Between 1958 and 1975, the U.S. Army studied servicemen exposed voluntarily to an array of chemical warfare agents (NRC, 1982, 1985). During the program, the Army investigated only acute short-term effects. Approximately 6,720 soldiers (between the ages of 20 and 25 years) were exposed at Edgewood Arsenal, Maryland, to one or more of 254 chemicals in five classes. About 1,406 of the soldiers were exposed to 15 anticholinesterases. Of this group, 246 were tested with sarin under different conditions (e.g., i.v. or inhalation of sarin vapor), but the committee was unable to determine the actual doses to most of the soldiers by either route. However, for approximately 10 percent of this group, i.v. doses were reported to range from 3.0 to 4.0 μg/kg, alone or in combination with other agents (NRC, 1982); twenty-one soldiers were exposed to cyclosarin.7 The servicemen were above average in physical and mental ability.
Five years after the program ended, the Department of the Army requested that the National Research Council’s (NRC’s) Board on Toxicology and Environmental Health Hazards examine the possible long-term health effects in servicemen tested in the research program. In a series of reports, the NRC designed and conducted a follow-up survey and examined soldiers’ hospitalization and mortality. Two comparison groups of soldiers in the testing program were used as controls (i.e., those who received no test chemicals8 and those who received chemicals other than the one under scrutiny). The NRC results and conclusions were based primarily on anticholinesterases as a class, rather than on sarin or cyclosarin.
The NRC questionnaire contained 27 outcome variables relating to health, social adjustment, and reproductive experience of the participants. Mailed survey questionnaires were returned by 64 percent of the overall population of soldiers tested. No long-term health consequences were reported by those responding to the questionnaire, including those exposed to anticholinesterases. Nonrespondents reported having had no health problems to report, when contacted later about their reasons for not returning the questionnaire. Nevertheless, the NRC cautioned that the study had low statistical power and that the exposed group was a highly selected, healthier subset than those who were unexposed. Thus, despite no major identifiable long-term effects, the NRC concluded that “the limited information available from the follow-up on these soldiers does not permit definitive conclusions regarding the nature and extent of possible long-term problems resulting from chemical exposure at Edgewood” (NRC, 1985).
The NRC also reviewed Army data tapes for hospitalizations of volunteers while still in the service (1958–1983) and reviewed Veterans Administration