Air pollution linked to higher risk of COVID-19 hospitalization in some patients
03 Feb 2021
Long-term exposure to fine particulate matter (PM2.5) carries a greater risk of hospitalization in COVID-19 patients with pre-existing asthma or chronic obstructive pulmonary disorder (COPD), according to a study.
The study included 1,128 COVID-19 patients (median age, 46 years) diagnosed at the University of Cincinnati hospitals and clinics. Most of these patients resided in Ohio (96.6 percent), and the remaining 3.4 percent resided in Kentucky, Indiana, New York, South Carolina, West Virginia, or Iowa.
The 10-year average PM2.5 exposure was a mean of 11.34 μg/m3, while the 10-year maximal PM2.5 had a mean of 13.83 μg/m3. Exposure levels tended to be higher in women, non-Hispanic Blacks, individuals with a median household income below $50,000, and in patients with diabetes, asthma, or COPD.
In logistic regression models adjusted for covariates, long-term exposure to PM2.5 was associated with greater odds of COVID-19 hospitalization but only in the presence of a pre-existing respiratory disease (ie, asthma or COPD).
Specifically, each 1-μg/m3 increment in 10-year PM2.5 exposure increased the likelihood of COVID-19 hospitalization by 62–65 percent among patients with a pre-existing respiratory disease (average PM2.5: odds ratio [OR], 1.62, 95 percent confidence interval [CI], 1.00–2.64; maximal PM2.5: OR, 1.65, 95 percent CI, 1.16–2.35).
However, among COVID-19 patients with neither asthma nor COPD, PM2.5 exposure was not associated with higher incidence of hospitalizations (average PM2.5: OR, 0.84, 95 percent CI, 0.65–1.09; maximal PM2.5: OR, 0.78, 95 percent CI, 0.65–0.95).
The findings are in line with reports that PM2.5 exposure may exacerbate asthma and COPD by causing airway inflammation through the release of proinflammatory cytokines and free radicals from activated alveolar macrophages. [J Allergy Clin Immunol 2020;146:61-63; Am J Respir Crit Care Med 2019;200:712-720; Environ Res 2012;117:36-45]
If confirmed in future studies, COVID-19 hospitalization and morbidity can be reduced by implementing appropriate measures to prevent SARS-CoV-2 infection particularly in patients with respiratory disease residing in high PM2.5 exposure areas.