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Air pollution

Prenatal Exposure to Air Pollution Linked to Autism Spectrum Disorders

Strategic Insights

— 1 min read

A new study published in the journal Environment International investigates the association between prenatal exposure to air pollution and the risk of autism spectrum disorders (ASD) in children born in California between 1990 and 2018. The study, conducted by researchers from the University of California, Los Angeles (UCLA), found that exposure to certain air pollutants, particularly traffic-related air toxics, was linked to increased ASD risk, even after adjusting for other factors.

Key Takeaways:

  • The study used a population-based cohort of 13,591,003 children born in California between 1990 and 2018, with 138,460 cases of ASD diagnosed through 2022.
  • Prenatal exposure to PM2.5 and NO2 was associated with increased ASD risk, with effect sizes declining over time.
  • The association between PM2.5 exposure and ASD risk was attenuated when adjusting for NO2 exposure, while the association with NO2 exposure remained largely unchanged.
  • Among air toxics, benzene and nickel were strongly associated with ASD, with associations persisting across time.
  • Stratified analyses revealed that associations differed by race/ethnicity, socioeconomic status, and region, with air toxics consistently exhibiting elevated ASD risks.
  • The study concluded that prenatal/early-life exposure to air pollution, especially traffic-related toxics, is linked to increased ASD risk with temporal and spatial variability.

Statistics:

  • 13,591,003 children born in California between 1990 and 2018 were included in the study.
  • 138,460 cases of ASD were diagnosed through 2022.
  • OR: 1.10 (95% CI: 1.04, 1.17) for ASD risk associated with prenatal exposure to PM2.5.
  • OR: 1.25 (95% CI:1.16, 1.35) for ASD risk associated with prenatal exposure to NO2.
  • OR: 1.55 (95% CI:1.51, 1.59) for ASD risk associated with prenatal exposure to benzene.
  • OR: 1.32 (95% CI:1.21, 1.45) for ASD risk associated with prenatal exposure to nickel.

Sources:

  • Prenatal exposure to criteria air pollution and traffic-related air toxics and risk of autism spectrum disorder: A population-based cohort study of California births (1990-2018). Environment International, 2025,201():109562.
  • University of California, Los Angeles. Fielding School of Public Health, Department of Epidemiology.
  • California Air Resources Board.
  • California Department of Public Health.
  • California Department of Developmental Services.

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