Long-Term Exposure to Ambient Air Pollution and Mortality among Four Million COVID-19 Cases in Italy: The EpiCovAir Study

• Published in: Environmental health perspectives Vol. 131; no. 5; pp. 57004 - 10
• Main Authors: Stafoggia, Massimo, Ranzi, Andrea, Ancona, Carla, Bauleo, Lisa, Bella, Antonino, Cattani, Giorgio, Nobile, Federica, Pezzotti, Patrizio, Iavarone, Ivano
• Format: Journal Article
• Language: English
• Published: United States National Institute of Environmental Health Sciences 01.05.2023; Environmental Health Perspectives
• Subjects: Age; Aged; Air Pollutants - analysis; Air pollution; Air Pollution - analysis; Air quality; Chronic exposure; COVID-19; Diameters; Environmental aspects; Environmental Exposure - analysis; Enzymes; Exposure; Fatalities; Health aspects; Hospitals; Humans; Intensive care units; Mortality; Nitrogen dioxide; Nitrogen Dioxide - analysis; Outdoor air quality; Pandemics; Particulate emissions; Particulate matter; Particulate Matter - analysis; Pollutants; Pollution levels; Principal components analysis; Risk factors; Sex; Socioeconomic factors; Spatial distribution; Italy; United Kingdom > UK; England
• ISSN: 0091-6765; 1552-9924; 1552-9924
• DOI: 10.1289/EHP11882

The role of chronic exposure to ambient air pollutants in increasing COVID-19 fatality is still unclear. The study aimed to investigate the association between long-term exposure to air pollutants and mortality among 4 million COVID-19 cases in Italy. We obtained individual records of all COVID-19 cases identified in Italy from February 2020 to June 2021. We assigned 2016-2019 mean concentrations of particulate matter (PM) with aerodynamic diameter ( ), PM with aerodynamic diameter ( ), and nitrogen dioxide ( ) to each municipality ( ) as estimates of chronic exposures. We applied a principal component analysis (PCA) and a generalized propensity score (GPS) approach to an extensive list of area-level covariates to account for major determinants of the spatial distribution of COVID-19 case-fatality rates. Then, we applied generalized negative binomial models matched on GPS, age, sex, province, and month. As additional analyses, we fit separate models by pandemic periods, age, and sex; we quantified the numbers of COVID-19 deaths attributable to exceedances in annual air pollutant concentrations above predefined thresholds; and we explored associations between air pollution and alternative outcomes of COVID-19 severity, namely hospitalizations or accesses to intensive care units. We analyzed 3,995,202 COVID-19 cases, which generated 124,346 deaths. Overall, case-fatality rates increased by 0.7% [95% confidence interval (CI): 0.5%, 0.9%], 0.3% (95% CI: 0.2%, 0.5%), and 0.6% (95% CI: 0.5%, 0.8%) per increment in , , and , respectively. Associations were higher among elderly subjects and during the first (February 2020-June 2020) and the third (December 2020-June 2021) pandemic waves. We estimated COVID-19 deaths were attributable to pollutant levels above the World Health Organization 2021 air quality guidelines. We found suggestive evidence of an association between long-term exposure to ambient air pollutants with mortality among 4 million COVID-19 cases in Italy. https://doi.org/10.1289/EHP11882.