Exposure to air pollution during pregnancy and childhood, and white matter microstructure in preadolescents
Background: Air pollution has been related to brain structural alterations, but a relationship with white matter microstructure is unclear. Objectives: We assessed whether pregnancy and childhood exposures to air pollution are related to white matter microstructure in preadolescents. Methods: We used data of 2,954 children from the Generation R Study, a population-based birth cohort from Rotterdam, Netherlands (2002-2006). Concentrations of 17 air pollutants including nitrogen oxides (NOX), particulate matter (PM), and components of PM were estimated at participants' homes during pregnancy and childhood using land-use regression models. Diffusion tensor images were obtained at child's 9-12 years of age, and fractional anisotropy (FA) and mean diffusivity (MD) were computed. We performed linear regressions adjusting for socioeconomic and lifestyle characteristics. Single-pollutant analyses were followed by multipollutant analyses using the Deletion/Substitution/Addition (DSA) algorithm. Results: In the single-pollutant analyses, higher concentrations of several air pollutants during pregnancy or childhood were associated with significantly lower FA or higher MD (p<0.05). In multipollutant models of pregnancy exposures selected by DSA, higher concentration of fine particles was associated with significantly lower FA [−0.71 (95% CI: −1.26, −0.16) per 5μg/m3 fine particles] and higher concentration of elemental silicon with significantly higher MD [0.06 (95% CI: 0.01, 0.11) per 100ng/m3 silicon]. Multipollutant models of childhood exposures selected by DSA indicated significant associations of NOX with FA [−0.14 (95% CI: −0.23, −0.04) per 20-μg/m3 NOX increase], and of elemental zinc and the oxidative potential of PM with MD [0.03 (95% CI: 0.01, 0.04) per 10-ng/m3 zinc increase and 0.07 (95% CI: 0.00, 0.44) per 1-nmolDTT/min/m3 oxidative potential increase]. Mutually adjusted models of significant exposures during pregnancy and childhood indicated significant associations of silicon during pregnancy, and zinc during childhood, with MD. Discussion: Exposure in pregnancy and childhood to air pollutants from tailpipe and non-tailpipe emissions were associated with lower FA and higher MD in white matter of preadolescents. https://doi.org/10.1289/EHP4709. ; The general design of the Generation R Study is made possible by financial support from the Erasmus Medical Center, Rotterdam; the Erasmus University Rotterdam; Netherlands Organization for Health Research and Development (ZonMw); the Netherlands Organization for Scientific Research (NWO); and the Ministry of Health, Welfare and Sport. Air pollution exposure assessment was made possible by funding from the European Community's Seventh Framework Program (Grant Agreement no. 211250, Grant Agreement no. 243406). In addition, the study was made possible by financial support from the ZonMw (Geestkracht Program 10.000.1003 and TOP 40-00812-98-11021). Neuroimaging was supported by the ZonMw TOP project no. 91211021 to T.W., Sophia Foundation Project S18-20 to R.L.M., and super computing computations for imaging processing were supported by the NWO Physical Sciences Division (Exacte Wetenschappen) and SURFsara (Cartesius compute cluster, https://www.surf.nl). Research described in this article was also conducted under contract to the HEI, an organization jointly funded by the U.S. EPA (Assistance Award No. R-82811201) and certain motor vehicle and engine manufacturers. The contents of this article do not necessarily reflect the views of HEI, or its sponsors, nor do they necessarily reflect the views and policies of the U.S. EPA or motor vehicle and engine manufacturers. V.W.V.J. and H.T. received funding from the ZonMw (VIDI 016.136.361 and NWO-grant 016.VICI.170.200, respectively), the European Research Council (ERC-2014-CoG-64916), and the European Union's Horizon 2020 research and innovation program under grant agreement no. 633595 (DynaHEALTH) and no. 733206 (LifeCycle). H.E.M. was supported by Stichting Volksbond Rotterdam and the Dutch Brain Foundation (De Hersenstichting, project number GH2016.2.01), and by the 2019 NARSAD Young Investigator Grant from the Brain and Behavior Research Foundation. M.G. is funded by a Miguel Servet fellowship (MS13/00054, CP13/00054, CI18/00018) awarded by the Spanish Institute of Health Carlos III. W.D. is funded in part by the Research Council of Norway (RCN) (grant 249779) and through the RCN Centers of Excellence funding scheme (grant 262700).