Comparison of Two Dose Assessment Methods for Exposures to Nuclear Detonation Radiation
Condition: Radiation Exposure
Study type: Observational

Summary: 
      Background:

      - The National Cancer Institute was funded to study how much radiation U.S. veterans who
      served in the 1950s were exposed to. Researchers want to estimate how much radiation these
      veterans received. They will use two methods and compare them. One is to interview the
      veterans and study their military records. The other is to take blood samples and look for
      certain types of changes in the blood cells. Being exposed to some kinds of radiation is
      known to cause changes in blood cells. The amount of changes to these cells tells scientists
      about how much radiation was received.

      Objectives:

      - To better understand how to measure how much radiation a person has received.

      Eligibility:

        -  Veterans who were exposed to radiation at a specific site in the Pacific in 1954 or
           other sites in the 1950s.

        -  Veterans close in age to the first group, who have low levels of exposure to radiation.

        -  Men about 25 years old with no exposure to radiation.

      Design:

        -  Participants will have 1 visit, in their home.

        -  All participants will have blood drawn. This will take 10 minutes.

        -  The exposed veterans will be interviewed. They will answer questions about the nuclear
           events they experienced. This will take up to 40 minutes.

        -  For the exposed veterans, researchers will look at their military records, if they can.
           They will estimate how much radiation the veteran received.
    

Detailed description: 
      Understanding the potential consequences of exposures from nuclear detonations is a current
      national security concern. In the event of a nuclear detonation, an important priority for
      the scientific and national security community is to be able to estimate exposure to the
      general population for medical triage, treatment, follow-up and risk projection for public
      health purposes. The only available comprehensive exposure estimates for persons exposed to
      nuclear detonation radiation are from studies of wartime atomic bomb survivors. There is an
      urgent need to evaluate exposure assessment methods in other populations and to determine how
      well each works and the obstacles involved in the application of each.

      In the absence of other studies of exposures to nuclear detonation radiation, the Atomic
      Veterans Epidemiologic Study (AVES)1, a large ongoing study of atomic veterans of 115,000
      atomic veterans who participated in aboveground nuclear weapon tests during 1945-1962
      provides a unique opportunity to evaluate the lasting biological effects of radiations
      received during nuclear detonations. That study has the means for identifying veterans who
      received the highest exposures as well as control subjects with minimal to no exposure. An
      overview of the AVES can be found at
      http://www.vbdr.org/meetings/2013/Presentations/02_Dr_Boice.pdf.

      We propose to conduct a small methodologic investigation with the following objective:
      evaluate the level of agreement between radiation exposure estimates from the generally
      simple and inexpensive assessment strategy of model-based dose reconstruction with the only
      well-established long-term biologically-based dose estimation technique - quantification of
      chromosome aberration frequency. In this study, the dose reconstruction would include
      individual interview data.

      The study would be conducted using a group of U.S. veterans exposed to nuclear detonation
      radiation during the 1950s and 1960s. While there are many thousands of veterans still alive
      today who participated in nuclear testing-related activities, only 16 have been identified
      that are still living and that have estimated exposures of sufficient magnitude for the
      chromosome aberration frequency assay to be successful. These particular veterans were
      exposed on Rongerik Atoll in the Pacific in 1954 and at the Nevada Test Site in 1951-1952.
      The dose estimates will also be compared against individual records of exposure obtained from
      radiation film-badges, when available. All the persons to be studied are part of the study
      cohort in the AVES study.

      The primary purpose of evaluating the model-based dose reconstruction with the dose estimates
      based on chromosome aberration frequency will be to assess the presence of any substantial
      differences (either systematic or random) in doses now being estimated via model-based dose
      reconstruction in the AVES. Because the chromosome aberration frequency assay is difficult,
      expensive and somewhat invasive (requiring a blood sample), it is not practical in a study of
      many thousands of subjects as in the AVES. Determination that the model-based dose
      estimations are not systematically different from FISH-estimated doses is of substantial
      value to the AVES. To a limited degree, i.e., within the constraints of the small sample
      size, the study may be indicative of the potential for model-based dose estimates to be
      relied upon if mass exposures were to take place from a nuclear detonation.

      It is noteworthy that the collection of samples and data to evaluate doses in this study will
      take advantage of a one-of-a-kind situation to obtain exposure-related data from a unique
      (and rapidly dwindling) population living persons exposed to atomic weapons detonation
      radiation a situation that cannot be repeated except under wartime or actual national threat
      situations.
    

Observational model: Case-Control
Time perspective: Retrospective
Keywords: Dose Estimation; Dose Reconstruction; Methods; Fallout; Radiation Exposure