Long-term exposure to fine particulate matter and hospitalization in COVID-19 patients.

BACKGROUND

Ecological evidence suggests that exposure to air pollution affects coronavirus disease 2019 (COVID-19) outcomes. However, no individual-level study has confirmed the association to date.

METHODS

We identified COVID-19 patients diagnosed at the University of Cincinnati hospitals and clinics and estimated particulate matter ≤2.5 μm (PM) exposure over a 10-year period (2008-2017) at their residential zip codes. We used logistic regression to evaluate the association between PM exposure and hospitalizations for COVID-19, adjusting for socioeconomic characteristics and comorbidities.

RESULTS

Among the 1128 patients included in our study, the mean (standard deviation) PM was 11.34 (0.70) μg/m for the 10-year average exposure and 13.83 (1.03) μg/m for the 10-year maximal exposures. The association between long-term PM exposure and hospitalization for COVID-19 was contingent upon having pre-existing asthma or chronic obstructive pulmonary (COPD) (P = 0.030 for average PM and P = 0.001 for maximal PM). In COVID-19 patients with asthma or COPD, the odds of hospitalization were 62% higher with 1 μg/m increment in 10-year average PM (odds ratio [OR]: 1.62, 95% confidence interval [CI]: 1.00-2.64) and 65% higher with 1 μg/m increase in 10-year maximal PM levels (OR: 1.65, 95% CI: 1.16-2.35). However, among COVID-19 patients without asthma or COPD, PM exposure was not associated with higher hospitalizations (OR: 0.84, 95% CI: 0.65-1.09 for average PM and OR: 0.78, 95% CI: 0.65-0.95 for maximal PM).

CONCLUSIONS

Long-term exposure to PM is associated with higher odds of hospitalization in COVID-19 patients with pre-existing asthma or COPD.