title: Meta-analysis of adverse health effects due to air pollution in Chinese populations.
abstract: BACKGROUND
  Pooled estimates of air pollution health effects are important drivers of environmental risk communications and political willingness. In China, there is a lack of review studies to provide such estimates for health impact assessments.
  
  
  METHODS
  We systematically searched the MEDLINE database using keywords of 80 major Chinese cities in Mainland China, Hong Kong and Taiwan on 30 June 2012, yielding 350 abstracts with 48 non-duplicated reports either in English or Chinese after screening. We pooled the relative risks (RR) per 10 μg/m3 of particulate matter (PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2) and ozone (O3).
  
  
  RESULTS
  For short-term effects, the pooled RR (p<0.05) ranges were: 1.0031 (PM10) to 1.0140 (NO2) for all-cause mortality, 1.0034 (cardiopulmonary, PM10) to 1.0235 (influenza and pneumonia, SO2) for 9 specific-causes mortality, 1.0021 (cardiovascular, PM10) to 1.0162 (asthma, O3) for 5 specific-causes hospital admissions. For birth outcomes, the RR (p<0.05) ranged from 1.0051 (stillbirth, O3) to 1.1189 (preterm-birth, SO2) and for long-term effect on mortality from 1.0150 (respiratory, SO2) to 1.0297 (respiratory, NO2). Publication bias was absent (Egger test: p=0.326 to 0.624). Annual PM10 and NO2 concentrations were inversely associated with RR of mortality (p=0.017-0.028).
  
  
  CONCLUSIONS
  Evidence on short-term effects of air pollution is consistent and sufficient for health impact assessment but that on long-term effects is still insufficient.
authors.forename: Hak-Kan
authors.initials: HK
authors.lastname: Lai
authors.forename: Hilda
authors.initials: H
authors.lastname: Tsang
authors.affiliation: Department of Community Medicine, School of Public Health, The University of Hong Kong, Hong Kong, SAR, China. hrmrwcm@hku.hk.
authors.forename: Chit-Ming
authors.initials: CM
authors.lastname: Wong
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000401:mortality; D002423:Cause of Death; D002681:China / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D009585:Nitrogen Dioxide / Q000009:adverse effects; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects; D011247:Pregnancy; D011256:Pregnancy Outcome; D012140:Respiratory Tract Diseases / Q000209:etiology* / Q000401:mortality; D013458:Sulfur Dioxide / Q000009:adverse effects; D013624:Taiwan / Q000453:epidemiology
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D009585:Nitrogen Dioxide