The association between air pollution and COVID-19 related mortality in Santiago, Chile: A daily time series analysis

BACKGROUND: Exposure to ambient air pollution is a risk factor for morbidity and mortality from lung and heart disease. RESEARCH QUESTION: Does short term exposure to ambient air pollution influence COVID-19 related mortality? STUDY DESIGN AND METHODOLOGY: Using time series analyses we tested the association between daily changes in air pollution measured by stationary monitors in and around Santiago, Chile and deaths from laboratory confirmed or suspected COVID-19 between March 16 and August 31, 2020. Results were adjusted for temporal trends, temperature and humidity, and stratified by age and sex. RESULTS: There were 10,069 COVID-19 related deaths of which 7659 were laboratory confirmed. Using distributed lags, the cumulative relative risk (RR) (95% CI) of mortality for an interquartile range (IQR) increase in CO, NO(2) and PM(2.5) were 1.061 (1.033–1.089), 1.067 (1.023–1.103) and 1.058 (1.034–1.082), respectively There were no significant differences in RR by sex.. In those at least 85 years old, an IQR increase in NO(2) was associated with a 12.7% (95% CI 4.2–22.2) increase in daily mortality. CONCLUSION: This study provides evidence that daily increases in air pollution increase the risk of dying from COVID-19, especially in the elderly.