Motor inhibition and learning impairments in school-aged children following exposure to organophosphate pesticides in infancy

Despite the critical role of acetylcholinesterase (AChE) in cortical function and development, no long-term studies have been conducted in humans on the long-term sequelae of the disruption of the cholinergic system in early childhood. We report a neuropsychological assessment of healthy school-aged children, who had been hospitalized in infancy following exposure to organophosphate pesticides, compared with children exposed to other toxins such as kerosene, and age- and sex-matched non-exposed children. Although overall, the children seem to have overcome the acute one-time exposure incident, and they all attend regular schools, a finer assessment of specific cognitive abilities indicates they are impaired compared with the matched controls. Specifically, the children who had been exposed to organophosphate pesticides had a deficit in inhibitory motor control. Children with pesticide or kerosene poisoning had a retrieval deficit on the acquisition phase of a verbal learning task.