title: Role of exposure to air pollutants in the development of type 1 diabetes before and after 5 yr of age.
abstract: OBJECTIVE
  To assess the role of ambient air pollutants in type 1 diabetes in children.
  
  
  METHODS
  Prediagnosis exposure to five air pollutants was studied in two subgroups with onset of type 1 diabetes before and after 5 yr of age, and two matched subgroups of healthy children. Zip codes and dates of residence from birth to diagnosis were used to obtain geographic- and time-specific air concentrations of SO(2), NO(2), ozone (O(3)), SO(4), and particulate matter < 10 micro m in diameter (PM(10)). Prediagnosis time-adjusted pollutant exposure levels were created by summing up zip code-specific pollution data and dividing by months of exposure from birth to diagnosis. Two-tailed t-test and logistic regression were used to evaluate relative effects and test data between cases and controls.
  
  
  RESULTS
  Prediagnosis average O(3) exposure was significantly higher in children with type 1 diabetes than in healthy controls. Prediagnosis PM(10) exposure was significantly higher in children diagnosed before 5 yr of age, when compared with healthy controls. SO(2) exposure was significantly higher in children with later-onset diabetes compared with those with early-onset diabetes (EOD). NO(2), SO(2) and SO(4) exposure was significantly lower in children diagnosed after 5 yr of age, when compared with healthy controls. O(3), NO(2), SO(4) and PM(10) levels did not significantly differ between the two diabetic subgroups.
  
  
  CONCLUSIONS
  Increased ozone exposure may be a contributory factor to the increased incidence of type 1 diabetes. PM(10) may be a specific contributory factor to the development of type 1 diabetes before 5 yr of age.
authors.affiliation: Pediatric Diabetes Center, Loma Linda University Children's Hospital, CA 92354, USA. Ehathout@ahs.llumc.edu
authors.forename: Eba H
authors.initials: EH
authors.lastname: Hathout
authors.forename: W Lawrence
authors.initials: WL
authors.lastname: Beeson
authors.forename: Fadi
authors.initials: F
authors.lastname: Nahab
authors.forename: Alissar
authors.initials: A
authors.lastname: Rabadi
authors.forename: Wendy
authors.initials: W
authors.lastname: Thomas
authors.forename: John W
authors.initials: JW
authors.lastname: Mace