title: Association of outdoor air pollution and indoor renovation with early childhood ear infection in China.
abstract: BACKGROUND
  Otitis media (OM) is a common infection in early childhood with repeated attacks that lead to long-term complications and sequelae, but its risk factors still remain unclear.
  
  
  OBJECTIVE
  To examine the risk of childhood OM for different indoor and outdoor air pollutants during different timing windows, with a purpose to identify critical windows of exposure and key components of air pollution in the development of OM.
  
  
  METHODS
  We conducted a retrospective cohort study of 1617 children aged 3-4 years in Changsha, China (2011-2012). Children's life-time prevalence of OM and exposure to indoor air pollution related to home renovation activities were surveyed by a questionnaire administered by the parents. Children's exposure to outdoor air pollution, including nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter with an aerodynamic diameter ≤ 10 μm (PM10), was estimated using the measured concentrations at municipal monitoring stations. The odds ratio (OR) and 95% confidence interval (CI) of childhood OM for prenatal and postnatal exposure to indoor and outdoor air pollution were examined by using logistic regression model.
  
  
  RESULTS
  Life-time prevalence of OM in preschool children (7.3%) was associated not only with prenatal exposure to industrial air pollutant with adjusted OR (95% CI) = 1.44 (1.09-1.88) for a 27 μg/m3increase in SO2but also with postnatal exposure to indoor renovations with OR (95% CI) = 1.62 (1.05-2.49) for new furniture and 1.81 (1.12-2.91) for redecoration, particularly in girls. Combined exposure to outdoor SO2and indoor renovation significantly increased OM risk. Furthermore, we found that exposure to outdoor SO2and indoor renovation were significantly associated with the onset but not repeated attacks of OM.
  
  
  CONCLUSIONS
  Prenatal exposure to outdoor industrial air pollution and postnatal exposure to indoor renovation are independently associated with early childhood OM in China and may cause the OM onset.
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China; XiangYa School of Public Health, Central South University, Changsha, Hunan, China. Electronic address: qhdeng@csu.edu.cn.
authors.forename: Qihong
authors.initials: Q
authors.lastname: Deng
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Chan
authors.initials: C
authors.lastname: Lu
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Jinping
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Linjing
authors.initials: L
authors.lastname: Deng
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects*; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide / Q000032:analysis; D010033:Otitis Media / Q000453:epidemiology / Q000209:etiology*; D052638:Particulate Matter / Q000032:analysis*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D009585:Nitrogen Dioxide
keywords: Ambient air pollution; Home renovation; Indoor air pollution; Otitis media; Postnatal; Prenatal