Dosimetry associated with veterans who participated in nuclear weapons testing

Abstract

Background

This article summarizes the methodology, results, and challenges of the reconstruction of red bone marrow and male breast doses for a 1982-person sub-cohort of ∼114,270 U.S. military veterans who participated in eight atmospheric nuclear weapons tests between 1945 and 1962. These doses are being used in an epidemiological investigation of leukemia and male breast cancer as part of a study of one million U.S. persons to investigate risk from chronic low-dose radiation exposure.

Methods

Previous doses to these veterans had been estimated for compensation and tended to be biased high but newly available documentation made calculating individual doses and uncertainties using detailed exposure scenarios for each veteran possible. The techniques outlined in this report detail the methodology for developing individual scenarios and accounting for bias and uncertainty in dose based on the assumptions made about exposure.

Results

Doses to the atomic veterans in this sub-cohort were relatively low, with about two-thirds receiving red bone marrow doses <5 mGy and only four individuals receiving a red bone marrow dose >50 mGy. The average red bone marrow dose for members of the sub-cohort was 5.9 mGy. Doses to male breast were approximately 20% higher than red bone marrow doses.

Discussion and challenges

Relatively low uncertainty was achieved as a result of our methodology for reconstructing exposures based on knowledge of the individual veterans’ locations and activities from military records. Challenges did arise from use of military records to determine probability of participation in specific activities but accounted for in estimates of uncertainty.

Keywords:

• Atomic veterans
• nuclear weapons tests
• radiation dose assessment
• uncertainty
• nevada test site
• pacific proving grounds

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 The Pacific Proving Grounds was renamed Enewetak Proving Ground prior to the HARDTACK I test series in 1958.

2 A large number of unmanned “target” ships were anchored close to surface zero during the CROSSROADS test BAKER. Some of these ships were later re-boarded to assess damage and to decontaminate if possible.

3 The predecessor of DTRA was the Defense Nuclear Agency (DNA) whose legacy goes back to the Manhattan Project, which directed the development of the first atomic weapons. The DTRA program has been ongoing since the early 1980s.

4 NuTRIS (Nuclear Test Review Information System) is a database developed and populated by NTPR that contains all of the pertinent information about each veteran including the dose estimated by NTPR.

5 Although, as discussed in Till et al. (2014), some of the film badges for REDWING suffered environmental damage, those doses were replaced by reconstructed doses and thus the uncertainties in total dose were not significantly impacted.

6 A CV of 0.5 would correspond to a geometric standard deviation (GSD) of 1.6 while a CV of 3.4 would correspond to a GSD of ∼5, assuming the uncertainty distributions are approximately lognormal.

7 The Air Force was not a separate branch of service until 1947; thus, “Air Force” participants at TRINITY and CROSSROADS were actually in the Army Air Force.

8 Corresponding to GSD ∼1.5–1.6, assuming an approximate lognormal distribution.

Additional information

Funding

This research was supported in part by contracts and grants from the National Cancer Institute [Grant no. U01 CA137026], the U.S. Department of Energy [Grant no. DE-SC0008944 awarded to the National Council on Radiation Protection and Measurements], and a Discovery Grant from the Vanderbilt-Ingram Cancer Center [Center no. 404-357-9682]. Dr John D. Boice, Jr is the principal investigator for the Million Person Study. This support is acknowledged and appreciated. The authors also acknowledge Dr Paul Blake, Director, Chief, Nuclear Test Personnel Review, Defense Threat Reduction Agency, Department of Defense and his staff for their technical support of the project.

Notes on contributors

John E. Till

John E. Till, Ph.D, is the founder and President of Risk Assessment Corporation with more than 40 years of experience in environmental dosimetry. He received the E.O Lawrence award from the Department of Energy in 1995 and delivered the L.S. Taylor lecture for the National Council on Radiation Protection and Measurements in 2013. He also served in the U.S. Navy Nuclear Submarine Program, retiring as a Rear Admiral in 1999.

Harold L. Beck

Harold Beck, B.S, is a leading expert on radiation dose reconstruction with more than 50 years of experience in radiation dosimetry, radiation metrology, and dose reconstruction uncertainty. He served for over 36 years in various scientific and management positions in the Department of Energy Environmental Measurements Laboratory.

Jill W. Aanenson

Jill Weber Aanenson, M.S, has over two decades of experience in environmental risk assessment, including emphasis on contaminant transport and modeling, uncertainty estimation and statistics, environmental monitoring, environmental database development, and exposure and risk assessment, with a special interest in radiation exposures in dentistry.

Helen A. Grogan

Helen A. Grogan, Ph.D, has more than 30 years of experience in radioecology, dose reconstruction, and assessment of hazardous wastes, with a special interest in validation of environmental fate and transport models. She’s been a U.S. delegate to UNSCEAR since 2014.

H. Justin Mohler

H. Justin Mohler, M.S, has 20 years of experience in various aspects of environmental health physics, including sampling and measurement, data analysis and interpretation, transport modeling and exposure and risk assessment, as well as extensive experience with database design and management.

S. Shawn Mohler

S. Shawn Mohler, M.S, has almost 20 years of experience in risk assessment and dose reconstruction projects, particularly related to exposure analysis, exposure scenario development, technical editing and review, and technical graphic design. Shawn comes from an occupational health and safety background with an M.S. in environmental health specializing in industrial hygiene.

Paul G. Voillequé

Paul G. Voillequé, M.S, is an expert in historical dose reconstruction whose broad interests range from personnel protection and internal dosimetry to the behavior of radionuclides within nuclear facilities and in the environment. He was a member of the Subcommittee on DTRA Dose Reconstruction Procedures of the Veterans’ Board on Dose Reconstruction.