Ambient Air Pollutant Exposures and COVID-19 Severity and Mortality in a Cohort of Patients with COVID-19 in Southern California
Zhanghua Chen, Margo A. Sidell, Brian Z. Huang, Ting Chow, Sandrah P. Eckel, Mayra P. Martinez, Roya Gheissari, Fred Lurmann, Duncan C. Thomas, Frank D. Gilliland, Anny H. Xiang
Abstract
Abstract Rationale Ecological studies have shown air pollution associations with coronavirus disease (COVID-19) outcomes. However, few cohort studies have been conducted. Objectives To conduct a cohort study investigating the association between air pollution and COVID-19 severity using individual-level data from the electronic medical record. Methods This cohort included all individuals who received diagnoses of COVID-19 from Kaiser Permanente Southern California between March 1 and August 31, 2020. One-year and 1-month averaged ambient air pollutant (particulate matter ⩽2.5 μm in aerodynamic diameter [PM2.5], NO2, and O3) exposures before COVID-19 diagnosis were estimated on the basis of residential address history. Outcomes included COVID-19–related hospitalizations, intensive respiratory support (IRS), and ICU admissions within 30 days and mortality within 60 days after COVID-19 diagnosis. Covariates included socioeconomic characteristics and comorbidities. Measurements and Main Results Among 74,915 individuals (mean age, 42.5 years; 54% women; 66% Hispanic), rates of hospitalization, IRS, ICU admission, and mortality were 6.3%, 2.4%, 1.5%, and 1.5%, respectively. Using multipollutant models adjusted for covariates, 1-year PM2.5 and 1-month NO2 average exposures were associated with COVID-19 severity. The odds ratios associated with a 1-SD increase in 1-year PM2.5 (SD, 1.5 μg/m3) were 1.24 (95% confidence interval [CI], 1.16–1.32) for COVID-19–related hospitalization, 1.33 (95% CI, 1.20–1.47) for IRS, and 1.32 (95% CI, 1.16–1.51) for ICU admission; the corresponding odds ratios associated with 1-month NO2 (SD, 3.3 ppb) were 1.12 (95% CI, 1.06–1.17) for hospitalization, 1.18 (95% CI, 1.10–1.27) for IRS, and 1.21 (95% CI, 1.11–1.33) for ICU admission. The hazard ratios for mortality were 1.14 (95% CI, 1.02–1.27) for 1-year PM2.5 and 1.07 (95% CI, 0.98–1.16) for 1-month NO2. No significant interactions with age, sex or ethnicity were observed. Conclusions Ambient PM2.5 and NO2 exposures may affect COVID-19 severity and mortality.