title: Air pollution and children's respiratory symptoms in six cities of Northern China.
abstract: OBJECTIVE
  The associations between air pollution and children's respiratory health in the high pollution range have not yet been clearly characterized. We evaluated the effects of outdoor air pollution on respiratory morbidity in children selected from multiple sites in a heavy industrial province of northeastern China.
  
  
  METHODS
  The study included 11,860 children aged 3-12 years, selected from 18 districts of 6 cities in Liaoning province, the participation rate is 89.9%. Informed consent and written responses to surveys about children's historic and current health status, personal and household characteristics, and other information were obtained from parents. A two-stage regression approach was applied in data analyses.
  
  
  RESULTS
  There were wide gradients for TSP (188-689 μg/m(3)), SO(2) (14-140 μg/m(3) and NO(2) (29-94 μg/m(3)) across the 18 districts of 6 cities. The three air pollutants significantly increased the prevalence of persistent cough (21-28%), persistent phlegm (21-30%) and current asthma (39-56%) for each interquartile range increment (172 μg/m(3) for TSP, 69 μg/m(3) for SO(2), 30 μg/m(3) for NO(2)), showing larger between-city effects than within-city. Rates of respiratory symptoms were significantly higher for children with younger age, atopy, respiratory disease in early age, family history of asthma or chronic bronchitis, and tobacco smoke exposure.
  
  
  CONCLUSIONS
  The high levels of outdoor air pollution in north China are positively associated with children's respiratory symptoms, the associations with TSP appear to be stronger than SO(2) and NO(2).
authors.affiliation: Department of Environmental Epidemiology, Liaoning Provincial Center for Disease Control and Prevention, 42-1 Jixian St, Heping Dis, Shenyang, PR China. panpgw@yahoo.com.cn
authors.forename: Guowei
authors.initials: G
authors.lastname: Pan
authors.forename: Shujuan
authors.initials: S
authors.lastname: Zhang
authors.forename: Yiping
authors.initials: Y
authors.lastname: Feng
authors.forename: Ken
authors.initials: K
authors.lastname: Takahashi
authors.forename: Jun
authors.initials: J
authors.lastname: Kagawa
authors.forename: Lianzheng
authors.initials: L
authors.lastname: Yu
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Meijuan
authors.initials: M
authors.lastname: Liu
authors.forename: Qinan
authors.initials: Q
authors.lastname: Liu
authors.forename: Shuwen
authors.initials: S
authors.lastname: Hou
authors.forename: Bailing
authors.initials: B
authors.lastname: Pan
authors.forename: Jianping
authors.initials: J
authors.lastname: Li
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D002681:China; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide / Q000633:toxicity*; D010316:Particle Size; D015995:Prevalence; D012140:Respiratory Tract Diseases / Q000209:etiology*; D013458:Sulfur Dioxide / Q000633:toxicity*; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D000393:Air Pollutants; D014028:Tobacco Smoke Pollution; D013458:Sulfur Dioxide; D009585:Nitrogen Dioxide