SELF-REPORTED EXPOSURE TO NEUROTOXIC CHEMICAL-COMBINATIONS IN THE GULF-WAR - A CROSS-SECTIONAL EPIDEMIOLOGIC-STUDY

Objective.-To identify risk factors of factor analysis-derived Gulf Wa r-related syndromes. Design.-A cross-sectional survey. Participants.-A total of 249 Gulf War veterans from the Twenty-fourth Reserve Naval M obile Construction Battalion. Data Collection.-Participants completed standardized booklets measuring self-reported wartime exposures and pr esent symptoms. Main Outcome Measures.-Associations of factor analysis -derived syndromes with risk factors for chemical interactions that in hibit butyrylcholinesterase and neuropathy target esterase. Results.-R isk of syndrome 1 (''impaired cognition'') was greater in veterans who reported wearing flea collars during the war (5 of 20, 25%) than in t hose who never wore them (7 of 229, 3%; relative risk [RR], 8.7; 95% c onfidence interval [CI], 3.0-24.7; P<.001). Risk of syndrome 2 (''conf usion-ataxia'') increased with a scale of advanced adverse effects fro m pyridostigmine bromide (chi(2) for trend, P<.001), was greater among veterans who believed they had been involved in chemical weapons expo sure (18 of 108, 17%) than in those who did not (3 of 141, 2%; RR, 7.8 ; 95% CI, 2.3-25.9; P<.001), and was increased in veterans who had bee n in a sector of far northeastern Saudi Arabia on the fourth day of th e air war (6 of 21, 29%) than in those who had not been (15 of 228, 7% ; RR, 4.3; 95% CI, 1.9-10.0; P=.004). Effects of perceived chemical we apons exposure and advanced adverse effects from pyridostigmine were s ynergistic (Rothman S, 5.3; 95% CI, 1.04-26.7), Risk of syndrome 3 ('' arthro-myo-neuropathy'') increased with an index of frequency and amou nt of government-issued insect repellent containing 75% DEET (N,N-diet hyl-m-toluamide) in ethanol applied during the war (chi(2) for trend, P<.001) and with advanced adverse effects from pyridostigmine (chi(2) for trend, P<.001). Conclusion.-Some Gulf War Veterans may have delaye d, chronic neurotoxic syndromes from wartime exposure to combinations of chemicals that inhibit butyrylcholinesterase and neuropathy target esterase.