Organophosphate Pesticide Exposure and Attention in Young Mexican-American Children
Tags: Attention, CHAMACOS Study, Neurodevelopment, Organophosphate Pesticides (OPs), Pesticides
Marks AR, Harley K, Bradman A, Kogut K, Barr DB, Johnson C, et al. Organophosphate Pesticide Exposure and Attention in Young Mexican-American Children. Environ Health Perspect. 2010. 118:1768-1774.
Background: In utero exposure to organophosphate (OP) pesticides, well-known neurotoxicants, has been associated with neurobehavioral deficits in children.
Objectives: We investigated whether OP exposure, as measured by maternal urinary dialkyl phosphate (DAP) metabolites during pregnancy, was associated with attention-related outcomes among Mexican-American children living in the agricultural Salinas Valley and followed to ages 3½ (n=331) and 5 (n=323) years.
Methods: Mothers completed the Child Behavior Checklist (CBCL). We administered the NEPSY-II visual attention subtest to children at 3½ years and the Conners’ Kiddie Continuous Performance Test (K-CPT) at 5 years. The K-CPT yielded a standardized attention deficit/hyperactivity disorder (ADHD) Confidence Index score. Psychometricians scored 5-year olds’ behavior during testing using the Hillside Behavior Rating Scale (HBRS).
Results: Prenatal DAPs were non-significantly associated with maternal report of attention problems and ADHD at age 3½, but were significantly related at age 5 (Attention: β = 0.7; 95% confidence interval (CI), 0.2, 1.2; ADHD:β =1.3; 95% CI, 0.4, 2.1). DAPs were associated with the K-CPT ADHD Confidence Index (OR=5.1; 95% CI, 1.7, 15.7) and non-significantly associated with HBRS ADHD (β = 0.4, 95% CI, -0.04, 0.9). DAPs were also associated with a composite ADHD indicator of the various measures (OR=3.6, 95% CI, 1.2, 11.0). Some outcomes exhibited interaction by sex with associations found only among boys.
Conclusions: In utero DAPs were associated adversely with attention in young children as assessed by maternal report, psychometrician observation, and direct assessment. These associations were more robust at 5 than 3½ years and stronger in boys.