title: In utero exposure to toxic air pollutants and risk of childhood autism.
abstract: BACKGROUND
  Genetic and environmental factors are believed to contribute to the development of autism, but relatively few studies have considered potential environmental risks. Here, we examine risks for autism in children related to in utero exposure to monitored ambient air toxics from urban emissions.
  
  
  METHODS
  Among the cohort of children born in Los Angeles County, California, 1995-2006, those whose mothers resided during pregnancy in a 5-km buffer around air toxics monitoring stations were included (n = 148,722). To identify autism cases in this cohort, birth records were linked to records of children diagnosed with primary autistic disorder at the California Department of Developmental Services between 1998 and 2009 (n = 768). We calculated monthly average exposures during pregnancy for 24 air toxics selected based on suspected or known neurotoxicity or neurodevelopmental toxicity. Factor analysis helped us identify the correlational structure among air toxics, and we estimated odds ratios (ORs) for autism from logistic regression analyses.
  
  
  RESULTS
  Autism risks were increased per interquartile range increase in average concentrations during pregnancy of several correlated toxics mostly loading on 1 factor, including 1,3-butadiene (OR = 1.59 [95% confidence interval = 1.18-2.15]), meta/para-xylene (1.51 [1.26-1.82]), other aromatic solvents, lead (1.49 [1.23-1.81]), perchloroethylene (1.40 [1.09-1.80]), and formaldehyde (1.34 [1.17-1.52]), adjusting for maternal age, race/ethnicity, nativity, education, insurance type, parity, child sex, and birth year.
  
  
  CONCLUSIONS
  Risks for autism in children may increase following in utero exposure to ambient air toxics from urban traffic and industry emissions, as measured by community-based air-monitoring stations.
authors: From the aDepartment of Community Health Sciences, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA; bDepartment of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA; cDepartment of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA; and dDepartment of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA.
authors: Ondine S
authors: OS
authors: von Ehrenstein
authors: Hilary
authors: H
authors: Aralis
authors: Myles
authors: M
authors: Cockburn
authors: Beate
authors: B
authors: Ritz
mesh_terms: D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D001321:Autistic Disorder / Q000139:chemically induced* / Q000453:epidemiology*; D001719:Birth Certificates; D002648:Child; D004781:Environmental Exposure / Q000009:adverse effects*; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D012306:Risk; D001335:Vehicle Emissions / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D001335:Vehicle Emissions