A team of scientists from the University of Montreal and Harvard University have discovered that exposure to organophosphate（有机磷酸酯） pesticides（农药，杀虫剂） is associated with increased risk of Attention-Deficit Hyperactivity Disorder (ADHD注意力不集中症) in children. Published in the journal Pediatrics, the investigation found a connection between exposure pesticides and the presence of symptoms（症状） of ADHD. The study focused on 1,139 children from the general U.S. population and measured pesticide levels in their urine. The authors conclude that exposure to organophosphate pesticides, at levels common among U.S. children, may contribute to a diagnosis of ADHD.

"Previous studies have shown that exposure to some organophosphate compounds cause hyperactivity（极度活跃） and cognitive deficits in animals," says lead author Maryse F. Bouchard of the University of Montreal Department of Environmental and Occupational Health and the Sainte-Justine Hospital Research Center. "Our study found that exposure to organophosphates in developing children might have effects on neural（神经的） systems and could contribute to ADHD behaviors, such as inattention（疏忽，粗心） , hyperactivity, and impulsivity（冲动） ."