Mark Griffon

SRS Work Group Chair 

Prepared for the December 7-8, 2011, ABRWH 

Meeting

Tampa, Florida

SRS SEC-00103

Status and Definition of Addition to SEC 

Proposed by NIOSH
SRS Thorium-232: Overview

• In November 2008, NIOSH published its Evaluation Report for the SRS 

Special Exposure Cohort Petition SES-00103. The topic of thorium was 

reserved to 1960.

• On April 28, 2010, NIOSH published an addendum to its Evaluation report 

(ER) on Th-232, covering thorium metal handling and processing in the 

300-M area, covering the period to 1965.

• On August 9, 2011, published its second addendum to its Evaluation 

report (ER) on Th-232, covering thorium metal handling and processing in 

the 300-M area. (The ER was published in 2008.) Hereafter Addendum 2.

• Addendum 2 proposed that certain SRS workers who worked in certain 

areas from January 1, 1953 to September 310, 1972 be added to the SEC. 

The basis was that NIOSH determined it was not feasible to do thorium 

dose reconstruction for those workers for that period. The workers were 

to be identified by Area codes (up to December 31, 1957, and dosimetry

codes for the rest of the period. 
Area and dosimetry codes proposed in 

Addendum 2

• Area codes from January 1, 1953 through 

December 31, 1957: A, G, CMX, or TNX; 

• Dosimetry codes from January 1, 1958 

through September 30, 1972: 5A, 5C, 6B 

through 6Z, 12D through 12H, or 12J through 

12Z

• 250 SEC qualified work days required
SC&A review

• SC&A reviewed was asked to review a small sample of 

claims to examine whether the area and dosimetry

codes were present in claim records and whether the 

data were sufficient to implement the SEC in a claimant 

favorable way.

• SC&A provided a report dated November 28, 2011 to 

the Work Group. It was discussed during the 

December 3, 2011 WG teleconference.

• SC&A reviewed 10 claims for records completeness 

relative to the proposed definition.

• Small sample, not random; most claims examined 

derived from claimant representative suggestions. 
Main SC&A finding re dosimetry

records

• Main finding: There are extensive gaps in the records. 

Only 1 case out of 10 had complete records, with no 

uncertainties or discrepancies. Four (4) of the 10 cases 

have codes corresponding to inclusion in the proposed 

SEC class; these cases also have gaps. Five (5) of the 10 

cases have incomplete, illegible, and/or indeterminate 

records of work location. In these cases, it appears that 

excluding workers due to the lack of an SEC code per 

the proposed NIOSH SEC class definition would not be 

claimant favorable, since it would be impossible to 

assure that they did not, in fact, qualify. 
Finding details

• 55% of all employee-years for the 10 claimants had complete 

records. Gaps, illegible records, blank records, unavailable records, 

etc. affect the other 45% of employee-years fully or partially. Total 

work years for the 10 claims = 139 employee-years.

• Of the problem records, scratched out records, illegible records and 

unreadable records are more prevalent in the early years to 1957 

inclusive) and gaps an unknown work location dosimetry code 

(0000) characterize the latter period, 1958 to Sept 1972).

• A detailed comparison of work locations in dosimetery codes and 

Computer Assisted Telephone Interviews (CATIs) was not possible. 

CATIs are generally too broad in their descriptions of work locations 

to be useful in this context especially to ensure that a worker was 

not present in the SEC areas during some part of his/her period of 

employment. 
Work Group meeting

• SC&A presented its report during the Dec. 3, 2011 WG 

teleconference call.

• NIOSH stated that the gaps in the records may be 

explainable and may not be true missing records. NIOSH 

will provide more details at the Board meeting.

• Upon review of the SC&A report and their own research, 

NIOSH suggested that the class proposed in Addendum 2 of 

the ER be expanded as regards areas and illegible records, 

in the period 1953-1957, and that employees with the 

unknown code 0000 be added in the period Jan. 1, 1958 to 

Sept 30, 1972.

• The WG asked to see a written proposal and NIOSH is 

providing one for consideration at the Board meeting.