title: Can we identify sources of fine particles responsible for exercise-induced ischemia on days with elevated air pollution? The ULTRA study.
abstract: Epidemiologic studies have shown that ambient particulate matter (PM) has adverse effects on cardiovascular health. Effective mitigation of the health effects requires identification of the most harmful PM sources. The objective of our study was to evaluate relative effects of fine PM [aerodynamic diameter<or=2.5 microm (PM2.5)] from different sources on exercise-induced ischemia. We collected daily outdoor PM2.5 samples between autumn 1998 and spring 1999 in Helsinki, Finland. The mass of PM2.5 was apportioned between five sources. Forty-five elderly nonsmoking persons with stable coronary heart disease visited a clinic biweekly for submaximal exercise testing, during which the occurrence of ST segment depressions was recorded. Levels of PM2.5 originating from local traffic and long-range transport were associated with ST segment depressions>0.1 mV, with odds ratios at 2-day lag of 1.53 [95% confidence interval (CI), 1.19-1.97] and 1.11 (95% CI, 1.02-1.20) per 1 microg/m3, respectively. In multipollutant models, where we used indicator elements for sources instead of source-specific PM2.5, only absorbance (elemental carbon), an indicator of local traffic and other combustion, was associated with ST segment depressions. Our results suggest that the PM fraction originating from combustion processes, notably traffic, exacerbates ischemic heart diseases associated with PM mass.
authors: Environmental Epidemiology Unit, National Public Health Institute, Kuopio, Finland, and Environmental and Occupational Health Division, Institute for Risk Assessment Sciences, Utrecht University, the Netherlands. timo.lanki@ktl.fi
authors: Timo
authors: T
authors: Lanki
authors: Jeroen J
authors: JJ
authors: de Hartog
authors: Joachim
authors: J
authors: Heinrich
authors: Gerard
authors: G
authors: Hoek
authors: Nicole A H
authors: NA
authors: Janssen
authors: Annette
authors: A
authors: Peters
authors: Matthias
authors: M
authors: Stölzel
authors: Kirsi L
authors: KL
authors: Timonen
authors: Marko
authors: M
authors: Vallius
authors: Esko
authors: E
authors: Vanninen
authors: Juha
authors: J
authors: Pekkanen