Air pollution and COVID-19 mortality in the United States: Strengths and limitations of an ecological regression analysis

• Published in: Science advances Vol. 6; no. 45
• Main Authors: Wu, X., Nethery, R. C., Sabath, M. B., Braun, D., Dominici, F.
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 01.11.2020
• Subjects: Air Pollution; Coronavirus; Coronavirus Infections - epidemiology; Coronavirus Infections - mortality; Coronavirus Infections - virology; COVID-19; Ecology; Environmental Studies; Health and Medicine; Humans; Pandemics; Pneumonia, Viral - epidemiology; Pneumonia, Viral - mortality; Pneumonia, Viral - virology; Regression Analysis; SciAdv r-articles; United States - epidemiology; United States
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.abd4049

We describe the challenges and opportunities of analyzing links between exposure to air pollution and vulnerability to COVID-19. Assessing whether long-term exposure to air pollution increases the severity of COVID-19 health outcomes, including death, is an important public health objective. Limitations in COVID-19 data availability and quality remain obstacles to conducting conclusive studies on this topic. At present, publicly available COVID-19 outcome data for representative populations are available only as area-level counts. Therefore, studies of long-term exposure to air pollution and COVID-19 outcomes using these data must use an ecological regression analysis, which precludes controlling for individual-level COVID-19 risk factors. We describe these challenges in the context of one of the first preliminary investigations of this question in the United States, where we found that higher historical PM 2.5 exposures are positively associated with higher county-level COVID-19 mortality rates after accounting for many area-level confounders. Motivated by this study, we lay the groundwork for future research on this important topic, describe the challenges, and outline promising directions and opportunities.