study using a survey almost identical with the 1985 one (Page, 2003). The study, which was conducted at least 25 years after the end of the testing program, included a mortality study and a telephone survey of 4,022 members of the program. The survey was designed to assess neuropsychologic, neurologic, and vestibular symptoms possibly related to anticholinesterase exposure in the three exposure groups: a group exposed to anticholinesterase, a group exposed to two or more nonanticholinesterase agents (such as, scopolamine and atropine), and a nonexposed group that at the program’s inception was ineligible for participation because of low scores on general intelligence tests and the Minnesota Multiphasic Personality Inventory. The anticholinesterase-exposed group was exposed to at least one of 15 anticholinesterase agents, the most common being Agent VX (n = 740), sarin (n = 246), and eserine (physostigmine, n = 138). Exact doses are not known, but in an appendix to the 2003 study, the authors note that their review of original records found 17 of 25 sarin-exposed servicemen to have experienced the acute cholinergic syndrome. The authors were unable to assemble a sarin-only group because three-fourths of the original sample of 246 either had died (n = 67) or had unusable dose data. As noted earlier, a mortality study was also conducted.

There were no statistically significant differences among the three groups in overall health, disability, reproductive history, and psychologic symptoms after adjustment for age, initial fitness, race, and chemical exposures outside the program. However, MFUA believed that, because of selection bias, the nonexposed group was less healthy than the anticholinesterase-exposed group, whereas the nonanticholinesterase group was likely to be healthier. Only sleep disturbances were more prevalent in the anticholinesterase group than in the nonexposed group (sleep disturbances score, 0–9; mean difference, +0.28; 95% CI did not include 1). Attention problems were reported less frequently in the anticholinesterase group than in the nonanticholinesterase group. There was, however, significantly lower all-cause mortality in the anticholinesterase group than in the nonexposed group (relative risk [RR] for all-cause mortality, 0.82; 95% CI, 0.68–0.99). There were no mortality differences for specific conditions, such as suicide, accidental deaths, cancer, and heart disease. Although the results of the study show no association, it is somewhat uninformative for the purpose of this committee because of the lack of dose information, the fact that the nonexposed control group was likely to be less healthy, and the mixed nature of the exposures analyzed (there was no analysis of a sarin-only group).

In an uncontrolled study of UK servicemen who volunteered to be exposed to sarin (sarin vapors at 15 mg/min-m³, in 1983–1984) and displayed some signs of the acute cholinergic syndrome (Baker and Sedgwick, 1996; discussed in IOM, 2000), the authors interpreted an increased jitter 3 h after exposure and still