Pesticides Linked to ADHD in Kids

By Todd Neale, Staff Writer, MedPage Today
Published: May 17, 2010
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner

Children with greater exposure to organophosphate pesticides appear to have an increased risk of developing attention-deficit/hyperactivity disorder (ADHD), a cross-sectional study showed.

A 10-fold increase in the concentration of the most common dialkyl phosphate metabolites -- a measure of organophosphate exposure -- was associated with a 1.55-fold increase in the odds of having ADHD (OR 1.55, 95% CI 1.14 to 2.10), according to Maryse Bouchard, PhD, of the University of Montreal, and colleagues.

The relationship was not explained by gender, age, race/ethnicity, poverty to income ratio, fasting duration, or urinary creatinine concentration, the researchers reported in the June issue of Pediatrics.

"These findings support the hypothesis that organophosphate exposure, at levels common among U.S. children, may contribute to ADHD prevalence," they wrote.

Causality could not be established, however, and it is possible that the behavior of children with ADHD increases their exposure to pesticides.

"Future studies should use a prospective design, with multiple urine samples collected over time, for better assessment of chronic exposure and critical windows of exposure, and should establish appropriate temporality."