Biomass Burning as a Source of Ambient Fine Particulate Air Pollution and Acute Myocardial Infarction

BACKGROUND:Biomass burning is an important source of ambient fine particulate air pollution (PM2.5) in many regions of the world. METHODS:We conducted a time-stratified case-crossover study of ambient PM2.5 and hospital admissions for myocardial infarction (MI) in three regions of British Columbia, Canada. Daily hospital admission data were collected between 2008-2015 and PM2.5 data were collected from fixed-site monitors. We used conditional logistic regression models to estimate odds ratios (ORs) describing the association between PM2.5 and the risk of hospital admission for MI. We used stratified analyses to evaluate effect modification by biomass burning as a source of ambient PM2.5 using the ratio of levoglucosan/PM2.5 mass concentrations. RESULTS:Each 5 µg/m increase in 3-day mean PM2.5 was associated with an increased risk of MI among elderly subjects (≥ 65 years) (OR=1.06, 95% CI1.03, 1.08); risk was not increased among younger subjects. Among the elderly, the strongest association occurred during colder periods (