title: Exposure to air pollution from traffic and neurodevelopmental disorders in Swedish twins.
abstract: BACKGROUND
  Recent studies have reported associations between air pollution exposure and neurodevelopmental disorders in children, but the role of pre- and postnatal exposure has not been elucidated.
  
  
  OBJECTIVE
  We aimed to explore the risk for autism spectrum disorders (ASD) and attention-deficit hyperactivity disorder (ADHD) among children in relation to pre- and postnatal exposure to air pollution from road traffic.
  
  
  METHODS
  Parents of 3,426 twins born in Stockholm during 1992-2000 were interviewed, when their children were 9 or 12 years old, for symptoms of neurodevelopmental disorders. Residence time-weighted concentrations of particulate matter with a diameter <10 μm (PM10) and nitrogen oxides (NOx) from road traffic were estimated at participants' addresses during pregnancy, the first year, and the ninth year of life using dispersion modeling, controlling for seasonal variation. Multivariate regression models were used to examine the association between air pollution exposure and neurodevelopmental outcomes, adjusting for potential confounding factors.
  
  
  RESULTS
  No clear or consistent associations were found between air pollution exposure during any of the three time windows and any of the neurodevelopmental outcomes. For example, a 5-95% difference in exposure to NOx during pregnancy was associated with odds ratios (ORs) of 0.92 (95% confidence interval (CI): 0.44-1.96) and 0.90 (95% CI: 0.58-1.40) for ASD and ADHD respectively. A corresponding range in exposure to PM10 during pregnancy was related to ORs of 1.01 (95% CI: 0.52-1.96) and 1.00 (95% CI: 0.68-1.47) for ASD and ADHD.
  
  
  CONCLUSIONS
  Our data do not provide support for an association between pre- or postnatal exposure to air pollution from road traffic and neurodevelopmental disorders in children.
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Tong
authors.initials: T
authors.lastname: Gong
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Catarina
authors.initials: C
authors.lastname: Almqvist
authors.affiliation: Department of Women's and Children's Health,Center of Neurodevelopmental Disorders (KIND),Karolinska Institutet,Stockholm,Sweden.
authors.forename: Sven
authors.initials: S
authors.lastname: Bölte
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Paul
authors.initials: P
authors.lastname: Lichtenstein
authors.affiliation: Department of Pharmacology,Institute of Neuroscience and Physiology,Sahlgrenska Academy,University of Gothenburg,Gothenburg,Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Anckarsäter
authors.affiliation: Center for Occupational and Environmental Medicine,Stockholm County Council,Stockholm,Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Lind
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lundholm
authors.affiliation: Center for Occupational and Environmental Medicine,Stockholm County Council,Stockholm,Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Pershagen
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology* / Q000235:genetics; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000209:etiology* / Q000235:genetics; D004200:Diseases in Twins / Q000209:etiology* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D018986:Motor Vehicles; D018570:Risk Assessment; D013548:Sweden