REPORT TO THE ADVISORY BOARD 

ON RADIATION AND WORKER HEALTH

National Institute of Occupational Safety and Health 

Audit of Case PIID* from Fernald 

Contract No. 200-2004-03805 

Task Order No. 4 

SCA-TR-TASK4-CNPIID* 

Prepared by 

S. Cohen & Associates 

6858 Old Dominion Road, Suite 301 

McLean, Virginia 22101 

February 2005 

NOTICE: This information is protected by Privacy Act 5 USC §552a; disclosure to any third party without 

the written consent of the individual to whom the information pertains is strictly prohibited. 
Document No. 

SCA-TR-TASK4-CNPIID* 

Effective Date: 

February 4, 2005 

S. Cohen & Associates:

Technical Support for the Advisory Board on 

Radiation & Worker Health Review of 

NIOSH Dose Reconstruction Program Revision No. 1 

AUDIT OF CASE PIID* FROM FERNALD Page 2 of 11 

Task Manager: ___________________ Date: 02/04/05 

 U. Hans Behling, PhD, MPH 

Project Manager: _________________ Date: 02/04/05 

 John Mauro, PhD, CHP 

Supersedes: 

Draft Rev. 0 

Fernald Case PIID* 2 S. Cohen & Associates 
TABLE OF CONTENTS 

1.0 Summary Background Information .................................................................................... 4 

1.1 Audit Objectives ..................................................................................................... 5 

1.2 Summary of Audit Findings.................................................................................... 5 

2.0 Audit of Internal Doses....................................................................................................... 8 

2.1 Reviewer’s Comments............................................................................................ 9 

References..................................................................................................................................... 10 

Appendix A: IREP Input.............................................................................................................. 11 

Fernald Case PIID* 3 S. Cohen & Associates 
1.0 SUMMARY BACKGROUND INFORMATION 

This report presents the results of an independent audit of a dose reconstruction performed by the 

National Institute of Occupational Safety and Health (NIOSH) for an energy employee that 

worked at the Feed Materials Production Company (FMPC or Fernald) for nearly PIID* years, 

from PIID*, to PIID*, as a PIID*. 

As a result of the claimant’s employment, the worker experienced occupational exposures to 

external radiation sources, as well as exposure to internally deposited radioactive material. The 

worker was periodically monitored for uranium intake by analyzing urine samples for total 

uranium. External exposures were not evaluated by NIOSH for this case, so factors involved in 

the employee’s external dose estimates were not evaluated. 

The employee was diagnosed with lung cancer on PIID*. The employee was also diagnosed 

with numerous skin cancers between PIID* and PIID*. Because lung cancer was involved, 

NIOSH first determined the probability of causation (POC) for the lung cancer due to inhalation 

of alpha-emitting radionuclides. Annual dose to the lung from the time of initial employment to 

the time of diagnosis was determined from urine bioassay results measured during the years of 

employment, and the results were input into IREP. Per NIOSH and ORAU procedures, this case 

was determined to have a POC of 57.4% for lung cancer. 

Table 1 presents an overall summary of NIOSH’s dose reconstruction. 

Table 1. Summary of External Exposures as Estimated by NIOSH 

Appendix A 

Exposure Entry No.

Dose 

(rem) 

External Dose: 

 ▪ Photon Dosimeter Dose NC* — 

 ▪ Photon Missed Dose NC* — 

 ▪ Neutron Dosimeter Dose NC* — 

 ▪ Neutron Missed Dose NC* — 

 ▪ Occupational Medical NC* — 

 ▪ Onsite Ambient NC* — 

Internal Dose: 1 – 50 66.388 

Total 66.388 

*NC = Not considered because exposure scenario was not needed to show causation 

Fernald Case PIID* 4 S. Cohen & Associates 
1.1 AUDIT OBJECTIVES

SC&A’s audit was performed with the following objectives: 

• To determine if NIOSH assigned doses that are consistent with monitoring 

records provided by the DOE and with the information contained in the CATI 

report 

• To determine if the dose reconstruction process complied with applicable 

procedures that include generic procedures developed by NIOSH and ORAUT, as 

well as data/procedures that are site-specific 

• In instances when procedure(s) provide more than one option or require subjective 

decisions, determine if the process is scientifically defensible and/or claimant 

favorable 

In pursuit of these objectives, a two-step process is followed in this audit. The first step of this 

audit is to independently duplicate, and therefore validate, doses derived by NIOSH. This step of 

the audit process is not only contractually mandated under Task 4, but provides NIOSH and the 

Advisory Board with a high level of assurance that the SC&A reviewer understands which 

procedures, models, site-specific data, and assumptions NIOSH used to perform its dose 

reconstruction. The second step of the audit critically evaluates whether the methods employed 

by NIOSH are technically defensible, consistent with applicable procedures, and claimant 

favorable. 

Lastly, in compliance with the Privacy Act, this report makes no reference to the claimant’s 

name, SSN, address, or any personal data that might reveal the identity of the claimant. 

1.2 SUMMARY OF AUDIT FINDINGS 

An overview of SC&A’s audit findings for Case PIID* is provided in Table 2 in the form of a 

checklist. This checklist evaluates the data collection process, information obtained from the 

CATI interview, and all methods used in the dose reconstruction. When deficiencies are 

identified by the audit, such deficiencies are further characterized with regard to their impact(s) 

by means of the following definitions: (1) low means that the deficiency has only a marginal 

impact on dose; (2) medium means that the deficiency substantially impacts the dose, but is 

unlikely to impact the compensability of the case; and (3) high means that the deficiency 

substantially impacts the dose and may also impact the compensability of the case. A full 

description of deficiencies identified in the checklist is provided in the text of the audit that 

follows. 

Fernald Case PIID* 5 S. Cohen & Associates 
Table 2. Case Review Checklist 

CASE PIID* ASSIGNED DOSE: 66.388 rem POC: 57.4% 

Audit Response If No, Potential Significance No. Description of Technical Elements of Review YES N/A NO LOW1 MEDIUM2 HIGH3

A. REVIEW OF DATA COLLECTION: 

A.1 Did NIOSH receive all requested data for the DOE or 

AWE site from any relevant data source? T

A.2 Is the data used by NIOSH for the case adequate to 

make a determination with regard to POC? T

B. REVIEW OF INTERVIEW AND DOCUMENTATION PROVIDED BY CLAIMANT 

B.1 Did NIOSH properly address all work history 

dates/locations of employment reported by claimant? T

B.2 Did NIOSH properly address all 

incidents/occurrences reported by claimant? T

B.3 Did NIOSH properly address monitoring/ personal 

protection/work practices reported by claimant? T

B.4 Is the interview information consistent with data used 

for dose estimate? T

C. REVIEW OF PHOTON DOSES 

C.1 Was the appropriate procedure used for determining: 

C.1.1 - Recorded Photon Dose? T

C.1.2 - Missed Photon Dose? T

C.1.3 - Occupational Medical Dose? T

C.1.4 - Onsite-Ambient Dose? T

C.2 Did the DR properly account for all: 

C.2.1 - Recorded Photon Dose? T

C.2.2 - Missed Photon Dose? T

C.2.3 - Occupational Medical Dose? T

C.2.4 - Onsite-Ambient Dose? T

C.3 Is the recorded/assigned dose properly converted to the organ dose of interest for: 

C.3.1 - Recorded Photon Dose? T

C.3.2 - Missed Photon Dose? T

C.3.3 - Occupational Medical Dose? T

C.3.4 - Onsite-Ambient Dose? T

C.4 Is the organ dose uncertainty properly determined for: 

C.4.1 - Recorded Photon Dose? T

C.4.2 - Missed Photon Dose? T

C.4.3 - Occupational Medical Dose? T

C.4.4 - Onsite-Ambient Dose? T

D. REVIEW OF SHALLOW (i.e., 7 mg/cm2)/ELECTRON DOSES 

D.1 Was the appropriate procedure used for determining: 

D.1.1 - Recorded Shallow/Electron Dose? T

D.1.2 - Missed Shallow/Electron Dose? T

D.1.3 - Onsite Ambient Dose? T

D.2 Did the DR properly account for all: 

D.2.1 - Recorded Shallow/Electron Dose? T

D.2.2 - Missed Shallow/Electron Dose? T

D.2.3 - Onsite Ambient Dose? T

 

1 Low means that the deficiency has only a marginal impact on dose. 2 Medium means that the deficiency substantially impacts the dose, but is unlikely to impact the compensability of the case. 3 High means that the deficiency substantially impacts the dose and may also impact the compensability of the case. 

Fernald Case PIID* 6 S. Cohen & Associates 
CASE PIID* ASSIGNED DOSE: 66.388 rem POC: 57.4% 

Audit Response If No, Potential Significance No. Description of Technical Elements of Review YES N/A NO LOW1 MEDIUM2 HIGH3

D.3 Is the recorded/assigned dose properly converted to the organ dose of interest for: 

D.3.1 - Recorded Shallow/Electron Dose? T

D.3.2 - Missed Shallow/Electron Dose? T

D.3.3 - Onsite Ambient Dose? T

D.4 Is the organ dose uncertainty properly determined for: 

D.4.1 - Recorded Shallow/Electron Dose? T

D.4.2 - Missed Shallow/Electron Dose? T

D.4.3 - Onsite Ambient Dose? T

E. REVIEW OF NEUTRON DOSES 

E.1 Was the appropriate procedure used for determining: 

E.1.1 - Recorded Neutron Dose? T

E.1.2 - Assigned Neutron Dose? T

E.1.3 - Missed Neutron Dose? T

E.2 Did the DR properly account for all: 

E.2.1 - Recorded Neutron Dose? T

E.2.2 - Assigned Neutron Dose? T

E.2.3 - Missed Neutron Dose? T

E.3 Is the recorded/assigned dose properly converted to the organ dose of interest for: 

E.3.1 - Recorded Neutron Dose? T

E.3.2 - Assigned Neutron Dose? T

E.3.3 - Missed Neutron Dose? T

E.4 Is the organ dose uncertainty properly determined for: 

E.4.1 - Recorded Neutron Dose? T

E.4.2 - Assigned Neutron Dose? T

E.4.3 - Missed Neutron Dose? T

F. REVIEW OF INTERNAL DOSE: BASED ON HYPOTHETICAL MODEL 

F.1 Is the use of the selected hypothetical internal dose 

model appropriate, based on the likely POC value? T

F.2 Is the use of a hypothetical internal dose model 

appropriate/conservative, based on claimant’s 

available bioassay data,? 

T

F.3 Was the hypothetical dose value correctly derived? T

G. REVIEW OF INTERNAL DOSE: BASED ON BIOASSAY/IMBA 

G.1 Was the appropriate procedure (or section of 

procedure) used for determining likely (>50%), 

unlikely (<50%), or undetermined POC and 

compensability? 

T

G.2 Are bioassay data sufficiently adequate for internal 

dose reconstruction? T

G.3 Are assumptions pertaining to dates of uptake 

reasonable/conservative? T

G.4 Are critical parameters (e.g., solubility class, particle 

size, etc.) used for IMBA organ dose estimates 

appropriate? 

T

G.5 Are assigned uncertainties (measurement errors) for 

bioassay data (used as input to IMBA) appropriate? T

H. Total Number of Deficiencies and Their Combined Potential Significance 0 

_____________________________ 

1

 Low means that the deficiency has only a marginal impact on dose. 2

 Medium means that the deficiency substantially impacts the dose, but is unlikely to impact the compensability of the case. 3

 High means that the deficiency substantially impacts the dose and may also impact the compensability of the case. 

Fernald Case PIID* 7 S. Cohen & Associates 
2.0 AUDIT OF INTERNAL DOSES 

On the basis of a preliminary review of information/data, it was concluded that only a partial 

dose reconstruction was needed in behalf of this claim. 

The employee was diagnosed with lung cancer on PIID*. The employee was also diagnosed 

with numerous skin cancers between PIID* and PIID*. Because lung cancer was involved, 

NIOSH first determined the probability of causation (POC) for the lung cancer due to inhalation 

of alpha-emitting radionuclides alone. Because the POC was greater than 50% for lung cancer, 

additional evaluations were not necessary. Thus, internally deposited radionuclides resulting in 

dose to the lungs were the primary exposure evaluated in the dose reconstruction. Uranium 

bioassay results were the basis for the reconstruction. 

The employee’s dose records, provided by DOE, show that the claimant’s urine was analyzed via 

bioassay for total uranium on 73 occasions. Because the urinalysis was for total uranium 

concentration in the urine (μg/L), the type of uranium to which the employee was exposed is not 

known. The uranium used and found at Fernald ranged from depleted uranium to enriched 

uranium, so NIOSH assumed a radionuclide mix consistent with natural uranium. This means 

that for the natural uranium found at the site, the material had an activity concentration of 

0.338 pCi/μg of uranium-234 and 0.334 pCi/μg of uranium-238. 

The total uranium concentration results (μg of uranium per L of urine) from the bioassays were 

in units of μg/L. Total urine excretion volume per day was assumed to be 1.4 L/day. 

According to SD-2008, non-occupational natural uranium is excreted in urine at a rate of 0.05 to 

0.5 μg/day. In order to minimize dose, NIOSH selected the upper bound of this range, 

0.5 μg/day, and subtracted that value from the daily excreted uranium calculated from the 

bioassay results. 

The above factors were used with the bioassay results to determine the daily radioactivity 

excreted in the urine in units of pCi/day of U-234, U-235, and U-238). 

Other assumptions necessary to determine the lung dose pertained to the solubility of uranium. 

The employee’s work history showed that the claimant in Plants 1, 2, 3, 4, and 5 may have 

uranium in the three solubility classes (Type F, Type M, and Type S). Technical references 

report solubility components in some airborne contamination samples at Fernald to be greater 

than 60% insoluble. NIOSH assumed a mix of 30% Type S and 70% Type M in performing this 

dose reconstruction, and intake was assumed to be chronic. 

From urine data, IMBA was used to first calculate the inhalation intake to the lung. The 

previously calculated radioactivity content in urine and the solubility factors above were used as 

input. Secondly, based on inhalation intake, IMBA was used to calculate annual lung dose. The 

ICRP 66 lung model with default aerosol characteristics was assumed. 

The IMBA results included annual dose to the lungs from U-234, U-238, and total uranium. 

Annual results were calculated from the time of initial employment to the year of cancer 

Fernald Case PIID* 8 S. Cohen & Associates 
diagnosis, PIID*. The calculation resulted in a total dose to the lungs of 66.388 rem. For 

reasons of efficiency, uncertainty was not included. 

Appendix A presents the results of NIOSH’s reconstruction of the annual lung doses to the 

energy employee for the purpose of deriving the POC using IREP. In addition to the lung dose, 

the claimant’s status as a former smoker was also taken into account in the IREP POC 

calculation. 

Because the POC for the lung cancer from bioassay data along was 57.4%, additional dose 

determinations, such as external dose, occupational medical dose, etc., were not performed. 

2.1 REVIEWER’S COMMENTS 

This partial dose reconstruction was performed on the assumption that the POC was likely 

>50%. As such, the procedure to follow for the dose estimate is given in OCAS-IG-002 (NIOSH 

2002), Section 6.2. It appears that steps 1–5 of that procedure were followed, but step 6 was not. 

Step 6 directs the assessor to repeat the preliminary dose estimate for all potential solubility 

classes to determine the one that produces the lowest dose. The assessor selected 30% Type S 

and 70% Type M, with no documentation as to whether that would produce the lowest dose 

result. In fact, the ratio of solubility classes selected was stated to be claimant favorable. While 

this ratio of solubility classes appears to be reasonable, based on site history, it does not comply 

with the implementation guide. 

The ratio of uranium radionuclides used in the dose estimation was assumed to be natural 

uranium, without consideration of enriched uranium. This would result in a likely underestimate 

of the claimant’s dose, and is valid for this case, where the claimant was compensated. 

The total daily urine excretion volume of 1.4 L/day assumed by the assessor is reasonable. The 

subtraction of 0.5 μg/day total uranium from naturally-occurring (non-occupational) sources is 

also valid in this “efficiency” model that provides the lowest dose. Selecting the upper end of 

the range for elimination of natural uranium would support that model. 

The calculations performed by NIOSH to estimate the uranium radioactivity excreted per day 

(and subsequently used as input to IMBA) were performed correctly. The IMBA calculations 

were correctly reported in the dose reconstruction and used as input to IREP. The use of the 

ICRP 66 lung model and default aerosol characteristics are also valid assumptions. 

In summary, this audit concludes that the calculations performed in the reconstruction of dose 

are generally valid and procedurally compliant. While most of the steps performed in this dose 

reconstruction comply with NIOSH procedures, the selection of solubility class should have been 

one that result in the lowest dose. A reference to “claimant favorable” should not have been a 

deciding factor for determining this parameter, since the objective of a partial dose 

reconstruction (with a likely POC >50%) is to minimize the dose.

Fernald Case PIID* 9 S. Cohen & Associates 
REFERENCES 

NIOSH 2002, “Internal Dose Reconstruction Implementation Guideline,” OCAS-IG-002, Rev 0, 

August 2002. 

Fernald Case PIID* 10 S. Cohen & Associates 
APPENDIX A: IREP INPUT

Table below has been deleted – please see hard copy marked ‘#18 – Fernald’ 

Fernald Case PIID* 11 S. Cohen & Associates