Effects of COVID-19 lockdowns on fine particulate matter concentrations

Melanie S Hammer; Aaron van Donkelaar; Randall V Martin; Erin E McDuffie; Alexei Lyapustin; Andrew M Sayer; N Christina Hsu; Robert C Levy; Michael J Garay; Olga V Kalashnikova; Ralph A Kahn

doi:10.1126/sciadv.abg7670

Effects of COVID-19 lockdowns on fine particulate matter concentrations

Sci Adv. 2021 Jun 23;7(26):eabg7670. doi: 10.1126/sciadv.abg7670. Print 2021 Jun.

Authors

Melanie S Hammer^{1

2}, Aaron van Donkelaar^{2

3}, Randall V Martin^{3

2}, Erin E McDuffie^{3

2}, Alexei Lyapustin⁴, Andrew M Sayer^{4

5}, N Christina Hsu⁴, Robert C Levy⁴, Michael J Garay⁶, Olga V Kalashnikova⁶, Ralph A Kahn^{4

7}

Affiliations

¹ Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA. melanie.hammer@wustl.edu.
² Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada.
³ Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
⁴ Earth Sciences Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
⁵ Goddard Earth Sciences Technology and Research, Universities Space Research Association, Greenbelt, MD 21046, USA.
⁶ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
⁷ Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20742, USA.

Abstract

Lockdowns during the COVID-19 pandemic provide an unprecedented opportunity to examine the effects of human activity on air quality. The effects on fine particulate matter (PM_2.5) are of particular interest, as PM_2.5 is the leading environmental risk factor for mortality globally. We map global PM_2.5 concentrations for January to April 2020 with a focus on China, Europe, and North America using a combination of satellite data, simulation, and ground-based observations. We examine PM_2.5 concentrations during lockdown periods in 2020 compared to the same periods in 2018 to 2019. We find changes in population-weighted mean PM_2.5 concentrations during the lockdowns of -11 to -15 μg/m³ across China, +1 to -2 μg/m³ across Europe, and 0 to -2 μg/m³ across North America. We explain these changes through a combination of meteorology and emission reductions, mostly due to transportation. This work demonstrates regional differences in the sensitivity of PM_2.5 to emission sources.

Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).