title: Epidemiological evidence on association between ambient air pollution and stroke mortality.
abstract: BACKGROUND
  Inconsistent results have been found on the association between air pollution and stroke mortality. Additionally, evidence on people who are potentially sensitive to air pollution-associated stroke mortality is limited.
  
  
  METHODS
  Daily stroke mortality of adults aged over 65 between 2003 and 2008 in Shanghai, China were collected. The time-stratified case-crossover approach was used to assess the association between daily concentrations of air pollutants including particles with size <10 µm, sulfur dioxide (SO2) and nitrogen dioxide (NO2) and stroke mortality.
  
  
  RESULTS
  Both total-stroke and ischaemic-stroke mortalities were found to be significantly associated with all three air pollutants. Haemorrhagic stroke was significantly associated with SO2 and NO2 only. Substantial differences were observed for effect estimates of ischaemic-stroke mortality in relation to NO2 among people with cardiac diseases compared with those without; for an increase of 10 μg/m(3) in NO2, the increase in ischaemic-stroke mortality was 7.05% (95% CI 1.92% to 12.17%) for people with comorbid cardiac diseases versus 0.60% (95% CI -0.49% to 1.68%) for those without. We did not find evidence of effect modification by hypertension and diabetes.
  
  
  CONCLUSIONS
  This study provides new evidence for the association between exposure to ambient air pollution and stroke mortality. Our results also suggest that underlying cardiac disorder may increase the risk for ischaemic-stroke mortality in relation to air pollution exposure, especially NO2. .
authors: Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors: Yifeng
authors: Y
authors: Qian
authors: Meiying
authors: M
authors: Zhu
authors: Binxin
authors: B
authors: Cai
authors: Qing
authors: Q
authors: Yang
authors: Haidong
authors: H
authors: Kan
authors: Guixiang
authors: G
authors: Song
authors: Wenzheng
authors: W
authors: Jin
authors: Ming
authors: M
authors: Han
authors: Chunfang
authors: C
authors: Wang
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000009:adverse effects; D000397:Air Pollution; D002545:Brain Ischemia / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide / Q000009:adverse effects*; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects*; D012621:Seasons; D017678:Sex Distribution; D020521:Stroke / Q000401:mortality*; D013458:Sulfur Dioxide / Q000009:adverse effects*; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D009585:Nitrogen Dioxide
keywords: Air Pollution; Environmental Health; Mortality; Stroke