title: Weather, pollution, and acute myocardial infarction in Hong Kong and Taiwan.
abstract: BACKGROUND
  Several previous studies examined the association between acute myocardial infarction (AMI) incidence and temperature and/or air pollution. Results of these studies have been inconsistent and few studies have been done in cities with sub-tropical or tropical climates.
  
  
  METHODS
  Daily data on AMI hospitalizations, mean temperature and humidity, and pollutants, were collected for 2000-2009 for three warm-climate Asian cities. Poisson Generalized Additive Models were used to regress daily AMI counts on temperature, humidity, and pollutants while controlling for day of the week, long-term trends and seasonal effects. Smoothing splines allowing non-linear associations were used for temperature and humidity while pollutants were modeled as linear terms.
  
  
  RESULTS
  A 1°C drop below a threshold temperature of 24°C was significantly (p<.0001) associated with AMI hospitalization increases of 3.7% (average lag 0-13 temperature) in Hong Kong, 2.6% (average lag 0-15) in Taipei, and 4.0% (average lag 0-11) in Kaohsiung. No significant heat effects were observed. Among pollutants same day nitrogen dioxide (NO2) levels were the strongest predictors in all three cities, with a 10mg/m(3) increase in NO2 being associated with a 1.1% rise in AMI hospitalization in Hong Kong, and a 10 ppb rise being associated with 4.4% and 2.6% rises in Taipei and Kaohsiung, respectively.
  
  
  CONCLUSIONS
  Cool temperatures and higher NO2 levels substantially raised AMI risk in these warm-climate cities and the effect sizes we observed were stronger than those found in previous studies. More attention should be paid to the health dangers of cold weather in warm-climate cities.
authors.affiliation: Division of Biostatistics, School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong. wgoggins@cuhk.edu.hk
authors.forename: William B
authors.initials: WB
authors.lastname: Goggins
authors.forename: Emily Y Y
authors.initials: EY
authors.lastname: Chan
authors.forename: Chun-Yuh
authors.initials: CY
authors.lastname: Yang
mesh_terms: D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D016208:Databases, Factual / Q000639:trends; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology; D013696:Temperature; D014887:Weather
chemical_list: D000393:Air Pollutants