Air pollution exposure during fetal life and childhood, and brain morphological alterations in school-age children

PDS 73: Neurological effects, Johan Friso Foyer, Floor 1, August 26, 2019, 10:30 AM - 12:00 PM Background. Studies investigating the relationship between exposure to air pollution and brain development using magnetic resonance images are emerging. However, most studies have focused only on prenatal exposures and have included a limited selection of pollutants. Here, we aim to expand the current knowledge by assessing the relationship between exposure during fetal life and childhood to a wide selection of air pollutants and brain morphological alterations in a large population of school-age children. Methods. We used data from 3,133 children from a birth cohort from Rotterdam, The Netherlands (enrollment: 2002-2006). Concentrations of nitrogen oxides, particles of various sizes, and composition of fine particles were estimated at each home address that the participants have resided in during fetal life and childhood. Structural images were obtained when the participants were 9-12 years old. We assessed the relationships between air pollution exposure and global metrics of brain volume, area and thickness, as well as surface-based morphometric data, adjusting for child and parental socioeconomic, and life-style characteristics. Results. We found strong positive associations between fetal life and childhood exposures to various air pollutants and cortical and sub cortical brain volumes (e.g. an increase in volume of putamen of 773.4 mm3 [95% CI: 293.2 to 1253.7] for each 5 µg/m3 increase in fine particles during childhood). Higher childhood exposure to air pollution was also associated with larger pial surface area. Conversely, we observed associations between higher exposure to air pollution and a decrease in cortical thickness, although these associations disappeared when we corrected the results for multiple testing. Conclusion. Higher fetal and childhood exposure to air pollution was associated with larger brain volume and pial surface area. These brain structural alterations observed at ages 9-12 years could be an indication of a delay or deficiency in synaptic pruning, an essential process in brain development.