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DOE Review Release 09/02/2010

Document Title:

Lawrence Livermore National Laboratory –

Occupational Medical Dose

Document Number: ORAUT-TKBS-0035-3

Revision: 01

Effective Date: 08/27/2010

Type of Document: TBD

Supersedes: Revision 00 PC-1

Subject Expert(s): James E. Turner and Elyse M. Thomas

Site Expert(s): N/A

Approval: Signature on File Approval Date: 08/26/2010

Ralph W. Kenning, Document Owner

Concurrence: Signature on File Concurrence Date: 08/26/2010

John M. Byrne, Objective 1 Manager

Concurrence: Signature on File Concurrence Date: 08/25/2010

Edward F. Maher, Objective 3 Manager

Concurrence: Signature on File Concurrence Date: 08/25/2010

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 08/27/2010

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-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 2 of 20

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

08/22/2005 00 New technical basis document for the Lawrence Livermore National 

Laboratory – Occupational Medical Dose. First approved issue. 

Initiated by Jay J. Maisler.

10/26/2005 00 PC-1 First approved page change. Page change initiated to incorporate 

recent direction from NIOSH to include DOL review comments on 

page 5. No sections were deleted. Retraining is not required. 

Initiated by Jay J. Maisler. Approval:

Jay J. Maisler, TBD Team Leader

Signature on File 10/14/2005

Judson L. Kenoyer, Task 3 Manager

Signature on File 10/13/2005

Richard E. Toohey, Project Director

Signature on File 10/16/2005

James W. Neton, Associate Director for Science

Signature on File 10/26/2005

08/27/2010 01 Revised to include organ dose from lateral and oblique chest 

projections that were taken on some workers but not initially listed in 

the records submitted by LLNL. Also included are skin doses for all 

projections and periods. Incorporates formal internal and NIOSH 

review comments. Constitutes a total rewrite of the document. 

Training required: As determined by the Task Manager. Initiated by 

Ralph W. Kenning. 
Document No. ORAUT-TKBS-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 3 of 20

TABLE OF CONTENTS

SECTION TITLE

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

PAGE

4

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

3.2 Occupational Medical X-Rays .....................................................................................................6

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

3.4 Organ Dose Equivalents .............................................................................................................8

3.5 Uncertainty..................................................................................................................................8

3.6 Attributions and Annotations ..................................................................................................... 15

References ........................................................................................................................................16

Glossary ............................................................................................................................................18

LIST OF TABLES

TABLE TITLE

3-1 Frequency of occupational chest X-ray screening ....................................................................

PAGE

7

3-2 LLNL X-ray equipment .............................................................................................................7

3-3 Organ doses for chest projections for all periods...................................................................... 9

3-4 Skin dose guidance for various chest projections and periods ............................................... 10

3-5 Skin dose from various chest projections, 1952–1990............................................................ 11

3-6 Skin dose from various chest projections, 1991–present........................................................ 13
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ACRONYMS AND ABBREVIATIONS

CFR Code of Federal Regulations

cm centimeter

DOE U.S. Department of Energy

EEOICPA Energy Employees Occupational Illness Compensation Program Act

ENSD Entrance Skin Dose

EXSD Exit Skin Dose

ESE entrance skin exposure

FDA Food and Drug Administration

Gy gray

HVL half-value layer

keV kiloelectron-volt (1,000 electron volts)

kVp kilovolts-peak

LAT lateral

LLNL Lawrence Livermore National Laboratory

m meter

mA milliampere

mm millimeter

mR milliroentgen

mrem millirem

NCRP National Council on Radiation Protection and Measurements

NIOSH National Institute for Occupational Safety and Health

OBL oblique 

PA posterior-anterior

POC probability of causation

R roentgen

RAO right anterior oblique

RSD Remote Skin Dose

s second

SSD source-to-skin distance

TBD technical basis document

U.S.C. United States Code

§ section, sections
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3.1 INTRODUCTION

Technical basis documents (TBDs) 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 historic 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)] states 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

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 2007):

] guidelines established under 

subsection (c) ...” [42 U.S.C. § 7384n(b)]. Neither the statute nor the POC guidelines (nor the dose 

reconstruction regulation, 42 CFR Part 82) define “performance of duty” for DOE employees with a 

covered cancer or restrict the “duty” to nuclear weapons work (NIOSH 2007).

• 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 is ultimately responsible under the EEOICPA for determining the POC.
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3.2 OCCUPATIONAL MEDICAL X-RAYS

Chest X-ray examinations have been prescribed for occupational health screening by Health Services 

Department clinicians at Lawrence Livermore National Laboratory (LLNL) beginning in 1952 (Author 

unknown 1987, pg. 23; Noonan 2002). The purpose of this TBD is to develop estimates of doses 

from occupational medical X-rays to the lungs and other organs of the body. These doses, 

determined for radiographic chest examinations during different periods at LLNL, are based on the 

operating parameters of the machines and the conditions of exposure, insofar as these are known.

From 1952 until about 1990, baseline X-rays were required for all preemployment evaluations 

(Noonan 2002; Schaer 1964). The earliest document found mentions the preemployment chest X-ray 

policy in existence in 1964 (Schaer 1964). This document also mentions that the periodic physical 

examinations, without specific mention of X-rays during these, occurred no more frequently than on 

an annual basis, and in many cases occurred on a biennial frequency. A sample of LLNL claim file 

records and an analysis of the chest X-ray frequency in relation to the number of years worked shows 

that, on average, workers were X-rayed about every 4 years [1]. In the absence of records, dose 

reconstructors should assume a biennial chest X-ray frequency. 

All the historical documents state that a single, posterior-anterior (PA) chest projection comprised the 

preemployment X-ray screen (Noonan 1991, 1992; Thomas 1991). For the most part, the claim file 

records support these statements [2]. While it appears that not all chest projections in addition to the 

PAs that were performed on workers were initially reported by LLNL, the additional records LLNL has 

provided since they were made aware of this issue show that about 40% contain differences from the 

first submission. In some cases, these are lateral (LAT) chest projections that were performed at the 

same time as the PA, and therefore should be included in dose reconstruction [3]. However, in 

several cases, the second submittal from LLNL contains what appear to be individual specific 

diagnostic (as opposed to screening) projections such as right LAT chests, oblique (OBL) chests, or 

lordotic chests that were performed a week or two following the PA chest screening exam. None of 

these additional projections appear to have occurred frequently enough in the population of LLNL 

workers to consider including dose from them for all workers as a default assumption when records 

are not available, nor should the dose from these be included in dose reconstruction when records 

show that they clearly were performed as additional projections during a followup or “call back” visit

[4]. The few lumbar spine records in claim files do not appear to have been performed for screening 

since they were performed on workers whose job description probably did not include heavy lifting 

(i.e. scientists and engineers) and because they were performed mid career as opposed to preemployment [5]. Therefore, the dose from lumbar spines should not be included in dose 

reconstruction.

Starting around 1990, historical records suggest that periodic X-ray screening would be performed on 

an as-needed basis (LLNL, 1991; Van Pelt 1990). LLNL Health Services Department Radiography 

Program, March 1991 (LLNL, 1991), provides the following information: 

Requisition of X-ray studies for the purpose of diagnostic information should be based 

on clinical evaluation. Diagnostic X-ray examinations will be requested after an 

appropriate medical history and physical examination has been performed, in

accordance with reasonable medical practice and occupational guidelines. Diagnostic 

objective, relevant medical history and X-ray procedure requested will be recorded on 

the radiographic request form. ... Based on the unique nature of the work performed 

at LLNL, a pre-employment baseline PA [posterior-anterior] chest X-ray examination is 

required. This film may be done at the time of pre-employment examination or a copy 

of a previous film or report may be requested and kept on file. Medical surveillance

programs may mandate periodic chest X-rays. Periodic chest X-ray examinations 
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unrelated to job exposure will not be done routinely but may be ordered by the 

examiner if clinically indicated.

No evidence of photofluorography at LLNL has been found in the historical records, claim file records, 

or a review of film archives performed by previous TBD authors [5]. No evidence has been found in 

the historical records or claim file records of X-rays taken at the time of termination. Table 3-1 

contains a summary of the frequency of occupational chest X-ray screening at LLNL and can be used 

by the dose reconstructors in the absence of claim file records.

Table 3-1. Frequency of occupational chest X-ray screening.

a

Period Workers Frequency Chest projections

1952 to 

1990

All employees Preemployment PA

All employees Biennially PA

Asbestos workers ≥50 years old: Biennially PA, LAT, RAO

40-49 years old: every 3 years PA, LAT, RAO

<40 years old: every 5 years PA, LAT, RAO

1990–

present

All employees Preemployment PA 

Employees subject to inhalation 

exposure

Biennially PA 

Asbestos workers ≥50 years old: Biennially PA, LAT, RAO

40-49 years old: every 3 years PA, LAT, RAO

<40 years old: every 5 years PA, LAT, RAO

a. Author unknown (1987); LLNL (1991).

3.3 EQUIPMENT AND TECHNIQUES

Table 3-2 lists the medical X-ray machines used at LLNL, as well as can be determined from existing 

records. Reported data for entrance skin exposures (ESEs) for PA chest examinations were found on

all three systems and are included in Table 3-2. 

Table 3-2. LLNL X-ray equipment.

Period Equipment and operating parameters

1952-1969 Equipment unknown, Doses from ORAUT-OTIB-0006 (ORAUT 2005)

1970–1980 Fischer X-ray machine: 100 kVp, 100 mA, 1/20 s, filtration of 3 mm Al, effective 

energy 32 keV, “satisfactory” collimation, measured ESE = 19 mR at SSD = 157 

cm (Graham and Williams 1975; Myers and Williams 1979)

1981–1990 Xonics: Stationary general-purpose X-ray system, phototiming, Kodak M-35 film 

processor using Kodak XRP chemistry, blue-light-sensitive film, measured ESE = 

45 mR (Shingleton 1985; de Castro 1989; Van Pelt 1990)

1991– 1992 Upgraded Xonics system: Blue-light-sensitive film replaced with green-lightsensitive Kodak T-MAT G and T-MAT L films, new cassette holders with 

compatible emitting screens, manual control techniques applied, measured ESE = 

11 to 15 mR (Winstanley 1990a,b; Noonan 1991; Thomas 1991)

1993–present Bennett: Stationary general-purpose radiographic system, Kodak M35A X-OMAT 

film processor, Lanex Regular screens, ESE = 12 mR (Thomas 1993) to 14 mR 

(Miles 1999); also 110 kVp, 200 mA, 0.017 s, ESE = 14 mR (LLNL 2004)

No information is known about the X-ray equipment used from 1952 to about 1970 and, therefore, the 

doses from this period come from the default values in ORAUT-OTIB-0006 (ORAUT 2005). 

Graham and Williams (1975) describe results of an in-house radiation survey of the Fischer X-ray 

machine in the Medical Department by the LLNL Health Physics Group. Measurements resulted in an 

ESE of 19 mR [at a source-to-skin distance (SSD) of 157 cm], for a “typical” chest radiograph (100 

kVp, 100 mA, 1/20 s), and filtration of 3.0 mm Al. This would result in an HVL of about 3.0 at 100 kVp 

(NCRP 1989). Beam collimation was “satisfactory,” although the position of the light beam used for 
Document No. ORAUT-TKBS-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 8 of 20

centering needed correction. The results of the survey indicated that the facility was operating 

properly and had adequate shielding. Another survey report found for the Fischer unit (Myers and 

Williams 1979) compares design features with those recommended by the National Council on 

Radiation Protection and Measurements and the State of California. 

The Fischer system was replaced by a Xonics general-purpose radiographic machine sometime 

around mid-1980. Surveys of the Xonics machine were made in 1980 (Stephens 1980), 1985 

(Shingleton 1985), 1989 (de Castro 1989), 1990 (Van Pelt 1990), and 1991 (Thomas 1991). The 

pertinent technical data from these surveys are that the measured ESE for a PA chest was as high as 

45 mR for this period (Van Pelt 1990), the kVp used for PA chests was around 114 kVp (Thomas 

1991), and the HVL for that period was likely to be about 4.0 mm Al equivalent for 110 kVp (Stephens 

1980; de Castro 1989; NCRP 1989). Another document dated after the August 15, 1990, survey by 

Van Pelt but before LLNL had received the written results of that survey mentions an ESE of 60 mR 

for PA chests (Winstanley 1990a). However, this appears to be an initial estimate that was lowered to 

45 mR once the raw data had been analyzed and the formal report written. Van Pelt attributed the 

relatively high ESE of 45 mR to the blue-light-emitting screens and the blue-light-sensitive film, and 

recommended that LLNL update the screen/film combination to a more sensitive green-light-emitting 

screen used in combination with green-light-sensitive film. LLNL acted on this recommendation, and 

made the switch to the more sensitive screens and film in 1991 (Noonan 1991). This change resulted 

in a reduction of the ESE for a PA chest from 45 mR to 12 mR (Thomas 1991). For dose 

reconstruction, an ESE of 45 mR is assumed for 1981 through 1990 and 15 mR for 1991 through 

1992, when the machine was retired. 

The Bennett X-ray machine was installed at LLNL in September 1992 (Higginson 1992), replacing the 

Xonics unit. The Bennett machine uses a high-frequency generator that produces a more constant 

voltage across the X-ray tube and more radiation output per unit mAs (LLNL 2004). The new system 

underwent a complete in-depth survey by the Food and Drug Administration (FDA) on October 27, 

1992 (Thomas 1993). All items tested were within Federal specifications. The estimated ESE with 

automatic exposure control was reported as 12.15 mR for a PA chest. Values of ESE in the range of 

12 to 14 mR were reported for the PA chest projection from surveys during this period and a 

measured HVL of 4 mm Al at 90 kVp (Miles 1999; LLNL 2004).

3.4 ORGAN DOSE EQUIVALENTS 

Table 3-3 lists the resultant organ dose equivalents (except for skin) for the periods during which each 

X-ray system was in use. Table 3-4 provides skin dose guidance for various chest projections and 

periods. Tables 3-5 and 3-6 provide the dose equivalent to various areas of the skin for all periods 

and chest projections.

3.5 UNCERTAINTY

ORAUT-OTIB-0006 (ORAUT 2005) lists the major sources of uncertainty in X-ray output intensity and 

subsequent 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 SSD 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 resulting from differences of standard chest thickness of ±7.5 

cm. 

Information on worker thickness is rarely available, even in the medical literature. However, at the 

Savannah River Site, entrance skin dose measurements were made on nine workers of varying chest 

thicknesses (builds) (Cooley 1967). While Cooley did not report the measured chest thicknesses for 

these nine workers, the entrance skin doses were reported and reflect the increases in exposure 
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Table 3-3. Organ dose equivalents (rem) for chest projections for all periods.

Organ Projection 1952–1969a 1970–1980 1981–1990 1991–1992 1993–present

Thyroid PA 3.48E-02 8.74E-04 3.51E-03 1.17E-03 1.09E-03

LAT/OBL 6.85E-02 6.32E-03 1.85E-02 6.15E-03 5.74E-03

Eye/brain PA 6.40E-03 8.74E-04 3.51E-03 1.17E-03 1.09E-03

LAT/OBL 6.85E-02 6.32E-03 1.85E-02 6.15E-03 5.74E-03

Ovaries PA 2.50E-02 3.42E-05 2.34E-04 7.80E-05 7.28E-05

LAT/OBL 1.30E-02 4.28E-05 2.81E-04 9.38E-05 8.75E-05

Urinary/bladder PA 2.50E-02 3.42E-05 2.34E-04 7.80E-05 7.28E-05

LAT/OBL 1.30E-02 4.28E-05 2.81E-04 9.38E-05 8.75E-05

Colon/rectum PA 2.50E-02 3.42E-05 2.34E-04 7.80E-05 7.28E-05

LAT/OBL 1.30E-02 4.28E-05 2.81E-04 9.38E-05 8.75E-05

Testes PA 5.00E-03 1.90E-07 4.50E-07 1.05E-07 1.40E-07

LAT/OBL 2.50E-03 4.75E-06 1.13E-05 3.75E-06 3.50E-06

Lungs (male) PA 8.38E-02 9.42E-03 2.83E-02 9.42E-03 8.79E-03

LAT/OBL 9.65E-02 1.12E-02 3.52E-02 1.17E-02 1.10E-02

Lungs (female) PA 9.02E-02 1.02E-02 3.03E-02 1.01E-02 9.44E-03

LAT/OBL 1.10E-01 1.27E-02 3.95E-02 1.32E-02 1.23E-02

Thymus PA 9.02E-02 1.02E-02 3.03E-02 1.01E-02 9.44E-03

LAT/OBL 1.10E-01 1.27E-02 3.95E-02 1.32E-02 1.23E-02

Esophagus PA 9.02E-02 1.02E-02 3.03E-02 1.01E-02 9.44E-03

LAT/OBL 1.10E-01 1.27E-02 3.95E-02 1.32E-02 1.23E-02

Stomach PA 9.02E-02 1.02E-02 3.03E-02 1.01E-02 9.44E-03

LAT/OBL 1.10E-01 1.27E-02 3.95E-02 1.32E-02 1.23E-02

Bone surface PA 9.02E-02 1.02E-02 3.03E-02 1.01E-02 9.44E-03

LAT/OBL 1.10E-01 1.27E-02 3.95E-02 1.32E-02 1.23E-02

Liver/gall bladder/spleen PA 9.02E-02 1.02E-02 3.03E-02 1.01E-02 9.44E-03

LAT/OBL 1.10E-01 1.27E-02 3.95E-02 1.32E-02 1.23E-02

Remainder organs PA 9.02E-02 1.02E-02 3.03E-02 1.01E-02 9.44E-03

LAT/OBL 1.10E-01 1.27E-02 3.95E-02 1.32E-02 1.23E-02

Breast PA 9.80E-03 1.31E-03 5.22E-03 1.74E-03 1.62E-03

LAT/OBL 1.28E-01 1.36E-02 3.86E-02 1.29E-02 1.20E-02

Uterus PA 2.50E-02 4.37E-05 2.34E-04 7.80E-05 7.28E-05

LAT/OBL 1.30E-02 4.28E-05 2.36E-04 7.88E-05 7.35E-05

Bone marrow (male) PA 1.84E-02 2.22E-03 8.01E-03 2.67E-03 2.49E-03

LAT/OBL 1.85E-02 2.28E-03 8.55E-03 2.85E-03 2.66E-03

Bone marrow (female) PA 1.72E-02 2.13E-03 7.74E-03 2.58E-03 2.41E-03

LAT/OBL 1.45E-02 1.81E-03 6.64E-03 2.21E-03 2.07E-03

Entrance skinb PA 2.70E-01 2.66E-02 6.30E-02 2.10E-02 1.96E-02

LAT/OBL 6.75E-01 6.65E-02 1.58E-01 5.25E-02 4.90E-02

a. Doses before 1970 are based on values in ORAUT-OTIB-0006 (ORAUT 2005).

b. Entrance skin dose is determined by multiplying the entrance air kerma in air by the backscatter factors of 1.35 and 1.40 for HVL of 2.5 mm Al and 

3.0 or 4.0 mm Al, respectively, from NCRP Report 102 (NRCP 1989, Table B-8). Skin doses for all areas of skin are provided in Tables 3-4 and 3-5. 
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Table 3-4. Skin dose guidance for various chest projections and periods.

a

Area of skin

PA 

before 1970

LAT 

before 1970

RAO

before 1970

PA 

after 1970

LAT 

after 1970

RAO

after 1970

Right front shoulder EXSD ENSD EXSD EXSD ENSD EXSD

Right back shoulder ENSD ENSD ENSD ENSD ENSD ENSD

Left front shoulder EXSD EXSD EXSD EXSD EXSD EXSD

Left back shoulder ENSD EXSD ENSD ENSD EXSD ENSD

Right upper arm to elbow ENSD ENSD ENSD 10% ENSD ENSD 10% ENSD

Left upper arm to elbow ENSD EXSD ENSD 10% ENSD EXSD 10% ENSD

Left hand ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD

Right hand ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD

Left elbow, forearm, wrist ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD

Right elbow, forearm, wrist ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD 10% ENSD

Right side of head (including ear and temple) 10% ENSD Eye/brain 10% EXSD 10% ENSD 10% ENSD 10% EXSD

Left side of head (including ear and temple) 10% ENSD Eye/brain 10% ENSD 10% ENSD 10% ENSD 10% ENSD

Front left thigh RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m)

Back left thigh RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m)

Front right thigh RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m)

Back right thigh RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m) RSD (0.52 m)

Left knee and below RSD (0.86 m) RSD (0.86 m) RSD (0.86 m) RSD (0.86 m) RSD (0.86 m) RSD (0.86 m)

Right knee and below RSD (0.86 m) RSD (0.86 m) RSD (0.86 m) RSD (0.86 m) RSD (0.86 m) RSD (0.86 m)

Left side of face Eye/brain Eye/brain ENSD Eye/brain 10% ENSD 10% ENSD

Right side of face Eye/brain Eye/brain EXSD Eye/brain 10% ENSD 10% EXSD

Left side of neck ENSD Eye/brain ENSD 10% ENSD 10% ENSD 10% ENSD

Right side of neck ENSD Eye/brain EXSD 10% ENSD 10% ENSD 10% EXSD

Back of head 10% ENSD Eye/brain 10% ENSD 10% ENSD 10% ENSD 10% ENSD

Front of neck Eye/brain Eye/brain Eye/brain Thyroid 10% ENSD Thyroid

Back of neck ENSD Eye/brain ENSD 10% ENSD 10% ENSD 10% ENSD

Front torso: base of neck to end of sternum EXSD Lung EXSD EXSD Lung EXSD

Front torso: end of sternum to lowest rib EXSD Lung EXSD EXSD Lung EXSD

Front torso: lowest rib to iliac crest EXSD Lung EXSD 10% EXSD 10% lung 10% EXSD

Front torso: iliac crest to pubis 10% EXSD 10% lung 10% EXSD 10% EXSD 10% lung 10% EXSD

Back torso: base of neck to mid-back ENSD Lung ENSD ENSD Lung ENSD

Back torso: mid-back to lowest rib ENSD Lung ENSD ENSD Lung ENSD

Back torso: lowest rib to iliac crest ENSD Lung ENSD 10% ENSD 10% lung 10% ENSD

Back torso: buttocks (Iliac crest and below) 10% ENSD 10% lung 10% ENSD 10% ENSD 10% lung 10% ENSD

Right torso: base of neck to end of sternum ENSD ENSD EXSD ENSD ENSD EXSD

Right torso: end of sternum to lowest rib ENSD ENSD EXSD ENSD ENSD EXSD

Right torso: lowest rib to iliac crest ENSD ENSD EXSD 10% ENSD 10% ENSD 10% EXSD

Right torso: iliac crest to pubis (right hip) 10% ENSD 10% ENSD 10% EXSD 10% ENSD 10% ENSD 10% EXSD

Left torso: base of neck to end of sternum ENSD EXSD ENSD ENSD EXSD ENSD
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Area of skin

PA 

before 1970

LAT 

before 1970

RAO

before 1970

PA 

after 1970

LAT 

after 1970

RAO

after 1970

Left torso: end of sternum to lowest rib ENSD EXSD ENSD ENSD EXSD ENSD

Left torso: lowest rib to iliac crest ENSD EXSD ENSD 10% ENSD 10% EXSD 10% ENSD

Left torso: iliac crest to pubis (left hip) 10% ENSD 10% EXSD 10% ENSD 10% ENSD 10% EXSD 10% ENSD

a. The general method for calculating skin doses is presented in ORAUT-OTIB-0006, Appendix A. (ORAUT 2005)

Table 3-5. Skin dose (rem) from various chest projections, 1952–1990.

a

Area of skin

PA 

1952–

1969

LAT 

1952–

1969

RAO 

1952–

1969

PA 

1970–

1980

LAT 

1970–

1980

RAO 

1970–

1980

PA 

1981–

1990

LAT 

1981–

1990

RAO 

1981–

1990

Right front shoulder 5.9E-03 6.75E-01 3.0E-03 7.E-04 6.65E-02 3.E-04 2.1E-03 1.58E-01 1.2E-03

Right back shoulder 2.70E-01 6.75E-01 6.75E-01 2.66E-02 6.65E-02 6.65E-02 6.30E-02 1.58E-01 1.58E-01

Left front shoulder 5.9E-03 3.0E-03 3.0E-03 7.E-04 3.E-04 3.E-04 2.1E-03 1.2E-03 1.2E-03

Left back shoulder 2.70E-01 3.0E-03 6.75E-01 2.66E-02 3.E-04 6.65E-02 6.30E-02 1.2E-03 1.58E-01

Right upper arm to elbow 2.70E-01 6.75E-01 6.75E-01 2.7E-03 6.65E-02 6.7E-03 6.3E-03 1.58E-01 1.58E-02

Left upper arm to elbow 2.70E-01 3.0E-03 6.75E-01 2.7E-03 3.E-04 6.7E-03 6.3E-03 1.2E-03 1.58E-02

Left hand 2.70E-01 6.75E-02 6.75E-02 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Right hand 2.70E-01 6.75E-02 6.75E-02 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Left elbow, forearm, wrist 2.70E-01 6.75E-02 6.75E-02 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Right elbow, forearm, wrist 2.70E-01 6.75E-02 6.75E-02 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Right side of head including ear and 

temple

2.70E-02 6.85E-02 3.E-04 2.7E-03 6.7E-03 3.E-05 6.3E-03 1.58E-02 1.E-04

Left side of head including ear and temple 2.70E-02 6.85E-02 6.75E-02 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Front left thigh 8.E-05 1.E-04 1.E-04 9.E-06 1.E-05 1.E-05 2.E-05 3.E-05 3.E-05

Back left thigh 8.E-05 1.E-04 1.E-04 9.E-06 1.E-05 1.E-05 2.E-05 3.E-05 3.E-05

Front right thigh 8.E-05 1.E-04 1.E-04 9.E-06 1.E-05 1.E-05 2.E-05 3.E-05 3.E-05

Back right thigh 8.E-05 1.E-04 1.E-04 9.E-06 1.E-05 1.E-05 2.E-05 3.E-05 3.E-05

Left knee and below 3.E-05 4.E-05 4.E-05 3.E-06 4.E-06 4.E-06 9.E-06 1.E-05 1.E-05

Right knee and below 3.E-05 4.E-05 4.E-05 3.E-06 4.E-06 4.E-06 9.E-06 1.E-05 1.E-05

Left side of face 6.4E-03 6.85E-02 6.75E-01 9.E-04 6.7E-03 6.7E-03 3.5E-03 1.58E-02 1.58E-02

Right side of face 6.4E-03 6.85E-02 3.0E-03 9.E-04 6.7E-03 3.E-05 3.5E-03 1.58E-02 1.E-04

Left side of neck 2.70E-01 6.85E-02 6.75E-01 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Right side of neck 2.70E-01 6.85E-02 3.0E-03 2.7E-03 6.7E-03 3.E-05 6.3E-03 1.58E-02 1.E-04

Back of head 2.70E-02 6.85E-02 6.75E-02 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Front of neck 6.4E-03 6.85E-02 6.85E-02 9.E-04 6.7E-03 6.3E-03 3.5E-03 1.58E-02 1.85E-02

Back of neck 2.70E-01 6.85E-02 6.75E-01 2.7E-03 6.7E-03 6.7E-03 6.3E-03 1.58E-02 1.58E-02

Front torso: base of neck to end of 

sternum

5.9E-03 1.10E-01b 3.0E-03 7.E-04 1.27E-02b 3.E-04 2.1E-03 3.95E-02b 1.2E-03

Front torso: end of sternum to lowest rib 5.9E-03 1.10E-01b 3.0E-03 7.E-04 1.27E-02b 3.E-04 2.1E-03 3.95E-02b 1.2E-03

Front torso: lowest rib to iliac crest 5.9E-03 1.10E-01b 3.0E-03 7.E-05 1.3E-03b 3.E-05 2.E-04 3.9E-03b 1.E-04
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Area of skin

PA 

1952–

1969

LAT 

1952–

1969

RAO 

1952–

1969

PA 

1970–

1980

LAT 

1970–

1980

RAO 

1970–

1980

PA 

1981–

1990

LAT 

1981–

1990

RAO 

1981–

1990

Front torso: iliac crest to pubis 6.E-04 1.10E-02b 3.E-04 7.E-05 1.3E-03b 3.E-05 2.E-04 3.9E-03b 1.E-04

Back torso: base of neck to mid-back 2.70E-01 1.10E-01b 6.75E-01 2.66E-02 1.27E-02b 6.65E-02 6.30E-02 3.95E-02b 1.58E-01

Back torso: mid-back to lowest rib 2.70E-01 1.10E-01b 6.75E-01 2.66E-02 1.27E-02b 6.65E-02 6.30E-02 3.95E-02b 1.58E-01

Back torso: lowest rib to iliac crest 2.70E-01 1.10E-01b 6.75E-01 2.7E-03 1.3E-03b 6.7E-03 6.3E-03 3.9E-03b 1.58E-02

Back torso: buttocks (Iliac crest and below) 2.70E-02 1.10E-02b 6.75E-02 2.7E-03 1.3E-03b 6.7E-03 6.3E-03 3.9E-03b 1.58E-02

Right torso: base of neck to end of 

sternum

2.70E-01 6.75E-01 3.0E-03 2.66E-02 6.65E-02 3.E-04 6.30E-02 1.58E-01 1.2E-03

Right torso: end of sternum to lowest rib 2.70E-01 6.75E-01 3.0E-03 2.66E-02 6.65E-02 3.E-04 6.30E-02 1.58E-01 1.2E-03

Right torso: lowest rib to iliac crest 2.70E-01 6.75E-01 3.0E-03 2.7E-03 6.7E-03 3.E-05 6.3E-03 1.58E-02 1.E-04

Right torso: iliac crest to pubis (right hip) 2.70E-02 6.75E-02 3.E-04 2.7E-03 6.7E-03 3.E-05 6.3E-03 1.58E-02 1.E-04

Left torso: base of neck to end of sternum 2.70E-01 3.0E-03 6.75E-01 2.66E-02 3.E-04 6.65E-02 6.30E-02 1.2E-03 1.58E-01

Left torso: end of sternum to lowest rib 2.70E-01 3.0E-03 6.75E-01 2.66E-02 3.E-04 6.65E-02 6.30E-02 1.2E-03 1.58E-01

Left torso: lowest rib to iliac crest 2.70E-01 3.0E-03 6.75E-01 2.7E-03 3.E-05 6.7E-03 6.3E-03 1.E-04 1.58E-02

Left torso: iliac crest to pubis (left hip) 2.70E-02 3.E-04 6.75E-02 2.7E-03 3.E-05 6.7E-03 6.3E-03 1.E-04 1.58E-02

a. Values less than 1 mrem shown to one significant digit. 

b. Based on value for female lung.
Document No. ORAUT-TKBS-0035 3 Revision No. 01 Effective Date: 08/27/2010 Page 13 of 20

Table 3-6. Skin dose (rem) from various chest projections, 1991–present.

a

Area of skin

PA 

1991–

1992

LAT 

1991–

1992

RAO

1991–

1992

PA 

1993

–present

LAT 

1993–

present

RAO

1993–

present

Right front shoulder 7.E-04 5.25E-02 4.E-04 7.E-04 4.90E-02 4.E-04

Right back shoulder 2.10E-02 5.25E-02 5.25E-02 1.96E-02 4.90E-02 4.90E-02

Left front shoulder 7.E-04 4.E-04 4.E-04 7.E-04 4.E-04 4.E-04

Left back shoulder 2.10E-02 4.E-04 5.25E-02 1.96E-02 4.E-04 4.90E-02

Right upper arm to elbow 2.1E-035.25E-02 5.3E-03 2.0E-03 4.90E-02 4.9E-03

Left upper arm to elbow 2.1E-03 4.E-04 5.3E-03 2.0E-03 4.E-04 4.9E-03

Left hand 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Right hand 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Left elbow, forearm, wrist 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Right elbow, forearm, wrist 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Right side of head including ear and temple 2.1E-03 5.3E-03 4.E-05 2.0E-03 4.9E-03 4.E-05

Left side of head including ear and temple 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Front left thigh 8.E-06 1.E-05 1.E-05 8.E-06 1.E-05 1.E-05

Back left thigh 8.E-06 1.E-05 1.E-05 8.E-06 1.E-05 1.E-05

Front right thigh 8.E-06 1.E-05 1.E-05 8.E-06 1.E-05 1.E-05

Back right thigh 8.E-06 1.E-05 1.E-05 8.E-06 1.E-05 1.E-05

Left knee and below 3.E-06 4.E-06 4.E-06 3.E-06 4.E-06 4.E-06

Right knee and below 3.E-06 4.E-06 4.E-06 3.E-06 4.E-06 4.E-06

Left side of face 1.2E-03 5.3E-03 5.3E-03 1.1E-03 4.9E-03 4.9E-03

Right side of face 1.2E-03 5.3E-03 4.E-05 1.1E-03 4.9E-03 4.E-05

Left side of neck 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Right side of neck 2.1E-03 5.3E-03 4.E-05 2.0E-03 4.9E-03 4.E-05

Back of head 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Front of neck 1.2E-03 5.3E-03 6.2E-03 1.1E-03 4.9E-03 5.7E-03

Back of neck 2.1E-03 5.3E-03 5.3E-03 2.0E-03 4.9E-03 4.9E-03

Front torso: base of neck to end of sternum 7.E-04 1.32E-02 4.E-04 7.E-04 1.23E-02 4.E-04

Front torso: end of sternum to lowest rib 7.E-04 1.32E-02 4.E-04 7.E-04 1.23E-02 4.E-04

Front torso: lowest rib to iliac crest 7.E-05 1.3E-03 4.E-05 7.E-05 1.2E-03 4.E-05

Front torso: iliac crest to pubis 7.E-05 1.3E-03 4.E-05 7.E-05 1.2E-03 4.E-05

Back torso: base of neck to mid-back 2.10E-02 1.32E-025.25E-02 1.96E-02 1.23E-02 4.90E-02

Back torso: mid-back to lowest rib 2.10E-02 1.32E-02 5.25E-02 1.96E-02 1.23E-02 4.90E-02

Back torso: lowest rib to iliac crest 2.1E-03 1.3E-03 5.3E-03 2.0E-03 1.2E-03 4.9E-03

Back torso: buttocks (Iliac crest and below) 2.1E-03 1.3E-03 5.3E-03 2.0E-03 1.2E-03 4.9E-03

Right torso: base of neck to end of sternum 2.10E-02 5.25E-02 4.E-04 1.96E-02 4.90E-02 4.E-04

Right torso: end of sternum to lowest rib 2.10E-02 5.25E-02 4.E-04 1.96E-02 4.90E-02 4.E-04

Right torso: lowest rib to iliac crest 2.1E-03 5.3E-03 4.E-05 2.0E-03 4.9E-03 4.E-05

Right torso: iliac crest to pubis (right hip) 2.1E-03 5.3E-03 4.E-05 2.0E-03 4.9E-03 4.E-05
Document No. ORAUT-TKBS-0035 3 Revision No. 01 Effective Date: 08/27/2010 Page 14 of 20

Area of skin

PA 

1991–

1992

LAT 

1991–

1992

RAO

1991–

1992

PA 

1993

–present

LAT 

1993–

present

RAO

1993–

present

Left torso: base of neck to end of sternum 2.10E-02 4.E-04 5.25E-02 1.96E-02 4.E-04 4.90E-02

Left torso: end of sternum to lowest rib 2.10E-02 4.E-04 5.25E-02 1.96E-02 4.E-04 4.90E-02

Left torso: lowest rib to iliac crest 2.1E-03 4.E-05 5.3E-03 2.0E-03 4.E-05 4.9E-03

Left torso: iliac crest to pubis (Left hip) 2.1E-03 4.E-05 5.3E-032.0E-03 4.E-05 4.9E-03

a. Values less than 1 mrem shown to one significant digit. 
Document No. ORAUT-TKBS-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 15 of 20

needed to radiograph thicker body parts, in this case chests. Cooley reported the mean of the 

measured entrance skin doses as 27 mrem. The standard uncertainty of the range of measurements 

is 5.6, resulting in an uncertainty of 21% from this source. 

Substituting this value into the calculation for combined uncertainty described in ORAUT-OTIB-0006 

(ORAUT 2005) rather than the 10% value used in that document, the resultant standard uncertainty is 

34% from these five sources. Rounding this up to 35% would seem to provide an adequate and 

suitably conservative indication of uncertainty. 

3.6 ATTRIBUTIONS AND ANNOTATIONS

Where appropriate in this document, bracketed callouts have been inserted to indicate information, 

conclusions, and recommendations provided to assist in the process of worker dose reconstruction.

These callouts are listed here in the Attributions and Annotations section, with information to identify 

the source and justification for each associated item. Conventional References, which are provided in 

the next section of this document, link data, quotations, and other information to documents available 

for review on the Project’s Site Research Database (SRDB).

[1] Thomas, Elyse M. ORAU Team. Principal Medical Dosimetrist. April 2010.

Analysis of a random sample of claim file records from LLNL.

[2] Thomas, Elyse M. ORAU Team. Principal Medical Dosimetrist. April 2010.

Analysis of a random sample of claim file records from LLNL.

[3] Thomas, Elyse M. ORAU Team. Principal Medical Dosimetrist. April 2010.

Analysis of a random sample of claim file records from LLNL.

[4] Thomas, Elyse M. ORAU Team. Principal Medical Dosimetrist. April 2010.

Analysis of a random sample of claim file records from LLNL. Radiation from X-rays received 

in the diagnosis of injuries or illnesses or for therapeutic reasons is excluded from radiation 

dose reconstruction under EEOICPA.

[5] Thomas, Elyse M. ORAU Team. Principal Medical Dosimetrist. April 2010.

Analysis of a random sample of claim file records from LLNL.

[6] Thomas, Elyse M. ORAU Team. Principal Medical Dosimetrist. April 2010.

Dr. James Turner, author of this TBD reviewed the archived X-ray portfolios of seven randomly 

selected individuals who were employed at LLNL in the 1950s and 1960s. No small-format 

films were found.
Document No. ORAUT-TKBS-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 16 of 20

REFERENCES

Author Unknown, 1987, DOE/EH Beryllium Operations Review February 17-19, 1987. [SRDB Ref ID: 

6173, p. 23]

Cooley, R. C., 1967, “Personnel Radiation Exposures from Medical X-rays – Savannah River Plant –

Part II”. [SRDB Ref ID: 68124]

de Castro, T., 1989, “X-Ray Unit Survey 1985,” Lawrence Berkeley Laboratory, Berkeley, California, 

August 30. [SRDB Ref ID 13901]

Graham, C. L., and G. E. Williams, 1975, “Radiation Survey of the X-Ray Unit at Building 310”, 

interdepartmental memorandum to Dr. J. O. Beatty, Lawrence Livermore National Laboratory, 

Livermore, California, April 1. [SRDB Ref ID 13877]

Higginson, J., 1992, “Report of Assembly of a Diagnostic X-Ray System, LLNL Health Services 

Department,” Department of Health and Human Services, Public Health Service, September 

17. [SRDB Ref ID 14087]

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

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

LLNL (Lawrence Livermore National Laboratory), 1991, LLNL Health Sciences Department 

Radiography Program, Livermore, California, March. [SRDB Ref ID 23011]

LLNL (Lawrence Livermore National Laboratory), 2004, Radiological data sheets, Health Services, 

Livermore, California, June 25. [SRDB Ref ID 23010]

Miles, K., 1999, Radiation survey of LLNL medical X-ray facility, letter to K. Noonan (Lawrence 

Livermore National Laboratory), Department of Health and Human Services, Public Health 

Service, Food and Drug Administration, Oakland, California, October 18. [SRDB Ref ID 

13897]

Myers, D., and G. Williams, 1979, “Review of Medical X-Ray Unit in Building 310”, interdepartmental 

memorandum to George Liu, Lawrence Livermore National Laboratory, Livermore, California, 

March 9. [SRDB Ref ID 13882]

NCRP (National Council on Radiation Protection and Measurements), 1989, Medical X-Ray, Electron 

Beam and Gamma-Ray Protection for Energies up to 50 MeV, Report No. 102, Bethesda, 

Maryland. 

NIOSH (National Institute for Occupational Safety and Health), 2007, Radiation Exposures Covered 

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

Compensation Program Act, OCAS-IG-003, Rev. 0, Office of Compensation Analysis and 

Support, Cincinnati, Ohio, November. [SRDB Ref ID: 35987]

Noonan, K., 1991, untitled letter to W. F. Van Pelt (Department of Health and Human Services, Public 

Health Service, Food and Drug Administration), Lawrence Livermore National Laboratory, 

Livermore, California, January 10. [SRDB Ref ID 14032]

Noonan, K., 1992, “Health Services Department Radiographic System,” memorandum to file, 

Lawrence Livermore National Laboratory, Livermore, California, October 20. [SRDB Ref ID 

13898]
Document No. ORAUT-TKBS-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 17 of 20

Noonan, K., 2002, “NIOSH Request for Description of X-ray Protocols,” memorandum To Whom It 

May Concern, Lawrence Livermore National Laboratory, Livermore, California, May 17.

[SRDB Ref ID 23021]

ORAUT (Oak Ridge Associated Universities Team), 2005, Dose Reconstruction from Occupationally 

Related Diagnostic X-Ray Procedures, ORAUT-OTIB-0006, Rev. 03 PC-1, Oak Ridge, 

Tennessee, December 21.

Schaer, L.R., 1964, Medical Division Examination Information 1961 – 1964, Lawrence Livermore 

National Laboratory, Livermore, California. [SRDB Ref ID: 72126]

Shingleton, K. L., 1985, “Calibration of OHS X-Ray Machine,” interdepartmental memorandum to G. 

Liu, Lawrence Livermore National Laboratory, Livermore, California, July 9. [SRDB Ref ID: 

14081]

Stephens, 1980, Medical Department X-Ray Machine Performance and Safety Survey. [SRDB Ref ID: 

72832]

Thomas, M., 1991, “Results of FDA Diagnostic X-Ray Survey," memorandum to J. H. Spickard 

(Health Sciences Department, Lawrence Livermore National Laboratory), United States Food 

and Drug Administration, San Francisco, California, September 20. [SRDB Ref ID: 13881]

Thomas, M., 1993, “Results of FDA Diagnostic X-Ray Survey,” memorandum to Dr. J. Spickard 

(Lawrence Livermore National Laboratory), United States Food and Drug Administration, San 

Francisco, California, January 20. [SRDB Ref ID: 13874]

Van Pelt, W. F., 1990, letter to Dr. J. H. Spickard (Health Sciences Department, Lawrence Livermore 

National Laboratory), Department of Health and Human Services, Public Health Service, Food 

and Drug Administration, Bothell, Washington, August 29. [SRDB Ref ID: 14086]

Winstanley, J., 1990a, “LLNL Medical X-Ray Unit,” internal memorandum to G. Mansfield, Lawrence 

Livermore National Laboratory, Livermore, California, August 21. [SRDB Ref ID: 23012]

Winstanley, J. L., 1990b, “Medical X-Ray Exposure Evaluation,” interdepartmental memorandum to 

Dr. J. Spickard, Lawrence Livermore National Laboratory, Livermore, California, October 18.

[SRDB Ref ID: 23013]
Document No. ORAUT-TKBS-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 18 of 20

GLOSSARY

absorbed dose

Amount of energy (ergs or joules) deposited in a substance by ionizing radiation per unit mass 

(grams or kilograms) of the substance and measured in units of rads or grays.

ampere (A) 

International System unit of electrical current equal to 1 coulomb per second.

backscatter

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

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 roentgens, rads, reps, or grays. 

dose equivalent

In units of rem or sievert, product of absorbed dose in tissue multiplied by a weighting factor 

and sometimes by other modifying factors to account for the potential for a biological effect 

from the absorbed dose. See dose.

entrance air kerma in air

The sum of kinetic energy of all charge particles liberated per unit mass of air at the point 

where an X-ray beam enters the skin surface (without backscatter). The unit is the joule per 

kilogram (J kg-1

) and is given the special name gray (Gy).

entrance skin exposure (ESE)

Exposure in air, measured in units of roentgens, at the point where an X-ray beam enters the 

skin surface (without backscatter).

exposure

(1) In general, the act of being exposed to ionizing radiation. (2) Measure of the ionization 

produced by X- and gamma-ray photons in air in units of roentgens.

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.

half-value layer (HVL) 

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

that filters an X-ray beam to reduce the kerma rate by one-half. 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.
Document No. ORAUT-TKBS-0035-3 Revision No. 01 Effective Date: 08/27/2010 Page 19 of 20

lateral (LAT, 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.

lordotic

Projection radiograph of the chest used to diagnose conditions affecting the chest, its 

contents, and nearby structures.

milliampere-second (mAs) 

In relation to radiography, product of the average X-ray beam current in milliamperes and the 

time of the exposure in seconds. These factors are selectable on the control panel of most 

medical X-ray equipment.

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 used for 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- 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. Not to be confused with fluoroscopy.

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.

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.

primary X-rays

X-rays that emerge from the exit port of an X-ray tube and through the tube housing and/or 

collimator. Also called primary beam or useful beam.

probability of causation (POC) 

For purposes of dose reconstruction for the Energy Employees Occupational Illness 

Compensation Program Act, the percent likelihood, at the 99th percentile, that a worker 

incurred a particular cancer from occupational exposure to radiation.

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.

rad

Traditional unit for expressing absorbed radiation dose, which is the amount of energy from 

any type of ionizing radiation deposited in any medium. A dose of 1 rad is equivalent to the 

absorption of 100 ergs per gram (0.01 joules per kilogram) of absorbing tissue. The rad has 

been replaced by the gray in the International System of Units (100 rads = 1 gray). The word 

derives from radiation absorbed dose. 
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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.

radiography 

The process of producing images on film (or other media) with radiation. 

radiology 

Science of using X-rays to produce images on photographic film, especially for medical 

purposes, as well as of interpreting those images. 

rem

Traditional unit of radiation dose equivalent that indicates the biological damage caused by 

radiation equivalent to that caused by 1 rad of high-penetration X-rays multiplied by a quality 

factor. The sievert is the International System unit; 1 rem equals 0.01 sievert. The word 

derives from roentgen equivalent in man; rem is also the plural.

roentgen

Unit of photon (gamma or X-ray) exposure for which the resultant ionization liberates a positive 

or negative charge equal to 2.58 × 10-4 coulombs per kilogram (or 1 electrostatic unit of 

electricity per cubic centimeter) of dry air at 0°C and standard atmospheric pressure. An 

exposure of 1 R is approximately equivalent to an absorbed dose of 1 rad in soft tissue for 

higher energy photons (generally greater than 100 kiloelectron-volts). 

source-to-skin distance (SSD) 

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

distance varies with the size of the person being radiographed. 

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.