- (1) Hospital Del Mar, grid.411142.3
- (2) Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain.
- (3) From the ISGlobal, Barcelona, Spain.
- (4) Pompeu Fabra University, grid.5612.0
- (5) Department of Epidemiology Lazio Regional Health Service, ASL Roma 1, Italy.
- (6) Sophia Children's Hospital, grid.416135.4
- (7) Institut Albert Bonniot, grid.418110.d
- (8) Karolinska Institute, grid.4714.6
- (9) Utrecht University, grid.5477.1
- (10) Danish Cancer Society, grid.417390.8
- (11) Institute of Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Germany.
- (12) Leibniz Institute of Environmental Medicine, grid.435557.5
- (13) Karolinska University Hospital, grid.24381.3c
- (14) Faculty of Psychology, Basque Country University UPV/EHU, San Sebastian, Spain.
- (15) Biodonostia, grid.432380.e
- (16) Research Institute, Department of Pediatrics, Marien-Hospital,Wesel, Germany.
- (17) French Institute of Health and Medical Research, grid.7429.8
- (18) Paris Descartes University, grid.10992.33
- (19) University of Valencia, grid.5338.d
- (20) Instituto de Investigación Biosanitaria, grid.507088.2
- (21) University of Granada, grid.4489.1
- (22) University of the Basque Country, grid.11480.3c
- (23) Ludwig Maximilian University of Munich, grid.5252.0
- (24) Imperial College London, grid.7445.2
- (25) Aarhus University, grid.7048.b, AU
- (26) Academic Medical Center, grid.5650.6
- (27) University of Copenhagen, grid.5254.6, KU
- (28) Stockholm County Council, grid.425979.4
- (29) University Medical Center Utrecht, grid.7692.a
BACKGROUND: Exposure to air pollution during pregnancy may increase attention-deficit/hyperactivity disorder (ADHD) symptoms in children, but findings have been inconsistent. We aimed to study this association in a collaborative study of eight European population-based birth/child cohorts, including 29,127 mother-child pairs. METHODS: Air pollution concentrations (nitrogen dioxide [NO2] and particulate matter [PM]) were estimated at the birth address by land-use regression models based on monitoring campaigns performed between 2008 and 2011. We extrapolated concentrations back in time to exact pregnancy periods. Teachers or parents assessed ADHD symptoms at 3-10 years of age. We classified children as having ADHD symptoms within the borderline/clinical range and within the clinical range using validated cutoffs. We combined all adjusted area-specific effect estimates using random-effects meta-analysis and multiple imputations and applied inverse probability-weighting methods to correct for loss to follow-up. RESULTS: We classified a total of 2,801 children as having ADHD symptoms within the borderline/clinical range, and 1,590 within the clinical range. Exposure to air pollution during pregnancy was not associated with a higher odds of ADHD symptoms within the borderline/clinical range (e.g., adjusted odds ratio [OR] for ADHD symptoms of 0.95, 95% confidence interval [CI] = 0.89, 1.01 per 10 µg/m increase in NO2 and 0.98, 95% CI = 0.80, 1.19 per 5 µg/m increase in PM2.5). We observed similar associations for ADHD within the clinical range. CONCLUSIONS: There was no evidence for an increase in risk of ADHD symptoms with increasing prenatal air pollution levels in children aged 3-10 years. See video abstract at, http://links.lww.com/EDE/B379.