title: An investigation into neurologic and neurobehavioral effects of long-term agrichemical use among deciduous fruit farm workers in the Western Cape, South Africa.
abstract: Long-term exposure to organophosphates (OPs) in the absence of acute poisoning is increasingly suspected of causing chronic neurologic and neurobehavioral effects. A cross-sectional survey of 163 spray operators on deciduous fruit farms in the Western Cape, South Africa, and 84 nonspraying labororers was conducted in 1993 to investigate the relationship between long-term OP exposures and neurological and neurobehavioral outcomes. The study also sought to evaluate the performance of a set of neurobehavioral test batteries based on the information-processing theory of cognitive psychology, relative to the more established World Health Organization's Neurobehavioral Core Test Battery (WHO NCTB). These information-processing tests were designed for use in studies of subjects with little education, which are frequently conducted in developing countries in agriculture. They draw on experience from a previous South African study in which problems were encountered with a lack of cross-cultural validity of conventional test batteries. No evidence was found of a relationship between long-term OP exposure and loss of vibration sense. Small associations were found with the NCTB Pursuit-Aiming and Santa Ana (nondominant hand) subtests. The overall evidence of neurologic and neurobehavioral effects of long-term OP exposure was small; exposure misclassification may have contributed to this finding. Important confounders such as brain injury, alcohol consumption, and nutritional status were identified.
authors.affiliation: Department of Community Health, University of Cape Town, Cape Town, South Africa.
authors.forename: L
authors.initials: L
authors.lastname: London
authors.forename: J E
authors.initials: JE
authors.lastname: Myers
authors.forename: V
authors.initials: V
authors.lastname: Nell
authors.forename: T
authors.initials: T
authors.lastname: Taylor
authors.forename: M L
authors.initials: ML
authors.lastname: Thompson
mesh_terms: D000382:Agricultural Workers' Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000503:physiopathology; D016573:Agrochemicals / Q000506:poisoning*; D001519:Behavior / Q000187:drug effects*; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D006801:Humans; D009420:Nervous System / Q000187:drug effects* / Q000503:physiopathology; D016273:Occupational Exposure; D013019:South Africa / Q000453:epidemiology
chemical_list: D016573:Agrochemicals