Draft

Advisory Board on Radiation and Worker Health

National Institute for Occupational Safety and Health

A Review of ORAUT-RPRT-0085 for Probability of Causation 

Evaluation of ICRP 116 Anterior-Posterior, Isotropic, and 

Rotational Geometries

Contract No. 75D30119C04183

Document No. SCA-TR-2023-PR085, Revision 1 

Prepared by

Ron Buchanan, PhD, CHP

Douglas Farver, CHP

Kathleen Behling

SC&A, Inc.

2200 Wilson Blvd., Suite 300

Arlington, VA 22201-3324

May 11, 2023 

DISCLAIMER

This is a working document provided by the Centers for Disease Control and Prevention (CDC) 

technical support contractor, SC&A for use in discussions with the National Institute for 

Occupational Safety and Health (NIOSH) and the Advisory Board on Radiation and Worker 

Health (ABRWH), including its Working Groups or Subcommittees. Documents produced by 

SC&A, such as memorandum, white paper, draft or working documents are not final NIOSH or 

ABRWH products or positions, unless specifically marked as such. This document prepared by 

SC&A represents its preliminary evaluation on technical issues.

NOTICE: This document has been reviewed to identify and redact any information that is 

protected by the Privacy Act 5 U.S.C. § 552a and has been cleared for distribution. 
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SC&A, Inc. technical support for the Advisory Board on Radiation and Worker Health’s 

review of NIOSH dose reconstruction program

Document title A Review of ORAUT-RPRT-0085 for Probability of Causation Evaluation 

of ICRP 116 Anterior-Posterior, Isotropic, and Rotational Geometries

Document number SCA-TR-2023-PR085

Revision number 1 (Draft)

Supersedes 0 

Effective date May 11, 2023 

Task manager Kathleen Behling [signature on file]

Project manager Bob Barton, CHP [signature on file]

Document reviewer(s) Bob Barton, CHP [signature on file]

Record of revisions

Revision number Effective date Description of revision

0 (Draft) 4/25/2023 Initial issue

1 (Draft) 5/11/2023 Corrected description of SC&A’s calculation of 30–250 

keV photon DCFs in section 3.4.4. Two minor editorial 

corrections.
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Table of Contents

List of Tables................................................................................................................... 4

Abbreviations and Acronyms........................................................................................... 5

1 Introduction and Background.................................................................................... 6

2 RPRT-0085, Revision 00 .......................................................................................... 7

2.1 NIOSH’s methods and approach for assessing data in RPRT-0085 .................. 7

2.2 NIOSH’s data analysis results............................................................................ 8

3 SC&A’s Evaluation of RPRT-0085............................................................................ 9

3.1 IREP models ...................................................................................................... 9

3.2 Dosimeter locations............................................................................................ 9

3.3 Irradiation geometry factors................................................................................ 9

3.4 Probability of causation analysis ...................................................................... 13

3.5 Dose-only analysis ........................................................................................... 23

3.6 Documentation................................................................................................. 29

4 Summary Conclusions............................................................................................ 30

5 References ............................................................................................................. 31
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List of Tables

Table 1. SC&A’s ROT neutron IGFs based on RPRT-0085, table 2-3, ROT IGFs........ 10

Table 2. SC&A’s ISO neutron IGFs based on RPRT-0085, table 2-4, ISO IGFs........... 11

Table 3. SC&A’s ROT photon IGFs based on RPRT-0085, table 2-5, ROT IGFs ......... 11

Table 4. SC&A’s ISO photon IGFs based on RPRT-0085, table 2-6, ISO IGFs............ 12

Table 5. Notable differences between SC&A’s IGFs based on RPRT-0085 and 

RPRT-0068 IGFs................................................................................................ 13

Table 6. SC&A’s 30–250 keV photon DCFs based on RPRT-0069 .............................. 17

Table 7. SC&A’s 0.1–2 MeV neutron DCFs based on RPRT-0069............................... 17

Table 8. Comparison of SC&A POC values and NIOSH POC values for eight female 

organs for photon energies 30–250 keV............................................................. 18

Table 9. Comparison of SC&A POC values and NIOSH POC values for eight male 

organs for photon energies 30–250 keV............................................................. 19

Table 10. Comparison of SC&A POC values and NIOSH POC values for eight female 

organs for neutron energies 0.1–2 MeV ............................................................. 20

Table 11. Comparison of SC&A POC values and NIOSH POC values for eight male 

organs for neutron energies 0.1–2 MeV ............................................................. 22

Table 12. Comparison of SC&A doses and NIOSH doses for eight female organs for 

30–250 keV photons........................................................................................... 25

Table 13. Comparison of SC&A doses and NIOSH doses for eight male organs for 30–

250 keV photons................................................................................................. 25

Table 14. Comparison of SC&A doses and NIOSH doses for eight female organs for 

0.1–2.0 MeV neutrons ........................................................................................ 26

Table 15. Comparison of SC&A doses and NIOSH doses for eight male organs for 0.1–

2.0 MeV neutrons ............................................................................................... 27

Table 16. LCP-to-LC ratios for the AP doses in RPRT-0085, attachment C, for the nine 

cancers assessed by SC&A ............................................................................... 28
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Abbreviations and Acronyms

ABRWH Advisory Board on Radiation and Worker Health 

AP anterior-posterior 

CC center chest

CW center waist

DCC dose conversion coefficient 

DCF dose conversion factor 

EE energy employee 

FCF fluence conversion factors

GSD geometric standard deviation

Hp(10) personal deep dose equivalent 

Hp(10)/ø personal deep dose equivalent divided by fluence 

ICRP International Commission on Radiological Protection

IGF irradiation geometry factor 

IREP Interactive RadioEpidemiological Program

ISO isotropic

keV kiloelectron volt

LC left collar

LCP left chest pocket

Leuk leukemia 

MeV mega-electron volt 

mrem millirem

NA not applicable 

NIOSH National Institute for Occupational Safety and Health

ORAUT Oak Ridge Associated Universities Team

pGy picogray 

POC probability of causation

pSv picosievert

QF quality factor

RBM red bone marrow 

ROT rotational

SI small intestine

SRDB Site Research Database

yr year

UB urinary bladder
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1 Introduction and Background

In 2005, SC&A reviewed OCAS-IG-001, revision 1, “External Dose Reconstruction 

Implementation Guideline” (NIOSH, 2002), and determined that applying the OCAS-IG-001 

rotational (ROT) and isotropic (ISO) dose conversion factors (DCFs) could lead to an 

underestimate of the external dose (SC&A, 2005). This underestimate is due to the fact that the 

DCFs were developed assuming that the radiation beam is perpendicular (incident angle = 0) in 

relation to the personal deep dose equivalent, ambient deep dose equivalent, and exposure 

measurements using either film badge or thermoluminescent dosimetry. In the interim, the 

National Institute for Occupational Safety and Health (NIOSH) directed dose reconstructors to 

use only the anterior-posterior (AP) geometry. However, NIOSH determined the AP DCF values 

were not the most claimant favorable for the bone (red marrow and surface), esophagus, and lung 

when the dosimeter is worn on the chest. Therefore, ROT and ISO DCF correction factors were 

developed. NIOSH published these correction factors in table 4.1a of OCAS-IG-001, revision 3 

(NIOSH, 2007, p. 39: “IG-001”). It should be noted that IG-001, revision 3, erroneously contains 

two tables designated as table 4.1a. The table 4.1a referenced in this report is the second 

table 4.1a, shown on page 39 of IG-001, not the first table 4.1a on page 38. NIOSH has been 

made aware of this error but to date has not revised IG-001 to correct the table numbers. 

In anticipation of introducing International Commission on Radiological Protection (ICRP) 

Publication 116 (ICRP, 2010; “ICRP 116”) dose conversion coefficients (DCCs) in the dose 

reconstruction process, NIOSH issued ORAUT-RPRT-0085, revision 00, “Probability of 

Causation Evaluation of ICRP 116 Anterior-Posterior, Isotropic, and Rotational Geometries,” on 

November 6, 2017 (NIOSH, 2017; “RPRT-0085”). The purpose of RPRT-0085 was to determine 

if the ROT and ISO DCFs for bone (red marrow and surface), esophagus, and lung listed in table

4.1a of IG-001, revision 3, are still valid. 

On October 26, 2022, SC&A was tasked with the technical review of RPRT-0085. This report 

presents SC&A’s evaluation of the technical approach, methods used, and documentation in 

RPRT-0085, revision 00. 
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2 RPRT-0085, Revision 00

2.1 NIOSH’s methods and approach for assessing data in RPRT-0085

NIOSH’s method for assessing the most claimant-favorable exposure geometries was to derive a 

probability of causation (POC) and dose for each combination of ICRP 116 organs, gender, 

dosimeter location, exposure type, and energy range. 

For assessing POC values, NIOSH used the Monte Carlo method to generate Interactive 

RadioEpidemiological Program (IREP) sheets for the following:

• All ICRP 116 organs (RPRT-0085, table 2-1)

– 29 organs 

– 33 IREP models 

• Gender 

– male

– female

• Radiation types 

– neutrons 

– photons 

• Exposure geometries 

– AP

– ROT

– ISO

• IREP energy ranges 

– 32 neutron energies between 0.000000001 and 20 mega-electron volts (MeV) 

– 20 photon energies between 0.01 and 3 MeV

• Dose type 

– Hp(10) (personal deep dose equivalent) 

– exposure 

• 4 dosimeter locations (RPRT-0085, table 2-2)

– center chest

– left collar

– center waist

– left chest pocket 

Doses were calculated using irradiation geometry factors (IGFs) developed in ORAUT-RPRT0068, revision 00, “Correction Factors for Use with ICRP Publication 116 Isotropic and 

Rotational Dose Conversion Coefficients” (NIOSH, 20016a; “RPRT-0068”). RPRT-0068 

determined IGFs for ISO and ROT geometries for neutrons (RPRT-0085, tables 2-3 and 2-4) and 

photons (RPRT-0085, tables 2-5 and 2-6). 

NIOSH performed IREP calculations assuming a 5-year work period starting at age 35 with a 

latency period of 3 years for leukemia, 7 for thyroid, and 10 for all other cancers. NIOSH applied 

a dose of 2,000 millirem per year (mrem/yr) as a normal distribution with a 30 percent error. 
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In addition to determining POC values, NIOSH also performed a dose-only analysis. This 

analysis assumed 500 mrem of measured dose and 500 mrem of missed dose combined with 

ICRP 116 DCCs and RPRT-0068 IGFs for the four dosimeter locations. Based on the method 

described in ORAUT-RPRT-0069, revision 00, “Updated ICRP 116 Dose Conversion Factors 

and Comparison to ICRP 74 Dose Conversion Factors” (NIOSH, 2016b; “RPRT-0069”), the 

DCC is treated as a continuous distribution. NIOSH used a four-point Lagrange interpolation, as 

recommended by ICRP 116 (ICRP, 2010), to determine DCF values between discrete points.

2.2 NIOSH’s data analysis results

2.2.1 POC analysis results

Using data generated in RPRT-0085, NIOSH found that concise geometry determinations could 

not be drawn, as listed in table 4.1a of IG-001. For most radiation types, organs, and dosimeter 

location, the AP and ROT geometries were found to deliver the largest POC, except for the 

female adrenals, for which ISO was more prominent for photons. Attachment A of RPRT-0085 

shows the results of the POC analysis.

In addition, NIOSH evaluated a subset of the data for photon energies of 30 to 250 kiloelectron

volts (keV) and neutrons from 100 keV to 2 MeV. These radiation energies represent the most 

consequential to POC determination. NIOSH’s analysis determined which geometries result in 

the highest dose for each pairing of organ and dosimeter location. POC results for consequential 

radiation energies are presented in attachment B of RPRT-0085. 

In summary, the ROT geometry resulted in the highest POC for most pairings for energy ranges 

of 30–250 keV photons. However, for the left chest pocket, either AP or ISO delivered the 

highest POC for 13 of the ICRP 116 organs. Table 3-1 of RPRT-0085 lists the organs for each 

dosimeter location where ROT was found not to result in the most favorable geometry. 

For male and female, the organs with the higher POCs for 30–250 keV photons are mostly the 

same, except for the adrenals, where ISO is most favorable.

For 0.1–2 MeV neutrons, the ROT geometry also delivers the highest POC for most locations. 

However, for many organs, the AP or ISO geometries are more claimant favorable for both the 

center waist and left chest pocket dosimeter locations. Table 3-2 of RPRT-0085 list the organs 

for which ROT is not the most favorable geometry for 100 keV–2 MeV neutrons. 

2.2.2 Dose analysis results

NIOSH’s derived dose-only results provided an additional comparison of data. These results 

showed with few exceptions an overwhelming agreement between the dose and POC analysis 

results. Attachment C of RPRT-0085 provides the dose analysis results.

2.2.3 Summary of results

Table 4.1a of IG-001 provides a concise list of organs in which geometries other than AP are 

more claimant favorable. The use of ICRP 116 DCCs in combination with the IGFs in 

RPRT-0068 does not produce a list that agrees with IG-001. Inconsistent with current 

recommendations in IG-001, the analysis using ICRP 116 heavily favors the ROT geometry. 
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3 SC&A’s Evaluation of RPRT-0085

The following sections summarize SC&A’s evaluation of the technical approach and 

documentation used by NIOSH to assess the most claimant-favorable exposure geometries. It 

should be noted that in performing this assessment, SC&A found that NIOSH relied on data 

published in RPRT-0068 and RPRT-0069. SC&A has not been tasked to review these 

documents; therefore, these data were used without verification of their accuracy, since the 

assessment of these reports is beyond the scope of this review. 

3.1 IREP models 

3.1.1 NIOSH’s IREP models

In table 2-1 of RPRT-0085, NIOSH list the ICRP 116 cancers and the associated IREP model

used in their POC evaluation. SC&A’s review of table 2-1 included a comparison of listed IREP 

models for ICRP 116 organs and tissues to those identified in ORAUT-OTIB-0005, revision 05, 

“Internal Dosimetry Organ, External Dosimetry Organ, and IREP Model Selection by ICD-9 

Code” (NIOSH, 2012; “OTIB-0005”). 

3.1.2 SC&A’s evaluation of IREP models

Based on SC&A’s review of the IREP models used in RPRT-0085, SC&A concluded that 

NIOSH’s selection of associated IREP models agrees with those identified in OTIB-0005, 

revision 05. For the muscle, which is not specifically listed in OTIB-0005, SC&A considers 

NIOSH’s selection of connective tissues to be appropriate. 

3.2 Dosimeter locations

3.2.1 NIOSH’s dosimeter location selection

NIOSH calculated doses for four dosimeter locations considered to approximate the standard 

locations of the dosimeters worn by energy employees (EEs). These locations included the center 

chest (CC), left collar (LC), center waist (CW), and left chest pocket (LCP). Table 2-2 of RPRT0085 provides a detailed description of where the dosimeter was placed on the adult male and 

adult female phantoms. 

3.2.2 SC&A’s evaluation of dosimeter locations

SC&A considered these dosimeter locations as reasonable, although the center waist location is 

less likely for EEs. Based on knowledge of site-specific practices and information in the 

computer-assisted telephone interview reports, SC&A assumed that the most likely dosimeter 

placement would be the left chest pocket or left collar.

3.3 Irradiation geometry factors

3.3.1 NIOSH’s IGF values

RPRT-0085 used the IGFs developed in RPRT-0068 for calculating ISO and ROT photon and 

neutron doses. All AP IGFs are 1, because that is the geometry of the ICRP 116 DCCs. The 

RPRT-0068 IGFs are based on the incident energy of the particle. The IGFs are the quotient of 

the particle fluence in the dosimeter cell for AP irradiations divided by the particle fluence in the 

dosimeter cell for the ROT or ISO irradiation geometry, as appropriate. 
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Tables 3-1 and 3-2 of RPRT-0068 list the IGF factors developed in RPRT-0068 for photons that 

irradiated the adult female and male phantoms in the ROT and ISO irradiation geometries

respectively, averaged over the IREP energy regions (i.e., <30 keV, 30–250 keV, and >250 keV). 

The IGF factors for neutrons that irradiated the phantoms in the ROT and ISO irradiation 

geometries, averaged over the IREP energy regions (i.e., <10 keV, 10–100 keV, 100 keV–

2 MeV, and 2–20 MeV), are listed in tables 3-3 and 3-4, respectively, of RPRT-0068. 

Tables 2-3 and 2-4 of RPRT-0085 list ROT and ISO IGFs, respectively, for 32 neutron energies

for the four dosimeter locations on the adult female and adult male phantoms. Tables 2-5 and 2-6 

of RPRT-0085 list ROT and ISO IGFs, respectively, for 20 photon energies for the four

dosimeter locations on the adult female and adult male phantoms. 

3.3.2 SC&A’s evaluation of IGF values

For our evaluation of IGF values, SC&A derived IGFs using an arithmetic mean value of the 

IGFs in RPRT-0085, tables 2-3 through 2-6, for the typical IREP photon and neutron energy 

ranges. It should be noted that RPRT-0085 IGF values were listed for 200 keV and 300 keV. To 

assess the 30–250 keV photon energy range, SC&A averaged the 200–300 keV values to derive 

the 250 keV IGF. For neutrons, SC&A used the 2 MeV IGF value for both the 100 keV– 2 MeV 

and 2–20 MeV ranges. Thereafter, SC&A compared its mean IGF value to those values in 

RPRT-0068, tables 3-1 through 3-4. Tables 1–4 of this report show the results of SC&A’s IGF

calculations and RPRT-0068 comparison. 

Table 1. SC&A’s ROT neutron IGFs based on RPRT-0085, table 2-3, ROT IGFs

Dosimeter location and 

energy regions for 

Hp(10), adult phantom

SC&A adult 

female IGF

RPRT-0068 

adult female IGF

SC&A adult 

male IGF

RPRT-0068 

adult male IGF

CC ≤10 keV 2.09 1.68 2.03 1.74

CC 10–100 keV 2.05 2.02 2.01 2.00

CC 100 keV–2 MeV 1.98 2.04 1.98 2.02

CC 2–20 MeV 1.57 2.11 1.63 2.05

LC ≤10 keV 2.00 1.68 1.88 1.64

LC 10–100 keV 1.99 1.97 1.86 1.86

LC 100 keV–2 MeV 1.94 1.99 1.84 1.86

LC 2–20 MeV 1.56 2.03 1.54 1.90

CW ≤10 keV 1.82 1.58 1.86 1.64

CW 10–100 keV 1.79 1.77 1.83 1.82

CW 100 keV–2 MeV 1.76 1.79 1.80 1.84

CW 2–20 MeV 1.50 1.84 1.55 1.88

LCP ≤10 keV 1.59 1.43 1.67 1.51

LCP 10–100 keV 1.58 1.57 1.65 1.65

LCP 100 keV–2 MeV 1.55 1.58 1.63 1.66

LCP 2–20 MeV 1.38 1.60 1.45 1.69

Average ≤10 keV 1.88 1.53 1.86 1.63

Average 10–100 keV 1.85 1.83 1.84 1.83
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Dosimeter location and 

energy regions for 

Hp(10), adult phantom

SC&A adult 

female IGF

RPRT-0068 

adult female IGF

SC&A adult 

male IGF

RPRT-0068 

adult male IGF

Average 100 keV–2 MeV 1.81 1.85 1.81 1.84

Average 2–20 MeV 1.50 1.89 1.54 1.88

Table 2. SC&A’s ISO neutron IGFs based on RPRT-0085, table 2-4, ISO IGFs

Dosimeter location and 

energy regions for 

Hp(10), adult phantom

SC&A adult 

female IGF

RPRT-0068 

adult female IGF

SC&A adult 

male IGF

RPRT-0068 

adult male IGF

CC ≤10 keV 2.02 1.65 2.05 1.77

CC 10–100 keV 1.98 1.95 2.02 2.01

CC 100 keV–2 MeV 1.92 1.98 1.99 2.02

CC 2–20 MeV 1.59 2.05 1.68 2.07

LC ≤10 keV 2.26 1.80 2.12 1.77

LC 10–100 keV 2.22 2.17 2.08 2.06

LC 100 keV–2 MeV 2.13 2.21 2.03 2.08

LC 2–20 MeV 1.68 2.28 1.67 2.15

CW ≤10 keV 1.85 1.65 1.92 1.72

CW 10–100 keV 1.82 1.81 1.89 1.88

CW 100 keV–2 MeV 1.79 1.82 1.86 1.89

CW 2–20 MeV 1.57 1.88 1.64 1.94

LCP ≤10 keV 1.59 1.43 1.65 1.50

LCP 10–100 keV 1.57 1.56 1.63 1.62

LCP 100 keV–2 MeV 1.55 1.57 1.61 1.63

LCP 2–20 MeV 1.38 1.60 1.45 1.67

Average ≤10 keV 1.93 1.64 1.93 1.69

Average 10–100 keV 1.90 1.87 1.91 1.89

Average 100 keV–2 MeV 1.85 1.90 1.87 1.90

Average 2–20 MeV 1.56 1.95 1.61 1.96

Table 3. SC&A’s ROT photon IGFs based on RPRT-0085, table 2-5, ROT IGFs

Dosimeter location and 

energy regions for 

Hp(10), adult phantom

SC&A adult 

female IGF

RPRT-0068 

adult female IGF

SC&A adult 

male IGF

RPRT-0068 

adult male IGF

CC ≤30 keV 2.06 2.02 2.02 2.00

CC 30–250 keV 1.78 1.77 1.84 1.84

CC >250 keV 1.48 1.37 1.56 1.44

LC ≤30 keV 2.00 1.97 1.87 1.86

LC 30–250 keV 1.79 1.79 1.75 1.75

LC >250 keV 1.51 1.40 1.50 1.40
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Dosimeter location and 

energy regions for 

Hp(10), adult phantom

SC&A adult 

female IGF

RPRT-0068 

adult female IGF

SC&A adult 

male IGF

RPRT-0068 

adult male IGF

CW ≤30 keV 1.80 1.78 1.85 1.82

CW 30–250 keV 1.65 1.65 1.71 1.71

CW >250 keV 1.44 1.35 1.50 1.40

LCP ≤30 keV 1.58 1.56 1.66 1.65

LCP 30–250 keV 1.49 1.49 1.57 1.49

LCP >250 keV 1.33 1.27 1.41 1.27

Average ≤30 keV 1.86 1.83 1.85 1.83

Average 30–250 keV 1.68 1.68 1.72 1.72

Average >250 keV 1.44 1.35 1.49 1.39

Table 4. SC&A’s ISO photon IGFs based on RPRT-0085, table 2-6, ISO IGFs

Dosimeter location and 

energy regions for Hp(10), 

adult phantom

SC&A adult 

female IGF

RPRT-0068 

adult female IGF

SC&A adult 

male IGF

RPRT-0068 

adult male IGF

CC ≤30 keV 1.99 1.96 2.03 2.00

CC 30–250 keV 1.77 1.76 1.85 1.85

CC >250 keV 1.52 1.42 1.59 1.54

LC ≤30 keV 2.23 2.18 2.10 2.07

LC 30–250 keV 1.91 1.91 1.87 1.87

LC >250 keV 1.58 1.46 1.59 1.53

CW ≤30 keV 1.85 1.82 1.90 1.88

CW 30–250 keV 1.70 1.71 1.77 1.77

CW >250 keV 1.53 1.43 1.58 1.53

LCP ≤30 keV 1.59 1.57 1.65 1.63

LCP 30–250 keV 1.48 1.48 1.55 1.55

LCP >250 keV 1.35 1.28 1.42 1.40

Average ≤30 keV 1.91 1.88 1.92 1.90

Average 30–250 keV 1.72 1.71 1.76 1.76

Average >250 keV 1.49 1.40 1.55 1.50

SC&A’s RPRT-0085 and RPRT-0068 IGF comparison found that, for most energy ranges, there 

was reasonable agreement in IGF values. However, SC&A did identify several RPRT-0085 ROT 

and ISO neutron IGFs that deviate 20–25 percent from the RPRT-0068 values, as discussed in 

observation 1.

Observation 1: SC&A questions why NIOSH’s neutron IGFs for several dosimeter 

locations differ from those in RPRT-0068

Using NIOSH’s RPRT-0085 IGF values, SC&A’s mean IGF values for several neutron ROT and 

ISO dosimeter placements were generally about 20–25 percent less than those values listed in 

RPRT-0068. With only one exception (ROT CC <10 keV), these differences were noted in the 
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2–20 MeV neutron energy region. SC&A questions why NIOSH’s RPRT-0085 IGF values 

differed from those listed in RPRT-0068, when NIOSH stated that RPRT-0068 was the basis for 

their IGFs. Table 5 details these differences. 

Table 5. Notable differences between SC&A’s IGFs based on RPRT-0085 and 

RPRT-0068 IGFs

Dosimeter location 

and neutron energy 

regions for Hp(10), 

adult phantom

SC&A adult 

female IGF

RPRT-0068 

adult female 

IGF

% 

Diff.

SC&A adult 

male IGF

RPRT-0068 

adult male 

IGF

% 

Diff. 

ROT CC ≤10 keV 1.68 2.09 + 24 NA NA NA

ROT CC 2–20 MeV 1.57 2.11 – 25 1.63 2.05 – 20

ROT LC 2–20 MeV 1.56 2.03 – 23 NA NA NA

ISO CC 2–20 MeV 1.59 2.05 – 22 1.68 2.07 – 18

ISO LC 2–20 MeV 1.68 2.28 – 26 1.67 2.15 – 22

3.4 Probability of causation analysis

3.4.1 NIOSH’s POC calculations

NIOSH’s IREP calculations assumed a 5-year work period starting at age 35 with an assumed 

latency period of 3 years for leukemia, 7 for thyroid, and 10 for all other cancers. NIOSH 

assumed a dose of 2,000 mrem per year was applied as a normal distribution with a 30 percent

error. 

NIOSH calculated POC values using the enterprise edition of IREP version 5.8. The enterprise 

edition performed the POC calculation 30 times, each time using a different seed value, and each 

exposure was sampled 10,000 times. The average of the resultant POC values were used for 

NIOSH’s comparisons. 

NIOSH used Monte Carlo simulations to combine the following elements, shown in equation 1 

(equation 2-1 in RPRT-0085): 

IREP Exposure = Dose × DCC × IGF (1) 

where: 

Dose = 2,000 mrem/yr applied as a normal distribution with a 30 percent error.

DCC = value based on the method in RPRT-0069 (NIOSH, 2016b). The DCC is treated 

as a continuous distribution. A four-point Lagrange interpolation, as 

recommended by ICRP 116 (ICRP, 2010), was used to determine DCC values 

between discrete points.

IGF = 1 for AP, values in RPRT-0085, tables 2-3 through 2-6, for ISO and ROT 

geometries. The IGF was treated as a continuous distribution using a four-point 

Lagrange interpolation. 
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3.4.2 SC&A’s approach to evaluating NIOSH’s POCs

Considering the vast number of iterations assessed by NIOSH, SC&A’s evaluation included only 

a subset of photon and neutron energy ranges, dosimeter locations, and cancers. 

For the energy ranges, SC&A selected the dominate energy ranges of 30–250 keV photons and 

0.1–2 MeV neutrons. 

SC&A evaluated only two of the four dosimeter locations used by NIOSH. SC&A considered 

left chest pocket and left collar as the most likely dosimeter badge wear positions for EEs. 

For evaluation of cancers, SC&A selected the following eight female and eight male cancers: 

1. lung 

2. esophagus 

3. red bone marrow (RBM) (leukemia)

4. adrenals 

5. bladder (upper bowel wall) 

6. breast

7. thymus 

8. prostate (male)/ovaries (female)

SC&A began our review of RPRT-0085 doses and resulting POC values by familiarizing 

ourselves with ICRP 116 and RPRT-0069, which were the basis for NIOSH’s calculation. A 

summary of pertinent information from these documents follows. 

3.4.2.1 ICRP-116 

Photons

ICRP 116 annex B, PDF pages 142–170, lists the picogray (pGy) values, which are absorbed 

dose per unit fluence (i.e., similar to rad per photon per square centimeter (cm2), or ergs per 

photon per cm2

). These values are called “dose conversion coefficients” in ICRP 116 (PDF p. 

11). The DCC values are listed as a function of male or female organs and exposure geometries

of AP, ROT, and ISO (which are of interest in dose reconstruction) for a photon energy range of 

0.01–10 MeV. 

Neutrons 

ICRP-116 annex C, PDF pages 174–203, lists the pGy values, which are absorbed dose, per unit 

fluence (i.e., similar to rad per neutron/cm2, or ergs per neutron/cm2). The DCC values are listed 

as a function of male or female organs and exposure geometries of AP, ROT, and ISO, for a 

neutron energy range of 1E-9 MeV–1E4 MeV.

3.4.2.2 RPRT-0069

Photons

RPRT-0069, table 3-2 (p. 11), lists the “Photon fluence conversion factors” (photon FCF) for 

photon energies ranging from 0.01 to 3.0 MeV. The values applicable to dose reconstruction are 

in the second column, personal deep dose equivalent divided by fluence (Hp(10)/ø), in units of 

picosievert (pSv)-cm2). The values range from 0.065 to 10.950 pSv-cm2. This is the dose 

equivalent per unit fluence (i.e., similar to rem per photon per cm2).
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Equation 3-2 

This equation (reproduced here as equation 2) provides the resulting DCF obtained by dividing 

the photon DCC (pGy-cm2) from ICRP 116 by the photon FCF (pSv-cm2) from table 3-2, 

leaving a fraction with units of pGy/pSv. Therefore, this must be multiplied by the effective dose 

to absorbed dose factor (i.e., Sv/Gy, the quality factor or QF), which is 1.0 for photons in the 

dose reconstruction energy range. This results in pGy/pSv × pSv/pGy = a fraction without units, 

which is what is needed because the DCF is a unitless multiplying factor of dose (2,000 mrem in 

this case). The values in equation 2 are calculated assuming colon cancer, male, AP geometry, 

and a photon energy of 0.100 MeV. 

 (2) 

= 0.512 / 0.67 

= 0.7776512 

Although the review of RPRT-0069 is outside the scope of this review, SC&A was able to 

confirm that equation 2 is correctly using ICRP 116 photon organ dose and RPRT-0069 photon 

FCF. 

Neutrons

RPRT-0069, table 3-3 (p. 12), lists the “Neutron fluence conversion factors” (neutron FCF) for 

neutron energies ranging from 1E-9 MeV to 20 MeV. The values applicable to DR are in the 

second column, Hp(10)/ø in units of pSv-cm2. The values range from 8.19 to 600 pSv-cm2. This 

is the dose equivalent per unit fluence (i.e., similar to rem per neutron per cm2

).

Equation 3-3 

This equation (reproduced here as equation 3), provides the resulting DCF obtained by dividing 

the neutron DCC (pGy-cm2) from ICRP-116 by the neutron FCF (pSv-cm2) from table 3-3, 

leaving a fraction with units of pGy/pSv. Therefore, this must be multiplied by the effective dose 

to absorbed dose factor, which is wR (equation 3-1 of RPRT-0069, p. 10), as a function of 

neutron energy. (However, ICRP Publication 74 (1996), table 2, PDF p. 15, provides an averaged 

wR for 0.1–2.0 MeV neutrons of 20.) Multiplying equation 3-3 by wR results in pGy/pSv × 

pSv/pGy = a fraction without units, which is what is needed because the DCF is a unitless 

multiplying factor of dose. The values in equation 3 are calculated assuming colon cancer, male, 

AP geometry, and an energy of 0.100 MeV neutrons. 

 (3) 

Using the ICRP 116 neutron organ dose and RPRT-0069 neutron FCF, SC&A was able to 

calculate the same value shown in equation 3. 
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3.4.3 SC&A’s evaluation of NIOSH’s IREP exposure equation 2-1 

SC&A evaluated NIOSH’s equation for calculating doses for entry in IREP. Although NIOSH’s

equation (reproduced as equation 1 in this report), uses the term DCC in the calculation, SC&A 

found that it is more accurate to introduce the DCF value, which incorporates the DCC values as 

shown in equation 4. 

Dose equivalent (rem) = Dose (rem) × DCF × IGF

= Dose (rem) × [(DCC × 1/FCF) × (QF or wR)] × IGF (4) 

where:

DCC = the dose conversion coefficient in units of pGy-cm2 from ICRP 116 annex B for 

photons and annex C for neutrons. 

FCF = the fluence conversion factor in units of pSv-cm2 from RPRT-0069 table 3-2 for 

photons and table 3-3 for neutrons. 

QF = the quality factor (or weighting factor, wR,), which is 1 for photons and an 

average of 20 for 0.1–2.0 MeV neutrons, in units of pSv/pGy. 

IGF = the irradiation geometry factor, which is a function of four dosimeter badge 

positions. 

3.4.4 SC&A’s DCF values

As stated in section 2-1, NIOSH employed Monte Carlo methods for calculating doses to be 

entered in IREP. For evaluating POC values, SC&A did not use Monte Carlo techniques for 

calculating doses but derived an average DCF values from data in RPRT-0069, attachments A 

and B. Attachment A of RPRT-0069 lists photon organ DCF values for AP, PA, ROT, and ISO 

geometries for all ICRP 116 cancers. The photon DCFs are separated into 20 energies within the 

range 0.01 MeV through 3 MeV. Attachment B lists the neutron organ DCF values divided into 

33 energies within the range 1.0E-9 through 2 MeV. 

Since RPRT-0069 gives photon DCF values for 0.2 MeV and 0.3 MeV photons, SC&A averaged 

those values to derive the 250 keV photon energy DCF. Then, SC&A derived a 30–250 keV 

photon DCF value using the eight DCF energies listed in RPRT-0069 along with the arithmetic 

mean of the 0.2 MeV and 0.3 MeV photon DCFs. SC&A also used the 10 DCF energy values 

from RPRT-0069 attachment B to calculate an average 0.1–2 MeV neutron DCF. Tables 6 and 7 

show the resulting photon and neutron DCF values, respectively, for the eight female and eight 

male cancers for the AP, ROT, and ISO geometries. 
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Table 6. SC&A’s 30–250 keV photon DCFs based on RPRT-0069

Organ Adult female 

AP DCF

Adult female 

ROT DCF

Adult female 

ISO DCF

Adult male 

AP DCF

Adult male 

ROT DCF

Adult male 

ISO DCF

Lung 0.5972 0.4683 0.3777 0.6120 0.4103 0.3379

Esophagus 0.6820 0.4318 0.3152 0.5573 0.3820 0.2897

RBM 0.6330 0.5267 0.4198 0.5816 0.4832 0.3853

Adrenals 0.3260 0.2667 0.3910 0.2765 0.3796 0.2866

UB-wall 0.8814 0.4317 0.3508 0.7252 0.3937 0.2954

Breast 0.8202 0.4769 0.4288 0.8308 0.4677 0.4380

Thymus 0.8778 0.4403 0.3676 0.8727 0.4327 0.3539

Prostate NA NA NA 0.5432 0.3541 0.2711

Uterus 0.5604 0.3557 0.2770 NA NA NA

Table 7. SC&A’s 0.1–2 MeV neutron DCFs based on RPRT-0069

Organ Adult female 

AP DCF

Adult female 

ROT DCF

Adult female 

ISO DCF

Adult male 

AP DCF

Adult male 

ROT DCF

Adult male 

ISO DCF

Lung 0.4887 0.3653 0.2800 0.5439 0.3378 0.2654

Esophagus 0.5417 0.3468 0.2551 0.5155 0.3267 0.2397

RBM 0.4452 0.3435 0.2641 0.4273 0.3435 0.2627

Adrenals 0.3341 0.3119 0.2169 0.2137 0.3100 0.2203

UB-wall 0.9220 0.3662 0.2801 0.6675 0.3067 0.2211

Breast 1.2789 0.6185 0.5401 1.4138 0.6811 0.6183

Thymus 0.9940 0.3928 0.3044 1.0410 0.4172 0.3241

Prostate NA NA NA 0.5009 0.2741 0.1982

Uterus 0.4931 0.2676 0.1988 NA NA NA

3.4.5 SC&A’s POC values

Using IGF values for the LCP and LC from tables 1 through 4 of this report and AP, ISO, and 

ROT DCF values from tables 6 and 7, SC&A generated POC values assuming a 2.000 rem 

measured 30–250 keV photon dose per year for 5 years and a 2.000 rem measured 0.1–2.0 MeV 

neutron dose per year for 5 years. SC&A calculated the POCs using IREP-EE v.5.9 and entered

doses in IREP as a normal dose distribution with a geometric standard deviation (GSD) of 30 

percent. 

Tables 8 through 11 compare SC&A’s and NIOSH’s POC values generated for 30–250 keV 

photons and 0.1–2.0 MeV neutrons for the eight female and eight male cancers. 
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Table 8. Comparison of SC&A POC values and NIOSH POC values for eight female 

organs for photon energies 30–250 keV

Geometry/dosimeter

location/female 

organ

SC&A 

photon 

DCF

SC&A 

photon 

IGF 

SC&A 

photon 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC 

Ratio of SC&A 

to NIOSH POC

AP/LCP/Adrenals 0.3260 1.00 0.652 22.78% 18.41% 0.81

ISO/LCP/Adrenals 0.3910 1.48 1.157 36.00% 29.48% 0.82

ROT/LCP/Adrenals 0.2667 1.48 0.789 27.06% 21.96% 0.81

AP/LC/Adrenals 0.3260 1.00 0.652 22.77% 18.41% 0.81

ISO/LC/Adrenals 0.3910 1.91 1.494 40.73% 35.43% 0.87

ROT/LC/Adrenals 0.2667 1.91 1.019 30.98% 26.76% 0.86

AP/LCP/Breast 0.8202 1.00 1.640 24.91% 23.39% 0.94

ISO/LCP/Breast 0.4288 1.48 1.269 20.99% 18.91% 0.90

ROT/LCP/Breast 0.4769 1.48 1.412 23.07% 20.70% 0.90

AP/LC/Breast 0.8202 1.00 1.640 24.82% 23.39% 0.94

ISO/LC/Breast 0.4288 1.91 1.638 25.57% 23.37% 0.91

ROT/LC/Breast 0.4769 1.91 1.822 26.52% 25.41% 0.96

AP/LCP/Lung 0.5972 1.00 1.194 54.03% 50.64% 0.94

ISO/LCP/Lung 0.3777 1.48 1.118 52.99% 48.88% 0.92

ROT/LCP/Lung 0.4683 1.48 1.386 58.46% 54.66% 0.93

AP/LC/Lung 0.5972 1.00 1.194 53.98% 50.64% 0.94

ISO/LC/Lung 0.3777 1.91 1.443 59.39% 55.07% 0.93

ROT/LC/Lung 0.4683 1.91 1.789 62.66% 61.23% 0.98

AP/LCP/Esophagus 0.6820 1.00 1.364 34.22% 31.01% 0.91

ISO/LCP/Esophagus 0.3152 1.48 0.933 26.90% 22.86% 0.85

ROT/LCP/Esophagus 0.4318 1.48 1.278 34.00% 29.50% 0.87

AP/LC/Esophagus 0.6820 1.00 1.364 34.45% 31.01% 0.90

ISO/LC/Esophagus 0.3152 1.91 1.204 32.23% 28.17% 0.87

ROT/LC/Esophagus 0.4318 1.91 1.650 38.42% 25.27% 0.66

AP/LCP/Uterus 0.5604 1.00 1.121 0.72% 0.57% 0.79

ISO/LCP/Uterus 0.2770 1.48 0.820 0.51% 0.40% 0.78

ROT/LCP/Uterus 0.3557 1.48 1.053 0.68% 0.53% 0.78

AP/LC/Uterus 0.5604 1.00 1.121 0.71% 0.57% 0.80

ISO/LC/Uterus 0.2770 1.91 1.058 0.67% 0.53% 0.79

ROT/LC/Uterus 0.3557 1.91 1.359 0.84% 0.72% 0.86

AP/LCP/RBM-Leuk 0.6330 1.00 1.266 79.08% 64.26% 0.81

ISO/LCP/RBM-Leuk 0.4198 1.48 1.243 78.76% 63.81% 0.81

ROT/LCP/RBM-Leuk 0.5267 1.48 1.559 82.62% 69.19% 0.84

AP/LC/RBM-Leuk 0.6330 1.00 1.266 79.03% 64.26% 0.81

ISO/LC/RBM-Leuk 0.4198 1.91 1.604 82.89% 69.84% 0.84

ROT/LC/RBM-Leuk 0.5267 1.91 2.012 85.25% 74.77% 0.88

AP/LCP/Thymus 0.8778 1.00 1.756 21.00% 19.63% 0.93
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Geometry/dosimeter

location/female 

organ

SC&A 

photon 

DCF

SC&A 

photon 

IGF 

SC&A 

photon 

dose 

(rem)

NIOSH 

RPRT-0085 

SC&A 

calculated 

POC POC 

Ratio of SC&A 

to NIOSH POC

ISO/LCP/Thymus 0.3676 1.48 1.088 14.62% 12.51% 0.86

ROT/LCP/Thymus 0.4403 1.48 1.303 17.20% 14.91% 0.87

AP/LC/Thymus 0.8778 1.00 1.756 20.94% 19.63% 0.94

ISO/LC/Thymus 0.3676 1.91 1.404 18.29% 15.99% 0.87

ROT/LC/Thymus 0.4403 1.91 1.682 20.07% 18.89% 0.94

AP/LCP/UB-Wall 0.8814 1.00 1.763 39.66% 37.90% 0.96

ISO/LCP/UB-Wall 0.3508 1.48 1.038 28.91% 25.67% 0.89

ROT/LCP/UB-Wall 0.4317 1.48 1.278 33.38% 30.25% 0.91

AP/LC/UB-Wall 0.8814 1.00 1.763 39.77% 37.90% 0.95

ISO/LC/UB-Wall 0.3508 1.91 1.340 34.42% 31.33% 0.91

ROT/LC/UB-Wall 0.4317 1.91 1.649 37.79% 36.24% 0.96

Table 9. Comparison of SC&A POC values and NIOSH POC values for eight male 

organs for photon energies 30–250 keV

Geometry/dosimeter

location/male organ

SC&A 

photon 

DCF

SC&A 

photon 

IGF

SC&A 

photon 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC

Ratio of

SC&A to

NIOSH 

POC

AP/LCP/Adrenals 0.2765 1.00 0.553 10.46% 7.93% 0.76

ISO/LCP/Adrenals 0.2866 1.55 0.888 15.62% 12.58% 0.81

ROT/LCP/Adrenals 0.3796 1.57 1.192 19.86% 16.50% 0.83

AP/LC/Adrenals 0.2765 1.00 0.553 10.41% 7.93% 0.76

ISO/LC/Adrenals 0.2866 1.87 1.072 18.16% 14.08% 0.78

ROT/LC/Adrenals 0.3796 1.75 1.328 21.44% 18.15% 0.85

AP/LCP/Breast 0.8308 1.00 1.662 28.07% 26.53% 0.95

ISO/LCP/Breast 0.4380 1.55 1.358 24.53% 22.64% 0.92

ROT/LCP/Breast 0.4677 1.57 1.469 26.39% 24.11% 0.91

AP/LC/Breast 0.8308 1.00 1.662 27.94% 26.53% 0.95

ISO/LC/Breast 0.4380 1.87 1.638 28.10% 26.24% 0.93

ROT/LC/Breast 0.4677 1.75 1.637 28.36% 26.23% 0.92

AP/LCP/Lung 0.6120 1.00 1.224 30.98% 27.97% 0.90

ISO/LCP/Lung 0.3379 1.55 1.048 28.91% 24.70% 0.85

ROT/LCP/Lung 0.4103 1.57 1.288 33.10% 29.13% 0.88

AP/LC/Lung 0.6120 1.00 1.224 30.91% 27.97% 0.90

ISO/LC/Lung 0.3379 1.87 1.264 32.85% 28.71% 0.87

ROT/LC/Lung 0.4103 1.75 1.436 35.61% 31.56% 0.89

AP/LCP/Esophagus 0.5573 1.00 1.115 20.87% 18.10% 0.87

ISO/LCP/Esophagus 0.2897 1.55 0.898 18.33% 14.87% 0.81

ROT/LCP/Esophagus 0.3820 1.57 1.199 23.21% 19.32% 0.83
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Geometry/dosimeter

location/male organ

SC&A 

photon 

DCF

SC&A 

photon 

IGF

SC&A 

photon 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC

Ratio of

SC&A to

NIOSH 

POC

AP/LC/Esophagus 0.5573 1.00 1.115 20.81% 18.10% 0.87

ISO/LC/Esophagus 0.2897 1.87 1.083 21.37% 17.62% 0.82

ROT/LC/Esophagus 0.3820 1.75 1.337 25.21% 21.25% 0.84

AP/LCP/Prostate 0.5432 1.00 1.086 12.36% 9.92% 0.80

ISO/LCP/Prostate 0.2711 1.55 0.840 9.79% 7.63% 0.78

ROT/LCP/Prostate 0.3541 1.57 1.112 12.71% 10.16% 0.80

AP/LC/Prostate 0.5432 1.00 1.086 12.37% 9.92% 0.80

ISO/LC/Prostate 0.2711 1.87 1.014 11.67% 9.25% 0.79

ROT/LC/Prostate 0.3541 1.75 1.239 14.04% 11.32% 0.81

AP/LCP/RBM-Leuk 0.5816 1.00 1.163 79.77% 64.82% 0.81

ISO/LCP/RBM-Leuk 0.3853 1.55 1.194 80.61% 65.45% 0.81

ROT/LCP/RBM-Leuk 0.4832 1.57 1.517 84.12% 70.99% 0.84

AP/LC/RBM-Leuk 0.5816 1.00 1.163 79.70% 64.82% 0.81

ISO/LC/RBM-Leuk 0.3853 1.87 1.441 83.84% 69.84% 0.83

ROT/LC/RBM-Leuk 0.4832 1.75 1.691 85.50% 73.35% 0.86

AP/LCP/Thymus 0.8727 1.00 1.745 10.85% 10.02% 0.92

ISO/LCP/Thymus 0.3539 1.55 1.097 7.57% 6.25% 0.83

ROT/LCP/Thymus 0.4327 1.57 1.359 9.15% 7.80% 0.85

AP/LC/Thymus 0.8727 1.00 1.745 10.92% 10.02% 0.92

ISO/LC/Thymus 0.3539 1.87 1.323 9.03% 7.59% 0.84

ROT/LC/Thymus 0.4327 1.75 1.515 10.10% 8.71% 0.86

AP/LCP/UB-Wall 0.7252 1.00 1.450 20.13% 17.78% 0.88

ISO/LCP/UB-Wall 0.2954 1.55 0.916 14.17% 11.63% 0.82

ROT/LCP/UB-Wall 0.3937 1.57 1.236 18.25% 15.42% 0.84

AP/LC/UB-Wall 0.7252 1.00 1.450 20.09% 17.78% 0.89

ISO/LC/UB-Wall 0.2954 1.87 1.105 16.65% 13.90% 0.83

ROT/LC/UB-Wall 0.3937 1.75 1.378 19.65% 17.02% 0.87

Table 10. Comparison of SC&A POC values and NIOSH POC values for eight female 

organs for neutron energies 0.1–2 MeV

Geometry/dosimeter

location/female 

organ

SC&A 

neutron 

DCF

SC&A 

neutron 

IGF

SC&A 

neutron 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC

Ratio of 

SC&A to 

NIOSH 

POC

AP/LCP/Adrenals 0.3341 1.00 0.668 11.03% 11.15% 1.01

ISO/LCP/Adrenals 0.2169 1.49 0.646 11.40% 10.82% 0.95

ROT/LCP/Adrenals 0.3119 1.49 0.929 15.79% 14.85% 0.94

AP/LC/Adrenals 0.3341 1.00 0.668 11.04% 11.15% 1.01

ISO/LC/Adrenals 0.2169 1.79 0.776 14.90% 12.72% 0.85
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Geometry/dosimeter

location/female 

organ

SC&A 

neutron 

DCF

SC&A 

neutron 

IGF

SC&A 

neutron 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC

Ratio of 

SC&A to 

NIOSH 

POC

ROT/LC/Adrenals 0.3119 1.79 1.117 18.92% 17.34% 0.92

AP/LCP/Breast 1.2789 1.00 2.558 19.17% 18.66% 0.97

ISO/LCP/Breast 0.5401 1.49 1.610 14.19% 12.62% 0.89

ROT/LCP/Breast 0.6185 1.49 1.843 15.64% 14.18% 0.91

AP/LC/Breast 1.2789 1.00 2.558 19.24% 18.66% 0.97

ISO/LC/Breast 0.5401 1.79 1.934 18.33% 14.78% 0.81

ROT/LC/Breast 0.6185 1.79 2.214 18.76% 16.57% 0.88

AP/LCP/Lung 0.4887 1.00 0.977 31.21% 29.09% 0.93

ISO/LCP/Lung 0.2800 1.49 0.834 28.93% 25.93% 0.90

ROT/LCP/Lung 0.3653 1.49 1.089 34.60% 31.37% 0.91

AP/LC/Lung 0.4887 1.00 0.977 31.43% 29.09% 0.93

ISO/LC/Lung 0.2800 1.79 1.002 35.73% 29.61% 0.83

ROT/LC/Lung 0.3653 1.79 1.308 39.73% 35.45% 0.89

AP/LCP/Esophagus 0.5417 1.00 1.083 15.64% 14.54% 0.93

ISO/LCP/Esophagus 0.2551 1.49 0.760 11.76% 10.66% 0.91

ROT/LCP/Esophagus 0.3468 1.49 1.034 15.27% 13.97% 0.91

AP/LC/Esophagus 0.5417 1.00 1.083 15.52% 14.54% 0.94

ISO/LC/Esophagus 0.2551 1.79 0.913 15.28% 12.54% 0.82

ROT/LC/Esophagus 0.3468 1.79 1.242 18.42% 16.32% 0.89

AP/LCP/Uterus 0.4931 1.00 0.986 0.21% 0.20% 0.95

ISO/LCP/Uterus 0.1988 1.49 0.592 0.13% 0.12% 0.92

ROT/LCP/Uterus 0.2676 1.49 0.797 0.17% 0.16% 0.94

AP/LC/Uterus 0.4931 1.00 0.986 0.21% 0.20% 0.95

ISO/LC/Uterus 0.1988 1.79 0.712 0.17% 0.15% 0.88

ROT/LC/Uterus 0.2676 1.79 0.958 0.21% 0.20% 0.95

AP/LCP/RBM-Leuk 0.4452 1.00 0.890 69.60% 54.51% 0.78

ISO/LCP/RBM-Leuk 0.2641 1.49 0.787 68.05% 51.45% 0.76

ROT/LCP/RBM-Leuk 0.3435 1.49 1.024 73.77% 57.96% 0.79

AP/LC/RBM-Leuk 0.4452 1.00 0.890 69.58% 54.51% 0.78

ISO/LC/RBM-Leuk 0.2641 1.79 0.945 74.31% 55.99% 0.75

ROT/LC/RBM-Leuk 0.3435 1.79 1.230 77.51% 62.35% 0.80

AP/LCP/Thymus 0.9940 1.00 1.988 11.65% 10.69% 0.92

ISO/LCP/Thymus 0.3044 1.49 0.907 5.94% 5.18% 0.87

ROT/LCP/Thymus 0.3928 1.49 1.171 7.38% 6.59% 0.89

AP/LC/Thymus 0.9940 1.00 1.988 11.65% 10.69% 0.92

ISO/LC/Thymus 0.3044 1.79 1.090 7.84% 6.16% 0.79

ROT/LC/Thymus 0.3928 1.79 1.406 9.03% 7.18% 0.80

AP/LCP/UB-Wall 0.9220 1.00 1.844 25.40% 23.66% 0.93

ISO/LCP/UB-Wall 0.2801 1.49 0.835 13.34% 12.31% 0.92

ROT/LCP/UB-Wall 0.3662 1.49 1.091 16.65% 15.50% 0.93
Effective date: 5/11/2023 Revision No. 1 (Draft) Document No.: SCA-TR-2023-PR085 Page 22 of 31

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Geometry/dosimeter

location/female 

organ

SC&A 

neutron 

DCF

SC&A 

neutron 

IGF

SC&A 

neutron 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC

Ratio of 

SC&A to 

NIOSH 

POC

AP/LC/UB-Wall 0.9220 1.00 1.844 25.45% 23.66% 0.93

ISO/LC/UB-Wall 0.2801 1.79 1.003 17.39% 14.43% 0.83

ROT/LC/UB-Wall 0.3662 1.79 1.311 19.90% 18.06% 0.91

Table 11. Comparison of SC&A POC values and NIOSH POC values for eight male 

organs for neutron energies 0.1–2 MeV

Geometry/dosimeter

location/male organ

SC&A 

neutron 

DCF

SC&A 

neutron 

IGF 

SC&A 

neutron 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC 

Ratio of 

SC&A to 

NIOSH 

POC 

AP/LCP/Adrenals 0.2137 1.00 0.427 3.21% 3.52% 1.10

ISO/LCP/Adrenals 0.2203 1.61 0.709 5.87% 5.71% 0.97

ROT/LCP/Adrenals 0.3100 1.63 1.011 8.05% 7.94% 0.99

AP/LC/Adrenals 0.2137 1.00 0.427 3.21% 3.52% 1.10

ISO/LC/Adrenals 0.2203 2.03 0.894 7.24% 7.09% 0.98

ROT/LC/Adrenals 0.3100 1.84 1.141 9.03% 8.87% 0.98

AP/LCP/Breast 1.4138 1.00 2.828 23.72% 23.44% 0.99

ISO/LCP/Breast 0.6183 1.61 1.991 18.90% 17.73% 0.94

ROT/LCP/Breast 0.6811 1.63 2.220 20.18% 19.38% 0.96

AP/LC/Breast 1.4138 1.00 2.828 23.76% 23.44% 0.99

ISO/LC/Breast 0.6183 2.03 2.510 22.69% 21.37% 0.94

ROT/LC/Breast 0.6811 1.84 2.507 22.31% 21.35% 0.96

AP/LCP/Lung 0.5439 1.00 1.088 16.14% 14.30% 0.89

ISO/LCP/Lung 0.2654 1.61 0.855 12.40% 11.60% 0.94

ROT/LCP/Lung 0.3378 1.63 1.101 15.28% 14.45% 0.95

AP/LC/Lung 0.5439 1.00 1.088 15.24% 14.30% 0.94

ISO/LC/Lung 0.2654 2.03 1.078 15.04% 14.19% 0.94

ROT/LC/Lung 0.3378 1.84 1.243 17.00% 16.01% 0.94

AP/LCP/Esophagus 0.5155 1.00 1.031 9.37% 9.03% 0.96

ISO/LCP/Esophagus 0.2397 1.61 0.772 7.13% 6.92% 0.97

ROT/LCP/Esophagus 0.3267 1.63 1.065 9.56% 9.30% 0.97

AP/LC/Esophagus 0.5155 1.00 1.031 9.33% 9.03% 0.97

ISO/LC/Esophagus 0.2397 2.03 0.973 8.77% 8.57% 0.98

ROT/LC/Esophagus 0.3267 1.84 1.202 10.67% 10.37% 0.97

AP/LCP/Prostate 0.5009 1.00 1.002 4.70% 4.53% 0.96

ISO/LCP/Prostate 0.1982 1.61 0.638 2.96% 2.93% 0.99

ROT/LCP/Prostate 0.2741 1.63 0.894 4.11% 4.06% 0.99

AP/LC/Prostate 0.5009 1.00 1.002 4.68% 4.53% 0.97

ISO/LC/Prostate 0.1982 2.03 0.804 3.69% 3.67% 0.99
Effective date: 5/11/2023 Revision No. 1 (Draft) Document No.: SCA-TR-2023-PR085 Page 23 of 31

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Geometry/dosimeter

location/male organ

SC&A 

neutron 

DCF

SC&A 

neutron 

IGF 

SC&A 

neutron 

dose 

(rem)

NIOSH 

RPRT-0085 

POC

SC&A 

calculated 

POC 

Ratio of 

SC&A to 

NIOSH 

POC 

ROT/LC/Prostate 0.2741 1.84 1.009 4.61% 4.56% 0.99

AP/LCP/RBM-Leuk 0.4273 1.00 0.855 71.08% 56.53% 0.80

ISO/LCP/RBM-Leuk 0.2627 1.61 0.846 71.24% 56.27% 0.79

ROT/LCP/RBM-Leuk 0.3435 1.63 1.120 76.39% 63.01% 0.82

AP/LC/RBM-Leuk 0.4273 1.00 0.855 70.98% 56.53% 0.80

ISO/LC/RBM-Leuk 0.2627 2.03 1.067 75.55% 61.88% 0.82

ROT/LC/RBM-Leuk 0.3435 1.84 1.264 78.67% 65.79% 0.84

AP/LCP/Thymus 1.0410 1.00 2.082 5.80% 5.44% 0.94

ISO/LCP/Thymus 0.3241 1.61 1.044 3.02% 2.81% 0.93

ROT/LCP/Thymus 0.4172 1.63 1.360 3.91% 3.63% 0.93

AP/LC/Thymus 1.0410 1.00 2.082 5.82% 5.44% 0.93

ISO/LC/Thymus 0.3241 2.03 1.316 3.78% 3.51% 0.93

ROT/LC/Thymus 0.4172 1.84 1.535 4.38% 4.07% 0.93

AP/LCP/UB-Wall 0.6675 1.00 1.335 9.44% 8.98% 0.95

ISO/LCP/UB-Wall 0.2211 1.61 0.712 6.09% 5.00% 0.82

ROT/LCP/UB-Wall 0.3067 1.63 1.000 7.05% 6.88% 0.98

AP/LC/UB-Wall 0.6675 1.00 1.335 9.43% 8.98% 0.95

ISO/LC/UB-Wall 0.2211 2.03 0.898 6.35% 6.23% 0.98

ROT/LC/UB-Wall 0.3067 1.84 1.129 7.89% 7.70% 0.98

This comparison shows relatively close agreement between SC&A’s POC values and those 

generated by NIOSH. Some difference in POC values was expected, since NIOSH used Monte 

Carlo methods to generate dose and SC&A used average values. With only a few exceptions, 

SC&A’s values were less than NIOSH’s POC values. SC&A has no findings or observations 

about NIOSH’s RPRT-0085 POC values. 

3.5 Dose-only analysis

3.5.1 NIOSH’s dose analysis approach

In addition to determining POC values, NIOSH performed a dose-only analysis. This analysis 

assumed 500 mrem of measured dose and 500 mrem of missed dose combined with ICRP 116 

DCCs and RPRT-0068 IGFs for the four dosimeter locations. Doses were derived by applying 

Monte Carlo methods for generating DCCs and IGFs. The measured dose was assumed to

represent a normal distribution with a 30 percent error, and the missed dose was represented by a 

lognormal distribution with a GSD of 1.52. 
Effective date: 5/11/2023 Revision No. 1 (Draft) Document No.: SCA-TR-2023-PR085 Page 24 of 31

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3.5.2 SC&A’s dose analysis approach

As a means of comparison, SC&A also calculated doses based on NIOSH’s approach. However, 

since SC&A did not apply a Monte Carlo method, our dose equation was simplified as shown in 

equation 5: 

Total dose = (0.5 rem × DCF × IGF) + (0.5 rem × DCF × IGF)

= 1 rem × DCF × IGF

(5) 

Tables 12–15 compare SC&A and NIOSH doses generated for 30–250 keV photons and 0.1–

2.0 MeV neutrons for the eight female and eight male cancers.
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Table 12. Comparison of SC&A doses and NIOSH doses for eight female organs for 30–250 keV photons

Organ/ 

dosimeter

location

SC&A AP 

dose 

(rem)

SC&A 

ISO dose 

(rem)

SC&A 

ROT dose 

(rem)

NIOSH 

AP dose 

(rem)

NIOSH 

ISO dose 

(rem)

NIOSH 

ROT dose 

(rem)

Percentage 

AP SC&A/ 

NIOSH

Percentage 

ISO SC&A/ 

NIOSH

Percentage 

ROT SC&A/ 

NIOSH

Lung/LCP 0.5972 0.5598 0.6955 0.769 0.749 0.917 77.66% 74.74% 75.84%

Esophagus/LCP 0.6820 0.4671 0.6413 0.810 0.580 0.795 84.20% 80.54% 80.67%

RBM/LCP 0.6330 0.6222 0.7822 0.729 0.723 0.908 86.83% 86.05% 86.15%

Adrenals/LCP 0.3260 0.5796 0.3961 0.426 0.747 0.520 76.53% 77.59% 76.17%

UB-wall/LCP 0.8814 0.5200 0.6411 0.945 0.681 0.835 93.27% 76.35% 76.78%

Breast/LCP 0.8202 0.6355 0.7083 0.881 0.712 0.791 93.09% 89.26% 89.54%

Thymus/LCP 0.8778 0.5449 0.6539 0.949 0.733 0.875 92.50% 74.33% 74.73%

Uterus/LCP 0.5604 0.4106 0.5283 0.701 0.528 0.673 79.95% 77.76% 78.50%

Lung/LC 0.5972 0.7214 0.8381 0.668 0.943 1.096 89.41% 76.50% 76.47%

Esophagus/LC 0.6820 0.6019 0.7728 0.809 0.740 0.940 84.31% 81.34% 82.21%

RBM/LC 0.6330 0.8017 0.9426 0.729 1.008 1.078 86.83% 79.53% 87.44%

Adrenals/LC 0.3260 0.7468 0.4773 0.428 0.944 0.624 76.17% 79.11% 76.49%

UB-wall/LC 0.8814 0.6700 0.7725 0.949 0.862 0.991 92.88% 77.73% 77.95%

Breast/LC 0.8202 0.8189 0.8535 0.888 0.902 0.940 92.36% 90.79% 90.79%

Thymus/LC 0.8778 0.7021 0.7879 0.952 0.923 1.037 92.21% 76.07% 75.98%

Uterus/LC 0.5604 0.5291 0.6366 0.702 0.672 0.808 79.83% 78.73% 78.79%

Table 13. Comparison of SC&A doses and NIOSH doses for eight male organs for 30–250 keV photons

Organ/ 

dosimeter

location

SC&A AP 

dose 

(rem)

SC&A 

ISO dose 

(rem)

SC&A 

ROT dose 

(rem)

NIOSH 

AP dose 

(rem)

NIOSH 

ISO dose 

(rem)

NIOSH 

ROT dose 

(rem)

Percentage 

AP SC&A/ 

NIOSH

Percentage 

ISO SC&A/ 

NIOSH

Percentage 

ROT SC&A/ 

NIOSH

Lung/LCP 0.6120 0.5249 0.6432 0.689 0.655 0.792 88.82% 80.14% 81.21%

Esophagus/LCP 0.5573 0.4499 0.5987 0.757 0.583 0.767 73.62% 77.17% 78.06%

RBM/LCP 0.5816 0.5984 0.7574 0.680 0.710 0.889 85.52% 84.28% 85.20%

Adrenals/LCP 0.2765 0.4451 0.5949 0.369 0.573 0.747 74.94% 77.69% 79.64%
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Organ/ 

dosimeter

location

SC&A AP 

dose 

(rem)

SC&A 

ISO dose 

(rem)

SC&A 

ROT dose 

(rem)

NIOSH 

AP dose 

(rem)

NIOSH 

ISO dose 

(rem)

NIOSH 

ROT dose 

(rem)

Percentage 

AP SC&A/ 

NIOSH

Percentage 

ISO SC&A/ 

NIOSH

Percentage 

ROT SC&A/ 

NIOSH

UB-wall/LCP 0.7252 0.4588 0.6170 0.860 0.576 0.765 84.32% 79.66% 80.66%

Breast/LCP 0.8308 0.6803 0.7331 0.893 0.746 0.813 93.04% 91.19% 90.17%

Thymus/LCP 0.8727 0.5496 0.6783 0.947 0.752 0.902 92.15% 73.09% 75.19%

Prostate/LCP 0.5432 0.4211 0.5550 0.701 0.548 0.718 77.49% 76.84% 77.29%

Lung/LC 0.6120 0.6334 0.7168 0.798 0.780 0.879 76.69% 81.21% 81.54%

Esophagus/LC 0.5573 0.5429 0.6672 0.752 0.694 0.946 74.10% 78.23% 70.53%

RBM/LC 0.5816 0.7221 0.8441 0.681 0.844 0.993 85.40% 85.56% 85.00%

Adrenals/LC 0.2765 0.5372 0.6630 0.369 0.677 0.831 74.94% 79.35% 79.78%

UB-wall/LC 0.7252 0.5537 0.6876 0.861 0.692 0.847 84.22% 80.01% 81.18%

Breast/LC 0.8308 0.8209 0.8170 0.891 0.893 0.895 93.25% 91.93% 91.28%

Thymus/LC 0.8727 0.6632 0.7559 0.951 0.894 1.005 91.77% 74.19% 75.21%

Prostate/LC 0.5432 0.5081 0.6185 0.696 0.654 0.793 78.05% 77.69% 77.99%

Table 14. Comparison of SC&A doses and NIOSH doses for eight female organs for 0.1–2.0 MeV neutrons

Organ/ 

Dosimeter

location

SC&A AP 

dose 

(rem)

SC&A 

ISO dose 

(rem)

SC&A 

ROT dose 

(rem)

NIOSH 

AP dose 

(rem)

NIOSH 

ISO dose 

(rem)

NIOSH 

ROT dose 

(rem)

Percentage 

AP SC&A/ 

NIOSH

Percentage 

ISO SC&A/ 

NIOSH

Percentage 

ROT SC&A/ 

NIOSH

Lung/LCP 0.4887 0.4331 0.5678 0.535 0.472 0.623 91.35% 91.76% 91.13%

Esophagus/LCP 0.5417 0.3946 0.5390 0.586 0.418 0.573 92.44% 94.41% 94.07%

RBM/LCP 0.4452 0.4085 0.5339 0.466 0.436 0.570 95.54% 93.69% 93.66%

Adrenals/LCP 0.3341 0.3355 0.4847 0.330 0.339 0.494 101.23% 98.95% 98.12%

UB-wall/LCP 0.9220 0.4333 0.5692 1.006 0.462 0.597 91.65% 93.78% 95.35%

Breast/LCP 1.2789 0.8355 0.9612 1.356 0.926 1.046 94.31% 90.22% 91.90%

Thymus/LCP 0.9940 0.4709 0.6106 1.093 0.514 0.657 90.95% 91.62% 92.93%

Uterus/LCP 0.4931 0.3075 0.4159 0.512 0.307 0.416 96.31% 100.15% 99.97%

Lung/LC 0.4887 0.5971 0.7093 0.535 0.649 0.770 91.35% 92.00% 92.11%

Esophagus/LC 0.5417 0.5440 0.6734 0.582 0.572 0.712 93.08% 95.11% 94.58%
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Organ/ 

Dosimeter

location

SC&A AP 

dose 

(rem)

SC&A 

ISO dose 

(rem)

SC&A 

ROT dose 

NIOSH 

AP dose 

(rem) (rem)

NIOSH 

ISO dose 

(rem)

NIOSH 

ROT dose 

(rem)

Percentage 

AP SC&A/ 

NIOSH

Percentage 

ISO SC&A/ 

NIOSH

Percentage 

ROT SC&A/ 

NIOSH

RBM/LC 0.4452 0.5631 0.6670 0.471 0.597 0.709 94.52% 94.32% 94.07%

Adrenals/LC 0.3341 0.4624 0.6055 0.328 0.462 0.616 101.85% 100.09% 98.30%

UB-wall/LC 0.9220 0.5973 0.7111 1.007 0.630 0.746 91.56% 94.80% 95.32%

Breast/LC 1.2789 1.1517 1.2008 1.355 1.273 1.304 94.38% 90.47% 92.09%

Thymus/LC 0.9940 0.6492 0.7627 1.094 0.699 0.817 90.86% 92.87% 93.36%

Uterus/LC 0.4931 0.4239 0.5195 0.511 0.419 0.515 96.50% 101.16% 100.87%

Table 15. Comparison of SC&A doses and NIOSH doses for eight male organs for 0.1–2.0 MeV neutrons

Organ/ 

Dosimeter

location

SC&A AP 

dose 

(rem)

SC&A 

ISO dose 

(rem)

SC&A 

ROT dose 

(rem)

NIOSH 

AP dose 

(rem)

NIOSH 

ISO dose 

(rem)

NIOSH 

ROT dose 

(rem)

Percentage 

AP SC&A/ 

NIOSH

Percentage 

ISO SC&A/ 

NIOSH

Percentage 

ROT SC&A/ 

NIOSH

Lung/LCP 0.5439 0.4275 0.5518 0.586 0.461 0.585 92.81% 92.74% 94.33%

Esophagus/LCP 0.5155 0.3861 0.5337 0.541 0.396 0.550 95.29% 97.50% 97.04%

RBM/LCP 0.4273 0.4232 0.5610 0.444 0.445 0.586 96.24% 95.10% 95.74%

Adrenals/LCP 0.2137 0.3548 0.5064 0.194 0.362 0.513 110.14% 98.01% 98.72%

UB-wall/LCP 0.6675 0.3561 0.5010 0.697 0.362 0.508 95.76% 98.38% 98.63%

Breast/LCP 1.4138 0.9959 1.1126 1.470 1.085 1.181 96.17% 91.79% 94.21%

Thymus/LCP 1.0410 0.5220 0.6815 1.121 0.561 0.730 92.86% 93.06% 93.35%

Prostate/LCP 0.5009 0.3192 0.4478 0.511 0.317 0.442 98.03% 100.68% 101.31%

Lung/LC 0.5439 0.5384 0.6221 0.583 0.574 0.665 93.29% 93.79% 93.54%

Esophagus/LC 0.5155 0.4862 0.6017 0.543 0.498 0.618 94.94% 97.63% 97.36%

RBM/LC 0.4273 0.5329 0.6324 0.442 0.561 0.666 96.67% 94.99% 94.96%

Adrenals/LC 0.2137 0.4468 0.5709 0.193 0.455 0.581 110.71% 98.19% 98.26%

UB-wall/LC 0.6675 0.4485 0.5648 0.708 0.454 0.575 94.28% 98.78% 98.22%

Breast/LC 1.4138 1.2540 1.2542 1.464 1.374 1.345 96.57% 91.27% 93.25%

Thymus/LC 1.0410 0.6574 0.7682 1.125 0.707 0.826 92.53% 92.98% 93.00%

Prostate/LC 0.5009 0.4019 0.5048 0.509 0.396 0.498 98.41% 101.49% 101.36%
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This comparison shows relatively close agreement between SC&A’s doses and those generated 

by NIOSH. Some difference in dose was expected, since NIOSH used Monte Carlo methods and 

SC&A used average values. With only a few exceptions, SC&A’s photon and neutron doses 

were less than NIOSH’s doses. 

As expected, SC&A’s dose calculations for AP geometry are the same for the LCP as for the LC 

badge location. This is due to applying an IGF value of 1.0 because radiation beam is 

perpendicular (incident angle = 0) for the AP geometry. SC&A checked a subset of RPRT-0085 

attachment C organ doses and found that, in general, the 30–250 keV photon Hp(10) doses and 

neutron doses are within a few percentage points of each other for the four different badge 

positions. However, SC&A did notice for the male lung that the AP photon dose was different 

for the LCP (0.689 rem vs. about 0.798 rem for the other positions) and that the female lung AP 

photon dose was different for the LC (0.668 rem vs. about 0.769 rem for the other positions). 

Since NIOSH used MCNP and 4-point averaging for each of their runs, this may explain the 

small variance in the dose results. However, for the female and male lung, the difference in AP 

geometries for the four badge positions appears excessive, as discussed in observation 2. SC&A 

also noticed some difference for the male small intestine (SI) wall AP doses on p. 85 of RPRT0085 for the LCP dosimeter position; there may be others, but because of the large amount of 

data, SC&A did not check them all. 

Observation 2: SC&A questions why NIOSH’s AP doses for a few cancers deviate beyond 

expected values

SC&A cannot explain why NIOSH’s AP doses differ beyond a few percentage points, since the 

IGF values are 1.0. Although SC&A did not assess all ICRP 116 cancers, we did note that the 

female and male lung as well as the male SI-wall appeared to deviate beyond what is considered 

normal. Table 16 shows the percentage difference between the female and male AP geometry 

doses for those cancers assessed by SC&A. 

Table 16. LCP-to-LC ratios for the AP doses in RPRT-0085, attachment C, for the nine

cancers assessed by SC&A

Organ Female 

AP 

Male 

AP 

Lung 1.15 0.86

Esophagus 1.00 1.00

RBM 1.00 0.99

Adrenals 0.99 1.00

UB-wall 0. 0.99

Breast 0.99 1.00

Thymus 0.99 0.99

Prostate NA 1.00

Uterus 0.99 NA
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3.6 Documentation

SC&A evaluated the documentation used in RPRT-0085 for evaluating when an exposure 

geometry other than AP should be considered during the dose reconstruction process. SC&A 

found that NIOSH’s explanation of their approach and methods were relatively brief, and their 

calculations relied on several supporting documents. To gain an understanding of NIOSH’s 

process, SC&A needed to spend a relatively lengthy period of time evaluating the data used in 

the supporting documents. 

In addition, SC&A found some key terminology to be confusing and inconsistent, as discussed in 

observation 3.

Observation 3: NIOSH used the terms “DCC” and “DCF” incorrectly

It appears that RPRT-0085 is using the terms “DCC” and “DCF” inconsistently and incorrectly. 

RPRT-0085 equation 2-1 (p. 12) uses the term “DCC” incorrectly because the dose conversion 

coefficients in ICRP 116 have units of pGy-cm2 and, therefore, need to be divided by the fluence 

conversion factor as shown in equations 3-2 and 3-3 of RPRT-0069 (p. 11). Therefore, the 

“DCC” in equation 2-1 of RPRT-0085 should be DCF, not DCC. 

Additionally, the title of RPRT-0069, “Updated ICRP 116 Dose Conversion Factors and 

Comparison to ICRP 74 Dose Conversion Factors,” appears to be incorrect because a search of 

ICRP 116 does not show that it uses the terms “dose conversion factor” or “DCF.” Therefore, a 

more accurate title for RPRT-0069 would appear to be, “Updated ICRP 116 Dose Conversion 

Coefficients and Comparison to ICRP 74 Dose Conversion Coefficients.” 
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4 Summary Conclusions

SC&A evaluated the technical approach, methods, and documentation in RPRT-0085, 

revision 00 (NIOSH, 2017). SC&A assessed POC values and doses for eight female and eight 

male cancers listed in ICRP 116. SC&A’s POC values and doses were in relatively close 

agreement with those derived by NIOSH. However, SC&A did have three observations: 

• Observation 1: Using NIOSH’s RPRT-0085 IGF values, SC&A’s mean IGF values for 

several neutron ROT and ISO dosimeter placements were generally about 20–25 percent 

less than those values listed in RPRT-0068. 

• Observation 2: SC&A questions why several of NIOSH’s AP doses differ beyond a few 

percentage points, since the IGF values are 1.0. 

• Observation 3: It appears that RPRT-0085 is using the terms DCC and DCF 

inconsistently and incorrectly. 
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5 References

International Commission on Radiological Protection. (1996). Conversion coefficients for use in 

radiological protection against external radiation (Publication 74). Ann. ICRP, 26(3-4). 

International Commission on Radiological Protection. (2010). Conversion coefficients for 

radiological protection quantities for external radiation exposures (Publication 116). Ann. ICRP, 

40(2-5). 

National Institute for Occupational Safety and Health. (2002). External dose reconstruction 

implementation guideline (OCAS-IG-001, rev. 1).

National Institute for Occupational Safety and Health. (2007). External dose reconstruction 

implementation guideline (OCAS-IG-001, rev. 3). https://www.cdc.gov/niosh/ocas/pdfs/dr/oc-ig001-r3.pdf

National Institute for Occupational Safety and Health. (2012). Internal dosimetry organ, external 

dosimetry organ, and IREP model selection by ICD-9 code (ORAUT-OTIB-0005, rev. 05). 

SRDB Ref ID 121336

National Institute for Occupational Safety and Health. (2016a). Correction factors for use with 

ICRP Publication 116 isotropic and rotational dose conversion coefficients (ORAUT-RPRT0068, rev. 00). https://www.cdc.gov/niosh/ocas/pdfs/orau/oraurpts/or-rprt-68-r0-508.pdf 

National Institute for Occupational Safety and Health. (2016b). Updated ICRP 116 dose 

conversion factors and comparison to ICRP 74 dose conversion factors (ORAUT-RPRT-0069, 

rev. 00). SRDB Ref. ID 153955 

National Institute for Occupational Safety and Health. (2017). Probability of causation 

evaluation of ICRP 116 anterior-posterior, isotropic, and rotational geometries (ORAUTRPRT-0085, rev. 00). https://www.cdc.gov/niosh/ocas/pdfs/orau/oraurpts/or-rprt-85-r0-508.pdf

SC&A, Inc. (2005). The review of NIOSH/ORAUT procedures and methods used for dose 

reconstruction (SCA-TR-Task3, rev. 0). https://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/scadrprocs-r0.pdf