Long-Term Fine Particulate Matter Exposure and Mortality From Diabetes in Canada
- Robert D. Brook, MD1⇑,
- Sabit Cakmak, PHD2,
- Michelle C. Turner, PHD3,
- Jeffrey R. Brook, PHD4,5,
- Dan L. Crouse, PHD2,
- Paul A. Peters, PHD6,
- Aaron van Donkelaar, PHD7,
- Paul J. Villeneuve, PHD2,5,
- Orly Brion, PHD2,
- Michael Jerrett, PHD8,
- Randall V. Martin, PHD7,9,
- Sanjay Rajagopalan, MD10,
- Mark S. Goldberg, PHD11,
- C. Arden Pope III, PHD12 and
- Richard T. Burnett, PHD2,3
- 1Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan
- 2Health Canada, Ottawa, Canada
- 3McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, Canada
- 4Environment Canada, Downsview, Canada
- 5Division of Occupational and Environmental Health, University of Toronto, Toronto, Canada
- 6Statistics Canada, Ottawa, Canada
- 7Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
- 8Environmental Health Sciences Department, University of California, Berkeley, Berkeley, California
- 9Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts
- 10Davis Heart Lung Research Institute, The Ohio State University School of Medicine, Columbus, Ohio
- 11Department of Medicine, McGill University, Montreal, Quebec, Canada
- 12Department of Economics, Brigham Young University, Provo, Utah.
- Corresponding author: Robert D. Brook, .
OBJECTIVE Recent studies suggest that chronic exposure to air pollution can promote the development of diabetes. However, whether this relationship actually translates into an increased risk of mortality attributable to diabetes is uncertain.
RESEARCH DESIGN AND METHODS We evaluated the association between long-term exposure to ambient fine particulate matter (PM2.5) and diabetes-related mortality in a prospective cohort analysis of 2.1 million adults from the 1991 Canadian census mortality follow-up study. Mortality information, including ∼5,200 deaths coded as diabetes being the underlying cause, was ascertained by linkage to the Canadian Mortality Database from 1991 to 2001. Subject-level estimates of long-term exposure to PM2.5 were derived from satellite observations. The hazard ratios (HRs) for diabetes-related mortality were related to PM2.5 and adjusted for individual-level and contextual variables using Cox proportional hazards survival models.
RESULTS Mean PM2.5 exposure levels for the entire population were low (8.7 µg/m3; SD, 3.9 µg/m3; interquartile range, 6.2 µg/m3). In fully adjusted models, a 10-µg/m3 elevation in PM2.5 exposure was associated with an increase in risk for diabetes-related mortality (HR, 1.49; 95% CI, 1.37–1.62). The monotonic change in risk to the population persisted to PM2.5 concentration <5 µg/m3.
CONCLUSIONS Long-term exposure to PM2.5, even at low levels, is related to an increased risk of mortality attributable to diabetes. These findings have considerable public health importance given the billions of people exposed to air pollution and the worldwide growing epidemic of diabetes.
- Received October 29, 2012.
- Accepted April 20, 2013.
- © 2013 by the American Diabetes Association.
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