Air pollution exposure during fetal life, brain morphology, and cognitive function in school-age children

Abstract

Background: Air pollution exposure during fetal life has been related to impaired child neurodevelopment, but it is unclear if brain structural alterations underlie this association. The authors assessed whether air pollution exposure during fetal life alters brain morphology and whether these alterations mediate the association between air pollution exposure during fetal life and cognitive function in school-age children. Methods: We used data from a population-based birth cohort set up in Rotterdam, The Netherlands (2002–2006). Residential levels of air pollution during the entire fetal period were calculated using land-use regression models. Structural neuroimaging and cognitive function were performed at 6 to 10 years of age (n = 783). Models were adjusted for several socioeconomic and lifestyle characteristics. Results: Mean fine particle levels were 20.2 μg/m3 (range, 16.8–28.1 μg/m3). Children exposed to higher particulate matter levels during fetal life had thinner cortex in several brain regions of both hemispheres (e.g., cerebral cortex of the precuneus region in the right hemisphere was 0.045 mm thinner (95% confidence interval, 0.028–0.062) for each 5-μg/m3 increase in fine particles). The reduced cerebral cortex in precuneus and rostral middle frontal regions partially mediated the association between exposure to fine particles and impaired inhibitory control. Air pollution exposure was not associated with global brain volumes. Conclusions: Exposure to fine particles during fetal life was related to child brain structural alterations of the cerebral cortex, and these alterations partially mediated the association between exposure to fine particles during fetal life and impaired child inhibitory control. Such cognitive impairment at early ages could have significant long-term consequences.

This work was supported by European Community Seventh Framework Program Grant Nos. GA#211250 (to BB) and GA#243406 (BB; principal investigator, Ranjeet S. Sokhi) for air pollution exposure assessment; The Netherlands Organization for Health Research and Development (Geestkracht Program Grant No. 10.000.1003 (to HT) and Grant No. TOP 40-00812-98-11021 [to TW]); the Health Effects Institute, an organization jointly funded by the U.S. Environmental Protection Agency (Assistance Award Grant No. R-82811201), and certain motor vehicle and engine manufacturers (to MG); The Netherlands Organization for Health Research and Development Grant Nos. VIDI 016.136.361 (to VWVJ) and The Netherlands Organization for Scientific Research Grant No. 016.VICI.170.200 (to HT); European Research Council Grant No. ERC-2014-CoG-64916 (to VWVJ); European Union Horizon 2020 research and innovation program Grant Nos. 633595 (DynaHEALTH) (to HT) and 733206 (LifeCycle) (to VWVJ); a personal fellowship (EUR Fellow 2014) from the Erasmus University Rotterdam (to HEM); and Miguel Servet fellowship Grant Nos. MS13/00054 and CP13/00054 (to MG) awarded by the Spanish Institute of Health Carlos III (Ministry of Economy and Competitiveness).