Long-term Air Pollution Exposure on COVID-19 Risk and Severity

Abstract

Since the emergence of the COVID-19 pandemic, long-term exposure to air pollution has emerged as a possible risk factor for increased COVID-19 disease risk, severity, and mortality. The objective of this study was to examine the association between COVID-19 and long-term exposure to air pollution. This retrospective cohort study included patients who had a COVID-19 test at the University of Chicago Medicine Center from March 18, 2020, to March 30, 2021. Air pollution exposure was assessed using models developed for Chicago by the MESA Air Study and data from the Environmental Protection Agency’s EJSCREEN. Air pollution exposure estimates were linked to the University of Chicago Medicine patients using residential addresses. Air pollution measurements included PM2.5 (MESA Air and EPA), NO2, diesel PM, the respiratory hazard index, traffic proximity, and ozone. The outcome was COVID-19 risk and severity (ICU admission). Mixed effect analyses were performed to test whether poor air quality status was associated with COVID-19 risk and severity, controlling for demographic, smoking, and comorbidity indicators collected from the medical records. A total of 74,004 patients (mean [SD] age 44.0 [22.51] years; 42,979 [58.09%] women; and 32,870 [49.09%] African Americans) were linked to air quality exposure based on residence and other covariates using electronic medical record data in addition to COVID-19 test results. Overall, 8,463 participants (11.4%) tested positive for COVID-19. In the mixed effect analysis, long-term PM2.5 exposure was associated with increased risk of testing positive for COVID-19 (odds ratio [OR], 1.30; 95% CI, 1.23-1.38; P <0.01) and increased severity from COVID-19 (OR= 2.28; 95% CI, 2.00-2.60; P = <0.01). The results of this retrospective cohort study provide some evidence of the effect of long-term air pollution exposure on COVID-19 risk and severity.