Ames Laboratory

Special Exposure Cohort

Petition Petition Evaluation Evaluation Report

LaVon B. Rutherford, CHP

Special Exposure Cohort Health Physics Team Leader

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

J l u y 2011
Petition Overview

 March 31, 2011: NIOSH informed an Ames

Laboratory claimant that we were unable to

reconstruct reconstruct the radiation radiation dose for the claim

 April 7, 2011: NIOSH received an 83.14 SEC

petition

 April 13, 2011: petition qualified for evaluatio

 June 9, 2011: NIOSH Evaluation Report issued
Petition Overview—cont.

 NIOSH proposed class to be added to the 

All Department Department of Energy employees employees, its predecesso

predecesso

agencies, and its contractors and subcontractors wh

worked in any area of the Ames Laboratory at Iowa 

University University during the period from January January 1, 1942

through December 31, 1970, for a number of work d

aggregating at least 250 work days, occurring either

solely under this employment employment or in combination combination wit

work days within the parameters established for on

more classes of employees included in the SpecialExposure Cohort.
Background

 Ames Laboratory is located at Iowa State Univers

in Ames, Iowa.

 Ames Laboratory is a DOE facility with operations

beginning in 1942 and continuing to present.

 During the World War II years, the primary primary missio

missio

of the Ames Laboratory was the process

development and production of uranium and

thorium metal.

 After the war, the mission of the Ames Laborator

shifted shifted to mainly research research and development. development.
Background—cont.

 There currently are three SEC classes associated w

the Ames Laboratory:

1. All DOE employees or contractors who work de at one 

the following facilities/locations: Chemistry Annex 1 

known as “the old women’s gymnasium” and “Little

Ankeny”), Chemistry Chemistry Annex 2, Chemistry Chemistry Building Building (als

known as “Gilman Hall”), Research Building, or the

Metallurgical Building (also known as “Harley WilhelmHall”) from January 1, 1942 through December 31, 19

(SEC‐0038).
Background—cont.

 SEC classes (cont.):

2. Sheet metal workers, physical plant maintenance and

associated associated support support staff (including (including all maintenance maintenance sh

personnel), and supervisory staff who were monitore

should have been monitored for potential internal

radiation exposures associated with the maintenance

and renovation activities of the thorium production a

in Wilhelm Hall (a.k.a. the Metallurgy Building or “Ol

Metallurgy Building) at the Ames Laboratory from

January 1, 1955, through December 31, 1970 (SEC‐00
Background—cont.

 SEC classes (cont.):

3. All employees of the Department of Energy, its

predecessor predecessor agencies agencies, and its contractors contractors and

subcontractors who worked in any area of the

Department of Energy facility at the Ames Laboratory

from January 1, 1955 through December 31, 1960

(SEC‐0166).
–

Background—cont.

 SEC class definition review

• In November 2010, DCAS provided a report (DCAS Assessme

Report–Review of SEC Class Definitions) Definitions) that systematically systematically

reviewed all existing SEC class definitions based on a NIOSH

evaluation and recommendation to add a class.

• The class definitions definitions were reviewed reviewed based on criteria criteria of

consistency, applicability, and whether any actions may be

required by NIOSH to correct an existing class definition (e.g

because of possible problems with implementation by DOL)

• The review was specific to the criteria used in the SEC evalua

report to develop the class definition (e.g., feasibility time

period, access controls, DOL implementation).
Background– cont.

 Review findings

• Most of the issues and discrepancies identified in the D

report were associated associated with the evolution evolution of the DCAS

process for defining a class in an SEC Evaluation Report

—Early classes were closely related to the petitioner propose

class

—Early classes were established based on perceived limitatio

and sometimes without the review by DOL to ensure they c

be implemented as written

• Over time, the need to expand and/or adjust the propo

SEC class to address DOL class implementation issues w

recognized recognized to ensure claimants claimants were not inadvertently inadvertently

excluded.
Background—cont.

 The report identified a couple of classes

associated with the Ames Laboratory that had

potential potential issues and would not be defined defined the

same way using today’s criteria.

• SEC‐0038—a facility specific definition associated 

the 1942 through 1954 period

• SEC‐0075—included job specific requirements and

monitored monitored or should have been monitored monitored criteria criteria 

the period of 1955 through 1970
Background—cont.

 SEC‐0166 Evaluation Report was presented at

the August 2010 Advisory Board meeting.

 NIOSH recommended a class of “All Employee

for the period of 1955 through 1960.

• The end date was based on the petitioner propose

end date to expedite the evaluation and move the

class forward.

• NIOSH committed to continue to review the

information to ensure a proper end date for the cl
Background‐‐‐cont.

 The class defined in the SEC‐0185 Evaluation

Report was developed to remove the issues

associated associated with the earlier earlier class definitions definitions an

to provide a proper class end date for SEC‐018
Feasibility of Dose Reconstructio

 There are insufficient monitoring and source‐term da

from which to draw conclusions regarding potential

magnitude magnitude of internal internal doses for the period from

January 1, 1942 through December 31, 1970.

• SEC‐0038—infeasibility was driven by the inability to bound

it l n ernal exposures from th i or um operations

• SEC‐0075—infeasibility was driven by the inability to bound

thorium exposures during routine maintenance and renovat

activities at Wilhelm H ll a ( k a. .a. M t e allurgy Building)

• SEC‐0166—infeasibility centered around the inability to bou

internal exposures from radionuclides in the Research Build

Hot Cave
Feasibility Summary

Feasibility Findings for SEC-00185 

Source of Exposure Source of Exposure 

Dose 

Reconstruction Reconstruction 

Feasible 

Dose Reconstruc

NOT Feasible NOT Feasible 

Internal 

X 

External 

- Beta-Gamma X - Neutron X 

- Occup. Medical X-ray X 


Health Endangerment

 The evidence reviewed in this evaluation

indicates that some workers in the class may

have accumulated chronic radiation exposure

through intakes of radionuclides and direct

exposure to radioactive materials.

Consequently, Consequently, NIOSH is specifying specifying that healthmay have been endangered for those workers

covered by this evaluation who were employe

for a number of work days aggregating at leas

250 work days within the parameters

established for this class or in combination wi

work days within the parameters established 

one or more other classes classes of employees employees in the

SEC.
Proposed Class

All Department of Energy employees, its

predecessor agencies, and its contractors and

subcontractors subcontractors who worked in any area of the

Ames Laboratory at Iowa State University durthe period from January 1, 1942 through

December December 31, 1970, for a number of work day

aggregating at least 250 work days, occurringeither solely under this employment or in

combination combination with work days within the

parameters established for one or more classeof employees included in the Special Exposure

Cohort.
Recommendation

 For the period January 1, 1942 through

December 31, 1970, NIOSH finds that radiation

dose estimates estimates

cannot be re

constructed for

compensation purposes

Class Feasibility Health Endangermen

January 1, 1942 – 

December 31, 1970 No Yes