title: [Comparison of respiratory diseases and symptoms among school-age children in areas with different levels of air pollution].
abstract: OBJECTIVE
  To compare the differences of children's health in different area, and to confirm if the prevalence of respiratory diseases and symptoms among children are closely associated with the air pollution.
  
  
  METHODS
  A cross-sectional study was conducted in an urban area A and a suburban area B with different levels of air pollution in Beijing. Using a cluster sampling method, we recruited 4 564 children from 3 primary schools in urban A and 4 primary schools in suburban B. Respiratory symptoms were investigated using an international standardized questionnaire including characteristics of children, living conditions, respiratory diseases and symptoms and situation of parents. The concentrations of air pollutants for recent five years were obtained from Reports on the Quality of the Beijing Environment. SPSS 16.0 was used to analyze data.
  
  
  RESULTS
  The prevalence of cough, persistent cough, phlegm, persistent phlegm, wheeze and asthma in A area were higher than those in B area [(62.2% vs. 59.9%), (6.3% vs. 3.1%), (42.4% vs. 37.4%),(3.6% vs. 2.4%),(13.3% vs. 9.9%)and(9.5% vs. 5.4%)]. Except for cough, cough with cold, cough without cold, the prevalence of respiratory diseases and symptoms in A area were significantly higher than those in B area (P<0.05). Logistic regression analysis showed the prevalence of persistent cough, phlegm without cold, asthma in A area were significantly higher than those in B area (P<0.05).
  
  
  CONCLUSIONS
  Respiratory diseases and symptoms among school-age children were closely associated with the level of air pollution.
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing 100191, China.
authors.forename: Yi-dan
authors.initials: YD
authors.lastname: Zhu
authors.affiliation: Department of Environmental Health, Beijing Center for Diseases Control and Prevention, Beijing 100013, China.
authors.forename: Jian-rong
authors.initials: JR
authors.lastname: Wei
authors.affiliation: Department of Public Health, Dongcheng District Center for Diseases Control and Prevention, Beijing 100009, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Public Health, Yanqing County Center for Diseases Control and Prevention, Beijing 102100,China.
authors.forename: Shao-hua
authors.initials: SH
authors.lastname: Wang
authors.affiliation: Department of Environmental Health, Beijing Center for Diseases Control and Prevention, Beijing 100013, China.
authors.forename: Han-mei
authors.initials: HM
authors.lastname: Tian
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing 100191, China.
authors.forename: Xin-biao
authors.initials: XB
authors.lastname: Guo
mesh_terms: D000397:Air Pollution / Q000032:analysis*; D001249:Asthma / Q000453:epidemiology; D002648:Child; D002681:China; D002947:Cities; D003371:Cough / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004777:Environment; D006801:Humans; D015995:Prevalence; D012135:Respiratory Sounds; D012140:Respiratory Tract Diseases / Q000453:epidemiology*; D013383:Suburban Population; D011795:Surveys and Questionnaires; D014505:Urban Population