Prenatal exposure to organophosphate pesticides has been associated with reduced IQs, mental and motor delays among preschoolers, memory and attention deficits, and autism (review of 27 studies).
A higher likelihood of an autism diagnosis was observed for children born to women residing within (versus beyond) 1.5 km of organophosphate pesticide applications on agricultural fields. Another recent study showed that higher organophosphate pesticide metabolite concentrations in maternal urine during pregnancy were associated with autism traits identified in adolescence. Risks for impaired neurodevelopment were greater among children of farmworkers, who experience higher exposures, and children with genetic susceptibility factors that reduce capacity to detoxify organophosphate pesticides.
Still, these are associations and it is difficult to establish causality. Animal studies have shown effects on cognition, motor activity, and social behaviors when dosed in early life with concentrations of organophosphates.