the committee reviewed studies of any human populations—including veterans—that had been exposed to the agent of concern at any dose. These studies come primarily from occupational, clinical, and healthy volunteer settings.
The committee began its task by talking with representatives of veterans’ organizations, as an understanding of the veterans’ experiences and perspectives is an important point of departure for a credible scientific review. The committee opened several of its meetings to veterans and other interested individuals. The committee held a scientific workshop and two public meetings. It also received information in written form from veteran organizations, veterans, and other interested persons who made the committee aware of their experiences or their health status and provided information about research. This process provided valuable information about the Gulf War experience and helped the committee to identify the health issues of concern.
The committee and staff reviewed more than 10,000 abstracts of scientific and medical articles related to the agents selected for study and then carefully examined the full text of over 1,000 peer-reviewed journal articles, many of which are described in this report. For each agent, the committee determined—to the extent that available published scientific data permitted meaningful determinations—the strength of the evidence for associations between exposure to the agent and adverse health effects. Because of the general lack of exposure measurements in veterans (with some exceptions), the committee reviewed studies of other populations known to be exposed to the agents of interest. These include uranium-processing workers, individuals who may have been exposed to sarin as a result of terrorist activity (e.g., the sarin attacks in Japan), healthy volunteers (including military populations), and clinical populations (e.g., patients with myasthenia gravis treated with PB). By studying health effects in these populations, the committee could decide, in some cases, whether the putative agents could be associated with adverse health outcomes. The committee’s judgments have both quantitative and qualitative aspects, and reflect the evidence and the approach taken to evaluate that evidence. The committee’s methodology draws from the work of previous IOM committees and their reports on vaccine safety (IOM, 1991, 1994a), herbicides used in Vietnam (IOM, 1994b, 1996, 1999), and indoor pollutants related to asthma (IOM, 2000).
The committee adopted a policy of using only peer-reviewed published literature to form its conclusions. It did not collect original data or perform any secondary data analysis. Although the process of peer review by fellow professionals—which is one of the hallmarks of modern science—is the best assurance that a study has reached valid conclusions, peer review does not guarantee the validity or generalizability of a study. Accordingly, committee members read each research article critically. The committee used only peer-reviewed publications in forming its conclusions about the degree of association between exposure to a particular agent and adverse health effects. However, this report describes some non-peer-reviewed publications, which provided background information for the committee and raised issues that will require further research. In their evaluation of individual research articles, committee members