Background: The association between air pollution exposure and emotional and behavioural problems in children is unclear. We aimed to assess prenatal and postnatal exposure to several air pollutants and child's depressive and anxiety symptoms, and aggressive symptoms in children of 7–11 years. Methods: We analysed data of 13182 children from 8 European population-based birth cohorts. Concentrations of nitrogen dioxide (NO2), nitrogen oxides (NOx), particulate matter (PM) with diameters of ≤10 μm (PM10), ≤ 2.5 μm (PM2.5), and between 10 and 2.5 μm (PMcoarse), the absorbance of PM2.5 filters (PM2.5abs), and polycyclic aromatic hydrocarbons (PAHs) were estimated at residential addresses of each participant. Depressive and anxiety symptoms and aggressive symptoms were assessed at 7–11 years of age using parent reported tests. Children were classified in borderline/clinical range or clinical range using validated cut offs. Region specific models were adjusted for various socio-economic and lifestyle characteristics and then combined using random effect meta-analysis. Multiple imputation and inverse probability weighting methods were applied to correct for potential attrition bias. Results: A total of 1896 (14.4%) children were classified as having depressive and anxiety symptoms in the borderline/clinical range, and 1778 (13.4%) as having aggressive symptoms in the borderline/clinical range. Overall, 1108 (8.4%) and 870 (6.6%) children were classified as having depressive and anxiety symptoms, and aggressive symptoms in the clinical range, respectively. Prenatal exposure to air pollution was not associated with depressive and anxiety symptoms in the borderline/clinical range (e.g. OR 1.02 [95%CI 0.95 to 1.10] per 10 μg/m3 higher NO2) nor with aggressive symptoms in the borderline/clinical range (e.g. OR 1.04 [95%CI 0.96 to 1.12] per 10 μg/m3 higher NO2). Similar results were observed for the symptoms in the clinical range, and for postnatal exposures to air pollution. Conclusions: Overall, our results suggest that prenatal and postnatal exposure to air pollution is not associated with depressive and anxiety symptoms or aggressive symptoms in children of 7 to 11 years old.

ESCAPE Project. European Community's Seventh Framework Program (FP7/2007-2011-GA#211250). GENERATION R. The Generation R Study is conducted by the Erasmus Medical Center in close collaboration with the School of Law and Faculty of Social Sciences of the Erasmus University Rotterdam, the Municipal Health Service Rotterdam area, Rotterdam, the Rotterdam Homecare Foundation, Rotterdam, and the Stichting Trombosedienst and Artsenlaboratorium Rijnmond (STAR-MDC), Rotterdam. We gratefully acknowledge the contribution of children and parents, general practitioners, hospitals, midwives, and pharmacies in Rotterdam. The Generation R Study is supported by the Erasmus MC, Rotterdam, the Erasmus University Rotterdam, the Netherlands Organization for Health Research and Development (ZonMw), the Netherlands Organization for Scientific Research (NWO), and the Ministry of Health, Welfare and Sport. TNO received funding from the Netherlands Ministry of Infrastructure and the Environment to support exposure assessment. Generation R was supported by the European Union's Horizon 2020 research and innovation programme under grant agreement no 633595 (DynaHEALTH) and No. 733206 (LifeCycle). Henning Tiemeier received funding from the Netherlands Organization for Health Research and Development (NWO-grant 016.VICI.170.200). REPRO_PL. The REPRO_PL was mainly supported by the National Science Centre, Poland, under the grant DEC-2014/15/B/NZ7/00998, FP7 HEALS Grant N° 603946 and the Ministry of Science and Higher Education under grant agreement no. 3068/7.PR/2014/2. INMA. This study was funded by grants from Instituto de Salud Carlos III (Red INMA G03/176, CB06/02/0041, FIS-FEDER: PI03/1615, PI04/1509, PI04/1112, PI04/1931, PI04/1436, PI04/2018, PI05/1079, PI05/1052, PI06/1213, PI06/0867, PI07/0314, PI07/0252, PI08/1151, PI09/02647, PI09/02311, PS09/00090, PI11/02591, PI11/02038, PI13/02429, PI13/1944, PI13/2032, PI14/00891, PI14/01687, PI16/00118, PI17/00663, PI18/00909, and Miguel Servet-FEDER: MS13/00054, MS11/00178, MS16/00085, MSII16/00051, and CP18/00018), Generalitat de Catalunya-CIRIT 1999SGR 00241, La Fundació La Marató de TV3 (090430), Generalitat Valenciana (FISABIO-UGP 15-230, 15-244, and 15-249), Fundación Alicia Koplowitz, Department of Health of the Basque Government (2005111093 and 2009111069), Provincial Government of Gipuzkoa (DFG06/004 and DFG08/001), Obra Social Cajastur/Fundación Liberbank, Universidad de Oviedo, Consejería de Salud de la Junta de Andalucía (grant number 183/07), EU Commission (QLK4-1999-01422, QLK4-2002 00603, CONTAMED FP7-ENV-12502, and FP7-ENV-2011 cod 282957), and Fundación Roger Torné.