Associations of long-term exposure to ultrafine particles and nitrogen dioxide with increased incidence of congestive heart failure and acute myocardial infarction
Bai L, Weichenthal S, Kwong JC, Burnett RT, Hatzopoulou M, Jerrett M, van Donkelaar A, Martin RV, Van Ryswyk K, Lu H, Kopp A, Chen H. Am J Epidemiol. 2019; 188(1):151-9. Epub Aug 28.
Although long-term exposure to traffic-related air pollutants such as nitrogen dioxide (NO2) has been linked to cardiovascular mortality, little is known about the association of ultrafine particles (UFPs) with incidence of major cardiovascular events. We conducted a population-based cohort study to assess the associations of chronic exposure to UFPs and NO2 with incident congestive heart failure (CHF) and acute myocardial infarction. Our study population comprised all long-term Canadian residents aged 30-100 years who lived in Toronto, Canada, 1996-2012. We estimated annual concentrations of UFPs and NO2 using land-use regression models and assigned these estimates to participants' postal-code addresses in each year during the follow-up period. We estimated hazard ratios (HRs) for UFPs and NO2 using random-effects Cox proportional hazards models. We controlled for smoking and obesity using an indirect adjustment method. Our cohorts comprised ~1.1 million individuals at baseline. In single-pollutant models, each interquartile increase in UFPs exposure was associated with increased incidence for CHF (HRiqr: 1.03; 95%CI: 1.02, 1.05) and acute myocardial infarction (HRiqr: 1.05; 95%CI: 1.02, 1.07), respectively. Adjustment for fine particles and NO2 did not materially change these estimated associations. Exposure to NO2 was also independently associated with higher CHF incidence (HRiqr: 1.04; 95%CI: 1.03, 1.06).