Ambient ozone and fine particulate matter exposures and autism spectrum disorder in metropolitan Cincinnati, Ohio

• Published in: Environmental research 2019-04, Vol.171, p.218-227
• Main Authors: Kaufman, John A., Wright, J. Michael, Rice, Glenn, Connolly, Natalia, Bowers, Katherine, Anixt, Julia
• Format: Article
• Language: English
• Subjects: Air Pollutants; Air pollution; Air Pollution - statistics & numerical data; Autism Spectrum Disorder - epidemiology; Case-Control Studies; Child; Environmental epidemiology; Environmental Exposure - statistics & numerical data; Environmental neurology; Environmental psychology; Female; Humans; Ohio - epidemiology; Ozone; Particulate Matter - analysis; Pregnancy
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2019.01.013

Epidemiological studies report fairly consistent associations between various air pollution metrics and autism spectrum disorder (ASD), with some elevated risks reported for different prenatal and postnatal periods. To examine associations between ASD and ambient fine particulate matter (PM2.5) and ozone concentrations during the prenatal period through the second year of life in a case-control study. ASD cases (n = 428) diagnosed at Cincinnati Children's Hospital Medical Center were frequency matched (15:1) to 6420 controls from Ohio birth records. We assigned daily PM2.5 and ozone estimates for 2005–2012 from US EPA's Fused Air Quality Surface Using Downscaling model to each participant for each day based on the mother's census tract of residence at birth. We calculated adjusted odds ratios (aORs) using logistic regression across continuous and categorical exposure window averages (trimesters, first and second postnatal years, and cumulative measure), adjusting for maternal- and birth-related confounders, both air pollutants, and multiple temporal exposure windows. We detected elevated aORs for PM2.5 during the 2nd trimester, 1st year of life, and a cumulative period from pregnancy through the 2nd year (aOR ranges across categories: 1.41–1.44, 1.54–1.84, and 1.41–1.52 respectively), and for ozone in the 2nd year of life (aOR range across categories: 1.29–1.42). Per each change in IQR, we observed elevated aORs for ozone in the 3rd trimester, 1st and 2nd years of life, and the cumulative period (aOR range: 1.19–1.27) and for PM2.5 in the 2nd trimester, 1st year of life, and the cumulative period (aOR range: 1.11–1.17). We saw limited evidence of linear exposure-response relationships for ASD with increasing air pollution, but the elevated aORs detected for PM2.5 in upper exposure categories and per IQR unit increases were similar in magnitude to those reported in previous studies, especially for postnatal exposures. •Highest results for ASD with PM2.5 were for exposures in 1st year of life.•Highest results for ASD with ozone were for exposures in 2nd year of life.•Stronger postnatal results in agreement with most prior ASD-air pollution studies.