Exposição a pesticidas organoclorados e desenvolvimento cognitivo em crianças e adolescentes residentes em uma area contaminada no Brasil

Abstract

Objectives: To assess the cognitive performance of children and adolescents living in an area contaminated with organochloride (OC) pesticides and factors associated with exposure. Methods: A cross-sectional study was conducted with 102 individuals aged between 6 and 16 years living in Cidade dos Meninos, in the Brazilian State of Rio de Janeiro, between 2012 and 2013. A subsample of 46 of these children had serum concentrations of OC pesticides and thyroid hormones determined between 2003 and 2004. Information on place of residence of the mother and duration of breastfeeding were provided for all participants. Cognitive performance was assessed using the WISC-III scale. Multivariate regression was employed to investigate associations. Results: At least 40% of the children presented with below average intelligence (IQ<90) in six cognitive categories. Executive function was the lowest score. Place of residence of the mother and duration of breastfeeding were not associated with cognition, except for the executive function. Levels of alphahexachlorocyclohexane (HCH) were associated with a reduction of 0.45, 0.33 and 0.46 points in the areas of execution, resistance to distraction (RD) and processing speed (PS), respectively; gamma-HCH was associated with a reduction of 1.74 points in RD and 1.84 points in PS; and p,p’-DDT (dichlorodiphenyl- trichloroethane) was associated with a lower score (-0.81) in PS. A slight inverse association was found between levels of total triiodothyronine and perceptual organization. Conclusions: The results suggest that chronic exposure to OC pesticides may have led to cognitive deficiencies in these children and adolescents.