Office of Research and Development Publications

AMBIENT OZONE AND FINE PARTICULATE MATTER EXPOSURES AND AUTISM SPECTRUM DISORDER IN METROPOLITAN CINCINNATI, OHIO

Citation:

Kaufman, J., Michael Wright, G. Rice, N. Connolly, K. Bowers, AND J. Anixt. AMBIENT OZONE AND FINE PARTICULATE MATTER EXPOSURES AND AUTISM SPECTRUM DISORDER IN METROPOLITAN CINCINNATI, OHIO. ENVIRONMENTAL RESEARCH. Elsevier B.V., Amsterdam, Netherlands, 171:218-227, (2019). https://doi.org/10.1016/j.envres.2019.01.013

Impact/Purpose:

Previous research indicates an association may exist between autism spectrum disorder (ASD) and exposure to air pollutant mixtures, but uncertainty remains as to which exposure windows are most critical and which constituents of the mixture are most relevant to examine. This community-based research examines air pollution exposures among a susceptible population of children in Cincinnati, OH in support of EPA’s Making a Visible Difference in Communities initiative. This study should help elucidate environmental contributions to ASD risk by focusing on gestational windows that may be most relevant for examining the influence of air pollution on neurodevelopment. As such, this research can help inform whether current air quality standards for ozone and PM2.5 still protect susceptible populations from harmful exposures.

Description:

Background: 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. Objective: 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. Methods: ASD cases (n=428) diagnosed at Cincinnati Children’s Hospital Medical Center were frequency matched (15:1) to 6,420 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, postnatal years 1 and 2, and cumulative measure), adjusting for sociodemographic confounders, both air pollutants, and multiple temporal exposure windows. Results: 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 sextiles: 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 sextiles: 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). Conclusions: 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 change-in-IQR models were similar in magnitude to those reported in previous studies, especially for postnatal exposures.