Associations between brake and tire wear-related PM2.5 metal components, particulate oxidative stress potential, and autism spectrum disorder in Southern California

Karl O'Sharkey; Qi Meng; Sanjali Mitra; Seung-A Paik; Jonathan Liu; Jiaqi Shen; Laura K Thompson; Ting Chow; Jason Su; Myles Cockburn; Scott Weichenthal; Susanne E Paulson; Michael Jerrett; Beate Ritz

doi:10.1016/j.envint.2024.108573

Associations between brake and tire wear-related PM_2.5 metal components, particulate oxidative stress potential, and autism spectrum disorder in Southern California

Environ Int. 2024 Mar:185:108573. doi: 10.1016/j.envint.2024.108573. Epub 2024 Mar 10.

Authors

Affiliations

¹ Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA 90095, USA.
² Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA 90095, USA.
³ Department of Atmospheric & Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁴ Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA 90032, USA.
⁵ Department of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA.
⁶ Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec H3A0G4, Canada.
⁷ Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA 90095, USA. Electronic address: britz@ucla.edu.

PMID: 38484609
DOI: 10.1016/j.envint.2024.108573

Abstract

Background: Air pollution is a global health concern, with fine particulate matter (PM_2.5) constituents posing potential risks to human health, including children's neurodevelopment. Here we investigated associations between exposure during pregnancy and infancy to specific traffic-related PM_2.5 components with Autism Spectrum Disorder (ASD) diagnosis.

Methods: For exposure assessment, we estimated PM_2.5 components related to traffic exposure (Barium [Ba] as a marker of brake dust and Zinc [Zn] as a tire wear marker, Black Carbon [BC]) and oxidative stress potential (OSP) markers (Hydroxyl Radical [OP^OH] formation, Dithiothreitol activity [OP^DTT], reactive oxygen species [ROS]) modeled with land use regression with co-kriging based on an intensive air monitoring campaign. We assigned exposures to a cohort of 444,651 children born in Southern California between 2016 and 2019, among whom 11,466 ASD cases were diagnosed between 2018 and 2022, Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained with logistic regression for single pollutant and PM_2.5 mass co-adjusted models, also adjusting for sociodemographic characteristics.

Results: Among PM_2.5 components, we found the strongest positive association with ASD for our brake wear marker Ba (OR_{per IQR} = 1.29, 95 % CI: 1.24, 1.34). This was followed by an increased risk for all PM_2.5 oxidative stress potential markers; the strongest association was with ROS formation (OR_{per IQR} = 1.22, 95 % CI: 1.18, 1.25). PM_2.5 mass was linked to ASD in Hispanic and Black children, but not White children, while traffic-related PM_2.5 and OSP markers increased ASD risk across all groups. In neighborhoods with the lowest socioeconomic status (SES), associations with ASD were stronger for all examined pollutants compared to higher SES areas.

Conclusions: Our findings suggest that brake wear-related PM_2.5 and PM_2.5 OSP are associated with ASD diagnosis in Southern California. These results suggest that strategies aimed at reducing the public health impacts of PM_2.5 need to consider specific sources.

Keywords: Air pollution; Autism; Metals; PM(2.5) components; Pregnancy; Traffic.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
Autism Spectrum Disorder* / chemically induced
Autism Spectrum Disorder* / etiology
California / epidemiology
Child
Dust
Environmental Exposure / adverse effects
Environmental Exposure / analysis
Female
Humans
Metals
Oxidative Stress
Particulate Matter / analysis
Pregnancy
Reactive Oxygen Species

Substances

Air Pollutants
Reactive Oxygen Species
Particulate Matter
Dust
Metals