During 1987-1991, WHO supported studies of exposures and short term neurobehavioral effects in a cohort (n=200) with occupational and community exposures to pesticide drift containing organophosphates from orchards and cotton fields in the Hula Valley. We aim (1) to re-examine neurobehavioral outcomes in members of the original cohort and (2) to examine cognitive effects in children with residential exposures. In adults, we will carry out assays of alkyl phosphates, PON1 (paraoxonase-1), NTE (Neuropathy Target Esterase), neurobehavioral tests of cognitive and performance skills, nerve conduction measurements and mood status. We will carry out Psycho-Didactic tests in children. The findings will advance knowledge on delayed term health effects of lengthy everyday exposure to OP pesticides and guide regulatory policy.