Public concern over exposure to ionizing radiation has increased, manifesting itself in different ways according to the individual perception of risk. One such group is composed of those servicemen who participated in the atmospheric testing of nuclear weapons at the Nevada test site, in the Pacific Proving Grounds, in cleanup activities in Hiroshima or Nagasaki, or who were prisoners of war in those cities during or shortly after the bombings. This concern led to the Radiation-Exposed Veteran's Compensation Act of 1988, which identified 13 cancers that were deemed to be presumptively service connected, and thus compensable, with 2 other cancer sites added by amendment in 1994.
Further concern, involving health issues related to the veterans' children, grandchildren, and spouses, led to a congressional directive to the VA. This mandated an IOM study to evaluate the feasibility of a study to determine the relationship between the exposure of veterans to ionizing radiation and
- the occurrence of genetic defects in their children,
- adverse reproductive outcomes experiences by their wives, and
- periparturient diseases of the mother that are the direct result of such adverse reproductive outcomes.
The task of the committee, as elaborated by the VA, was to address the following three questions:
- Is it feasible to conduct an epidemiologic study to determine whether there is an increased risk of adverse reproductive outcomes in the spouses and of adverse health effects in the children and grandchildren of Atomic Veterans?
- If such a study is feasible, approximately how much time and money would be required to organize and implement it?
- Are there other sources of information that would yield similar results at a lower cost or in less time?
There are insurmountable difficulties in finding and contacting a sufficiently large number of study subjects (offspring of Atomic Veterans), in establishing an accurate measure of dose for each veteran, in detecting the extremely small potential risk at low doses, in identifying and reliably documenting reproductive outcomes over a 50-year interval, and in the measuring of other factors that have been observed to cause reproductive problems, and therefore, might confound any observed relationship between radiation exposure and reproductive problems. These difficulties become even greater in the grandchildren of these veterans. The committee concluded, therefore, that as a result of the difficulties enumerated above, the cohort of Atomic Veterans does not provide a practical opportunity for a scientifically adequate and epidemiologically valid study.
Since the committee does not believe that an epidemiologic study is feasible, it did not consider in detail the time and money that would be required. However, on the basis of past and current studies of radiation-exposed cohorts, the committee estimates that such a study would cost tens of millions of dollars, and would last at least a decade.
While experimental animal studies could address some of the scientific issues discussed in this report, the committee has interpreted this charge to pertain to alternative epidemiologic studies that could yield similar results at a lower cost. The committee suggests some studies might be informative, but notes that these too will have limitations. Commonly, these limitations are related to sample size, population composition, uncertainty of dose, the presence of concurrent disease, and other confounding factors. Although studies of these groups may have their own merits, the committee concludes that they may not adequately address the immediate concerns of the Atomic Veterans.