Residential proximity to agricultural crops and adaptive behaviors in children with autism spectrum disorder from the French ELENA cohort

BACKGROUND AND AIM: Exposures to pesticides during key periods of brain development (pregnancy and early childhood) have been associated with increased risk of autism spectrum disorder (ASD) in children. No study has yet investigated the influence of these exposures on the clinical expression of children with ASD. The aim of this study was to investigate the associations between early residential exposure to agricultural crops and adaptive behaviors in children with ASD. METHODS: Children with ASD were recruited within the Etude Longitudinale de l’Enfant avec Autisme (ELENA) French cohort. Adaptive behaviors were assessed with the second edition of the Vineland Adaptive Behavior Scales (VABS-II). Baseline subscores in communication, daily living skills and socialization were considered. Residential exposure to agricultural crops was estimated by crops acreage within a 1000m radius around homes. We used multiple linear regression models to analyze the associations between exposures to agricultural crops during the pregnancy (n=183), the first two years of life (n=193) and adaptive behaviors in children with ASD. RESULTS:The mean (SD) age of children at the inclusion in the ELENA cohort was 6 (3) years, 39% of them presented an intellectual disability (ID). The mean communication score was 73.0 (15.8). On average, the crop acreage covered 29(27)% of the acreage formed by the 1000m radius around homes. Each increase of 20% in the crop acreage was associated with a significant decrease in communication score of the VABS-II in children without ID for pregnancy (β= -2.21, 95%CI: -4.16 to -0.27) and the first two years of life (β= -1.90, 95%CI: -3.68 to -0.11). No association was found in children with ID. CONCLUSIONS:This is the first study in children with ASD investigating and showing an association between early residential exposure to agricultural crops and impairments in adaptive behaviors. This study opens perspectives for future works to better understand ASD phenotypes. KEYWORDS: Exposure assessment, Pesticides, Neurodevelopmental outcomes, Children's environmental health, Environmental epidemiology