Abstract 9900: Air Pollution and Stroke: A Systematic Review and Meta-Analysis
Introduction: Stroke is responsible for 5 million deaths per annum with two-thirds occurring in low- and middle-income countries. Whilst exposure to outdoor air pollution is strongly associated with acute cardiac events, the relationship between air pollution and stroke is less clear. We systematically reviewed and meta-analysed the evidence examining the association between air pollution and stroke hospitalisation or mortality.
Methods: Five databases were searched for studies investigating the association between daily increases in gaseous pollutants (carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone) and particulate matter (diameter <2·5 or 10 μm: PM2·5 and PM10), and stroke hospitalisation or mortality. We used a random-effects model to derive overall risk estimates per pollutant.
Results: We identified 2,747 articles of which 238 were reviewed in-depth with 104 satisfying our inclusion criteria. This provided a total of 6.2 million events across 28 countries. Stroke hospitalisation or death from stroke was associated with an increase in sulphur dioxide (1.90% per 10 ppb, 95% confidence interval [CI] 1.09-2.71), nitrogen dioxide (1·41% per 10 ppb, 95% CI 0.92-1.90) and carbon monoxide (1.47% per 1 ppm, 95% CI: 0.38-2.55) concentration. Increases in PM2·5 and PM10 concentration were also associated with stroke hospitalisation or death (1.14% per 10 μg/m3, 95% CI 1·09-1.20 and 0.28% per 10 μg/m3, 95% CI 0.20-0.37 respectively). The weakest association was seen with ozone (0.09% per 10 ppb, 95% CI 0.00-0.17). Strongest associations were observed in low- and middle-income countries, and on the day of exposure with more persistent effects observed for PM2·5.
Conclusions: Gaseous and particulate air pollutants have a marked and close temporal association with stroke hospitalisation and death. Public and environmental health policies to reduce air pollution may reduce the burden of stroke, especially in low- and middle-income countries.
Author Disclosures: K. Lee: None. A.S. Shah: None. D.A. McAllister: None. A. Hunter: None. H. Nair: None. W. Whiteley: None. J.P. Langrish: None. D.E. Newby: None. N.L. Mills: None.
- © 2014 by American Heart Association, Inc.