title: Tobacco smoke increases the risk of otitis media among Greenlandic Inuit children while exposure to organochlorines remain insignificant.
abstract: BACKGROUND
  Prenatal exposure to environmental levels of organochlorines (OCs) has been demonstrated to have immunotoxic effects in humans. We investigated the relationship between prenatal exposure to OCs and the occurrence of otitis media (OM) among Inuit children in Greenland.
  
  
  METHODS
  We estimated the concentration of 14 PCB congeners and 11 pesticides in maternal and cord blood samples and in breast milk in a population-based cohort of 400 mother-child pairs. At follow-up, we examined the children's ears and used their medical records to assess the OM occurrence and severity. Multivariate regression analyses were used with adjustments for passive smoking, crowding, dietary habits, parent's educational level, breast feeding and the use of child-care.
  
  
  RESULTS
  The children were 4-10 years of age at follow-up and 223 (85%) participated. We found no association between prenatal OC exposure and the development of OM. Factors associated with the child's hazard of OM during the first 4 years of life were: mother's history of OM (HR 1.70, 95% CI 1.11-2.59, p=0.01); mother's smoking habits: current (HR 2.47, 95% CI 1.45-4.21, p<0.01) and previous (HR 2.00, 95% CI 1.19-3.36, p<0.01); number of smokers in the home (HR 1.17, 95% CI 1.05-1.31, p<0.01). After adjustment mothers' smoking habits remained significant.
  
  
  CONCLUSIONS
  We found no relationship between high levels of prenatal exposure of OCs and occurrence of OM. Passive smoking was found as the strongest environmental risk factor for the development of OM. Interventions to reduce passive smoke in children's environment are needed.
authors: Department of Otolaryngology, Head & Neck Surgery, Rigshospitalet, University Hospital of Copenhagen, Denmark. ramon@dadlnet.dk
authors: Ramon Gordon
authors: RG
authors: Jensen
authors: Anders
authors: A
authors: Koch
authors: Preben
authors: P
authors: Homøe
authors: Peter
authors: P
authors: Bjerregaard
mesh_terms: D000293:Adolescent; D000328:Adult; D001942:Breast Feeding / Q000706:statistics & numerical data; D002675:Child, Preschool; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis; D004787:Environmental Pollution / Q000706:statistics & numerical data*; D005260:Female; D006116:Greenland / Q000453:epidemiology; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism*; D007223:Infant; D007231:Infant, Newborn; D004930:Inuit / Q000706:statistics & numerical data; D008297:Male; D009035:Mothers; D010033:Otitis Media / Q000453:epidemiology* / Q000209:etiology; D012907:Smoking / Q000453:epidemiology; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D014028:Tobacco Smoke Pollution