COVID-19 perturbation on US air quality and human health impact assessment

Jian He; Colin Harkins; Katelyn O'Dell; Meng Li; Colby Francoeur; Kenneth C Aikin; Susan Anenberg; Barry Baker; Steven S Brown; Matthew M Coggon; Gregory J Frost; Jessica B Gilman; Shobha Kondragunta; Aaron Lamplugh; Congmeng Lyu; Zachary Moon; Bradley R Pierce; Rebecca H Schwantes; Chelsea E Stockwell; Carsten Warneke; Kai Yang; Caroline R Nowlan; Gonzalo González Abad; Brian C McDonald

doi:10.1093/pnasnexus/pgad483

COVID-19 perturbation on US air quality and human health impact assessment

PNAS Nexus. 2024 Jan 2;3(1):pgad483. doi: 10.1093/pnasnexus/pgad483. eCollection 2024 Jan.

Authors

Jian He^{1

2}, Colin Harkins^{1

2}, Katelyn O'Dell³, Meng Li^{1

2}, Colby Francoeur^{1

2

4}, Kenneth C Aikin^{1

2}, Susan Anenberg³, Barry Baker⁵, Steven S Brown², Matthew M Coggon², Gregory J Frost², Jessica B Gilman², Shobha Kondragunta⁶, Aaron Lamplugh^{1

2}, Congmeng Lyu^{1

2}, Zachary Moon^{5

7}, Bradley R Pierce⁸, Rebecca H Schwantes², Chelsea E Stockwell^{1

2}, Carsten Warneke², Kai Yang⁹, Caroline R Nowlan¹⁰, Gonzalo González Abad¹⁰, Brian C McDonald²

Affiliations

¹ Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309, USA.
² NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA.
³ Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, Washington, DC 20052, USA.
⁴ Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.
⁵ NOAA Air Resources Laboratory, College Park, MD 20740, USA.
⁶ NOAA National Environmental Satellite, Data, and Information Service, Center for Satellite Applications and Research, College Park, MD 20740, USA.
⁷ Earth Resources Technology (ERT) Inc., Laurel, MD 20707, USA.
⁸ Space Science and Engineering Center, University of Wisconsin-Madison, Madison, WI 53706, USA.
⁹ Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20742, USA.
¹⁰ Center for Astrophysics, Harvard and Smithsonian, Cambridge, MA 02138, USA.

Abstract

The COVID-19 stay-at-home orders issued in the United States caused significant reductions in traffic and economic activities. To understand the pandemic's perturbations on US emissions and impacts on urban air quality, we developed near-real-time bottom-up emission inventories based on publicly available energy and economic datasets, simulated the emission changes in a chemical transport model, and evaluated air quality impacts against various observations. The COVID-19 pandemic affected US emissions across broad-based energy and economic sectors and the impacts persisted to 2021. Compared with 2019 business-as-usual emission scenario, COVID-19 perturbations resulted in annual decreases of 10-15% in emissions of ozone (O₃) and fine particle (PM_2.5) gas-phase precursors, which are about two to four times larger than long-term annual trends during 2010-2019. While significant COVID-induced reductions in transportation and industrial activities, particularly in April-June 2020, resulted in overall national decreases in air pollutants, meteorological variability across the nation led to local increases or decreases of air pollutants, and mixed air quality changes across the United States between 2019 and 2020. Over a full year (April 2020 to March 2021), COVID-induced emission reductions led to 3-4% decreases in national population-weighted annual fourth maximum of daily maximum 8-h average O₃ and annual PM_2.5. Assuming these emission reductions could be maintained in the future, the result would be a 4-5% decrease in premature mortality attributable to ambient air pollution, suggesting that continued efforts to mitigate gaseous pollutants from anthropogenic sources can further protect human health from air pollution in the future.

Keywords: COVID-19; air quality; emission inventory; health impacts.