Air Pollution and COVID-19 Severity

Abstract Air pollution is a major concern that constitutes an important part of the climate change thread. Furthermore, since the outbreak of the pandemic, there is an increased interest in understanding the role of environmental conditions in determining the severity of infectious diseases. We contribute to this debate by quantifying the effect of short-term exposure to air pollution on COVID-19 mortality. We construct a novel county-level dataset of daily COVID-19 mortality and, in order to overcome the potential endogeneity problems caused by factors related to both the virus and mortality rates (such as county-level economic conditions), we use wind speed as an instrument for air pollution. Our results show that being exposed to one additional unit of nitrogen dioxide, particulate matter, and nitrogen oxides, increases COVID-19 mortality by a factor of 1.1–1.3. From a policy perspective, our findings provide insights on the design of public health actions to minimize the spread of contagious diseases and to maximize the positive impacts of pollution reduction policies on population health.