Effects of pesticides on the cognitive and behavioral functioning of Hispanic children in agricultural areas

Abstract

It has been suggested that Organophosphate (OP) pesticides have the potential to harm children's health by interfering with central nervous system functioning. The purpose of this study was to investigate how exposure to pesticides affects children's cognitive and behavioral functioning. Two groups of children were studied: Exposed and Non-Exposed. The children participated previously in the Children's Pesticide Survey (CPS) conducted in an agricultural area in the state of Arizona. They were selected based on the presence/absence of OP pesticides in an urine sample collected during the CPS. Both Exposed ( n = 25) and Non-Exposed (n = 23) children were assessed with cognitive measures: Wechsler Intelligence Scale for Children-Third Edition Short Form (WISC-III SF), Children's Memory Scale (CMS), Wisconsin Card Sorting Test (WCST), Trial Making Test A (TMTA), and Trial Making Test B (TMTB). Parents and teachers completed behavioral measures: Child Behavior Checklist (CBCL) and Teacher Report Form (TRF) respectively. All children provided an urine sample the day of cognitive assessment for analysis of OP pesticides metabolites. Data were analyzed using MANOVA and Pearson's correlation procedures. Results of the MANOVA indicated that children in the Exposed group did not perform significantly different than the Non-Exposed group on the WISC-III SF, the CMS, the TMTA, the CBCL and the TRF. However, Exposed children took significantly more time to complete the TMTB than the Non-Exposed group. Moreover, when Grade Level was considered, Exposed children in kindergarten and 1st grades made greater number of errors in the TMTB than the Non-Exposed children in the other Grade Levels (2nd and 3rd). This suggests that exposure to OP pesticides might have only a negative effect on such cognitive functions as speed of attention, sequencing, mental flexibility, visual search, and motor functioning in younger children. In addition, there were significant positive correlations between the OP metabolite concentrations on the day of cognitive assessment and some of the measures of the WCST. Further research is needed since this study represents a first approach to a complex problem.