Prenatal residential proximity to agricultural pesticide use and IQ in 7-year-old children

Abstract

BACKGROUND: Residential proximity to agricultural pesticide use has been associated with neural tube defects and autism, but more subtle outcomes such as cognition have not been studied. OBJECTIVES: We evaluated the relationship between prenatal residential proximity to agricultural use of potentially neurotoxic pesticides and neurodevelopment in 7-year-old children. METHODS: Participants included mothers and children (n=283) living in the agricultural Salinas Valley of California enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study. We estimated agricultural pesticide use within 1 km of maternal residences during pregnancy using a geographic information system, residential location, and California’s comprehensive agricultural Pesticide Use Report data. We used regression models to evaluate prenatal residential proximity to agricultural use of five potentially neurotoxic pesticide groups (organophosphates, carbamates, pyrethroids, neonicotinoids, and manganese fungicides) and five individual organophosphates (acephate, chlorpyrifos, diazinon, malathion, and oxydemeton-methyl) and cognition in 7-year-old children. All models included prenatal urinary dialkyl phosphate metabolite concentrations. RESULTS: We observed a decrease of 2.2 points [95% confidence interval (CI): -3.9, -0.5] in Full-Scale IQ and 2.9 points (95% CI: -4.4, -1.3) in Verbal Comprehension for each standard deviation increase in toxicity-weighted use of organophosphate pesticides. In separate models, we observed similar decrements in Full-Scale IQ with each standard deviation increase of use for two organophosphates (acephate and oxydemeton-methyl) and three neurotoxic pesticide groups (pyrethroids, neonicotinoids, and manganese fungicides). CONCLUSIONS: This study identified potential relationships between maternal residential proximity to agricultural use of neurotoxic pesticides and poorer neurodevelopment in children.