Impact of a long‐term air pollution exposure on the case fatality rate of COVID‐19 patients—A multicity study

Hou, Chang‐kai; Qin, Ya‐fei; Wang, Grace; Liu, Quan‐lei; Yang, Xin‐yu; Wang, Hao

Evidence in the literature suggests that air pollution exposure affects outcomes of patients with COVID‐19. However, the extent of this effect requires further investigation. This study was designed to investigate the relationship between long‐term exposure to air pollution and the case fatality rate (CFR) of patients with COVID‐19. The data on air quality index (AQI), PM2.5, PM10, SO(2), NO(2), and O(3) from 14 major cities in China in the past 5 years (2015–2020) were collected, and the CRF of COVID‐19 patients in these cities was calculated. First, we investigated the correlation between CFR and long‐term air quality indicators. Second, we examined the air pollutants affecting CFR and evaluated their predictive values. We found a positive correlation between the CFR and AQI (1, 3, and 5 years), PM2.5 (1, 3, and 5 years), and PM10 (1, 3, and 5 years). Further analysis indicated the more significant correlation for both AQI (3 and 5 years) and PM2.5 (1, 3, and 5 years) with CFR, and moderate predictive values for air pollution indicators such as AQI (1, 3, and 5 years) and PM2.5 (1, 3, and 5 years) for CFR. Our results indicate that long‐term exposure to severe air pollution is associated with higher CFR of COVID‐19 patients. Air pollutants such as PM2.5 may assist with the prediction of CFR for COVID‐19 patients.