title: Acute effect of ambient air pollution on stroke mortality in the China air pollution and health effects study.
abstract: OBJECTIVE
  There have been no multicity studies on the acute effects of air pollution on stroke mortality in China. This study was undertaken to examine the associations between daily stroke mortality and outdoor air pollution (particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide) in 8 Chinese cities.
  
  
  METHODS
  We used Poisson regression models with natural spline-smoothing functions to adjust for long-term and seasonal trends, as well as other time-varying covariates. We applied 2-stage Bayesian hierarchical statistical models to estimate city-specific and national average associations of air pollution with daily stroke mortality.
  
  
  RESULTS
  Air pollution was associated with daily stroke mortality in 8 Chinese cities. In the combined analysis, an increase of 10 μg/m(3) of 2-day moving average concentrations of particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide corresponded to 0.54% (95% posterior intervals, 0.28-0.81), 0.88% (95% posterior intervals, 0.54-1.22), and 1.47% (95% posterior intervals, 0.88-2.06) increase of stroke mortality, respectively. The concentration-response curves indicated linear nonthreshold associations between air pollution and risk of stroke mortality.
  
  
  CONCLUSIONS
  To our knowledge, this is the first multicity study in China, or even in other developing countries, to report the acute effect of air pollution on stroke mortality. Our results contribute to very limited data on the effect of air pollution on stroke for high-exposure settings typical in developing countries.
authors: School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, Fudan Tyndall Centre, Shanghai, China. haidongkan@gmail.com
authors: Renjie
authors: R
authors: Chen
authors: Yuhao
authors: Y
authors: Zhang
authors: Chunxue
authors: C
authors: Yang
authors: Zhuohui
authors: Z
authors: Zhao
authors: Xiaohui
authors: X
authors: Xu
authors: Haidong
authors: H
authors: Kan
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D001499:Bayes Theorem; D002681:China; D002947:Cities; D003906:Developing Countries; D004781:Environmental Exposure; D005843:Geography; D006801:Humans; D015233:Models, Statistical; D009585:Nitrogen Dioxide / Q000737:chemistry; D052638:Particulate Matter / Q000032:analysis; D016012:Poisson Distribution; D012044:Regression Analysis; D020521:Stroke / Q000209:etiology / Q000401:mortality; D013458:Sulfur Dioxide / Q000737:chemistry
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D009585:Nitrogen Dioxide