LONG-TERM USE OF ORGANOPHOSPHATES AND NEUROPSYCHOLOGICAL PERFORMANCE

This study evaluated neuropsychological effects due to chronic organop hosphate use among farmers with no history of acute poisoning. Fifty-s even male tree fruit farmers (exposed) were compared with 42 age-match ed male cranberry/blueberry growers and hardware store owners (unexpos ed). Univariate analyses of covariance (reading test as covariate) com paring exposed and unexposed subjects revealed significantly slower re action time. No other significant differences were noted on tests of c oncentration, visuomotor skills, memory, expressive language, or mood. Based on an exposure metric derived from detailed exposure histories, farmers were divided into high exposure (n = 40) and low exposure (n = 59) groups, and their neuropsychological performance was compared. A nalysis of covariance with age and reading test score as covariates re vealed that the high exposure group had significantly slower reaction time, dominant hand Long-term use of organophosphates without evidence of an acute poisoning episode appears to produce, at most, subtle cha nges in neuropsychological performance. (C) 1997 Wiley-Liss, Inc.