REPORT TO THE ADVISORY BOARD ON RADIATION AND 

WORKER HEALTH 

National Institute of Occupational Safety and Health 

Audit of Case #PIID* from the Bethlehem Steel Facility 

Contract No. 200-2004-03805 Task Order No. 4 

SCA-TR-TASK4-CNPIID* 

Prepared by 

John Mauro, PhD CHP 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. 
S. Cohen & Associates: 

Technical Support for the Advisory Board on Radiation 

& Worker Health Review of NIOSH Dose 

Reconstruction Program 

AUDIT OF CASE #PIID* FROM THE 

BETHLEHEM STEEL FACILITY 

Task Manager: ___________________ Date: 02/04/05 

Hans Behling, PhD, MPH 

Project Manager: _________________ Date: 02/04/05 

John Mauro, PhD, CHP 

Document No. 

SCA-TR-TASK4-CNPIID* 

Effective Date: February 4, 2005 

Revision No. 1 

Page 2 of 12 

 Supersedes: 

Draft Rev. 0 
 

TABLE OF CONTENTS 

Summary ........................................................................................................ 4 

1.0Introduction.................................................................................................................. 5 

2.0SummaryofDoses..................................................................................... 7 

3.0 Independent Reproduction and Review of Selected NIOSH Derived
 

Doses.... 9 

3.1Internal Dose from Inhalation ................................................................. 9 

3.2Conclusions............................................................................................ 11 

References ................................................................................................. 12 
 

 

 

 

 

 

 

 

 

 

 

 

SUMMARY 

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 (Case #PIID*) that worked at the Bethlehem Steel Corporation from 

PIID*, through PIID*. This time period includes the time period (1949 to 1952) when the 

Bethlehem Steel facility in Lackawanna, New York, was under contract with the Atomic 

Energy Commission (AEC) to develop rolling mill pass schedules for the rolling of 5-

inch natural uranium billets into 1.5-inch rods to be used in nuclear reactors. As a result 

of employment at the facility during and following the uranium rolling operations, the 

worker likely experienced internal exposures due to the inhalation of airborne particles of 

uranium oxide, and external exposure from working in the vicinity of the uranium billets, 

rods, and residual uranium. In addition, the worker is believed to have had routine x-rays 

as part of Bethlehem Steel’s medical surveillance program. The worker was not provided 

with film badge or thermoluminescent dosimeters (TLDs) to measure external exposures, 

nor were bioassays performed to estimate internal exposures. As a result, exposures 

experienced by the worker were estimated using the exposure matrix provided in the site 

profile or technical background document (TBD) prepared by NIOSH for the Bethlehem 

Steel plant (ORAUT-TKBS-0001, March 31, 2003). 

In PIID*, following employment, the energy employee was diagnosed with lung cancer. 

Table 1 summarizes the results of NIOSH’s reconstruction of the doses to the energy 

employee’s lung for the purpose of deriving the probability of causation (POC) using 

IREP. Table 1 also presents the results of the audit. The results of the audit are expressed 

in terms of whether we found the exposures to have been derived in a scientifically and 

claimant-favorable valid manner. 

Table 1. Summary of Internal and External Exposure to the Lung as Estimated by 

NIOSH, Along with the Audit Results 

(The values reported here are the modes of a triangular distribution) 

Exposure Scenario NIOSH Derived 

Annual Doses (rem) 

Scientifically 

Valid? 

Claimant 

Favorable? 

Internal exposure from inhalation (alpha) during operations About 9E-1 during 

AEC operations 

* * 

Internal exposures from ingestion (alpha) during operations ND** 

Internal exposure from inhalation (alpha) of residual 

resuspended particles following the conclusion of operations 

ND 

External exposures during operations (PIID*) 

Ground surface contamination (chronic) ND 

Natural Uranium Source (chronic) ND

 Submersion in airborne plume (chronic) ND 

Diagnostic x-rays (acute) ND 

Chronic external exposure to residual contamination 

following the conclusion of AEC operations in PIID* 

ND 
* This audit reveals that there are some aspects of the methods used by NIOSH to 

reconstruct the doses to the lungs of this worker that do not appear to be entirely 

scientifically valid or claimant favorable. However, since the claimant was compensated, 

our findings are of interest more from a theoretical, rather than a practical, perspective. 

** ND refers to Not Determined because the uranium dust inhalation doses alone 

were sufficient to consider the dose reconstruction complete. 

1.0 INTRODUCTION 

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 Bethlehem Steel facility in Lackawanna, New York. 

This audit is one of several dose reconstruction audits being performed by S. Cohen & 

Associates (SC&A, Inc.) on behalf of the Advisory Board on Radiation and Worker 

Health. 

This audit report makes extensive use of the findings provided in a separate report 

prepared by SC&A entitled Review of NIOSH Site Profile for Bethlehem Steel Plant, 

Lackawanna, NY, (SCA-TR-TASK1-001, October 2004). The review of the site 

profile prepared by SC&A is currently being reviewed by NIOSH. We expect that 

NIOSH will provide comments on the SC&A site profile review that, upon 

consideration by SC&A, may affect the findings of this audit report. 

The audit was performed in two parts, which correspond to the sections of this report. 

Part one presents a summary of our understanding of the doses derived by NIOSH, along 

with a brief description of the basic approach and assumptions employed by NIOSH to 

derive the doses. This material is extracted directly from the final dose reconstruction 

report published by NIOSH for this case, along with supporting documentation, including 

the technical basis document for the Bethlehem Steel facility (ORAUT-TKBS-0001, 

March 31, 2003). This section of the report summarizes our understanding of the 

methods used by NIOSH to reconstruct the doses to workers, and also serves as a 

baseline for the discussion and review provided in Section 3 of this report. 

Part two of the audit process (provided in Section 3 of this report) consists of an attempt 

to independently reproduce doses derived by NIOSH and a discussion of the validity of 

the methods employed. The doses selected for review are based on the judgment of the 

reviewers as to the importance of the particular doses to the totality of the doses 

experienced by the energy employee. The reason for this step in the audit process is to 

provide the author, NIOSH, and the Advisory Board with a level of assurance that the 

auditors understand how NIOSH went about deriving the doses provided in their dose 

reconstruction report. In the process of attempting to reproduce the NIOSH-derived 

doses, we also provide a critical review of the fundamental data, information, models, 

and assumptions used by NIOSH to perform the dose reconstruction. This review draws 
 

heavily from a draft review of the TBD prepared by SC&A and submitted to the 

Advisory Board in October 2004.1 This part of the audit explores the degree to which the 

data are adequate to support the dose reconstruction, and whether the models and 

assumptions adopted by NIOSH to perform the dose reconstruction are scientifically 

sound and claimant favorable. Areas where the methods are found to meet these criteria, 

or are deemed to be inadequate with regard to these criteria, are identified and discussed. 

The report is not exhaustive in the review of these matters, but is limited to those areas of 

inquiry that are judged by the reviewers to be significant with respect to the dose 

reconstruction and the derivation of the probability of causation (POC). 

Methods employed by NIOSH which are found to be either scientifically inappropriate 

or not necessarily clamant favorable are identified, but no attempt is made to correct 

these deficiencies and redo the dose calculations. It is assumed that NIOSH and the 

Advisory Board will have an opportunity to consider the results of this audit and 

determine whether a revision of the dose reconstruction is needed and, if so, how to go 

about making the necessary revisions. 1

 SC&A’s review of the Bethlehem Steel TBD was delivered to the Advisory Board in draft form 

in October 2004. The report is entitled Review of the NIOSH Site Profile for Bethlehem Steel Plant, 

Lackawanna, NY, Contract No. 200-2004-03805, Task Order No. 1, SCA-TR-TASK1-001, October 2004. 

The Board has not yet officially accepted the report, and NIOSH has not yet had an opportunity to respond 

to the SC&A’s findings. 
2.0 SUMMARY OF DOSES 

The energy employee worked at the Bethlehem Steel Corporation from PIID*, through 

PIID*. This time period includes the time period (1949 to 1952) when the Bethlehem 

Steel facility in Lackawanna, New York, was under contract with the Atomic Energy 

Commission (AEC) to develop rolling mill pass schedules for the rolling of 5-inch 

natural uranium billets into 1.5-inch rods to be used in nuclear reactors. In PIID*, 

following employment, the energy employee was diagnosed with lung cancer. Table 2 

presents the results of NIOSH’s reconstruction of the doses to the energy employee’s 

red bone marrow for the purpose of deriving the probability of causation (POC) using 

IREP. 

The notations used in Table 2 to present the doses include the year in which the dose was 

received by the organ of interest, the statistical distribution that was used, and the key 

parameters for the distribution. For example, for exposure period number 1 in Table 2 

(PIID*), internal exposure of the lungs to alpha emitters is assumed to have a triangular 

distribution with a minimum of 0, a mode of 5.65E-1, and a maximum of 2.8E-1 rem due 

to the inhalation of uranium dust. A discussion of various types of statistical distributions 

and other parameters used as input to NIOSH-IREP is provided in NIOSH (2002). The 

internal dose to the organ of interest was determined by NIOSH to have a range of 0 to 

246 rem, with a mode of 4.96 rem. Based on these reconstructed doses, the POC was 

determined to be greater than 50%, and the claimant was compensated. 

The final dose reconstruction report and the technical basis document (TBD) provide 

detailed descriptions of the methods and assumptions used by NIOSH to derive the 

doses presented in Table 2. As may be noted, Table 2 presents doses in terms of annual 

doses to the lungs due to internal alpha exposure resulting from the inhalation of 

uranium. No other sources of exposure, such as ingestion exposures or external 

exposures, are addressed, because the inhalation exposures alone were found to be 

sufficient to result in a POC greater than 50%. None of the dose estimates are based on 

bioassay data, such as urine or fecal analysis, or whole-body counting, which would 

have provided a generally reliable basis for estimating internal doses to most organs 

from the inhalation and/or ingestion of uranium. Instead, the doses were derived 

indirectly, using the generic methodologies described in the TBD. 
Table 2. Doses to the Lung of the Employee as Derived by NIOSH for Use as Input 

to IREP for the Purpose of Deriving Probability of Causation 

The following table was deleted – please see hard copy #4 
3.0 INDEPENDENT REPRODUCTION AND REVIEW OF 

SELECTED 

NIOSH DERIVED DOSES 

This section presents the results of IMBA calculations that attempt to reproduce selected 

doses derived by NIOSH. In so doing, we will have confirmed that we understand how 

NIOSH performed the dose reconstruction, and that the calculations are correct, given 

the models and assumptions employed by NIOSH. In the process of attempting to 

reproduce the doses, we also discuss and critically review the data, models, and 

assumptions employed by NIOSH to reconstruct the doses. 

3.1 INTERNAL DOSE FROM INHALATION 

As indicated in Table 1, the annual alpha doses to the lungs were determined by NIOSH 

to build up to a peak mode of 0.925 rem in PIID*, with a minimum of 0 and a maximum 

of 45.8 rem. After PIID*, when AEC rolling operations ceased, the annual alpha doses 

to the lungs gradually decline due to gradual clearance of the uranium from the lungs. 

In this section, the peak annual alpha dose delivered to the lungs in PIID* is checked by 

reviewing the source documents and by performing IMBA calculations. 

The starting point for this analysis is a description of the rolling operations and how 

workers were exposed to airborne particles of uranium. Uranium billets were shipped to 

Bethlehem Steel by freight cars, in which the billets were stored on site until the rolling 

operations were initiated. Since the facility was fully involved in rolling steel billets, 

uranium rolling operations at Bethlehem Steel took place only on weekends. Table 1 of 

the TBD presents NIOSH’s estimate of the dates when experimental and production 

rollings took place, along with an estimate of the number of billets that were rolled. In 

general, uranium rollings occurred on weekends, and, during the week, the workers 

returned to their normal activities, which involved rolling steel billets. 

During the rolling operations, airborne uranium dust was generated primarily as a result 

of the oxidation and flaking of uranium particles as the billets were processed through the 

rollers. NIOSH performed a review of uranium dust loading measurements made at the 

Bethlehem Steel facility and another similar facility, Simonds Saw. Based on a review of 

these air-sampling data, NIOSH concluded that the amount of air-sampling data was very 

limited, making it difficult to construct a reliable characterization of the airborne uranium 

dust concentrations at the facility as a function of time and work location. Because of 

these uncertainties, NIOSH elected to construct two alternative distributions of the 

airborne uranium dust concentrations at the Bethlehem Steel facility. One distribution 

was considered a lower-bound estimate of the range of dust loadings throughout the 

facility, and the other was considered an upper-bound estimate of the uranium dust 

loadings throughout the facility. The lower-bound distribution was used as a basis for 

quickly determining whether a claimant should be compensated; i.e., if the reconstructed 

doses using the lower-bound distribution were determined to be compensable, the 

analysis was considered complete. However, if the use of the lower-bound distribution 
 

 

 

 

 

 

yielded doses that were not compensable, then the upper-bound distribution was used as 

the basis for rejecting a claim. 

The dose reconstruction undergoing review in this report is for a worker whose claim 

was granted. As a result, the focus of attention of this review is the lower-end 

radionuclide concentration distribution employed by NIOSH, as provided in Table 2a of 

the TBD, and which is reproduced here as Table 3. 

Table 3. Internal Exposure Matrix-Lower Bound 

(Reproduced from Table 2a of the TBD) 

Work 

period Air Concentration (dpm/m3) Breathing Rate (m3/hr)* Hours Annual Intake (pCi)

 Min Mode Max Light/heavy Min Mode Max 

PIID* 0 140 4,900 1.2/1.7 120 0 9.16E3 4.54E5 

PIID* 0 140 4,900 1.2/1.7 120 0 9.16E3 4.54E5 

PIID* 0 140 4,900 1.2/1.7 130 0 9.93E3 4.92E5 

PIID* 0 140 4,900 1.2/1.7 110 0 8.40E3 4.17E5 

* The breathing rate of 1.2 m3/hr was used to calculate the minimum and 

mode intake. The breathing rate of 1.7m3/hr was used to calculate the maximum 

intake. 

As an example, the uranium inhalation of 9.16E3 pCi for 1949 was derived as follows: 

(140 dis/min per m3)/(60sec/min) = 2.33 dis/sec per m3 = 63 pCi/m3 

(63 pCi/m3)(1.2 m3/hr)(120 hr/yr) = 9072 pCi/yr 

This value does not exactly match the value in Table 3, but the difference is small and 

it is not considered necessary to further evaluate the reasons for the difference. 

In the TBD, NIOSH explains that the assumptions used to derive the above inhalation 

rates are reasonable because the values represent the lowest, mode, and maximum values 

observed at Bethlehem Steel. However, as described in Section 3.3 of the SC&A review 

of the TBD, we have some concerns with the selection of a triangular distribution for the 

data set, and we believe there are some air samples that were higher than the maximum 

value selected by NIOSH. Nevertheless, since the low-end table is not used to deny 

compensations, these concerns are not important to the audit of this case. On the other 

hand, the number of hours of exposure per year is conservative. For example, Table 1 of 

the TBD indicates that in PIID* and PIID*, there were only 6 and 7 days of rollings, 

respectively. Assuming 10 work hours per day, this would correspond to 60 and 70 hours 

of exposure per year, as opposed to the work hours employed in the TBD (i.e., the TBD 

assumed exposure durations that were approximately twice these values). For the 

purpose of deriving doses to the lungs, it was assumed that the uranium was Absorption 

Type S, and the particle size of the airborne dust was assumed to have an AMAD of 5 

micron. These assumptions are claimant favorable. 
 

Table 2 of this report, which was reproduced directly from the dose reconstruction 

report, presents the annual alpha doses to the lung for each year as a result of these 

inhalation rates and modeling assumptions. Our independent analysis using IMBA and 

the intake rates in Table 1 of the TBD agrees with the doses provided in Table 2 of this 

report. 

3.2 CONCLUSIONS 

We have found that the dose reconstruction is reasonable and appropriate for 

efficiently determining that the worker’s cancer is compensable. 

REFERENCES 

NIOSH 2002, “NIOSH-Interactive Radioepidemiological Program (NIOSH-IREP) 

Technical Documentation,” Final Report. June 18, 2002 

ORAUT-TKBS-0001, Technical Basis Document: Basis for Development of an Exposure 

Matrix for Bethlehem Steel Corporation, March 31, 2003.