of ionizing radiation doses in the United States from all
sources. Estimates or predictions were made for each decade of the peri-
od 1960 to 2000. The results are presented in Table VI-1 and Figures
VI-1 and VI-2 and are summarized below? It should be noted that in this
summary more digits are shown than are actually significant in order to
indicate trends. A number of sources were found to contribute insignifi-
cantly to the total annual dose to the United States population. The
sum of the doses contributed by these sources is also insignificant.
A. Environmental Radiation
A major source of radiation doses in the United States is natural
radiation. The total estimated annual whole-body dose increases from 23.8
million man-rem in 1960 to 41.7 million man-rem in the year 2000 from
cosmic and natural terrestrial sources. The increase is due exclusively
to increases in population size. Global fallout from nuclear explosives
tests contributed about 1 million man-rem (whole-body) in 1960, a high of
2.4 million man-rem in 1963, and 0.8 million man-rem in 1970. Future
doses from fallout for 1980 are predicted to be 1.1 million man-rem, in-
creasing to 1.6 million man-rem in 2000, the increase again being due to
population growth. The total dose contributed by all other environmental
sources increases from 0.015 million man-rem in 1960 to 0.15 million man-
rem in 2000.
B. Medical Radiation
By far the greatest portion of the man-made radiation dose to the
United States population is due to exposure accrued during medical diagnostic
Comparisons based on whole-body doses except for doses from medical radi-
ation, in which case the abdominal dose, an index of somatic dose, is used.
165
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10O —
10-
c
o
1 —
I
C
0.1-
0.01,
Total
Natural
Medical
Global Fallout
Miscellaneous
Occupational
Other
Environmental
196O
197O
1980
Year
199O
2OOO
Figure VI-1. Summary of Estimated Whole-body Radiation Man-rem
Doses in the United States
166
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100-
Total
Natural
Medical
10-
c
o
If)
1_
a;
a
\
0)
1-
Global Fallout
Miscellaneous
Occupational
Other
Environmental
0.1-
1960
197O
1980
Year
1990
2OOO
Figure VI-2. Summary of Estimated Average Whole-body Radiation
Doses in the United States (mrem/person)
167
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Table VI-1
Summary of Whole-body Annual Radiation Doses
in the United States - 1960
Radiation Source
Environmental
Natural
Global fallout
All other
Subtotal
Medical
Diagnostic *
Radiopharmaceut icals
Subtotal
Occupational
Miscellaneous
TOTAL
Population (millions)
Per capita dose (mrem)
*Medical diagnostic man
1960
23.
1
0.
24.
13.
0.
13.
0.
0.
38.
183
211
8
015
8
2
07
3
14
36
6
-rem doses
Man -rem
1970
26.
0.
0.
27.
14.
0.
15.
0.
0.
43.
205
211
based
6
82
012
4
8
4
2
16
55
3
on
to 2000
(millions) for Years
1980 1990 2000
30
1
0
31
17
3
20
0
0
53
237
224
.8
.1
.022
.9
.1
.3
.4
.19
.51
.0
an index
36
1
0
37
19
4
23
0
0
61
277
224
.0
.3
.062
.4
.9
.9
.24
.32
.9
of somatic
41
1
0
43
23
5
28
0
0
72
321
225
.7
.6
.15
.4
.1
.1
.28
.36
.1
dose ,
the "abdominal dose." For radiation therapy an annual per capita
genetically significant dose of approximately 5 mrem was estimated for
the year 1966, but an index of somatic dose is not considered applicable.
procedures. Medical diagnostic radiology accounts for at least 90 percent
of the total tuanmade radiation dose to which the United States population
is exposed. This is at least 35% of the total radiation dose from all
sources (including natural radioactivity). This comparison is based on
an interim index of somatic dose, the "abdominal dose," which was derived
from ovarian doses reported by the Public Health Service in 1964 and 1970.
The majority of this dose is accrued through medical diagnostic radiography
and fluoroscopy, with lesser doses accrued through the diagnostic uses of
radiopharmaceuticals and dental radiography. Estimates indicate that the
annual per capita "abdominal dose" from these sources to the whole pop-
ulation, as estimated some time during the past decade, were 72 mrem, 1
mrem and less than 0.3 mrem respectively, from medical diagnostic radio-
168
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graphy and fluoroscopy in 1970, the diagnostic uses of radiopharma-
ceuticals in 1966, and dental radiography in 1964. It appears that
the mean abdominal dose for the U.S. population as determined in 1964
and 1970 has remained relatively stable during the two study years. How-
ever, since the magnitude of the uncertainty surrounding the figures up-
on which the abdominal dose is based has not yet been determined, the
magnitude of whatever change may have occurred between 1964 and 1970
cannot be determined at this time. The per capita dose to the exposed
population (i.e., persons receiving examinations) were, of course,
significantly higher than those to the whole population. The estimated
total man-rem dose to the whole U.S. population in 1970 from the uses of
radiation in the healing arts is estimated to be 15.2 million man-rem
exclusive of occupational exposure and radiation therapy.
The "genetically significant dose" is an index of radiation received
by the genetic pool. Estimates of genetically significant doses indicate
values of 36 mrem (based on preliminary data from the 1970 U.S. Public
Health Service Survey) from medical and dental diagnostic radiation, 5
mrem from radiation therapy in 1966, and 0.3 mrem from the diagnostic
uses of radiopharmaceuticals (also in 1966). Preliminary U.S. Public
Health Service information indicates a drop in genetically significant
dose in 1970 relative to the 1964 value of 55 mrem. However, as above,
since the degree of uncertainty of these values have not as yet been
determined, the magnitude of the change which may have occurred between
1964 and 1970 is not clear at this time.
Projections of doses from diagnostic medical radiography must take
into consideration a variety of complex variables. Review of several
reports on the rate of increase of radiographic examinations leads to the
conclusion that, in the past decade, the rate of radiographic examinations
increased between 1 and 4 percent per year. Some of this increase appears
to be due to the expansion of radiological services to persons who pre-
viously did not have such care available. Furthermore, there is some
evidence that technical improvements may be keeping pace with increasing
usage. If this balance between increasing usage and technical improvement
is real, and i±_ it continues, the man-rem dose from diagnostic medical
169
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radiation would increase through population increase alone to about 23.1
million man-rem by the year 2000. Even before the year 2000, if the
current rate of increase in the uses of radiopharmaceuticals should
continue to 1980, the whole-body man-rem dose from this source to the
U.S. population could be greater than 3.3 million man-rem, or approx-
imately 15% of that from other medical sources.
The delivery of radiation for therapy is exluded in estimates of
accumulated man-rem doses to the population. There is no significant
information to indicate the direction that the doses from radiation
therapy will take in the future even though its use might increase.
Extrapolations and projections made in this study must be considered
in light of the uncertainties surrounding the base measurements, the
assumptions employed and the changing state of medical technology. If
technical improvements can keep pace with increased usage rates, it can
be concluded, based on the information presently available and discussed
in this report, that the annual per capita population dose from diagnostic
medical radiography could remain stable.
Finally, it should be noted that direct comparisons of medical x-ray
doses to the population with those from other sources is difficult because
x rays are administered purposefully to individuals at the discretion of
practitioners, and because they are delivered at higher dose rates to
limited areas of the body.
C. Occupational Radiation
The contribution of occupational exposures to total United States per
capita dose is estimated to be less than 1 mrem/yr. The major portion of
this dose during 1960 and 1970 was incurred through the use of ionizing
radiation in the practice of medicine and dentistry.
Increased industrial use of ionizing radiation, particularly the pro-
jected increase in nuclear power production, will increase the per capita
dose by approximately 0.1 mrem/yr. by 1990. During the 1990's the pop-
ulation dose from industrial sources and the practice of medicine and
dentistry will probably be about the same. The total dose from occupa-
tional exposure to the United States population is estimated to have been
0.14 million man-rem in 1960 and is projected to reach 0.28 million man-
170
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rem in the year 2000.
D. Miscellaneous Radiation
Miscellaneous radiation sources (e.g., television, consumer products,
and air transport) contribute to the radiation dose of the population of
the United States. Estimated annual average whole-body doses to the pop-
ulation are 2.0 and 2.6 mrem (0.36 million and 0.55 million man-rem) for
1960 and 1970, respectively. Projected annual doses are 2.1 mrem (0.51
million man-rem) for 1980 and 1.1 mrem (0.32 million and 0.36 million
man-rem) for 1990 and 2000.
E. Total Man-rem
The total man-rem to the United States population will increase in
the future due mainly to population growth. It will approximately double
between 1970 and 2000, 43 million to 72 million man-rem, the population
increasing from 205 million to 321 million.
171
c-U.S GOVERNMENT PRINTING OFFICE 1"?: 5U-Uo. IS 1-3
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