Associations of outdoor air pollution with hemorrhagic stroke mortality

J Occup Environ Med. 2011 Feb;53(2):124-6. doi: 10.1097/JOM.0b013e3182099175.


Objective: Evidence linking short-term exposure to outdoor air pollution with hemorrhagic stroke is inconsistent.

Methods: We evaluated the associations between outdoor air pollution and specific types of stroke in Tokyo, Japan, from April 2003 to December 2008. We obtained daily counts of stroke mortality (n = 41,440) and concentrations of nitrogen dioxide as well as particles less than 2.5 μm in diameter. Time-series analysis was employed.

Results: Although same-day air pollutants were positively associated with ischemic stroke and intracerebral hemorrhage mortality, both air pollutants were more strongly associated with subarachnoid hemorrhage mortality: rate ratio was 1.041 (95% confidence interval: 1.011-1.072) for each 10 μg/m3 increase in the previous-day particles less than 2.5 μm.

Conclusions: This study suggests that short-term exposure to outdoor air pollution increases the risks of hemorrhagic stroke mortality as well as ischemic stroke mortality.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / adverse effects
  • Air Pollution / adverse effects*
  • Air Pollution / statistics & numerical data*
  • Cerebral Hemorrhage / mortality
  • Environmental Exposure / statistics & numerical data
  • Humans
  • Nitrogen Dioxide / adverse effects
  • Particulate Matter / adverse effects
  • Risk Factors
  • Stroke / mortality*
  • Subarachnoid Hemorrhage / mortality
  • Tokyo / epidemiology


  • Air Pollutants
  • Particulate Matter
  • Nitrogen Dioxide