Long-Term Exposure to PM2.5, Facemask Mandates, Stay Home Orders and COVID-19 Incidence in the United States

Fang Fang; Lina Mu; Yifang Zhu; Jianyu Rao; Jody Heymann; Zuo-Feng Zhang

doi:10.3390/ijerph18126274

Long-Term Exposure to PM_2.5, Facemask Mandates, Stay Home Orders and COVID-19 Incidence in the United States

Int J Environ Res Public Health. 2021 Jun 10;18(12):6274. doi: 10.3390/ijerph18126274.

Authors

Fang Fang¹, Lina Mu², Yifang Zhu^{3

4}, Jianyu Rao^{1

5}, Jody Heymann⁶, Zuo-Feng Zhang^{1

7

8}

Affiliations

¹ Department of Epidemiology, Fielding School of Public Health, University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA.
² Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, NY 14214, USA.
³ Department of Environmental Health Science, University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA.
⁴ Institute of the Environment and Sustainability, University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA.
⁵ Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA.
⁶ WORLD Policy Analysis Center, University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA.
⁷ Jonsson Comprehensive Cancer Center, University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA.
⁸ Center for Human Nutrition, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA.

Abstract

Long-term PM_2.5 exposure might predispose populations to SARS-CoV-2 infection and intervention policies might interrupt SARS-CoV-2 transmission and reduce the risk of COVID-19. We conducted an ecologic study across the United States, using county-level COVID-19 incidence up to 12 September 2020, to represent the first two surges in the U.S., annual average of PM_2.5 between 2000 and 2016 and state-level facemask mandates and stay home orders. We fit negative binomial models to assess COVID-19 incidence in association with PM_2.5 and policies. Stratified analyses by facemask policy and stay home policy were also performed. Each 1-µg/m³ increase in annual average concentration of PM_2.5 exposure was associated with 7.56% (95% CI: 3.76%, 11.49%) increase in COVID-19 risk. Facemask mandates and stay home policies were inversely associated with COVID-19 with adjusted RRs of 0.8466 (95% CI: 0.7598, 0.9432) and 0.9193 (95% CI: 0.8021, 1.0537), respectively. The associations between PM_2.5 and COVID-19 were consistent among counties with or without preventive policies. Our study added evidence that long-term PM_2.5 exposure increased the risk of COVID-19 during each surge and cumulatively as of 12 September 2020, in the United States. Although both state-level implementation of facemask mandates and stay home orders were effective in preventing the spread of COVID-19, no clear effect modification was observed regarding long-term exposure to PM_2.5 on the risk of COVID-19.

Keywords: COVID-19; facemasks; nation-wide study; particulate matter; stay-home orders.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

COVID-19*
Humans
Incidence
Masks
Particulate Matter / analysis
SARS-CoV-2
United States / epidemiology

Substances

Particulate Matter

Abstract

Publication types

MeSH terms

Substances

Grants and funding