ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller I MJW Technical Services

Page 1 of 21

DOE Review Release 04/09/2013

Document Title:

Oak Ridge Gaseous Diffusion Plant (K-25) –

Occupational Medical Dose

Document Number: ORAUT-TKBS-0009-3

Revision: 01

Effective Date: 03/28/2013

Type of Document: TBD

Supersedes: Revision 00 PC-1

Subject Expert(s): Elyse Thomas

Approval: Signature on File Approval Date: 03/26/2013

Michalene Rodriguez, Document Owner

Concurrence: Signature on File Concurrence Date: 03/27/2013

John M. Byrne, Objective 1 Manager

Concurrence: Signature on File Concurrence Date: 03/27/2013

Edward F. Maher, Objective 3 Manager

Concurrence: Vickie S. Short Signature on File for Concurrence Date: 03/26/2013

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 03/28/2013

James W. Neton, Associate Director for Science

New Total Rewrite Revision Page Change

FOR DOCUMENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR 

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 2 of 21

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION

NUMBER DESCRIPTION

06/29/2004 00 New technical basis document for the Oak Ridge Gaseous Diffusion 

(K-25) plant – Occupational Medical Dose. First approved issue. 

Initiated by Jay J. Maisler.

11/07/2006 00 PC-1 Approved page change revision to update required language on 

pages 4 and 5 in Section 3.1. Updates acronyms and abbreviations 

on page 3. Adds a Purpose Section and a Scope Section on page 5. 

No sections were deleted. No further changes occurred as a result 

of formal internal review. No changes required to this document due 

to Worker Outreach comments. This revision results in no change to 

the assigned dose and no PER is required. Training as required by 

Task Manager. Initiated by Paul A. Szalinski. Approval: 

Signature on File 10/24/2006

Paul A. Szalinski, Document Owner

Signature on File 10/20/2006

John M. Byrne, Task 3 Manager

Signature on File 10/24/2006

Edward F. Maher, Task 5 Manager

Signature on File 10/23/2006

Kate Kimpan, Project Director

Signature on File 11/07/2006

James W. Neton, Associate Director for Science

03/28/2013 01 Revision to update doses according to site-specific information and 

recently revised ORAUT-OTIB-0006. Incorporates resolutions to 

Sanford Cohen & Associates comments. Also incorporates formal 

internal and NIOSH review comments. Constitutes a total rewrite of 

the document. Training required: As determined by the Objective 

Manager. Initiated by Michalene Rodriguez.
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 3 of 21

TABLE OF CONTENTS

SECTION TITLE PAGE

Acronyms and Abbreviations ............................................................................................................... 4

3.1 Introduction .............................................................................................................................. 5

3.1.1 Purpose........................................................................................................................ 6

3.1.2 Scope........................................................................................................................... 6

3.2 Examination Types and Frequencies ....................................................................................... 6

3.3 Equipment and Techniques...................................................................................................... 7

3.3.1 Photofluorography, April 1945–1956............................................................................. 7

3.3.2 Chest Radiography, 1944–1961 ................................................................................... 8

3.3.3 Chest Radiography, 1962–1970 ................................................................................... 8

3.3.4 Chest Radiography, 1971–1986 ................................................................................... 8

3.3.5 Chest Radiography, 1987–2000 ................................................................................... 8

3.4 Organ Dose Calculations ......................................................................................................... 9

3.5 Uncertainty............................................................................................................................... 9

3.6 Attributions and Annotations .................................................................................................. 16

References ........................................................................................................................................ 17

Glossary ............................................................................................................................................ 19

LIST OF TABLES

TABLE TITLE PAGE

3-1 Frequency of screening chest X-rays at K-25........................................................................... 6

3-2 X-ray equipment used at K-25 and incident air kerma values................................................... 9

3-3 Organ dose per X-ray procedure for chest X-ray examinations from 1944 to 2000................. 11

3-4 Skin dose guidance and skin dose equivalents for chest projections, 1944 through 

1970.......................................................................................................................................12

3-5 Skin dose guidance and skin dose equivalents for chest projections, 1971 through 

2000.......................................................................................................................................13
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 4 of 21

ACRONYMS AND ABBREVIATIONS

CFR Code of Federal Regulations

cGy centigray

cm centimeter

DCF dose conversion factor

DOE U.S. Department of Energy

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

ENSD entrance skin dose

EXSD exit skin dose

GE General Electric

Gy gray

HVL half-value layer

in. inch

IREP Interactive RadioEpidemiology Program

kVp peak kilovoltage

LAT lateral

mA milliampere

mm millimeter

NIOSH National Institute for Occupational Safety and Health

PA posterior-anterior

PER Program Evaluation Report

PFG photofluorography

POC probability of causation

RSD remote skin dose

s second

TBD technical basis document

U.S.C. United States Code

yr year

§ section or sections
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 5 of 21

3.1 INTRODUCTION

Technical basis documents and site profile documents are not official determinations made by the 

National Institute for Occupational Safety and Health (NIOSH) but are rather general working 

documents that provide historical background information and guidance to assist in the preparation of 

dose reconstructions at particular sites or categories of sites. They will be revised in the event 

additional relevant information is obtained about the affected site(s). These documents may be used 

to assist NIOSH staff in the completion of the individual work required for each dose reconstruction.

In this document the word “facility” is used as a general term for an area, building, or group of 

buildings that served a specific purpose at a site. It does not necessarily connote an “atomic weapons 

employer facility” or a “Department of Energy [DOE] facility” as defined in the Energy Employees 

Occupational Illness Compensation Program Act [EEOICPA; 42 U.S.C. § 7384l(5) and (12)]. 

EEOICPA defines a DOE facility as “any building, structure, or premise, including the grounds upon 

which such building, structure, or premise is located ... in which operations are, or have been, 

conducted by, or on behalf of, the Department of Energy (except for buildings, structures, premises, 

grounds, or operations ... pertaining to the Naval Nuclear Propulsion Program)” [42 U.S.C. § 

7384l(12)]. Accordingly, except for the exclusion for the Naval Nuclear Propulsion Program noted 

above, any facility that performs or performed DOE operations of any nature whatsoever is a DOE 

facility encompassed by EEOICPA.

For employees of DOE or its contractors with cancer, the DOE facility definition only determines 

eligibility for a dose reconstruction, which is a prerequisite to a compensation decision (except for 

members of the Special Exposure Cohort). The compensation decision for cancer claimants is based 

on a section of the statute entitled “Exposure in the Performance of Duty.” That provision [42 U.S.C. § 

7384n(b)] says that an individual with cancer “shall be determined to have sustained that cancer in the 

performance of duty for purposes of the compensation program if, and only if, the cancer ... was at 

least as likely as not related to employment at the facility [where the employee worked], as 

determined in accordance with the POC [probability of causation1

] guidelines established under 

subsection (c) ...” [42 U.S.C. § 7384n(b)]. Neither the statute nor the probability of causation 

guidelines (nor the dose reconstruction regulation, 42 C.F.R. Pt. 82) restrict the “performance of duty” 

referred to in 42 U S. C. § 7384n(b) to nuclear weapons work (NIOSH 2010).

The statute also includes a definition of a DOE facility that excludes “buildings, structures, premises, 

grounds, or operations covered by Executive Order No. 12344, dated February 1, 1982 (42 U.S.C. 

7158 note), pertaining to the Naval Nuclear Propulsion Program” [42 U.S.C. § 7384l(12)]. While this 

definition excludes Naval Nuclear Propulsion Facilities from being covered under the Act, the section 

of EEOICPA that deals with the compensation decision for covered employees with cancer [i.e., 42 

U.S.C. § 7384n(b), entitled “Exposure in the Performance of Duty”] does not contain such an 

exclusion. Therefore, the statute requires NIOSH to include all occupationally-derived radiation 

exposures at covered facilities in its dose reconstructions for employees at DOE facilities, including 

radiation exposures related to the Naval Nuclear Propulsion Program. As a result, all internal and 

external occupational radiation exposures are considered valid for inclusion in a dose reconstruction. 

No efforts are made to determine the eligibility of any fraction of total measured exposure for inclusion 

in dose reconstruction. NIOSH, however, does not consider the following exposures to be 

occupationally derived (NIOSH 2010):

• Background radiation, including radiation from naturally occurring radon present in 

conventional structures

• Radiation from X-rays received in the diagnosis of injuries or illnesses or for therapeutic 

reasons

 1 The U.S. Department of Labor (DOL) is ultimately responsible under the EEOICPA for determining the POC.
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 6 of 21

3.1.1 Purpose

This Technical Basis Document (TBD) documents historical practices at the Oak Ridge Gaseous 

Diffusion Plant (K-25) and provides the basis for organ dose from medical X-ray procedures 

performed for occupational health screening at K-25.

3.1.2 Scope

The K-25 occupational health and safety program required preemployment, periodic physical, and 

termination health monitoring examinations from the beginning of its operation in 1944 (Author 

unknown 1946, p. 94; Author unknown 1949, p. 2). These examinations typically included chest Xrays. The doses from these procedures depended on the characteristics of the X-ray machine and 

the techniques used. Site-specific information about the K-25 X-ray screening program is used to the 

extent it is known. 

3.2 EXAMINATION TYPES AND FREQUENCIES

The Carbide and Carbon Chemicals Corporation organized a medical department with a dispensary 

that contained X-ray equipment from the beginning of operations at K-25 in 1944 (Author unknown 

1946, pp. 95-96). Before the dispensary was operational, the workers had their preemployment 

examinations at the Medical Services Building of the Oak Ridge Hospital (Author unknown 1946, 

p. 95). Nothing is known about the X-ray machine at the Oak Ridge Hospital, but the dose from 

preemployment chest X-rays taken at this off-site location should be included in dose reconstruction 

because it is a covered facility (ORAUT 2011b). Workers from the Ford, Bacon, and Davis Company 

and the H. K. Ferguson Company, both contractors, were also examined at the K-25 dispensary 

(Author unknown 1946, p. 96).

During the early years at K-25, when little was known about health effects of working with uranium, 

X-ray examinations were performed frequently in an effort to monitor worker health, perhaps as often 

as every 6 months (Kammer 1948, p. 8). Bocher (1948) writes that workers handling process material 

might be being X-rayed excessively. Table 3-1 lists the nominal frequency of examinations over the 

years during which X-rays were required as part of occupational health screening. Some workers 

might have received these X-rays on a schedule different from that listed in Table 3-1. Dose 

reconstructors should assign dose according to the X-rays performed for screening listed in the claim 

file records, and in the absence of records, according to the frequency listed in Table 3-1 

Table 3-1. Frequency of screening chest X-rays at K-25.

Period Frequency Comment

1944–1945a Preemployment, 

annualb, and 

termination

All employees

1946–1959a Preemployment, 

annualb,c, and 

termination

All employees

1960–1979 Preemployment, 

every 1–2 yr, 

and termination

Radiation workers > 40 y oldd.

Preemployment, 

every 2+ yr, and 

termination

Radiation workers < 40 years oldd.

1980–1989 Preemployment, 

annual, and 

termination

All radiation workerse

1990–2002 Preemployment, All radiation workers
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 7 of 21

every 5th yr, 

and termination

a. From Author unknown (1949, p. 24).

b. Some workers semiannually, with potential for exposure to uranium dust

(Kammer 1948).

c. Nickel workers every few months (Stoddard 1952).

d. Author unknown (1964, p. 6).

e. Collins (1988).

Other radiographic examinations of K-25 employees that might have occurred were nonoccupational

in the sense they were necessitated by illness or injury and were not part of the employee 

occupational health screening process.

3.3 EQUIPMENT AND TECHNIQUES

3.3.1 Photofluorography, April, 1945–1956

X-ray service was provided in the K-25 dispensary in October 1944, and a photofluorography (PFG) 

machine was added in April 1945 (Author unknown 1946, p. 96). PFG had widespread use 

throughout the United States for tuberculosis screening in the 1930s and was state-of-the-art medical 

technology when work began at the K-25 plant as part of the Manhattan Project. Eventually, PFG 

was phased out in favor of the conventional chest X-ray examination using 14-in. × 17-in. film.

The PFG machine at K-25 was a General Electric (GE) Photoroentgen X-ray machine (Author 

unknown 1949, p. 12) that was used with a grid to produce miniature 4-in. × 5-in. stereoscopic 

posterior-anterior (PA) chest X-rays (Cardarelli 2000). The stereoscopic technique produces two 

images of the chest (on 4-in. × 10-in. film) at slightly different angles, resulting in a three-dimensional 

image of the chest when viewed through a stereoscope (Laughlin et al. 1957). While two references 

refer to PFG at K-25 on either 4-in. × 5-in. or 4-in. × 10-in. film (Cardarelli 2000, and author unknown 

1949, p. 12), the K-25 claim file records indicate PFG on 70 mm film, another common film type for 

PFG images (Laughlin et al. 1957). 

At K-25, a stereo PFG was “taken on every person hired by the companies served by the Dispensary” 

(Author unknown 1949, p. 12). Lyon (1949, p. 7) writes that both the preemployment and the annual 

examination were made on the PFG unit at K-25, with “all other chest X-rays” made on a 14-in. × 17-

in. film. Prior to 1957, the exam type is often unclear in records provided by the DOE. For instance 

the phrase “P.A. view of the chest” is recorded frequently, but this can imply either a conventional 14-

in. x 17-in. or a PFG X-ray. Recently, films located in the film jackets for several workers with 

employment prior to 1957 were measured. The results reveal that approximately 77% of the X-ray 

exams were 4-in x 10-in PFG examinations. 

Dose reconstructors should assign dose based on X-rays listed in the actual records of the energy 

employee. PFGs are sometimes described by the notation of “70 mm”; however, in many instances 

the film type is not mentioned in the medical records. Consequently, prior to 1957 dose 

reconstructors should assume that the statement “P.A. view of the chest” represents a PFG exam.

Dose reconstructors can also request that the film size be measured for accuracy. In the absence of 

records, the frequency listed in Table 3-1 should be assumed for PFG exams beginning April, 1945 

through 1956. Unless otherwise noted, X-rays performed at the Oak Ridge Hospital should be 

considered conventional 14-in. x 17-in. film and the dose values obtained from ORAUT-OTIB-0006.

A survey performed on the machines at K-25 listed the technique factors for PFG as 68 kVp, 200 mA, 

and 3/4 s (Gupton et al. 1957, p. 22). It is assumed that this technique is for one view (i.e., not stereo) 

and, therefore, is doubled to determine the incident air kerma for PFG. The survey does not include 

half-value layer (HVL) or total filtration information, so an HVL of 2.5 mm Al at 68 kVp is assumed for 
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 8 of 21

dose reconstruction. All the organ doses in this TBD are based on the assumption of stereo PFG.

The incident air kerma of 2.191 cGy for stereo PFG is determined from the technique factors used at 

K-25 (mentioned above), and the average air kerma rate from Table B-3 of NCRP Report 102 (1997), 

and corrected to the SSD.

There is no evidence of PFGs performed at K-25 after 1956 from a review of claim file records, which 

corroborates other information on K-25 (Cardarelli 2000; Cardarelli et al. 2002).

3.3.2 Chest Radiography, 1944–1961

A Westinghouse machine was used to produce 14-in. × 17-in. chest radiographs (Author unknown 

1949, p. 12). The radiographs were used to investigate suspicious areas on PFG images, so it is 

possible that some employees had both PFG and conventional chest X-rays from 1944 to 1956. After 

1956, only conventional PA chest radiographs were taken, which substantially reduced radiation dose 

per examination.

The 1957 survey (Gupton et al. 1957, p. 22) provides technique factors for conventional PA chest 

radiographs on 14-in. × 17-in. for the Westinghouse machine at K-25. According to the survey, PA 

chests were performed at 65 kVp, 200 mA, and 1/10 s. These data were used to determine the 

incident air kerma for conventional chest radiographs for this period, using an average air kerma rate 

from Table B-3 of NCRP Report 102 (1997), and corrected to the SSD, resulting in an incident air 

kerma of 2.79E-02 cGy. The survey does not include HVL or total filtration information, so an HVL of 

2.0 mm Al at 65 kVp is assumed for dose reconstruction. 

3.3.3 Chest Radiography, 1962–1970

A Westinghouse 300-mA machine replaced the 200-mA machine in 1962 (Cardarelli 2000; Cardarelli 

et al. 2002). 

Information on either technique factors or beam measurements was not found for the Westinghouse 

machine presumably installed in 1962. Therefore, the incident air kerma comes from Cardarelli 

(2000) for this time period. As recommended in ORAUT-OTIB-0006, poor collimation is assumed for 

this period.

3.3.4 Chest Radiography, 1971–1986

Additional X-ray exposure was introduced in the early 1970s when the health monitoring program 

added a lateral (LAT) chest projection to the chest X-ray examination procedure (Cardarelli 2000). 

The claim file records do not always indicate the LAT chest projection, but there is a change in the 

notation for the mid- to late 1970s from “PA chest” to “Chest,” which presumably included two 

projections (PA and LAT). Dose reconstructors should assign dose from both a PA and LAT chest for 

this period.

The X-ray machine used in this period is presumed to be the same as that for 1962 to 1970, the 

Westinghouse machine. However, because no information from this machine has been found, the 

incident air kerma comes from Cardarelli (2000) for this time period. As recommended in ORAUTOTIB-0006, good collimation is assumed for this period.

3.3.5 Chest Radiography, 1987–2000

In 1988, the Food and Drug Administration performed a survey of the Bennett general-purpose X-ray 

machine that had been installed “recently” at K-25 (Collins 1988). While the exact date of installation 

is not known, Cardarelli (2000) and Cardarelli et al. (2002) state that a new machine was installed in 
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 9 of 21

1987. They mention the Bennett machine, but also mention a Westinghouse machine in several 

places. It is assumed that a Bennett machine was installed, not a Westinghouse machine. The 

significance for dose reconstruction is that the Bennett machines used high-frequency generators in 

their designs. However, no other specific information is available about the Bennett machine or the 

technique factors used, so the incident air kerma comes from Cardarelli (2000) for this time period.

Table 3-2 lists the X-ray equipment used at K-25 and the incident air kerma assumed for dose 

reconstruction. 

Table 3-2. X-ray equipment used at K-25 and incident air kerma values.

Period X-ray machine

kVp

(kV)

Assumed HVL 

(mm Al)

Image size Incident air kerma (cGy)

PA chest LAT chest

1945–1956 GE (PFG) 68 2.5 4 in. × 5 in.

or 70 mm

2.191a --

1944–1961 Westinghouse 200-mA 65 2.0 14 in. × 17 in. 0.0279b --

1962–1970 Westinghouse 300-mA - 2.5c 14 in. × 17 in. 0.0260c

1971–1986 Westinghouse 300-mA - 4.0c 14 in. × 17 in. 0.010c 0.030c

1987–2000 Bennett - 4.0c 14 in. × 17 in. 0.022c 0.035c

a. Based on technique factors in Gupton, Tuck, Davis, and Lincoln (1957) and average kerma rates in NCRP (1997). The 

reported incident air kerma is for stereo PFG views.

b. Based on technique factors in Gupton, Tuck, Davis, and Lincoln (1957) and average kerma rates in NCRP (1997).

c. From Cardarelli (2000).

3.4 ORGAN DOSE CALCULATIONS

Organ doses for PFG, PA, and LAT chest X-rays were based on the method described in ORAUTOTIB-0006 (ORAUT 2011a) and dose conversion factors in ICRP Publication 34 (1982). ICRP (1982) 

provides tables of average absorbed dose (in milligrays) in selected organs for selected X-ray 

projections at 1-Gy entrance kerma (i.e., air kerma without backscatter) for selected projections and 

selected beam qualities (i.e., various HVLs). These tables list the basic dose conversion factors 

(DCFs) for converting air kerma to organ dose. Substitute DCFs for organs that are listed in the 

Interactive RadioEpidemiology Program (IREP) but without unique DCFs in ICRP Publication 34 

(1982) were selected as described in ORAUT-OTIB-0006 or are footnoted in the organ dose tables. 

Air kerma was obtained from Table 3-2.

Table 3-3 lists the organ doses for all periods. Skin doses for all skin areas were determined 

according to the method described in ORAUT-OTIB-0006 (ORAUT 2011a) and listed in Tables 3-4 

and 3-5.

3.5 UNCERTAINTY

ORAUT-OTIB-0006 (ORAUT 2011) lists the major sources of uncertainty in X-ray output intensity and 

subsequent effect on dose to the worker. The five sources of uncertainty are

1. X-ray beam measurement error (±2%),

2. Variation in peak kilovoltage (±9%),

3. Variation in X-ray beam current (±5%),

4. Variation in exposure time (±25%), and

5. Variation in source-to-skin distance as a result of worker size (±10%). 

The 10% uncertainty in output intensity as a result of worker size was based on an inverse square 

correction of output intensity changes from differences of standard chest thickness of ±7.5 cm.
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 10 of 21

These uncertainties are assumed to be random; therefore, the combined statistical uncertainty was 

calculated as the square root of the sum of the squares of all the uncertainties, which is ±28.9%. 

Rounding this up to ±30% provides an adequate and suitably conservative indication of uncertainty. 

Therefore, for a derived dose equivalent to an individual organ, a total combined standard uncertainty 

of ±30% can be assumed. Dose reconstructors should, therefore, input the organ dose equivalent as 

the mean of a normal distribution with a standard uncertainty of ±30%.
Document No. ORAUT-TKS-0009-3 Revision No. 01 Effective Date: 03/2

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Table 3-3. Organ dosea per X-ray procedure for chest X-ray examinations from 1944 to 2000.

Organ Projection

April, 1945–

1956

GE; PFG

(rem)

1944–1961

Westinghouse

14-in. × 17-in.

(rem)

1962–1970

Westinghouse

14-in. × 17-in.

(rem)b

1971–1986

Westinghouse

14-in. × 17-in.

(rem)b

1987–2000

Bennett

14-in. × 17-in.

(rem)b

Thyroid PA 3.81E-01c 4.18E-03c 4.52E-03c 7.80E-04 1.72E-03

LAT 4.92E-03 5.74E-03

Eye/brain PA 7.01E-02d 5.85E-04d 8.32E-04d 7.80E-04 1.72E-03

LAT 4.92E-03 5.74E-03

Ovaries PA 2.19E-03e 3.21E-03f 4.37E-03 5.20E-05 1.14E-04

LAT 7.50E-05 8.75E-05

Bladder/prostate PA 2.19E-03e 3.21E-03f 4.37E-03 5.20E-05 1.14E-04

LAT 7.50E-05 8.75E-05

Colon/rectum PA 2.19E-03e 3.21E-03f 4.37E-03 5.20E-05 1.14E-04

LAT 7.50E-05 8.75E-05

Testes PA 2.19E-05e 1.59E-04f 2.37E-04 1.00E-07 2.20E-07

LAT 3.00E-06 3.50E-06

Lungs (male) PA 9.18E-01 9.34E-03 1.09E-02 6.28E-03 1.38E-02

LAT 9.39E-03 1.10E-02

Lungs (female) PA 9.88E-01 9.90E-03 1.17E-02 6.74E-03 1.48E-02

LAT 1.05E-02 1.23E-02

Liver/gall bladder/spleen PA 9.88E-01 9.90E-03 1.17E-02 6.74E-03 1.48E-02

LAT 1.05E-02 1.23E-02

Thymus PA 9.88E-01 9.90E-03 1.17E-02 6.74E-03 1.48E-02

LAT 1.05E-02 1.23E-02

Esophagus PA 9.88E-01 9.90E-03 1.17E-02 6.74E-03 1.48E-02

LAT 1.05E-02 1.23E-02

Stomach PA 9.88E-01 9.90E-03 1.17E-02 6.74E-03 1.48E-02

LAT 1.05E-02 1.23E-02

Bone Surfaces PA 9.88E-01 9.90E-03 1.17E-02 6.74E-03 1.48E-02

LAT 1.05E-02 1.23E-02

Remainder PA 9.88E-01 9.90E-03 1.17E-02 6.74E-03 1.48E-02

LAT 1.05E-02 1.23E-02

Breast PA 1.07E-01 8.92E-04 1.27E-03 1.16E-03 2.55E-03

LAT 1.03E-02 1.20E-02

Uterus PA 2.85E-03e 2.87E-03f 3.87E-03 5.20E-05 1.14E-04

LAT 6.30E-05 7.35E-05

Bone marrow (male) PA 2.02E-01 1.92E-03 2.39E-03 1.78E-03 3.92E-03

LAT 2.28E-03 2.66E-03

Bone marrow (female) PA 1.88E-01 1.76E-03 2.24E-03 1.72E-03 3.78E-03

LAT 1.77E-03 2.07E-03
Document No. ORAUT-TKS-0009-3 Revision No. 01 Effective Date: 03/2

8/2013 Page 12 of 21

Organ Projection

April, 1945–

1956

GE; PFG

(rem)

1944–1961

Westinghouse

14-in. × 17-in.

(rem)

1962–1970

Westinghouse

14-in. × 17-in.

(rem)b

1971–1986

Westinghouse

14-in. × 17-in.

(rem)b

1987–2000

Bennett

14-in. × 17-in.

(rem)b

Entrance Skin PA 2.96E+00g 3.68E-02g 3.51E-02g 1.42E-02g 3.12E-02g

LAT 4.26E-02g 4.97E-02g

a. Dose conversion factors from Tables A.2 through A.9, ICRP (1982).

b. Based on Cardarelli (2000).

c. Dose conversion factor for anterior-posterior C-spine multiplied by depth dose correction factor of 0.20 as described in ORAUT-OTIB-0006 (2011a).

d. Dose conversion factor for PA chest.

e. Dose conversion factor for PA chest. Because of short SID used in PFG, these organs are not considered to be in the primary beam.

f. Dose conversion factor for PA abdomen, since these organs are considered to be in the primary beam of a poorly collimated field.

g. Incident air kerma multiplied by a backscatter factor (NCRP 1997) of 1.32, 1.35, or 1.4 for HVLs of 2.0, 2.5, and 4.0 mm Al, respectively.

Table 3-4. Skin dose guidance and skin dose equivalents (rem) for chest projections, 1944 through 1970a.

Area of skin

PFG April, 1945–1956 PA chest 1944–1961 PA chest 1962–1970

Guidance Dose Guidance Dose Guidance Dose

Right front shoulder EXSD 6.45E-02 EXSD 7.E-04 EXSD 8.E-04

Right back shoulder ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Left front shoulder EXSD 6.45E-02 EXSD 7.E-04 EXSD 8.E-04

Left back shoulder ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Right upper arm to elbow 10% ENSD 2.96E-01 ENSD 3.68E-02 ENSD 3.51E-02

Left upper arm to elbow 10% ENSD 2.96E-01 ENSD 3.68E-02 ENSD 3.51E-02

Left hand ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Right hand ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Left elbow, forearm, wrist 10% ENSD 2.96E-01 ENSD 3.68E-02 ENSD 3.51E-02

Right elbow, forearm, wrist 10% ENSD 2.96E-01 ENSD 3.68E-02 ENSD 3.51E-02

Right side of head (including ear and temple) 10% ENSD 2.96E-01 10% ENSD 3.7E-03 10% ENSD 3.5E-03

Left side of head (including ear and temple) 10% ENSD 2.96E-01 10% ENSD 3.7E-03 10% ENSD 3.5E-03

Front left thigh RSD (0.52 m) 8.E-04 RSD (0.52 m) 9.E-06 RSD (0.52m) 1.E-05

Back left thigh RSD (0.52 m) 8.E-04 RSD (0.52 m) 9.E-06 RSD (0.52m) 1.E-05

Front right thigh RSD (0.52 m) 8.E-04 RSD (0.52 m) 9.E-06 RSD (0.52m) 1.E-05

Back right thigh RSD (0.52 m) 8.E-04 RSD (0.52 m) 9.E-06 RSD (0.52m) 1.E-05

Left knee and below RSD (0.86 m) 3.E-04 RSD (0.86 m) 3.E-06 RSD (0.86m) 4.E-06

Right knee and below RSD (0.86 m) 3.E-04 RSD (0.86 m) 3.E-06 RSD (0.86m) 4.E-06

Left side of face Eye/brain 7.01E-02 Eye/brain 6.E-04 Eye/Brain 8.E-04

Right side of face Eye/brain 7.01E-02 Eye/brain 6.E-04 Eye/Brain 8.E-04

Left side of neck 10% ENSD 2.96E-01 ENSD 3.68E-02 ENSD 3.51E-02

Right side of neck 10% ENSD 2.96E-01 ENSD 3.68E-02 ENSD 3.51E-02

Back of head 10% ENSD 2.96E-01 10% ENSD 3.7E-03 10% ENSD 3.5E-03

Front of neck Eye/brain 7.01E-02 Eye/brain 6.E-04 Eye/Brain 8.E-04

Back of neck 10% ENSD 2.96E-01 ENSD 3.68E-02 ENSD 3.51E-02
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Area of skin

PFG April, 1945–1956 PA chest 1944–1961 PA chest 1962–1970

Guidance Dose Guidance Dose Guidance Dose

Front torso: base of neck to end of sternum EXSD 6.45E-02 EXSD 7.E-04 EXSD 8.E-04

Front torso: end of sternum to lowest rib EXSD 6.45E-02 EXSD 7.E-04 EXSD 8.E-04

Front torso: lowest rib to iliac crest EXSD 6.45E-02 EXSD 7.E-04 EXSD 8.E-04

Front torso: iliac crest to pubis 10% EXSD 6.4E-03 10% EXSD 7.E-05 10% EXSD 8.E-05

Back torso: base of neck to mid–back ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Back torso: mid–back to lowest rib ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Back torso: lowest rib to iliac crest ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Back torso: buttocks (Iliac crest and below) 10% ENSD 2.96E-01 10% ENSD 3.7E-03 10% ENSD 3.5E-03

Right torso: base of neck to end of sternum ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Right torso: end of sternum to lowest rib ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Right torso: lowest rib to iliac crest ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Right torso: iliac crest to pubis (right hip) 10% ENSD 2.96E-01 10% ENSD 3.7E-03 10% ENSD 3.5E-03

Left torso: base of neck to end of sternum ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Left torso: end of sternum to lowest rib ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Left torso: lowest rib to iliac crest ENSD 2.96E+00 ENSD 3.68E-02 ENSD 3.51E-02

Left torso: iliac crest to pubis (left hip) 10% ENSD 2.96E-01 10% ENSD 3.7E-03 10% ENSD 3.5E-03

a. Values less than 0.1 mrem shown to one significant digit. 

Table 3-5. Skin dose guidance and skin dose equivalents (rem) for chest projections, 1971 through 2000a

.

Area of skin

PA chest 1971–1986 LAT chest 1971–1986 PA chest 1987–2000 LAT chest 1987–2000

Guidance Dose Guidance Dose Guidance Dose Guidance Dose

Right front shoulder EXSD 5.E-04 ENSD 4.26E-02 EXSD 1.1E-03 ENSD 4.97E-02

Right back shoulder ENSD 1.42E-02 ENSD 4.26E-02 ENSD 3.12E-02 ENSD 4.97E-02

Left front shoulder EXSD 5.E-04 EXSD 3.E-04 EXSD 1.1E-03 EXSD 4.E-04

Left back shoulder ENSD 1.42E-02 EXSD 3.E-04 ENSD 3.12E-02 EXSD 4.E-04

Right upper arm to elbow 10% ENSD 1.4E-03 ENSD 4.26E-02 10% ENSD 3.1E-03 ENSD 4.97E-02

Left upper arm to elbow 10% ENSD 1.4E-03 EXSD 3.E-04 10% ENSD 3.1E-03 EXSD 4.E-04

Left hand 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Right hand 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Left elbow, forearm, wrist 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Right elbow, forearm, wrist 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Right side of head (including 

ear and temple)

10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Left side of head (including ear 

and temple)

10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Front left thigh RSD (0.52m) 6.E-06 RSD (0.52m) 8.E-06 RSD (0.52m) 1.E-05 RSD (0.52m) 9.E-06

Back left thigh RSD (0.52m) 6.E-06 RSD (0.52m) 8.E-06 RSD (0.52m) 1.E-05 RSD (0.52m) 9.E-06
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Area of skin

PA chest 1971–1986 LAT chest 1971–1986 PA chest 1987–2000 LAT chest 1987–2000

Guidance Dose Guidance Dose Guidance Dose Guidance Dose

Front right thigh RSD (0.52m) 6.E-06 RSD (0.52m) 8.E-06 RSD (0.52m) 1.E-05 RSD (0.52m) 9.E-06

Back right thigh RSD (0.52m) 6.E-06 RSD (0.52m) 8.E-06 RSD (0.52m) 1.E-05 RSD (0.52m) 9.E-06

Left knee and below RSD (0.86m) 2.E-06 RSD (0.86m) 3.E-06 RSD (0.86m) 4.E-06 RSD (0.86m) 3.E-06

Right knee and below RSD (0.86m) 2.E-06 RSD (0.86m) 3.E-06 RSD (0.86m) 4.E-06 RSD (0.86m) 3.E-06

Left side of face Eye/Brain 8.E-04 10% ENSD 4.3E-03 Eye/brain 1.7E-03 10% ENSD 5.0E-03

Right side of face Eye/Brain 8.E-04 10% ENSD 4.3E-03 Eye/brain 1.7E-03 10% ENSD 5.0E-03

Left side of neck 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Right side of neck 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Back of head 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Front of neck Thyroid 8.E-04 10% ENSD 4.3E-03 Thyroid 1.7E-03 10% ENSD 5.0E-03

Back of neck 10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Front torso: base of neck to 

end of sternum

EXSD 5.E-04 Lung 1.05E-02 EXSD 1.1E-03 Lung

1.23E-02

Front torso: end of sternum to 

lowest rib

EXSD 5.E-04 Lung 1.05E-02 EXSD 1.1E-03 Lung

1.23E-02

Front torso: lowest rib to iliac 

crest

10% EXSD 5.E-05 10% Lung 1.1E-03 10% EXSD 1.E-04 10% Lung

1.2E-03

Front torso: iliac crest to pubis 10% EXSD 5.E-05 10% Lung 1.1E-03 10% EXSD 1.E-04 10% Lung 1.2E-03

Back torso: base of neck to 

mid–back

ENSD 1.42E-02 Lung 1.05E-02 ENSD 3.12E-02 Lung

1.23E-02

Back torso: mid–back to 

lowest rib

ENSD 1.42E-02 Lung 1.05E-02 ENSD 3.12E-02 Lung

1.23E-02

Back torso: lowest rib to iliac 

crest

10% ENSD 1.4E-03 10% Lung 1.1E-03 10% ENSD 3.1E-03 10% Lung

1.2E-03

Back torso: buttocks (Iliac 

crest and below)

10% ENSD 1.4E-03 10% Lung 1.1E-03 10% ENSD 3.1E-03 10% Lung

1.2E-03

Right torso: base of neck to 

end of sternum

ENSD 1.42E-02 ENSD 4.26E-02 ENSD 3.12E-02 ENSD 4.97E-02

Right torso: end of sternum to 

lowest rib

ENSD 1.42E-02 ENSD 4.26E-02 ENSD 3.12E-02 ENSD 4.97E-02

Right torso: lowest rib to iliac 

crest

10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Right torso: iliac crest to pubis 

(right hip)

10% ENSD 1.4E-03 10% ENSD 4.3E-03 10% ENSD 3.1E-03 10% ENSD 5.0E-03

Left torso: base of neck to end 

of sternum

ENSD 1.42E-02 EXSD 3.E-04 ENSD 3.12E-02 EXSD 4.E-04

Left torso: end of sternum to 

lowest rib

ENSD 1.42E-02 EXSD 3.E-04 ENSD 3.12E-02 EXSD 4.E-04
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Area of skin

PA chest 1971–1986 LAT chest 1971–1986 PA chest 1987–2000 LAT chest 1987–2000

Guidance Dose Guidance Dose Guidance Dose Guidance Dose

Left torso: lowest rib to iliac 

crest

10% ENSD 1.4E-03 10% EXSD 3.E-05 10% ENSD 3.1E-03 10% EXSD 4.E-05

Left torso: iliac crest to pubis 

(left hip)

10% ENSD 1.4E-03 10% EXSD 3.E-05 10% ENSD 3.1E-03 10% EXSD 4.E-05

a. Values less than 0.1 mrem shown to one significant digit. 
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 16 of 21

3.6 ATTRIBUTIONS AND ANNOTATIONS

All information requiring identification was addressed in references in the reference section of this 

document.
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 17 of 21

REFERENCES

Author unknown, 1946, Manhattan District History, Book I - General, Volume 7 - Medical Program, 

December 31. [SRDB Ref ID: 40434]

Author unknown, 1949, “1949 Outline of Medical Services available on the Oak Ridge site. Includes 

physical, x-ray criteria.” [SRDB Ref ID: 850, pp. 2-18]

Author unknown, 1964, “Appraisal of Occupational Medical Program Activities or Contractors' Plants 

at Oak Ridge, Tennessee November 23 - 25, 1964.” [SRDB Ref ID: 84670]

Bocher, A. F., 1948, “Exposure of Personnel to Process Material,” memorandum to S. Visner, Carbide 

and Carbon Chemicals Corporation, Oak Ridge, Tennessee, October 12. [SRDB Ref ID: 

55764]

Cardarelli, J. J., 2000, A Potential Consequence of Excluding Work-Required X-Ray Exposures When 

Computing Cumulative Occupational Radiation Dose at a Uranium Enrichment Plant, 

Dissertation, University of Cincinnati, Cincinnati, Ohio. [SRDB Ref. ID: 11105]

Cardarelli, J., H. Spitz, C. Rice, R. Buncher, H. Elson, and P. Succop, 2002, “Significance of radiation 

exposure from work-related chest X-rays for epidemiological studies of radiation workers,” 

American Journal of Industrial Medicine, volume 42, pp. 490–501. [SRDB Ref. ID: 4037]

Collins, B, B., 1988, letter to J. Phillips [Martin Marietta Energy Systems (K-25 Plant)], Department of 

Health and Human Services, Food and Drug Administration, Nashville, Tennessee, June 1. 

[SRDB Ref ID: 75960]

Gupton, E., T. Tuck, Davis, and Lincoln, 1957, “Exposure Data Diagnostic Radiography,” Oak Ridge 

National Laboratory, Oak Ridge, Tennessee, September 22. [SRDB Ref ID: 8546, p. 22]

ICRP (International Commission on Radiological Protection), 1982, Protection of the Patient in 

Diagnostic Radiology, Publication 34, Pergamon Press, Oxford, England.

Kammer, A. G., 1948, “The Essential Medical Services at Oak Ridge Plants,” attachment to letter to 

A. H. Holland, Jr. (Medical Advisor, U.S. Atomic Energy Commission), Carbide and Carbon 

Chemicals Corporation, Oak Ridge, Tennessee, August 3. [SRDB Ref ID: 5485]

Laughlin, J. S., M. L. Muerk, I. Pullman, and R. S. Sherman, 1957, “Bone, Skin, and Gonadal Doses 

in Routine Diagnostic Procedures," American Journal of Roentgenology, Radium Therapy and 

Nuclear Medicine, volume 78, number 6, pp. 961–982. [SRDB Ref ID: 13071]

Lyon, J. S., 1949. “X-rays at K-25,” letter to A. H. Holland, Jr. (U.S. Atomic Energy Commission), 

Carbide and Carbon Chemicals Corporation, Oak Ridge, Tennessee, November 30. [SRDB 

Ref ID: 4692, p. 7]

NCRP (National Council on Radiation Protection and Measurements), 1997, Medical X-Ray, Electron 

Beam and Gamma-Ray Protection for Energies Up to 50 MeV (Equipment Design, 

Performance and Use), Report 102, Third Reprinting, Bethesda, Maryland.

NIOSH (National Institute for Occupational Safety and Health), 2010, Radiation Exposures Covered 

for Dose Reconstructions Under Part B of the Energy Employees Occupational Illness 

Compensation Program Act, DCAS-IG-003, Rev. 1, Division of Compensation Analysis and 

Support, Cincinnati, Ohio, October. 
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 18 of 21

ORAUT (Oak Ridge Associated Universities Team), 2011a, Dose Reconstruction from Occupational 

Medical X-Ray Procedures, ORAUT-OTIB-0006, Rev. 04, Oak Ridge Associated Universities, 

Oak Ridge, Tennessee, June 20.

ORAUT (Oak Ridge Associated Universities Team), 2011b, Guidance on Assigning Occupational 

X-ray Dose Under EEOICPA for X-rays Administered Off-Site, ORAUT-OTIB-0079, Rev. 00, 

Oak Ridge, Tennessee, January 3.

Stoddard, D. L., 1952, “Nickel and Nickel Carbonyl in the Barrier Plant,” memorandum to H. H. Stoner, 

Carbide and Carbon Chemicals Corporation, Oak Ridge, Tennessee, April 8. [SRDB Ref ID: 

55765]
Document No. ORAUT-TKBS-0009-3 Revision No. 01 Effective Date: 03/28/2013 Page 19 of 21

GLOSSARY

anterior-posterior

Physical orientation of the body relative to a penetrating directional radiation such that the 

radiation passes through the body from the front to the back. See exposure geometry.

backscatter

Reflection or refraction of radiation at angles over 90 degrees from its original direction.

bremsstrahlung

Electromagnetic radiation released as a result of inelastic scattering of a moving charged 

particle within the nucleus of an atom. X-rays produced in a typical medical X-ray tube 

frequently originate from inelastic scattering of accelerated electrons in the anode material.

collimation

Restriction of the size of an X-ray beam by various types of beam limiting devices. Collimation 

of the X-ray beam to the size of the image receptor (typically film) is considered good practice.

dose

In general, the specific amount of energy from ionizing radiation that is absorbed per unit of 

mass. Effective and equivalent doses are in units of rem or sievert; other types of dose are in 

units of rads, reps, or grays.

dose conversion factor

Ratio of dose equivalent in tissue or organ to entrance kerma in air at the surface of the 

person being radiographed.

error

Difference between the correct, true, or conventionally accepted value and the measured or 

estimated value. Sometimes used to mean estimated uncertainty. See uncertainty.

exposure geometry

Orientation (physical positioning) of a person or object in relation to a radiation source. This 

geometry is a factor in the radiation dose to various parts of the body. See anterior-posterior, 

posterior-anterior, and lateral in relation to radiography.

filtration

The process of filtering an X-ray beam, usually with millimeter thicknesses of aluminum 

material between the X-ray source and the film that preferentially absorbs photons from the 

beam. Usually measured in equivalent millimeters of aluminum. See half-value layer.

gaseous diffusion plant 

Facility where uranium hexafluoride (UF6) gas is filtered to enrich the 235U and separate it from 

238U. The process requires enormous amounts of electric power and results in an increase in 

235U enrichment from 1% to about 3%.

gray (Gy)

International System unit of absorbed radiation dose, which is the amount of energy from any 

type of ionizing radiation deposited in any medium; 1 Gy equals 1 joule per kilogram or 

100 rads.
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grid

Device that consists of a series of thin, closely spaced lead strips that is placed between the 

person being X-rayed and the X-ray film to reduce interaction of scattered radiation with the 

film.

half-value layer (HVL)

Thickness of a specified substance, usually specified in equivalent millimeters of aluminum, 

that reduces the kerma rate by one-half. A measure of the X-ray beam quality. See filtration.

kerma

Measure in units of absorbed dose (usually grays but sometimes rads) of the energy released 

by radiation from a given amount of a substance. Kerma is the sum of the initial kinetic 

energies of all the charged ionizing particles liberated by uncharged ionizing particles 

(neutrons and photons) per unit mass of a specified material. Free-in-air kerma refers to the 

amount of radiation at a location before adjustment for any external shielding from structures 

or terrain. The word derives from kinetic energy released per unit mass.

kilovoltage (kVp)

The electrical potential difference in units of kilovolts between the cathode and the anode in 

the X-ray generating tube. See technique.

lateral (LAT)

Orientation of the body during an X-ray procedure in which the X-rays pass from one side of 

the body to the other. See exposure geometry.

Manhattan Engineer District (MED)

Subdivision of the U.S. Army Corps of Engineers that administered the World War II 

Manhattan Project to develop the first nuclear bomb. The word Manhattan was chosen to 

divert attention from the Project’s real purpose. The U.S. Atomic Energy Commission 

assumed control of MED facilities and activities in 1946.

Manhattan Project

See Manhattan Engineer District.

occupational medical dose

Dose from X-ray procedures performed for medical screening of workers as part of an 

occupational health program. Doses from X-rays used to diagnose diseases or injuries, even 

if incurred on the job, are not considered occupational and are, therefore, not eligible to be 

included in dose reconstruction under EEOICPA.

photofluorography (PFG)

Historical radiographic technique to produce chest images for screening a large number of 

people in a short period of time. The X-ray image produced on a fluorescent screen was 

photographed on 4-inch by 5-inch film. PFG was the primary method of screening large 

populations for tuberculosis before the advent of nonradiographic screening methods. Also 

called fluorography or mass miniature radiography.

posterior-anterior (PA)

Physical orientation of the body relative to a penetrating directional radiation field such that the 

radiation passes through the body from the back to the front. See exposure geometry.
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preemployment X-ray

An X-ray, usually of the chest, taken before hire or assignment to a specific job. The purpose 

of preemployment X-rays was to screen for active disease, such as tuberculosis.

projection

Description of the path of an X-ray beam from the X-ray tube to the image receptor. For 

example, posterior-anterior and lateral are two common projections in chest radiography.

radiograph

Static images produced on radiographic film by gamma rays or X-rays after passing through 

matter. In the context of EEOICPA, radiographs are X-ray images of the various parts of the 

body used to screen for disease. See radiology.

stereoscopic

Noting or pertaining to simulated three-dimensional viewing of photographic or radiographic 

images with two views of the same image taken at slightly different angles.

source-to-skin distance

Distance from the X-ray machine target (anode) to the skin of the person being radiographed. 

This distance varies with the size of the person being radiographed.

technique

Combination of X-ray machine settings (technique factors) used to produce radiographs, which 

consists of the kilovoltage, tube current (milliamperes), and exposure time (seconds). The last 

two parameters are often multiplied to yield the electric charge that has crossed the X-ray tube 

during the exposure in units of milliampere-seconds. Any combination of time and tube 

current that produces a given product in milliampere-seconds produces the same exposure for 

a fixed peak kilovoltage. Also called technic.

uncertainty

Standard deviation of the mean of a set of measurements. The standard error reduces to the 

standard deviation of the measurement when there is only one determination. See error. Also 

called standard error.

X-ray

(1) See X-ray radiation. (2) See radiograph.

X-ray radiation

Electromagnetic radiation (photons) produced by bombardment of atoms by accelerated 

particles. X-rays are produced by various mechanisms including bremsstrahlung and electron 

shell transitions within atoms (characteristic X-rays). Once formed, there is no difference 

between X-rays and gamma rays, but gamma photons originate inside the nucleus of an atom.