Long-term use of organophosphates and neuropsychological performance

Am J Ind Med. 1997 Nov;32(5):487-96. doi: 10.1002/(sici)1097-0274(199711)32:5<487::aid-ajim8>3.0.co;2-p.


This study evaluated neuropsychological effects due to chronic organophosphate use among farmers with no history of acute poisoning. Fifty-seven male tree fruit farmers (exposed) were compared with 42 age-matched male cranberry/blueberry growers and hardware store owners (unexposed). Univariate analyses of covariance (reading test as covariate) comparing exposed and unexposed subjects revealed significantly slower reaction time. No other significant differences were noted on tests of concentration, 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. Analysis of covariance with age and reading test score as covariates revealed 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 changes in neuropsychological performance.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Aged
  • Agricultural Workers' Diseases / chemically induced
  • Agricultural Workers' Diseases / epidemiology*
  • Analysis of Variance
  • Case-Control Studies
  • Central Nervous System Diseases / chemically induced
  • Central Nervous System Diseases / epidemiology*
  • Humans
  • Insecticides / adverse effects*
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • New Jersey / epidemiology
  • Occupational Exposure / adverse effects*
  • Occupational Exposure / analysis
  • Organophosphorus Compounds*
  • Psychomotor Performance / drug effects
  • Reaction Time
  • Regression Analysis


  • Insecticides
  • Organophosphorus Compounds