Early Life Environmental Exposures and Brain Structural Alterations in Childhood

摘要

Background. Several environmental exposure have been related to impaired child neurodevelopment. However, they mainly used neuropsychological or clinical instruments to evaluate child neurodevelopment, limiting our understanding of which brain structural and functional alterations underlie these associations. We aimed to assess the relationship between several environmental exposures and brain morphology, cortical thickness, and white matter microstructure in children aged 6 to 12 years old. Methods. We used data from the Generation R study, a population-based birth cohort study set up in Rotterdam, The Netherlands (n=9,779, 2002-2006). Several environmental exposures have been estimated during fetal life and childhood including traffic-related air pollution, noise, and organophosphate pesticides. Selected children were scanned at 6-10 years (n=l,070) and the whole cohort was invited to be scanned at the 8-12 years (n=3,992). Structural imaging assessed cortical thickness and volumetric parametres. Diffusion tensor images assessed white matter miscrostructure. Results. Higher fetal particulate matter levels was related to thinner cortex in several brain regions at 6-10 years old (e.g. cerebral cortex in the precuneus region was 0.045mm thinner (95%CI 0.028-0.062) for each 5μg/m3 increase in PM2.5). The reduced cerebral cortex in some brain regions partially mediated the association between PM2.5 and impaired inhibitory control. Higher fetal exposure to PM2.5absorbance and childhood exposure to NOx, oxidative potential of PM2.5, and zinc content of PM2.5 were associated with white matter alterations at 8-12 years old. No relationship was found between fetal noise exposure and white matter miscrostructure. Conclusions. The use of MRI is gaining ground, making it possible to identify the structural and functional brain alterations that underlie the associations between environmental