Draft

ADVISORY BOARD ON

RADIATION AND WORKER HEALTH

National Institute for Occupational Safety and Health

SC&A’S EVALUATION OF ORAUT-OTIB-0075, REVISION 01, 

“USE OF CLAIMANT DATASETS FOR COWORKER 

MODELING” 

Contract No. 211-2014-58081 

SCA-TR-2017-PR011, Revision 0 

Prepared by

Ron Buchanan, PhD, CHP

Harry Chmelynski, PhD 

SC&A, Inc.

2200 Wilson Boulevard, Suite 300 

Arlington, Virginia, 22201 

Saliant, Inc.

5579 Catholic Church Road 

Jefferson, Maryland 21755 

October 2017 

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 Review of NIOSH Dose Reconstruction Program

DOCUMENT TITLE: 

SC&A’s Evaluation of ORAUT-OTIB-0075, Revision 01, “Use of 

Claimant Datasets for Coworker Modeling” 

DOCUMENT NUMBER/

DESCRIPTION:

SCA-TR-2017-PR011 

REVISION NO.: 0 (Draft)

SUPERSEDES: N/A

EFFECTIVE DATE: October 9, 2017

TASK MANAGER: Kathy Behling [signature on file]

PROJECT MANAGER: John Stiver, MS, CHP [signature on file]

DOCUMENT 

REVIEWER(S):

Kathy Behling [signature on file]

John Stiver, MS, CHP [signature on file]

Record of Revisions

Revision 

Number

Effective 

Date Description of Revision

0 (Draft) 10/9/2017 Initial issue
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TABLE OF CONTENTS

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

1.0 Introduction and Background ................................................................................ 5

2.0 Overview of ORAUT-OTIB-0075 ........................................................................ 5

3.0 SC&A’s Evaluation of ORAUT-OTIB-0075 ........................................................ 8

3.1 Evaluation of NIOSH’s Approach in ORAUT-OTIB-0075 ................................... 8

3.2 Evaluation of NIOSH’s Statistical Methods Used in ORAUT-OTIB-0075 ........... 8

3.2.1 SC&A’s Evaluation of Revision 00 to ORAUT-OTIB-0075 ..................... 8

3.2.2 SC&A’s Evaluation of Revision 01 to ORAUT-OTIB-0075 ..................... 9

3.3 Evaluation of Documentation in ORAUT-OTIB-0075 ........................................ 12

4.0 Summary and Conclusions .................................................................................. 12

5.0 References ........................................................................................................... 12

Appendix A: Summary of Findings from SC&A’s 2010 Evaluation of ORAUT-OTIB-0075 14

Appendix B: SC&A’s Analyses of Revised Tables 6-1 and 6-2 of ORAUT-OTIB-0075, 

Revision 01 .......................................................................................................... 16
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ABBREVIATIONS AND ACRONYMS

ABRWH Advisory Board on Radiation and Worker Health 

b slope 

d day 

dpm disintegration per minute

e natural logarithm (value of 2.72) 

GM geometric mean

GSD geometric standard deviation 

m intercept

m number of iterations 

Mound Mound Laboratory

NIOSH National Institute for Occupational Safety and Health

NOCTS NIOSH OCAS Claimant Tracking System

OCAS Office of Compensation Analysis and Support 

ORAUT Oak Ridge Associated Universities Team 

pCi picocurie 

R2

 coefficient of determination for regression analysis 

SRS Savannah River Site

Y-12 National Security Complex

Z-score probability distribution 
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1.0 INTRODUCTION AND BACKGROUND 

In June 2017, the Advisory Board on Radiation and Worker Health tasked SC&A with a 

technical review of ORAUT-OTIB-0075, Use of Claimant Datasets for Coworker Modeling, 

Revision 01, issued June 17, 2016 (NIOSH 2016, referred to as “OTIB-0075”). 

The National Institute for Occupational Safety and Health (NIOSH) had issued ORAUT-OTIB0075, Revision 00, in 2009 (NIOSH 2009). SC&A had evaluated ORAUT-OTIB-0075, Revision 

00, in 2010 (SC&A 2010). This current report consists of SC&A’s evaluation of OTIB-0075, 

Revision 01. 

2.0 OVERVIEW OF ORAUT-OTIB-0075

OTIB-0075 is a detailed document. For evaluation purposes, it is advantageous to provide a brief 

outline as follows. 

• Purpose: In OTIB-0075, NIOSH states:

the purpose of this document is to present the results of a study to 

determine if claimant datasets can be treated as random samples from the 

complete datasets from which they were drawn for the purpose of 

developing coworker models. The study consisted of taking sites where 

well-defined complete datasets are available and comparing these 

datasets with the claimant datasets. 

• The claimant and complete databases addressed in OTIB-0075 were: 

– National Security Complex (Y-12) uranium urine bioassay, 1950–1988 (Sections 3 

through 5 and Attachments A, B, and C). 

– Mound Laboratory (Mound) plutonium urine bioassay, 1960–1990 (Section 6 and 

Attachments D, E, and F). 

– Savannah River Site (SRS) tritium dose, 1991–2000 (Sections 6 and 7 and 

Attachments G, H, and I). 

• Terms:

– Complete dataset – Refers to all of the monitoring records in the database for the site 

relevant to the analysis. Note that the term “complete” does not necessarily indicate 

that all the workers were monitored at the site.

– Claimant dataset – Refers to the claimants’ monitoring records in the database 

obtained from the NIOSH OCAS Claimant Tracking System (NOCTS) relevant to the 

analysis. 
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• Outline of procedure used to determine annual 50th and 84th percentile values for 

each dataset:

– NIOSH constructed a table showing number of workers monitored in the complete 

dataset, number of workers monitored in the claimant dataset, ratio of the number of 

claimants to the number of workers, number of samples from the complete dataset, 

number of samples from the claimant dataset, and the ratio of the number of samples 

from the claimants to the number of samples from the complete dataset. For example, 

see Table 3-1, page 10, of OTIB-0075 for the Y-12 data. 

– The methodology in ORAUT-RPRT-0053, Analysis of Stratified Coworker Datasets, 

Revision 02 (NIOSH 2014), was used to create a lognormal probability plot—

uranium in urine (dpm/day) versus Z-Score probability—on an annual basis for each 

dataset. For example, see Figure 4-1, page 11, of OTIB-0075 for the Y-12 1952 

complete dataset. Attachments A, B, D, E, G, and H contain the annual lognormal 

probability plots for the claimant and complete datasets for the three sites analyzed in 

OTIB-0075. 

– The slope value (b) and intercept value (m) were obtained from the lognormal 

probability plot. For example, for the lognormal probability plot in Figure 4-1 of 

OTIB-0075, the slope was 3.216 and the intercept was 0.6092. 

– The 50th percentile (geometric mean [GM]) was calculated using Equation 4-1, page 

10, of OTIB-0075: 

GM = eb

For the lognormal probability plot in Figure 4-1 of OTIB-0075, the value of

GM = e3.216 = 24.93 disintegrations per minute per day (dpm/d). 

– The geometric standard deviation (GSD) was calculated using Equation 4-2, page 11, 

of OTIB-0075: 

GSD = em

For the lognormal probability plot in Figure 4-1 of OTIB-0075 the value of 

GSD = e0.6092 = 1.839 dpm/d. 

– The 84th percentile is the GM value multiplied by the GSD. For the lognormal 

probability plot in Figure 4-1 of OTIB-0075, the 84th percentile = 24.93 dpm/d × 

1.839 = 45.85 dpm/d. 

– A table was constructed showing the slope and intercept annual values from the 

complete dataset, the slope and intercept annual values from the claimant dataset, the 

50th and 84th percentile values for the complete dataset, and the 50th and 84th 

percentile values for the claimant dataset. For example, see Table 4-1, page 13, of 

OTIB-0075 for the Y-12 data.
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• Random Samples: To ensure that the claimant dataset is useful for estimating the slopes 

and intercepts of the complete dataset, it must be shown that the claimant dataset can be

treated as if it were a random sample. Section 5 of OTIB-0075 provides the process of 

selecting and analyzing random samples, and then comparing them to the results from the 

claimant and complete datasets. NIOSH used the following process: 

– A sample of k number of workers was randomly drawn from the complete dataset of 

n workers, without replacement. 

– A lognormal model was fitted to the bioassay results for the k workers for each year.

– These two steps were repeated m number of times (i.e., m number of iterations) for 

each year. 

– The values of the intercept versus the slope were plotted for each sample for each 

year (total of m points plotted on each annual plot). 

– A 95% joint confidence ellipse for m number of slope and intercept values was

calculated for each year and plotted on the same annual plot as the random sample 

results. 

– The intercept-versus-slope value from the claimant dataset was plotted on the same 

annual plot as the random sample results.

– The intercept-versus-slope values from the complete set were plotted on the same 

annual plot as the random sample results.

An example of a completed plot is illustrated for the Y-12 1952 data in Figure 5-1, 

page 17, of OTIB-0075. Attachments C, F, and I provide the annual plots containing the 

results for the random samples, claimant dataset, and complete dataset for the three sites 

analyzed in OTIB-0075. 

• NIOSH’s Conclusions:

NIOSH presents its conclusions in Section 8.0, page 28, of OTIB-0075, as summarized 

below. 

– At the three sites analyzed, a total of 4 years out of 80 years (5%) had coworker 

model parameters outside of the respective 95% confidence ellipses (Y-12 in 1950, 

Mound in 1982 and 1990, and SRS in 1991). 

– This result is in excellent agreement with what would be expected if the NOCTS 

datasets were random draws from the complete datasets (i.e., in the long run, we 

would expect to see 5% of the parameter estimates outside of the 95% confidence 

ellipse). 
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– This proof-of-principle technique was used to show that the claimant datasets from 

Y-12, Mound, and SRS can, in general, be used as if they were random samples for 

the purpose of estimating the slopes and intercepts of lognormal fits to the data. 

– This exercise can be used as a technical justification for applying the assumption that 

the claimant datasets can be used as if they were random samples for the purpose of 

estimating the slopes and intercepts of lognormal fits to the data to other sites for 

which complete datasets are not available.

3.0 SC&A’S EVALUATION OF ORAUT-OTIB-0075

The following sections summarize SC&A’s evaluation of the approach, statistical analysis, and 

documentation used by NIOSH in developing OTIB-0075. 

3.1 EVALUATION OF NIOSH’S APPROACH IN ORAUT-OTIB-0075 

SC&A did not identify any issues with the general approach used in OTIB-0075 to compare 

claimant datasets to complete datasets. 

3.2 EVALUATION OF NIOSH’S STATISTICAL METHODS USED IN 

ORAUT-OTIB-0075 

NIOSH issued the guide, Draft Criteria for the Evaluation and Use of Coworker Datasets, 

Revision 4, on February 26, 2015 (NIOSH 2015). In that guide, NIOSH recommended four areas 

that should be addressed when considering a dataset for use in constructing a coworker model: 

1. Data Adequacy

2. Data Completeness

3. Review and Analysis of Monitoring Program Data

4. Evaluation of Stratification.

In OTIB-0075, NIOSH analyzed the use of claimant data in the NOCTS database in place of 

using the complete dataset for constructing a coworker model and concluded that claimant 

datasets can be used for a site where the complete datasets are not available. The main areas in 

the guide (NIOSH 2015) that are applicable to OTIB-0075 are (1) the evaluation of the adequacy 

of the available data for assigning dose to unmonitored workers and (2) stratification according 

to job/title, area, time, radionuclides, etc. 

3.2.1 SC&A’s Evaluation of Revision 00 to ORAUT-OTIB-0075 

SC&A’s evaluation (SC&A 2010) of ORAUT-OTIB-0075, Revision 00 (NIOSH 2009), 

identified 13 findings concerning the Y-12, Mound, and SRS databases, which are summarized 

in Appendix A to this report. From the 2010 evaluation, SC&A concluded the following 

(page 55): 
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(1) The uranium dataset for Y-12 conforms to the OTIB-0075 hypothesis of 

claimant data representativeness. 

(2) The data for Mound indicate significant differences between claimant and 

all-worker plutonium bioassay data. 

(3) The SRS tritium data cover a very narrow period from 1990 to 2001. 

These data show no significant differences at the annual level of 

aggregation, but the sample size is very small... 

SC&A’s summary of the SRS NOCTS data, which was compiled by NIOSH as the basis for a 

coworker model to demonstrate the ability to reconstruct dose with sufficient accuracy, is as 

follows (page 55): 

(1) A conclusion that the claimant data from the 1990s for tritium are 

representative of the claimant population can, at best, be applied to that 

radionuclide and that period. This conclusion cannot be backextrapolated to other periods. Even within this period, there are 

differences between construction workers disaggregated by craft and nonconstruction workers. 

(2) There are considerable differences in exposure between job types and 

areas, even when data are aggregated by decade. This applies to all nonconstruction workers, as well as construction workers, when compared to 

others in the same group. 

(3) The data indicate that construction workers in some areas and periods 

had greater exposure potential than all non-construction workers. 

SC&A’s overall conclusion for the SRS coworker model is that the NOCTS claimant dataset is

inadequate for dose reconstruction with sufficient accuracy for SRS construction workers. A 

more complete compilation of the data and analyses by area, radionuclide, and job type are 

necessary to determine whether dose reconstruction with sufficient accuracy is feasible for SRS 

construction workers (i.e., stratification tests need to be performed). 

3.2.2 SC&A’s Evaluation of Revision 01 to ORAUT-OTIB-0075 

NIOSH’s OTIB-0075, Revision 01 (NIOSH 2016), is very much like the original document 

(NIOSH 2009), with the following changes: 

1. The number of monitored workers in the Y-12 claimant dataset increased from 731 to 

1,585, with the illustrative example based on 1952 data instead of 1953 data. 

2. The number of workers in the Mound claimant dataset increased from 225 to 301. 

3. The number of workers in the SRS claimant dataset increased from 451 to 920. 
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4. The data used in the analysis in Revision 01 were time-weighted-one-person-onestatistic.

The methodology used for the analyses and the number of workers in the complete dataset

remained essentially the same as in Revision 00.

SC&A analyzed the 13 original SC&A findings and found that Findings 2 and 6 are the only 

ones that may be influenced by the additional claimant data in ORAUT-0075, Revision 01. All 

the other findings (except Findings 1 and 3, which SC&A concurred with) were concerned with 

stratification issues that were not addressed in either Revision 00 or Revision 01 to OTIB-0075; 

these findings remain open. 

The following is SC&A’s review of Finding 2 and Finding 6 in view of the additional claimant 

data in OTIB-0075, Revision 01. 

Finding 2 (SC&A 2010) 

FINDING #2: At the Mound Laboratory, the complete (all-worker) and 

claimant datasets for plutonium in urine from 1960 to 1990 show significant 

differences at the annual level of aggregation. This finding raises questions 

concerning the conclusions reached in OTIB-0075 for plutonium at the Mound

Laboratory. 

SC&A reran the analysis for the Mound 1960–1990 plutonium bioassay data using the new data 

from Tables 6-1 and 6-2 of OTIB-0075, Revision 01 (NIOSH 2016). SC&A found that the 

additional claimant data indicate that the claimant dataset was similar to the complete dataset, as 

indicated in Figure 1. Appendix B to this report provides additional figures and a summary table 

supporting this conclusion. 
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Figure 1. Comparison of Mean Plutonium Concentration in Urine at Mound (1960 to 1990) 

Considering these additional data and analyses, SC&A finds that Finding 2 has been resolved 

and recommends closure.

Finding 6 (SC&A 2010) 

FINDING #6: At Y-12, only 37% of all claimants (3 out of 8) have data in the 

“complete” Y-12 uranium urine bioassay coworker database for 1950 to 1988. 

This subset of 731 claimants with uranium bioassay data had a total of 

approximately 70,000 bioassays. 

OTIB-0075, Revision 00, page 10, footnote 7, states that out of 1971 claimants, 731 claimants 

had bioassay records in the complete dataset, which is 37%. OTIB-0075, Revision 01, page 8, 

states that a total of 1,585 claimants submitted 119,044 uranium urine samples. However, there 

was no indication in the text or footnotes stating how many total claimants there were. Therefore, 

with the present information, SC&A could not determine the fraction of the number of claimants 

who were monitored (i.e., had bioassay records in the complete dataset) compared to the total 

number of claimants in the dataset. Therefore, Finding 6 remains open. 

Original Concerns Not Addressed

The increase in the number of workers in the claimant datasets may have improved the statistics 

for the claimant dataset but, except for Finding 2, it did little to address SC&A’s original 

concerns as expressed in our 2010 review (SC&A 2010) of OTIB-0075, Revision 00. These

concerns are (1) the adequacy of the data in the claimant dataset in NOCTS to represent the 

unmonitored workers (who were subjected to a wide variety of exposure potentials) and (2) in 

Revision 01 to OTIB-0075, there was no indication in the text or footnotes of how many total 

claimants there were to compare to the 1,585 claimants who submitted uranium urine samples 

y = 1.118x + 0.001

R2 = 0.921

0

0.1

0.2

0.3

0.4

0 0.1 0.2 0.3 0.4

Claimant Mean (pCi/day)

Complete Mean (pCi/day)
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(as related to the original Finding 6). The datasets may need to be tested to determine if 

stratification is needed concerning areas, time, radionuclide, construction versus nonconstruction workers, subcontractors versus prime, etc. Therefore, Findings 1, 3, 4, 5, 6, 7, 8, 9, 

10, 11, 12, and 13 remain open.

3.3 EVALUATION OF DOCUMENTATION IN ORAUT-OTIB-0075 

SC&A’s review of OTIB-0075 identified the following observations about documentation items.

• Observation 1: Tables 4-1, 5-1, 6-2, and 7-2 should have the units of dpm/d in the 

column headings as appropriate. 

• Observation 2: The data for 2001 were included in Table 7-1, Table 7-2, Figure 7-3, and

Figure 7-4 in Revision 00 to OTIB-0075. However, the year 2001 was not included in 

these tables and figures in Revision 01 to OTIB-0075. 

4.0 SUMMARY AND CONCLUSIONS

SC&A found the approach NIOSH used to be reasonable and without technical errors. 

However, while SC&A generally found the statistical methods used by NIOSH to be acceptable, 

the increase in the number of workers in the claimant datasets only served to improve the 

statistics of the claimant datasets. Except for Finding 2, the increase did little to address SC&A’s

original concerns as expressed in our 2010 evaluation (SC&A 2010) of OTIB-0075, Revision 00, 

regarding the need to test for stratification of the data (i.e., Findings 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 

12, and 13), and Revision 01 to OTIB-0075 did not indicate how many total claimants there were

to compare to the 1,585 claimant who submitted uranium urine samples (as related to Finding 6). 

SC&A also found several minor documentation issues (i.e., Observations 1 and 2) that could 

affect the readability or application of the information presented. 

5.0 REFERENCES

NIOSH 2009. Use of Claimant Datasets for Coworker Modeling, ORAUT-OTIB-0075, 

Revision 00, National Institute for Occupational Safety and Health, Cincinnati, Ohio. May 25, 

2009. 

NIOSH 2014. Analysis of Stratified Coworker Datasets, ORAUT-RPRT-0053, Revision 02, 

National Institute for Occupational Safety and Health, Cincinnati, Ohio. October 8, 2014. 

NIOSH 2015. Draft Criteria for the Evaluation and Use of Coworker Datasets, Revision 4, 

National Institute for Occupational Safety and Health, Cincinnati, Ohio. February 26, 2015. 

[SRDB Ref. ID 154214] 

NIOSH 2016. Use of Claimant Datasets for Coworker Modeling, ORAUT-OTIB-0075, 

Revision 01, National Institute for Occupational Safety and Health, Cincinnati, Ohio. June 17, 

2016. 
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SC&A 2010. Review of ORAUT-OTIB-0075: Use of Claimant Datasets for Coworker Modeling 

for Construction Workers at Savannah River Site, SC&A, Inc., Vienna, Virginia, and Saliant, 

Inc., Jefferson, Maryland. January 13, 2010. 
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APPENDIX A: SUMMARY OF FINDINGS FROM SC&A’S 2010 

EVALUATION OF ORAUT-OTIB-0075

FINDING 1: At the Y-12 Plant, the complete (all-worker) and claimant datasets for uranium in 

urine from 1950 to 1988 show no significant difference at the annual level of aggregation. This 

finding confirms the conclusions reached in OTIB-0075 for uranium at the Y-12 Plant. 

FINDING 2: At the Mound Laboratory, the complete (all-worker) and claimant datasets for 

plutonium in urine from 1960 to 1990 show significant differences at the annual level of 

aggregation. This finding raises questions concerning the conclusions reached in OTIB-0075 for 

plutonium at the Mound Laboratory. 

FINDING 3: At SRS, the complete (all-worker) and claimant datasets for annual tritium doses 

from 1991 to 2001 show no significant difference at the annual level of aggregation, but the 

sample size is very small and the regression results were dominated by a single year with high 

exposure, 1991. If this year is omitted, the complete and claimant datasets for annual tritium 

doses period from 1992 through 2001 again show no significant difference at the annual level of 

aggregation. 

FINDING 4: At SRS, OTIB-0075 includes data only for tritium from 1991 to 2001 in 

comparing the claimant population to that of all workers. No analysis of uranium or plutonium 

exposures at SRS was possible, because the available hardcopy data have not been reduced to 

electronic form. Similarly, no analysis of uranium or fission product exposures regarding the 

validity of the central hypothesis of OTIB-0075 for SRS could be done for any period. No 

analysis of tritium exposures before 1991 was done for the same reason. Furthermore, the tritium 

conclusion cannot be back-extrapolated in time, since the production and work conditions 

relating to tritium were different in earlier periods.

FINDING 5: Data for the entire SRS were aggregated by year for the NIOSH analysis, with no 

detail by work area or by job type. The proposed NIOSH coworker model for SRS construction 

workers includes no analysis of these details. 

FINDING 6: At Y-12, only 37% of all claimants (3 out of 8) have data in the “complete” Y-12 

uranium urine bioassay coworker database for 1950 to 1988. This subset of 731 claimants with 

uranium bioassay data had a total of approximately 70,000 bioassays. 

FINDING 7: Data for the entire Y-12 site were aggregated by year for the NIOSH analysis, with 

no detail by work area or by job type. The NIOSH approach includes no analysis of these details. 

FINDING 8: Data for the entire Mound Laboratory were aggregated by year for the NIOSH 

analysis, with no detail by work area or by job type. The NIOSH approach includes no attention 

to these details.

FINDING 9: At SRS, the 84th percentile of exposures to tritium, plutonium, uranium, and other 

radionuclides for non-construction workers in specific work areas show considerable differences 

from the 84th percentile of exposures to non-construction workers site-wide. Similar results are 

observed for the corresponding ratio of the GSDs. 
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FINDING 10: At SRS, the 84th percentile of exposures to tritium, plutonium, and other 

radionuclides for construction workers in specific work areas show considerable differences 

from the 84th percentile of exposures to all construction workers site-wide. Similar results are 

observed for the corresponding ratio of the GSDs. 

FINDING 11: At SRS, the 84th percentile of exposures to tritium and plutonium for 

construction workers in specific work areas show large differences from the 84th percentile of 

site-wide exposures to construction workers. Similar results are observed for the corresponding 

ratio of the GSDs. In many cases, there are insufficient data for construction workers to make a 

comparison for uranium, enriched uranium, and fission products. 

FINDING 12: At SRS, the 84th percentile of exposures to tritium for construction workers in 

specific crafts shows large differences from the 84th percentile of exposures to all construction 

workers. Similar results are observed for the corresponding ratio of the GSDs. 

FINDING 13: At SRS, the 84th percentile of exposures to tritium for construction workers in 

specific crafts shows large differences from the 84th percentile of site-wide exposures for 

non-construction workers. Similar results are observed for the corresponding ratio of the GSDs. 
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APPENDIX B: SC&A’S ANALYSES OF REVISED TABLES 6-1 AND 6-2 

OF ORAUT-OTIB-0075, REVISION 01

Figure B1. Mean Plutonium Concentrations in Urine at Mound for Claimant and Complete 

Datasets

0

0.1

0.2

0.3

0.4

Mean Plutonium Concentration in Urine (pCi/day)

1955 1960 1965 1970 1975 1980 1985 1990 1995

Complete Data Set (All Workers) Claimant Data Set
Effective Date:

10/9/2017

Revision No.

0 (Draft)

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17 of 18

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Privacy Act 5 U.S.C. § 552a and has been cleared for distribution. 

Figure B2. GSD of Plutonium Concentrations in Urine at Mound for Claimant and 

Complete Datasets

0

0.5

1

1.5

2

2.5

GSD of Plutonium Concentration in Urine (pCi/day)

1955 1960 1965 1970 1975 1980 1985 1990 1995

Complete Data Set (All Workers) Claimant Data Set
Effective Date:

10/9/2017

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2017-PR011

Page No.

18 of 18

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. 

Figure B3. Comparison of GSD of Plutonium Concentration in Urine at Mound (1960 to 

1990) 

Table B1. Summary of Regression Comparisons of Complete (All-Worker) and 31 

Claimant-Only Distributions for Plutonium at Mound (1960–1990) 

Lognormal 

Distribution 

Parameter

Regression 

Coefficient

Estimated 

Coefficient

Standard 

Error of 

Estimate

Hypothesis 

Tested

t-statistic 

for Test

p-level 

Pr{|X|>|t|}

Hypothesis 

Test Result

Mean Intercept 0.001 0.006 

Intercept=0

? 0.119 0.906 Accept

Mean Slope 1.118 0.061 Slope=1? 1.947 0.061 Accept

Mean R2 0.921 NA NA NA NA NA

GSD Intercept -0.099 0.051 

Intercept=0

? -1.941 0.062 Accept

GSD Slope 1.497 0.124 Slope=1? 4.021 0.000 Reject*

GSD R2 0.835 NA NA NA NA NA

* Although the null hypothesis that the slope is equal to 1 is rejected at the 95% confidence level, the estimated 

slope is significantly greater than 1, which is claimant favorable.

y = 1.497x - 0.099

R2 = 0.835

0

0.5

1

1.5

2

2.5

0 1 2

Claimant Dataset GSD (pCi/day)

Complete Dataset GSD (pCi/day)