| A Case–Control Analysis of Exposure to Traffic and Acute Myocardial Infarction Cathryn Tonne,1,2 Steve Melly,1 Murray Mittleman,2,3 Brent Coull,4 Robert Goldberg,5 and Joel Schwartz1,2 1Department of Environmental Health, and 2Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA; 3Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA; 4Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, USA; 5University of Massachusetts Medical School, Worcester, Massachusetts, USA Abstract
Background: Long-term exposure to particulate air pollution has been associated with an increased risk of dying from cardiopulmonary and ischemic heart disease, yet few studies have evaluated cardiovascular end points other than mortality. We investigated the relationship between long-term exposure to traffic and occurrence of acute myocardial infarction (AMI) in a case–control study. Methods: A total of 5,049 confirmed cases of AMI were identified between 1995 and 2003 as part of the Worcester Heart Attack Study, a community-wide study examining changes over time in the incidence of AMI among greater Worcester, Massachusetts, residents. Population controls were selected from Massachusetts resident lists. We used cumulative traffic within 100 m of subjects' residence and distance from major roadway as proxies for exposure to traffic-related air pollution. We estimated the relationship between exposure to traffic and occurrence of AMI using logistic regression, and we adjusted for the following potential confounders: age, sex, section of the study area, point sources emissions of particulate matter with aerodynamic diameter < 2.5 µm, area socioeconomic characteristics, and percentage of open space. Results: An increase in cumulative traffic near the home was associated with a 4% increase in the odds of AMI per interquartile range [95% confidence interval (CI) , 2–7%], whereas living near a major roadway was associated with a 5% increase in the odds of AMI per kilometer (95% CI, 3–6%) . Conclusions: These results provide support for an association between long-term exposure to traffic and the risk of AMI. Key words: air pollution, case–control studies, myocardial infarction, vehicle emissions. Environ Health Perspect 115:53–57 (2007) . doi:10.1289/ehp.9587 available via http://dx.doi.org/ [Online 11 October 2006]
Address correspondence to C. Tonne, Department of Environmental Health EER, Landmark Center, Room 415 W., P.O. Box 15677, 401 Park Dr., Boston, MA 02215 USA. Telephone: (617) 384-8756 Fax: (617) 384-8745. E-mail: ctonne@hsph.harvard.edu This study was supported by grants RO1 ES011636 and T32 ES07155 from the National Institute of Environmental Health Sciences. The authors declare they have no competing financial interests. Received 8 August 2006 ; accepted 11 October 2006.
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