Organophosphate Exposures, Financial Hardship and Child Neurodevelopmental Outcomes in the CHARGE study

Abstract

OPS 55: Pesticides and neurological outcomes, Room 412, Floor 4, August 26, 2019, 1:30 PM - 3:00 PM In-utero exposure to organophosphate pesticides has been associated with neurodevelopmental delay. This study examined whether maternal report of inability to pay for basic needs (food, housing, medical care and heating) modified the relationship between prenatal pesticide exposure and autism spectrum disorder (ASD). Methods: We studied 488 children with ASD and 329 typically-developing controls aged 2-5 years enrolled between 2003 and 2008 in the CHARGE (Childhood Autism Risks from Genetics and the Environment) study, a population-based, case-control investigation. Diagnoses were confirmed by standardized assessments and information regarding maternal factors was determined from a structured interview with the mother. Residential proximity to agricultural application of organophosphate pesticides, based on California Department of Pesticide Regulation data, was determined by spatial analysis of maternal residence before and during pregnancy. Multiple logistic regression was used to examine the association between exposure during several time points during the pregnancy, and effect modification by the experience of financial hardship. Results: 213 (26%) CHARGE study mothers lived within 1.5 km of agricultural application of organophosphate compounds during their pregnancies. ASD odds were elevated in those exposed to pesticides between the 3 months prior to conception up through delivery (adjusted odds ratio (aOR) 2.44; 95% CI [1.05, 5.63]). Odds for mothers with 2nd trimester organophosphate exposure was higher for women with financial hardship compared to those without, 3.01; 95% CI [1.34, 6.75] vs 1.92; 95% CI [1.35, 2.76], respectively. This disparity was particularly pronounced for chlorpyrifos exposure, where those with financial hardship exhibited odds ratios ranging from 5 to 15 at all pregnancy timepoints. Conclusions: This study identified financial hardship as an amplifier of the association between organophosphate pesticide exposures during pregnancy and offspring ASD. It adds to the existing evidence highlighting the importance of studying the co-exposure of social and environmental factors affecting children at early developmental stages.