ORAU Team

Dose Reconstruction Project for NIOSH

Technical Basis Document for the Los Alamos National 

Laboratory – Occupational Medical Dose

Document Number:

ORAUT-TKBS-0010-3 

Effective Date: 12/29/2004

Revision No.: 00

Controlled Copy No.: ______

Page 1 of 23

Subject Expert: Paul G. Johnson

Document Owner

Approval: Signature on File Date: 12/17/2004

Jack E. Buddenbaum, TBD Team Leader

Approval: Signature on File Date: 12/20/2004

Judson L. Kenoyer, Task 3 Manager

Concurrence: Signature on File Date: 12/20/2004

Richard E. Toohey, Project Director

Approval: Signature on File Date: 12/29/2004

James W. Neton, Associate Director for Science

Supersedes:

None

TABLE OF CONTENTS

Section

Record of Issue/Revisions ...................................................................................................................

Page

3

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

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

3.2 Examination Frequencies............................................................................................................5

3.3 Equipment and Techniques ........................................................................................................6

3.4 Organ Dose Calculations (Types II through V, 1964 - Present)...................................................9

3.5 Reconstruction Using Default Values........................................................................................11

3.5.1 Application and Reporting of Occupational Medical X-Ray Dose 

Reconstruction .................................................................................................................12

3.5.2 Photofluorography............................................................................................................ 12

3.6 Reconstruction of Organ Dose from Radiography Equipment Using Minimal 

Collimation................................................................................................................................13

References ........................................................................................................................................18

Attachment 3B Occupational Medical Dose ...................................................................................... 20
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LIST OF TABLES

Table

3-1 Frequency of occupational chest X-rays at LANL.....................................................................

Page

5

3-2 X-ray equipment used at LANL ................................................................................................7

3-3 Technique factors used for each type of X-ray equipment........................................................ 7

3-4 Beam quality and HVL values used to determine DCFs for dose calculations.......................... 9

3-5 Analogues for IREP organs not included in ICRP 34.............................................................. 12

3-6 Default dose values by procedure.......................................................................................... 12

3-7 Organ doses for default entrance kerma values ..................................................................... 15

3-8 Substitute dose conversion factors......................................................................................... 16

3B-1 Doses for organs identified in ICRP 34 PA chest view ........................................................... 21

3B-2 Dose for IREP organs not included in ICRP 34 PA chest view ............................................... 21

3B-3 Doses for organs identified in ICRP 34 LAT chest view.......................................................... 21

3B-4 Dose for IREP organs not included in ICRP 34 LAT chest view ............................................. 21

3B-5 Total dose for organs identified in ICRP 34 PA and LAT view ................................................ 22

3B-6 Total dose for IREP organs not included in ICRP 34 PA and LAT chest view......................... 22

3B-7 Organ doses for photofluorography examinations .................................................................. 23
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RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE 

DATE

REV. 

NO. DESCRIPTION

Draft 04/23/2004 00-A Technical basis document for the Los Alamos 

National Laboratory – Occupational Medical 

Dose. Initiated by Jack E. Buddenbaum.

Draft 06/02/2004 00-B Incorporates comments from internal and NIOSH 

review. Initiated by Jack E. Buddenbaum.

Draft 07/30/2004 00-C Incorporates comments from internal and NIOSH 

review. Initiated by Jack E. Buddenbaum.

Draft 10/09/2004 00-D Incorporates comments from internal and NIOSH 

review. Initiated by Jack E. Buddenbaum.

Draft 12/15/2004 00-E Incorporates additional comments from internal 

and NIOSH review. Initiated by Jack E. 

Buddenbaum.

12/29/2004 12/29/2004 00 First approved issue. Initiated by Jack E. 

Buddenbaum.
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 4 of 23

ACRONYMS AND ABBREVIATIONS

AP anterior-posterior

cm centimeter

DCF dose conversion factor

DOE U.S. Department of Energy

ESE Entrance Skin Exposure

Gy Gray

HVL half value layer

ICRP International Commission on Radiological Protection

in. inch

IREP Interactive RadioEpidemiological Program

kerma kinetic energy released in matter

keV kiloelectron-Volt

kVp kilovolt-peak

LANL Los Alamos National Laboratory

LASL Los Alamos Scientific Laboratory

LAT lateral

mAs milliampere-second

mGy milliGray

mm millimeter

mR milliroentgen

NCRP National Council on Radiation Protection and Measurements

PA posterior-anterior

PFG photofluorography

R roentgen

rad cgs unit for absorbed dose

rem cgs unit for dose equivalent

RMS root mean square

SID Source-to-Image Distance

SSD Source-to-Skin Distance

TBD technical basis document

UC University of California

U.S.C United States Code

WB whole body
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3.1 INTRODUCTION

Technical Basis Documents (TBDs) and Site Profile Documents are general working documents that 

provide guidance concerning 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 the National Institute for Occupational 

Safety and Health 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 facility” as defined in the Energy Employee 

Occupational Illness Compensation Program Act of 2000 (42 U.S.C. § 7384l (5) and (12)).

Los Alamos National Laboratory (LANL) required pre-employment and annual physical examinations 

as part of its occupational health and safety program. These medical examinations typically included 

diagnostic chest X-rays. The doses from these diagnostic procedures depended not only on the 

characteristics of the X-ray machine and the procedures used, but also on the frequency of the 

examinations. 

3.2 EXAMINATION FREQUENCIES

The frequency of examinations differed significantly over the years. Occupational X-rays might have 

occurred more frequently than the schedule indicated in Table 3-1. Supplemental claimant-specific 

frequency data might be recorded in the claimant file provided by the U.S. Department of Energy 

(DOE).

Table 3-1. Frequency of occupational chest X-rays at LANL. 

Period Frequencies Comment

1943-1963 Semiannual All UC and Zia Company workers

1964-1984 Annual Beryllium*, Health Research Laboratory workers

Annual All new hire baselines

1985-1990 Annual All employees

Annual All new hire baselines

1991-1992 Annual All new hire baselines

Annual Asbestos-beryllium-silica-cadmium-carcinogens*

1992-1994 Annual Asbestos-beryllium-silica-cadmium*

1994-2001 Annual Cadmium*

Based on age and years of exposure** Asbestos-beryllium-silica*

2001-present Every 5 years Beryllium*

Based on age and years of exposure** Asbestos*

* Specified for workers listed as potentially exposed to particular hazards;

** Estimated exposure frequencies:

(*) Years of 

exposure

Age of employee

15-35 35-45 45-over

0-10 Every 5 years Every 5 years Every 5 years

Over 10 Every 5 years Every 2 years Every 1 year

Table 3-1 lists frequencies of chest X-rays for different age groups through the years and identifies 

specific groups of workers (LASL 1944, LASL 1954). Beginning in the early 1960s, the X-ray units 

used for screening examinations were in the H-2 Division Occupational Medicine Building (SM-409). 

According to 1977 and 1978 letter reports, each examination included two chest radiographs 
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[posterior-anterior (PA) and lateral (LAT)] per patient (Gutierrez and Haynie 1977, 1978). The 

methods described in 1970s operating procedures are consistent with techniques and methods that 

were used in the early 1960s and through 1984 (LASL 1972, LASL 1976). The procedures mention 

that technicians received a copy of the latest revision of National Bureau of Standards Handbook 76 

and were expected to be familiar with the pertinent parts of that document. The procedures over the 

six-year period reflect changes in the methods and techniques used in the 1970s and presumed to 

continue up through 1984. In 1985, LANL occupational medicine group changed to the Type III 

equipment.

Laboratory records describe examination techniques used prior to 1957 involved the use of 

photofluorography (PFG) for the physical screening exams. Two references describe photoroentgen 

exams as the primary techniques for pre-employment examinations at LASL up until 1957 (Hardy 

1950; LASL 1957). Thus, assignment of medical dose for years prior to 1957 must use the use 

default values presented in Section 3.5.2. If the claim file does not include a specification of the type 

of examination performed (i.e., chest radiograph or PFG) prior to 1957 then the dose reconstructors 

should calculate doses using the default PFG parameters in Section 3.5.2, which will produce 

claimant-favorable dose estimates. Because PFG was discontinued in 1956 (according to LASL 

1957), all examinations after that date are assumed to be chest radiographs using DCFs published in 

International Commission on Radiological Protection (ICRP) Publication 34 (ICRP 1982). For chest 

examinations between 1957 and 1964, the unavailability of specific information on beam quality has 

led to the recommendation that the similar default values for dose conversion factors from ICRP 34 

(ICRP 1982) should also be used for chest radiographs for that particular period. These dose 

conversion factors (DCFs) assume minimum collimation for calculating organ doses. 

Specific organ doses attributed to PA chest X-rays are calculated on the basis of the DCFs identified 

in ICRP Publication 34 (ICRP 1982). Organ doses from LAT chest radiography have been estimated 

by assuming the LAT Entrance Skin Exposure (ESE) is 2.5 times higher than the PA ESE (ORAU 

2003a). The organ doses for the LAT views are then calculated by using the DCFs for these LAT 

views provided in Tables A.2 through A.8 of ICRP (1982). For organs not listed in ICRP Publication 

34 but specified in the Interactive RadioEpidemiological Program (IREP) computer code, doses were 

determined by analogy with anatomical location (see Table 3-5 in Section 3.5). Therefore, IREP code 

organs not included in ICRP Publication 34 were assigned the following equivalent surrogate doses:

Thoracic cavity = lungs

Head and neck organs (including eye, brain) = thyroid

The head and neck organ (i.e., eye/brain) dose estimates are likely to be somewhat greater than 

doses actually incurred (hence claimant-favorable) due to dose reduction factors experienced in 

comparison with the surrogate organs. These reductions are due to increased average distance from 

the X-ray beam or, in the case of the brain, due to attenuation by the bony cranium. In view of the 

variations in organ dose described in ICRP (1982), the higher of the doses listed for male or female 

was assumed.

3.3 EQUIPMENT AND TECHNIQUES

This TBD assumes that LANL medical practices followed accepted standards for radiology, including 

practices used during the 1940s and 1950s to minimize dose to the patient. However, there was the 

potential for significant dose from occupational medical X-ray examinations depending on the type of 

equipment, the technique factors, and the number of radiographic and PFG examinations performed 

through the years (Cardarelli et al. 2002). LANL medical records include notations in individual 

worker files regarding the date and purpose of X-ray examinations.
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X-ray organ dose estimates for occupational radiographic X-rays administered at LANL have been 

calculated for all the different types of X-ray equipment employed over the operational period. From 

1943 through 1956, Type I equipment was utilized as an alternative to PFG for a limited examinations 

(see Table 3-7 in Section 3.5 and Table 3-8 in Section 3.6 for DCFs). For example, in 1953 LASL 

performed 1508 “minifilms” (i.e., PFGs) versus 204 14” x 17” standard film X-ray examinations (LASL 

1954). The remaining types of X-ray equipment employed are designated Type II (used from 1964 

through 1984), Type III (1985 through 1994), Type IV (1995 through 2002), and Type V (2003 to the 

present). Table 3-2 lists all types of X-ray equipment used at LANL. Tables 3-3 and 3-4 list the 

specific technique factors and reported or estimated beam quality factors representative of these 

different machines and their methods of operation.

Table 3-2. X-ray equipment used at LANL.

Technique Period Equipment

PFGa 1943-1956 Unknown, 70mm fluororoentgenogram

Type I 1943- 1963 Unknown minimal collimation

Type II 1964-1976 General Electric KX810; 6.75-mm Al equivalent total filtration was used 

(LASL 1978, 1976).

Type II 1977-1984 General Electric KX810; 6.75-mm Al equivalent total filtration was used. 

This was reduced to 4 mm total filtration sometime in 1977 (LASL 1978, 

1976)

Type III 1985-1994 General Electric DXD 350IL Control, Single-Phase Generator, Auto 

Collimator, 12:1 Grid, 3-mm Al equivalent total filtration. Kodak X-Omatic 90 

second cold water processor, 400 speed film-screen system, Kodak Lanex 

cassettes-rare earth. Fuji Ortho G film

Type IVb 1995 – 2002 General Electric DXD 350IL Control, Single-Phase Generator, Auto 

Collimator, 12:1 Grid, 3-mm Al equivalent total filtration. Kodak X-Omatic 90 

second cold water processor, 400 speed film-screen system, Kodak Lanex 

cassettes-rare earth. Fuji Ortho G film

Type V 2003 – present Cosmos 22 Control, Three-Phase Generator, Varian X-ray tube, Heustis 

medical collimator. 2.5-mm Al equivalent total filtration. CXDI22 Canon 

sensor-digital camera.

a. PFG = Photofluorography

b. Type IV equipment same as Type III, different technique factors used.

Table 3-3. Technique factors used for each type of X-ray equipmenta. 

Machine View

Current

(mA)

Voltage

(kVp)

Exposure time

(sec.)

Type I 1943-1963 Unknown Unknown Unknown Unknown

Type II 1964-1984 PA 200 96 1/20

Type III – 1985 to 1994 PA 200 94-102b 1/30

Type IV – 1995 to 2002 PA 200 110 1/60

Type V – 2003 PA 200 104 1/30

a. PA indicates a posterior/anterior view; the average PA chest measures 24 cm, the average 

lateral chest measures 36 cm. 

b. For conservatism (i.e., higher ESE), all exposures assumed to be obtained at 102 kVp. 

The periods, specific technique factors, and equipment descriptions are based on document reviews 

and interviews with current and previous LANL employees. If additional documentation is identified 

with more specific information (i.e., periods, technique factors, or equipment descriptions), this TBD 

will be revised.

Because LANL identified no technique factors for Type I equipment, organ dose estimates for such 

equipment are determined using Table 3-7 (in Section 3.5.2). For both PA and LAT views, a standard 

Source-to-Image Distance (SID) of 72 in. (183 cm) was maintained for all types. It is assumed that all 
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the X-ray machines were single-phase except the three-phase Type V unit and that there was no air 

gap between the patient and the film. Based on the Al filtration (see Tables 3-2 and 3-4), the 

estimated half value layers (HVLs) obtained from National Council on Radiation Protection and 
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Table 3-4. Beam quality and HVL values used to determine DCFs for dose calculations. 

Machine type Dates of Use

Beam quality

[filtration, Al-equiv., mm]

(reported or estimated*)

HVL, based on 

filtration

(NCRP 1989)

HVL used for 

DCF selection

(ICRP 1982)

PFG 1943-1956 Unknown (2.5 mm*) 2.5 mm* 2.5 mm*

Type I 1943-1963 Unknown (2.5 mm*) 2.5 mm* 2.5 mm*

Type II (a) 1964-1976 6.75 mm 7.2 mm** 7.2 mm**

Type II (b) 1977-1984 4.0 mm 3.3 mm 3.5 mm

Type III 1985-1994 3.0 mm 3.1 mm 3.0 mm

Type IV 1995-2002 3.0 mm 3.4 mm 3.5 mm

Type V 2003-Present 2.5 mm 3.4 mm 3.5 mm

* Assumed, based upon Table 3-6 default per ICRP 34 (ICRP, 1982)

** Interpolated HVL = 7.2 for 6.75 mm Al filtration calculated from all available HVL data.

Measurements (NCRP) Report 102 (NCRP 1989, Table B.2) are 3.3 mm Al Type II, 3.1 mm Al Type 

III, 3.4 mm Al Type IV, and 3.4 mm Al Type V equipment. Because of the excessive total filtration 

(6.75 mm Al) for 1964 through 1976 and because NCRP (1989, Table B.2) has HVLs only for total 

filtration of up to 3.5 mm Al, an interpolation using all the listed total filtration values was performed. 

In addition to maximize the HVL and therefore the dose, an assumed peak tube potential of 120 kVp 

was assumed. Assuming a total filtration of 6.75 mm Al for 1964 to 1976, the HVL is calculated to be 

7.2 mm Al. As stated in an October 4, 1976 LASL memorandum, “the total filtration is unusually high” 

at 6.75-mm Al equivalent (Gutierrez and Haynie 1976). A recommendation was made to lower the 

total filtration by 2.5 to approximately 4 mm Al. The total filtration was reduced to 4 mm and it is 

assumed the beam quality was reduced based on the survey recommendations (Gutierrez 1978; 

Gutierrez and Haynie 1978). Tables 3-2 and 3-4 indicate that filtration was further reduced in 

subsequent periods as newer types of machines came into use.

DCFs derived for examinations using PFG and Type I equipment are based on default assumptions 

listed in Table 3-7 below. For examinations using Type II equipment from 1964 to 1976, the special 

value of DCF had to be calculated by interpolation of all listed HVLs, to estimate the DCFs for the HVL 

of 7.2 mm Al that was found, as noted above, to be representative of that particular period, and DCF 

values in ICRP (1982) are presented only for HVL values up to 4mm Al. DCFs for later use of Type II 

(1977 to 1984), Type IV, and Type V equipment are based on an HVL of 3.5 in Tables A.2 through 

A.8 in ICRP (1982). The DCFs for Type III equipment are based on an HVL of 3.0 in Tables A.2 

through A.8. 

Finally, to determine X-ray organ doses, the air kerma (see Tables 3B-1 through 3B-4 in Attachment 

3B) is estimated by using the data in Tables 3-2 and 3-3 and in Figure B.1 from NCRP (1989). Tables 

3B-1 through 3B-4 list organ doses for PA and LAT 14- x 17–in. chest films.

To determine PFG doses, additional LANL examination program records were reviewed. As part of 

the LANL physical program instituted in 1954 (Shipman 1955), a 70-mm fluororoentgenogram 

(photofluorographic chest X-ray) was routinely obtained unless history or physical examination 

indicated the desirability of a standard 14- x 17-in. radiographic chest film. Because no additional 

information was identified for LANL PFG chest X-rays, dose estimates were determined using 

methodology from ORAU (2003b). Table 3-6 (in Section 3.5.2) lists estimated organ doses for PFG 

examinations.

3.4 ORGAN DOSE CALCULATIONS (TYPES II THROUGH V, 1964 - PRESENT)

This section presents X-ray organ dose estimation methods for occupational X-rays administered at 

LANL for Type II equipment (used from 1964 through 1984), Type III equipment (1985 through 1994), 
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Type IV equipment (1995 through 2002), and Type V equipment 2003 to the present). For 

examinations conducted between 1943 and 1963, the following calculation methods do not apply 

because no technical factors were available for the Type I radiographic or PFG equipment used. For 

that period the dose reconstructor must use the default values presented in Section 3.6. If the claim 

file does not indicate the type of exam performed (i.e., chest radiograph or PFG) prior to 1964, base 

the dose estimates on PFG to be claimant-favorable. 

ICRP Publication 34 (ICRP 1982) contains tables of average absorbed dose (mGy) in selected organs 

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

selected views (including PA and LAT), and for selected beam qualities (i.e., various HVLs). These 

tables list basic dose conversion factors for converting air kerma to organ dose. Air kerma was 

obtained from Figure B.1 of NCRP Report 102 (NCRP 1989). The data in Figure B.1 were corrected 

for a distance of 183 cm. The average air kerma rates for the different machines are calculated using 

the cGy per mAs provided in NCRP Report 102 for specific voltage, current, phase of the machine, 

and distance to the film. 

Finally, the LANL organ doses are found by multiplying the ICRP (1982) organ dose conversion 

factors by the modified air kerma factors (ESE). The resulting LANL X-ray organ doses for all 

machines are listed in Attachment 3B, Tables 3B-1 through 3B-4. Table 3-6 (in Section 3.5.2) lists 

organ doses from photofluorographic chest X-rays in units of rem. LANL records should indicate the 

views obtained.

The following formulas were used to calculate the doses in Tables 3B-1 and 3B-3.

Based on the techniques in Table 3-3, the mAs for the types of equipment were calculated for each 

view:

Current (mA) × exposure time (sec) = Current for view (mAs) (3-1)

Example for PA view:

Type II 200 mA × 1/20s = 10 mAs

Type III 200 mA × 1/30s = 6.67 mAs

Type IV 200 mA × 1/60s = 3.33 mAs

Type V 200 mA × 1/30s = 6.67 mAs

The air kerma rate for Type II (1964-1976, 120 kVp ) was determined to be 0.16 cGy/100 mAs, Type II 

(1977-1984, 96 kVp) was 0.14 cGy/100 mAs, Type III (102 kVp), 0.23 cGy/100 mAs, Type IV (110 

kVp) 0.28 cGy/100 mAs, and Type V (104 kVp) 0.48 cGy/100 mAs [see Figure B.1 of NCRP (1989)] 

after applying an inverse square correction factor of 0.3 for a distance of 183 cm. The air kerma was 

calculated after conversion of the rate to air kerma per mAs.

Current for view (mAs) × Corrected air kerma rate (cGy/mAs) = Air kerma (cGy) (3-2)

Example for PA view:

Type II 10 mAs × 0.0016 cGy/mAs = 0.016 cGy

Type II 10 mAs × 0.0014 cGy/mAs = 0.014 cGy

Type III 6.67 mAs × 0.0023 cGy/mAs = 0.015 cGy

Type IV 3.33 mAs × 0.0028 cGy/mAs = 0.009 cGy

Type V 6.67 mAs × 0.0048 cGy/mAs = 0.032 cGy
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The air kerma was corrected for the thickness of the chest (24 cm) and for distance between the chest 

and the plane of the film (5 cm) to obtain the air kerma at skin entrance.

Air kerma at 183 cm × SID squared ÷ SSD squared = air kerma at skin entrance (3-3)

Example for Type IV PA view:

0.009 cGy × (183 cm)2 ÷ (154 cm)2 = 0.013 cGy

Air kerma at skin entrance was multiplied by the dose conversion factors in Tables A.2 through A.8 of 

ICRP (1982) for PA chest and HVL of 3.5 mm-Al equivalent.

Air kerma (cGy) × Dose conversion factor = Dose for view (cGy) (3-4)

Example for Type IV PA view, dose to thyroid:

0.013 cGy × 62 mGy/Gy × 1 Gy/100 cGy × 1 rad/10 mGy = 8.06 × 10-4 rad

Example for Type IV LAT view, dose to thyroid:

The air kerma at the skin entrance for the PA view was multiplied by 2.5 (ORAU 2003a).

Example for Type IV LAT view:

0.013 cGy × 2.5 = 0.0325 cGy (3-5)

Air kerma at skin entrance was multiplied by the dose conversion factors in Tables A.2 through A.8 of 

ICRP (1982) for LAT chest and HVL of 3.5 mm Al.

Air kerma (cGy) × Dose conversion factor = Dose for view (cGy)

Example for Type IV LAT view, dose to thyroid:

0.0325 cGy × 151 mGy/Gy × 1 Gy/100cGy × 1 rad/10 mGy = 4.91 × 10-3 rad (3-6)

For Type I equipment used prior to 1964, the tube was equipped with a diagnostic type housing with a 

beam port that provided minimal collimation. Therefore, organs not normally in the primary beam for 

PA chest X-rays were included in the primary beam by using ICRP (1982) organ dose conversion 

factors for procedures in which those organs would normally be included in the primary beam. For 

example, assuming minimal collimation, the ovaries would be in the primary beam, and dose 

conversion factors for the abdomen were used. Abdomen dose conversion factors were used for 

ovaries, embryo, and their analogues; the cervical spine dose conversion factor was used for the 

thyroid and its analogues; and the PA skull dose conversion factor was used for the eye/brain (see 

Table 3-5).

3.5 RECONSTRUCTION USING DEFAULT VALUES

Use of default values presented in the following sections is recommended for claims that have 

incomplete records or documentation of specific technique factors or output measurements. Default 

values of entrance kerma have been developed for the three most commonly used occupational 

medical diagnostic X-ray procedures: (1) PA chest radiography; (2) LAT chest radiography; (3) PFG 

chest films when actual measurement data or knowledge of technique factors were absent. The 
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Table 3-5. Analogues for IREP organs not included in 

ICRP 34.

Anatomical 

location

ICRP 34 

reference organ

IREP organ 

analogues

Thorax Lung Thymus

Esophagus

Stomach

Bone surface

Liver/gall bladder, spleen

Remainder organs

Abdomen Ovaries Urinary/bladder

Colon/rectum

Head and neck Thyroid Eye/brain

default values are maxima or upper-limit values developed from review of patient doses as reported in 

the literature, machine characteristics, and knowledge of X-ray procedures used during the periods 

indicated. Thus, it may be assumed that use of default values, when necessary and appropriate, will 

result in a claimant-favorable results.

Sufficient conservatism was included in the determination of the default values to ensure with near 

certainty (99+% confidence) that actual exposures from the specified procedures would not exceed 

the default values. In determining these factors, it was assumed that a minimum filtration was used 

along with low kilovoltage techniques, slow film speeds with standard development, and no additional 

collimation or use of cones. Table 3-6 lists default entrance kerma values for the three procedures.

Table 3-6. Default dose values by procedure. 

Period

Entrance kerma (cGy)

PA chest LAT chest PFG chest

Pre-1970 0.20 0.50 3.0

1970-1985 0.10 0.25 NA

Post 1985 0.05 0.13 NA

These default values can be used as described above in lieu of actual measurement data or entrance 

kerma derived from technique factors.

3.5.1

Table 3-7 lists organ dose conversion factors and organ dose calculations for dose reconstruction for 

the default case.

Application and Reporting of Occupational Medical X-Ray Dos e Recons truction

3.5.2

Photofluorography, also known as photoroentgenography, was utilized for routine chest radiography 

and, as well documented in the literature, typically produces higher patient doses than conventional 

radiography (Braestrup 1958, p. 140; Laughlin et al. 1957; Moeller, Terrill, and Ingraham 1953). 

Occupational, diagnostic chest X-rays at the DOE facilities and its predecessor agencies were 

commonly performed through the use PFGs. Los Alamos also made the use of PFGs for it’s preemployment and routine physical examinations up until 1957 when they stop using this method due to 

the higher radiation doses to the individuals. LASL reported doses as high as 30 mR per chest 

exposure (LASL 1958). PFG differed from conventional film radiography due to the facts that the kVp 

and mAmp settings could be manipulated by the technician and the exposure time was regulated by 

Photofluorography
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the amount of light generated in the unit with a cutoff or maximum exposure time. An exposure of 15 

mAs (150 mA for 0.1 second) was sufficient to produce a satisfactory image on 35mm film; larger film 

required greater exposures (Sante 1954, p. 129). 

Typical operating parameters reported for 1950s PFG were 24 mAs at 83 kVp at a target-to-film 

distance of 36 in. (Braestrup 1958, p. 143), and 30 mAs at 90 kVp with a target-to-film distance of 

40 in. and 2.4-mm added filtration. In the absence of data that describe LASL’s PFGs, dose 

reconstructors should assume added filtration of 2.5 mm for dose determinations, which is claimantfavorable (Feldman et al. 1958). The reported gonadal doses were 0.15 mrad and 0.36 mrad for 

females and males, respectively, in the United Kingdom (Stanford and Vance 1957), and 1 and 2 

mrad for females and males, respectively, in an American study (Laughlin et al. 1957). In another 

study in the United States, Feldman et al. (1958) reported gonadal exposures equivalent to doses of 

0.73 mrad for males and 15 mrad for females, the large difference attributable to assumed collimation. 

Data in the literature indicate an ESE of about 0.5 to 1 R (Laughlin et al. 1957; Feldman et al. 1958; 

Moeller, Terrill, and Ingraham 1953). 

Measurements at the Hanford Site indicated an ESE of 1.53 R for a 60-mAs PFG exposure at 100 

kVp (Rising and Soldat 1959). This is probably an upper limit value based on a large patient and is 

consistent with an ESE of about 600-700 mR for a 24-30 mAs exposure at somewhat lower kVp. 

Although the Hanford measured value is probably an upper limit and therefore an overstatement of 

the actual exposure from PFG to the average patient, dose reconstructors should use the 1.53 R ESE 

value in the absence of LASL-specific data for PFG.

Organ doses for chest PFG are calculated in an analogous manner to organ doses for conventional 

radiography using the entrance kerma values. Table 3-7 lists dose conversion factors for the ICRP 

organs based on a distance of 102 cm and beam quality of 2.5 mm Al HVL. If entrance kerma values 

are unavailable, dose reconstructors should use default values for organ doses; Table 3-7 lists these 

default organ doses. 

3.6 RECONSTRUCTION OF ORGAN DOSE FROM RADIOGRAPHY EQUIPMENT USING 

MINIMAL COLLIMATION

Prior to about 1970, X-ray measurement data, techniques, or beam port information might not be 

available to estimate the collimation of the X-ray beam. Several papers in the literature have 

considered the effects of cone size and centering on organ doses, and concluded that filtration, kVp, 

and the smallest possible cone size were most important to reduce these doses. Due to the reported 

variation in the literature and measurement data on the effects of collimation, it is claimant-favorable 

to assume the use of minimal or no additional external collimation when measurement data, 

technique, or other information to describe the collimation are not available for X-ray procedures 

performed prior to 1970. 

Without collimation, organs normally outside the primary beam are exposed to the primary beam. 

This necessitates the use of dose conversion factors from ICRP (1982) other than those for a PA or 

LAT chest X-ray, because the ICRP dose conversion factors are based on properly collimated beams. 

For minimally collimated beams used prior to 1964, the substitute dose conversion factors listed in 

Table 3-8 were used.

Dose estimates for PFG represent absolute upper limits, and dose reconstructors must use them in 

the absence of more specific information. At sites where measurements or technique factors are 

available, the organ doses could very possibly be lower.
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 14 of 23

Error (deviation from the correct, true, or conventionally accepted value of a quantity) and uncertainty

(defined in terms of the potential range of a stated, measured, assumed, or otherwise determined 
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 15 of 23

Table 3-7. Organ doses for default entrance kerma values. 

Organ View

Dose conversion factor 

(mGy per Gy air kerma)a

HVL 2.5 mm Al for PFG

Organ dose 

PFG (rem)

Dose 

conversion 

factor 

(mGy per Gy 

air kerma)a

HVL 2.5 mm Al

Organ dose 

pre-1970 

(rem),b,c

Beam for PFG includes thyroid, and 

thoracic organs. It does not include 

gonads, bladder, or colon/rectum.

Minimal 

collimation

Thyroid PA 174(f) 5.2E-1 174 (f) 3.48 E-2

LAT 137 6.85E-2

Eye/brain PA 32 9.60E-2 32 6.40E-3

LAT 137 6.85E-2

Ovaries PA N/A 2.5 E-2 (e) N/A 2.5 E-2 (e)

LAT N/A 1.3 E-2 (e)

Liver/gall 

bladder/spleen

PA 451 1.35E+00 451 9.02E-2

LAT 220 1.10E-1

Urinary bladder PA N/A 2.5 E-2 (e) N/A 2.5 E-2 (e)

LAT N/A 1.3 E-2 (e)

Colon/rectum PA N/A 2.5 E-2 (e) N/A 2.5 E-2 (e)

LAT N/A 1.3 E-2 (e)

Testes PA N/A 5.0 E-3 (e) N/A 5.0 E-3 (e)

LAT N/A 2.5 E-3 (e)

Lungs (male) PA 419 1.26E+00 419 8.38E-2

LAT 193 9.65E-2

Lungs (female) PA 451 1.35E+00 451 9.02E-2

LAT 220 1.10E-1

Thymus PA 451 1.35E+00 451 9.02E-2

LAT 220 1.10E-1

Esophagus PA 451 1.35E+00 451 9.02E-2

LAT 220 1.10E-1

Stomach PA 451 1.35E+00 451 9.02E-2

LAT 220 1.10E-1

Bone surfaces PA 451 1.35E+00 451 9.02E-2

LAT 220 1.10E-1

Remainder PA 451 1.35E+00 451 9.02E-2

LAT 220 1.10E-1

Breast PA 49 1.47E-1 49 9.80E-3

LAT 255 1.28E-1

Uterus

(embryo)

PA N/A 2.5 E-2 (e) N/A 2.5 E-2 (e)

LAT N/A 1.3 E-2 (e)

Bone marrow 

(male)

PA 92 2.76E-1 92 1.84E-2

LAT 37 1.85E-2

Bone marrow 

(female)

PA 86 2.58E-1 86 1.72E-2

LAT 29 1.45E-2

Skin (d) PA 4.05E+00 2.70E-1

LAT 6.75E-1

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

b. Source-to-Image-Distance 183 cm.

c. Image Receptor Size (cm) 35.6 × 43.2.

d. Calculated using backscatter factor of 1.35 for HVL of 2.5 mm Al from NCRP (1989, Table B-3.

e. Modified from Webster.

f. Dose Conversion Factor for AP c-spine, corrected for depth by 0.2.

value of a quantity) provide an indication of the confidence or validity of the dose estimates. Error 

implies knowledge of what the correct or actual value is, which is, of course, not known. Therefore, 

the more appropriate factor is uncertainty, which is expressed in terms of a confidence level, which in 

turn is expressed as a percent. Thus, the 99% confidence level indicates that the correct or true 

value, although not actually known, has a 99% probability of falling within the range cited. The 
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 16 of 23

Table 3-8. Substitute dose conversion factors. 

Organ of interest

Substitute view and organ for which dose conversion to use 

for minimally collimated beams

Thyroid AP cervical spine corrected for depth by factor of 0.2 (NCRP 1989, Table B-8)

LAT cervical spine

Eye/brain PA and LAT skull, or PA chest, whichever is larger.

Ovaries and analogues, 

testes, and uterus

PA and LAT abdomen despite what reference shows, it is unlikely that testes 

were in primary beam

statement of confidence level typically includes all potential sources of error, both random and 

systematic; the precision or reproducibility of the measurement; and accuracy, or how close the 

measurement or estimate of dose comes to the actual or correct value.

In theory, a large number of factors can introduce uncertainties or affect the X-ray machine output 

intensity and dose to the worker. However, in practice only five factors can reasonably have a 

meaningful or significant impact on dose uncertainty: 

1. Measurement error

2. Variation in applied kilovoltage

3. Variation in beam current

4. Variation in exposure time

5. Distance from the worker to the source of the X-rays [Source-to-Skin Distance (SSD)]

The influence of such other factors as use of screens, grids, reciprocity failure, film speed, and 

development, while potentially variable, do not affect the beam output intensity per se except indirectly 

insofar as these might determine the exposure settings (i.e., kVp, mA, and time) used.

Medical X-ray doses, when measured, were derived largely from actual measurement of X-ray 

machine output with R-meters or similar ionization chamber devices suitably designed for 

measurement of photons in the medical X-ray energy range. If properly calibrated and used, Rmeters and similar instruments typically and historically have had an uncertainty of +2% for photon 

energies below 400 keV (Kathren and Larson 1969). More recent versions of these instruments might 

provide a somewhat smaller uncertainty on the order of +1% (NBS 1985; 1988). To be conservative, 

the uncertainty range of +2% should be applied to measurements of X-ray intensity.

Theoretically, for a given set of machine settings and parameters, X-ray output should be constant 

and unvarying. However, this is not true in practice. Output is essentially constant unless focal, spot 

loading occurs as might be the case when the power rating of the machine is exceeded. It is unlikely 

that power ratings were ever exceeded because such an event would be difficult to achieve in practice 

and could result in damage to the X-ray tube. However, even with the use of constant voltage 

transformers to control line voltages, slight variations could have occurred in line voltage input or other 

internal voltages, which in turn could alter the kVp of the output beam. In general, for a given kVp 

setting, variation in kVp falls within +5% of the machine setting (Seibert, Barnes, and Gould 1991). 

Because, as noted above, beam intensity is approximately proportional to the 1.7 power of the applied 

kilovoltage; this translates to an uncertainty of approximately ±8.6% with respect to output beam 

intensity in the 80 to 100 kVp range used for diagnostic chest radiographs. For conservatism, this is 

rounded up to +9%.

Similarly, slight variations in tube current are normal; as a tube ages, or heats up from use, current 

can change and typically will drop. With all other factors constant, beam intensity will be reduced in 

direct proportion to the change in tube current. Typically, the reduction in beam output from current 

variation is not more than a few percent under normal operating conditions. Large decreases are 
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 17 of 23

readily detectable and manifest themselves as underexposed radiographs and result in required 

maintenance of the machine to restore the output or, as a temporary measure, an increase in the 

current or kVp to provide the necessary intensity for proper radiography. For a given kVp setting, the 

output of the beam is a function of the tube current, which in turn is measured by a milliammeter, 

which measures average tube current. The measurement is subject to uncertainties and there might 

be minor changes in output as the tube heats from normal use. These variations are typically small, 

and the estimated uncertainty in beam intensity or output attributable to current variation is +5%. 

Another parameter that has potential to affect the dose from a diagnostic radiograph, perhaps 

significantly, is the time of exposure. The potential importance of this parameter is underscored by 

noting that virtually all medical diagnostic X-ray units used in the DOE complex were of the full wave 

rectified type. A full wave rectified machine produces 120 pulses of X-rays per second. Thus, in a 

typical radiographic exposure time of 1/20 of a second, only six pulses would result. A small error in 

the timer that resulted in a change of only ±1 pulse would correspondingly affect the output by ±17%; 

for an exposure time of 1/30 of a second, the change in output corresponding to a deviation of +1 

pulse is ±25%. Early mechanical timers were notoriously inaccurate; accuracy improved significantly 

with the introduction of electronic timers. Measurements of reproducibility made in the late 1980s and 

beyond by the State of Washington for the machines at Hanford suggest that the timers, and indeed 

the entire X-ray output, were fairly constant. However, for conservatism, the assumed uncertainty in 

beam output attributable to timers has been taken to be ±25%. 

The final factor likely to affect worker dose relates to distance from the source of the X-rays, which is 

an important determinant of the entrance skin exposure from which organ doses are calculated. For a 

given individual, the SSD will be determined largely by body thickness and positioning of the body. 

For a typical worker, the estimated variation in SSD is no more than a few centimeters, with an upper 

limit of perhaps 7.5 cm. Using the inverse square, this indicates an uncertainty of ±10% from this 

source.

There are two approaches to determine the combined uncertainty from the five potential sources of 

dose uncertainty listed above. The first, and most conservative in that it gives the greatest range, 

would be to assume that the uncertainties are additive, which would give an uncertainty range of: 

2 + 9 +5 + 25 + 10 = ±51%

However, a more reasonable approach would be to assume that the uncertainties are in fact random, 

and to compute the statistical root mean square (RMS) value. The RMS value is simply the square 

root of the sum of the squares, and computes as ±28.9%. Rounding this up to +30% would seem to 

provide an adequate and suitably conservative indication of uncertainty. Thus, for an individual ESE 

or derived organ dose, an uncertainty of ±30% at the one sigma level can be assumed; to be further 

conservative, it might be appropriate to assume that errors are all positive, and only +30% should be 

used. 
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 18 of 23

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Cameron, J. F., 1970, Radiological Health Handbook, Revised Edition, compiled and edited by the 

Bureau of Radiological Health, U.S. Department of Health, Education and Welfare, Rockville, 

Maryland, p. 159.

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,” Amer. J. Indust. Med. 42:490-501.

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Building, TA-3-409,” Office Memorandum, Los Alamos Scientific Laboratory, Los Alamos, New 

Mexico, May 16.

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January 11.

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Mexico, August 10. 

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Diagnostic Radiology,” Publication 34, Annals of the ICRP, 9(2/3):1-82.

Kathren, R. L., and H. V. Larson, 1969, “Radiological Calibration and Standardization for Health 

Physics: A Program, A Plea and a Proposal,” Health Phys. 16:778-782.

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Los Alamos, New Mexico, May 1958.
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X-Ray Unit, SM-409, Los Alamos, New Mexico, December 30, 1976.

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Routine Diagnostic Procedures,” American Journal of Roentgenology, Radium Therapy and 

Nuclear Medicine 78:197-983

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Public Health Reports 67:57-65.

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Instrument, Publication 250-16, U.S. Department of Commerce, Gaithersburg, Maryland. 

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Performance and Use], Report No. 102, Bethesda, Maryland. 

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Occupational Medical Dose, ORAUT-TKBS-0006-3, Revision 00, Oak Ridge, Tennessee, 

September 16.

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Rising, F. L., and J. K. Soldat, 1959, “Radiation Exposures During Diagnostic Radiographic 

Examinations at Kadlec Methodist Hospital,” letter to Dr. W. D. Norwood, April 30.

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p. 61.

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American Institute of Physics, New York, New York.

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Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 20 of 23

ATTACHMENT 3B

OCCUPATIONAL MEDICAL DOSE

3B.1 LANL MEDICAL X-RAY

LANL conducted preemployment and annual physical examinations as part of its occupational health 

program. These examinations typically included a chest X-ray. For some workers and occupations, 

chest X-rays could be more frequent. 

3B.2 ORGAN DOSES FROM MEDICAL X-RAYS

Organ doses from occupational X-rays at LANL are estimated for all years from 1943 to the present. 

Table 3-1 of this TBD lists the schedule for these exams for all LANL employees over this period. Xray organ dose estimates were made for Type I equipment (used from 1943 to 1963), Type II (1964 to 

1984), Type III (1985 to 1994), Type IV (1995 to 2002), and Type V (2003 to the present). Minimal 

collimation was assumed for Type I equipment used prior to 1964. For organs outside the chest 

cavity, ICRP (1982) organ dose conversion factors other than PA chest were used to ensure that the 

organ doses reflected their presence in the primary beam. For example, the dose to the eye/brain for 

Type I equipment assumes that the eye/brain were in the primary beam, so the air kerma at the skin 

was multiplied by the dose conversion factor for LAT skull. .

Tables 3B-1 through 3B- 7 list LANL organ doses.
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 21 of 23

Table 3B-1. Doses for organs identified in ICRP 34 (1982) PA chest view. 

Period Frequency

LANL 

employee

Air kerma (cGy) 

at skin entrance

Organ doses per PA chest (rem)

Thyroid Ovaries Testes Lungs Breast Uterus/embryo Bone marrow

1943–1963 (Type I)a See Table 3-1 See Table 3-1 2.00E-01 3.48E-02 2.50E-02 5.00E-03 9.02E-02 9.80E-03 2.50E-02 1.84E-02

1964-1976 (Type ll) See Table 3-1 See Table 3-1 2.26E-02 3.66E-03 2.37E-04 <2.26E-07 2.78E-02 5.36E-03 2.35E-04 7.64E-03

1977–1984 (Type II) See Table 3-1 See Table 3-1 1.98E-02 1.22E-03 6.34E-05 <1.98E-07 1.21E-02 1.80E-03 5.94E-05 2.89E-03

1985–1994 (Type III) See Table 3-1 See Table 3-1 2.12E-02 9.75E-04 3.82E-05 <2.12E-07 1.13E-02 1.46E-03 4.88E-05 2.48E-03

1995–2002 (Type IV) See Table 3-1 See Table 3-1 1.30E-02 8.06E-04 4.16E-05 <1.3E-07 7.93E-03 1.18E-03 3.90E-05 1.90E-03

2003–present (Type V) See Table 3-1 See Table 3-1 4.52E-02 2.80E-03 1.45E-04 <4.52E-07 2.76E-02 4.11E-03 1.36E-04 6.60E-03

a. All values based on ORAUT-OTIB-006 (2003).

Table 3B-2. Dose for IREP organs not included in ICRP 34 (1982) PA chest view. 

Period Frequency

LANL 

employee

Organ doses per PA chest (rem)

Air kerma 

(cGy) Thymus

Liver/gall 

bladder/

Spleen

Eye/

brain Esophagus Stomach

Urinary

bladder

Colon

rectum

Bone

surface Skina Remainder

1943–1963 (Type I)b See Table 3-1 See Table 3-1 2.00E-01 9.02E-02 9.02E-02 6.40E-03 9.02E-02 9.02E-02 2.50E-02 2.50E-02 9.02E-02 2.70E-01 9.02E-02

1964-1976 (Type ll) See Table 3-1 See Table 3-1 2.26E-02 2.78E-02 2.78E-02 3.66E-03 2.78E-02 2.78E-02 2.35E-04 2.35E-04 2.78E-04 3.16E-02 2.78E-02

1977–1984 (Type II) See Table 3-1 See Table 3-1 1.98E-02 1.21E-02 1.21E-02 1.22E-03 1.21E-02 1.21E-02 6.34E-05 6.34E-05 1.21E-02 2.77E-02 1.21E-02

1985–1994 (Type III) See Table 3-1 See Table 3-1 2.12E-02 1.13E-02 1.13E-02 9.75E-04 1.13E-02 1.13E-02 3.82E-05 3.82E-05 1.13E-02 2.97E-02 1.13E-02

1995–2002 (Type IV) See Table 3-1 See Table 3-1 1.30E-02 7.93E-03 7.93E-03 8.06E-04 7.93E-03 7.93E-03 4.16E-06 4.16E-06 7.93E-03 1.82E-02 7.93E-03

2003–present (Type V) See Table 3-1 See Table 3-1 4.52E-02 2.76E-02 2.76E-02 2.80E-03 2.76E-02 2.76E-02 1.45E-04 1.45E-04 2.76E-02 6.33E-02 2.76E-02

a. Skin dose is entrance skin dose calculated from air kerma, multiplied by a backscatter factor of 1.35 or 1.4 from NCRP (1989), Table B-8, depending on HVL.

b. All values based on ORAUT-OTIB-006 (2003).

Table 3B-3. Doses for organs identified in ICRP 34 (1982) LAT chest view. 

Period Frequency

LANL 

employee

Air kerma (cGy) 

at skin entrance

Organ doses per LAT chest (rem)

Thyroid Ovaries Testes Lungs Breast Uterus/Embryo Bone marrow

1943–1963 (Type I)a See Table 3-1 See Table 3-1 5.00E-01 6.85E-02 1.30E-02 2.50E-03 1.10E-01 1.28E-01 1.30E-02 1.85E-02

1964-1976 (Type ll) See Table 3-1 See Table 3-1 5.65E-02 1.64E-02 2.94E-04 5.65E-06 3.79E-02 3.07E-02 2.49E-04 8.14E-03

1977–1984 (Type II) See Table 3-1 See Table 3-1 4.95E-02 7.47E-03 7.92E-05 4.95E-06 1.53E-02 1.56E-02 6.93E-05 3.02E-03

1985–1994 (Type III) See Table 3-1 See Table 3-1 5.30E-02 7.05E-03 4.77E-05 5.30E-06 1.42E-02 1.52E-02 4.77E-05 2.54E-03

1995–2002 (Type IV) See Table 3-1 See Table 3-1 3.25E-02 4.91E-03 5.20E-05 3.25E-06 1.01E-02 1.03E-02 4.55E-05 1.98E-03

2003–present (Type V) See Table 3-1 See Table 3-1 1.13E-01 1.71E-02 1.81E-04 1.13E-05 3.50E-02 3.57E-02 1.58E-04 6.89E-03 a

 All values based on ORAUT-OTIB-006 (2003).

Table 3B-4. Dose for IREP organs not included in ICRP 34 (1982) LAT chest view

Period Frequency

LANL 

employee

Organ doses per LAT chest (rem)

Air kerma 

(cGy) Thymus

Liver/gall 

bladder/

Spleen

Eye/

brain Esophagus Stomach

Urinary

bladder

Colon

rectum

Bone

surface Skina Remainder

1943–1963 (Type I)b See Table 3-1 See Table 3-1 5.00E-01 1.10E-01 1.10E-01 6.85E-02 1.10E-01 1.10E-01 1.30E-02 1.30E-02 1.10E-01 6.75E-01 1.10E-01

1964-1976 (Type ll) See Table 3-1 See Table 3-1 5.65E-02 3.79E-02 3.79E-02 1.64E-02 3.79E-02 3.79E-02 2.94E-04 2.94E-04 3.79E-02 7.91E-02 3.79E-02

1977–1984 (Type II) See Table 3-1 See Table 3-1 4.95E-02 1.53E-02 1.53E-02 7.47E-03 1.53E-02 1.53E-02 7.92E-05 7.92E-05 1.53E-02 6.93E-02 1.53E-02

1985–1994) (Type III) See Table 3-1 See Table 3-1 5.30E-02 1.42E-02 1.42E-02 7.05E-03 1.42E-02 1.42E-02 4.77E-06 4.77E-06 1.42E-02 7.42E-02 1.42E-02

1995–2002 (Type IV) See Table 3-1 See Table 3-1 3.25E-02 1.01E-02 1.01E-02 4.91E-03 1.01E-02 1.01E-02 5.20E-05 5.20E-05 1.01E-02 4.55E-02 1.01E-02

2003–present (Type V) See Table 3-1 See Table 3-1 1.13E-01 3.50E-02 3.50E-02 1.71E-02 3.50E-02 3.50E-02 1.81E-04 1.81E-04 3.50E-02 1.58E-01 3.50E-02

a. Skin dose is entrance skin dose calculated from air kerma, multiplied by a backscatter factor of 1.35 or 1.4 from NCRP (1989), Table B-8., depending on HVL.

b. All values based on ORAUT-OTIB-006 (2003).
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 22 of 23

Table 3B-5. Total dose for organs identified in ICRP 34 (1982) PA and LAT view. 

Period Frequency LANL employee

Organ doses per PA and LAT chest (rem)

Thyroid Ovaries Testes Lungs Breast Uterus/embryo Bone marrow

1943–1963(Type I) See Table 3-1 See Table 3-1 1.03E-01 3.80E-02 7.50E-03 2.00E-01 1.38E-01 3.80E-02 3.69E-02

1964–1976 (Type ll) See Table 3-1 See Table 3-1 2.00E-02 5.31E-04 5.88E-06 6.37E-02 3.61E-02 4.84E-04 1.58E-02

1977–1984 (Type II) See Table 3-1 See Table 3-1 8.69E-03 1.43E-04 5.15E-06 2.74E-02 1.74E-02 1.29E-04 5.91E-03

1985–1994 (Type III) See Table 3-1 See Table 3-1 8.03E-03 8.59E-05 5.51E-06 2.55E-02 1.67E-02 9.65E-05 5.02E-03

1995–2002 (Type IV) See Table 3-1 See Table 3-1 5.72E-03 9.36E-05 3.38E-06 1.80E-02 1.15E-02 8.45E-05 3.88E-03

2003–present (Type V) See Table 3-1 See Table 3-1 1.99E-02 3.26E-04 1.18E-05 6.26E-02 3.98E-02 2.94E-04 1.35E-02

Table 3B-6. Total dose for IREP organs not included in ICRP 34 (1982) PA and LAT view

Period Frequency

LANL 

employee

Organ doses per PA and LAT chest(rem)

Thymus

Liver/gall 

bladder/

spleen

Eye/

brain Esophagus Stomach

Urinary

bladder

Colon

rectum

Bone

surface Skin Remainder

1943–1963 (Type I) See Table 3-1 See Table 3-1 2.00E-01 2.00E-01 7.49E-02 2.00E-01 2.00E-01 3.80E-02 3.80E-02 2.00E-01 9.45E-01 2.00E-01

1964–1976 (Type ll) See Table 3-1 See Table 3-1 6.57E-02 6.57E-02 2.01E-02 6.57E-02 6.57E-02 5.29E-04 5.29E-04 6.57e-02 1.11E-01 6.57E-02

1977–1984 (Type II) See Table 3-1 See Table 3-1 2.74E-02 2.74E-02 8.69E-03 2.74E-02 2.74E-02 1.43E-04 1.43E-04 2.74E-02 9.70E-02 2.74E-02

1985–1994) (Type III) See Table 3-1 See Table 3-1 2.55E-02 2.55E-02 8.03E-03 2.55E-02 2.55E-02 4.30E-05 4.30E-05 2.55E-02 1.04E-01 2.55E-02

1995–2002 (Type IV) See Table 3-1 See Table 3-1 1.80E-02 1.80E-02 5.72E-03 1.80E-02 1.80E-02 5.62E-05 5.62E-05 1.80E-02 6.37E-02 1.80E-02

2003–present (Type V) See Table 3-1 See Table 3-1 6.26E-02 6.26E-02 1.99E-02 6.26E-02 6.26E-02 3.26E-04 3.26E-04 6.26E-02 9.83E-02 6.26E-02
Effective Date: 12/29/2004 Revision No. 00 Document No. ORAUT-TKBS-0010-3 Page 23 of 23

Table 3B-7. Organ doses for photofluorography examinations. 

Organ View

Dose conversion factor (mGy per Gy air kerma)a

HVL 2.5 mm Al for PFG

Organ dose 

PFG (rem)

Beam for PFG includes thyroid, and thoracic organs. 

It does not include gonads, bladder, or colon/rectum.

Thyroid PA 174(d) 5.2E-1

LAT

Eye/brain PA 32 9.60E-2

LAT

Ovaries PA N/A 2.5 E-2 (c)

LAT

Liver/gallbladder/spleen PA 451 1.35E+00

LAT

Urinary bladder PA N/A 2.5 E-2 (c)

LAT

Colon/rectum PA N/A 2.5 E-2 (c)

LAT

Testes PA N/A 5.0 E-3 (c)

LAT

Lungs (male) PA 419 1.26E+00

LAT

Lungs (female) PA 451 1.35E+00

LAT

Thymus PA 451 1.35E+00

LAT

Esophagus PA 451 1.35E+00

LAT

Stomach PA 451 1.35E+00

LAT

Bone surfaces PA 451 1.35E+00

LAT

Remainder PA 451 1.35E+00

LAT

Breast PA 49 1.47E-1

LAT

Uterus (embryo) PA N/A 2.5 E-2 (c)

LAT

Bone marrow (male) PA 92 2.76E-1

LAT

Bone marrow (female) PA 86 2.58E-1

LAT

Skin (b) PA 4.05E+00

LAT

a. Dose conversion factors from Tables A.2 through A.9, ICRP Publication 34 (1982).

b. Calculated using backscatter factor of 1.35 for HVL of 2.5 mm Al from NCRP (1989, Table B-3). 

c. Modified from Webster.

d. Dose Conversion Factor for AP c-spine, corrected for depth by 0.2.