Zero-emissions vehicle adoption and satellite-measured NO air pollution in California, USA, from 2019 to 2023: a longitudinal observational study

Authors

Sandrah P. Eckel, Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. Electronic address: eckel@usc.edu.
Futu Chen, Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Sam J. Silva, Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Department of Earth Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, USA.
Daniel L. Goldberg, Department of Environmental and Occupational Health, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.
Jill Johnston, Department of Environmental and Occupational Health, University of California Irvine, Irvine, CA, USA.
Lawrence A. Palinkas, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, CA, USA.
Alberto Campos, Southeast Los Angeles Collaborative, Bell Gardens, CA, USA.
Wilma Franco, Southeast Los Angeles Collaborative, Bell Gardens, CA, USA.
Erika Garcia, Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.

Document Type

Journal Article

Publication Date

1-22-2026

Journal

The Lancet. Planetary health

DOI

10.1016/j.lanplh.2025.101379

Abstract

BACKGROUND: Electrifying the transportation sector is a key climate-change mitigation strategy. Reductions in exhaust emissions have anticipated air quality co-benefits; yet, evidence is primarily based on projections. Using observed data in California, USA, we aimed to investigate whether reductions in exhaust emissions from the transition to zero-emissions vehicles (ZEVs: battery electric, plug-in hybrid, and hydrogen fuel cell) were detectable using Tropospheric Monitoring Instrument (TROPOMI) satellite measurements of nitrogen dioxide (NO) air pollution. METHODS: In this longitudinal observational study, we combined data from 2019 to 2023 on annual light-duty ZEV registrations in 1692 California ZIP code tabulation areas (ZCTAs; cross-walked from ZIP codes) with annual mean TROPOMI-measured NO. We used longitudinal linear mixed-effects models to assess the association between within-ZCTA ZEV changes and within-ZCTA NO changes, adjusting for temporal trends and time-varying potential confounding, or excluding 2020. In positive control analyses, we related internal combustion engine vehicle registrations to NO. In ground-truth analyses, we related ZEVs to NO concentrations using 123 Environmental Protection Agency monitors from 2012 to 2023. FINDINGS: The median within-ZCTA increase in ZEVs from 2019 to 2023 was 272 (IQR 18 to 839). A within-ZCTA increase of 200 ZEVs was associated with a 1·10% (95% CI -1·19 to -1·00) decrease in annual average NO. The main findings were supported by sensitivity analyses (-1·32% [-1·43 to -1·21] when excluding the year 2020), ground-truth analysis (-0·87% [-1·76 to 0·03] using NO from ground-level monitors), and positive control analysis (0·80% [0·63 to 0·97] increase in annual average NO per 800 increase in number of internal combustion engine vehicles). INTERPRETATION: Using a natural experiment, we found that within-ZCTA increases in ZEV registrations were associated with reductions in NO air pollution measured by satellite and replicated with ground-level monitors. This work in California serves as a proof-of-principle for future work using satellite-measured NO to quantify effects of climate-change mitigation efforts on combustion-related air pollution within the USA and internationally. FUNDING: National Institutes of Health, National Institute of Environmental Health Sciences, National Aeronautics and Space Administration Health and Air Quality Applied Sciences Team, and the National Aeronautics and Space Administration Atmospheric Composition Modeling and Analysis Program.

APA Citation

Eckel, Sandrah P.; Chen, Futu; Silva, Sam J.; Goldberg, Daniel L.; Johnston, Jill; Palinkas, Lawrence A.; Campos, Alberto; Franco, Wilma; and Garcia, Erika, "Zero-emissions vehicle adoption and satellite-measured NO air pollution in California, USA, from 2019 to 2023: a longitudinal observational study" (2026). GW Authored Works. Paper 8537.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/8537

Department

Environmental and Occupational Health