title: Urinary 1-hydroxypyrene in children living in city and rural residences in Denmark.
abstract: OBJECTIVE
  The present study aims to assess the biological uptake in children of polycyclic aromatic hydrocarbons measured as 1-hydroxypyrene in urine from children living in city and rural residences.
  
  
  METHODS
  103 children living in Copenhagen and 101 children living in rural residences of Denmark collected urine samples Monday to Friday morning. Each day, the family filled in a printed diary that included questions about the time and activity patterns of the child. Multiple regression analyses were used to identify predictors of the excreted 1-hydroxypyrene level.
  
  
  RESULTS
  During the week, the children excreted on average 0.07 [95% CI: 0.01-0.41] mumol urinary 1-hydroxypyrene per mol creatinine. Children living in urban residences excreted 0.02 [95% CI: 0.01-0.05] mumol more 1-hydroxypyrene than children living in rural residences. This was confirmed in the multiple regression analysis showing a 29% (95% CI: 2-64%) higher excretion among urban children than rural children. Moreover, the regression analysis showed that for each hour per day spent outside the children excreted 58% (1.58 [1.22-2.03]) more 1-hydroxypyrene in urine.
  
  
  CONCLUSIONS
  The present study indicates that children living in urban residences are more exposed to PAH than children living in rural residences. Time spent outdoors increased the excretion of 1-hydroxypyrene, which was most evident among urban children. Higher concentrations of ambient air pollution in urban areas may explain this finding. No influence of environmental tobacco smoke, cooking habits, and heating facilities was detected.
authors.affiliation: National Institute of Occupational Health, Copenhagen Ø, Denmark. aamh@ami.dk
authors.forename: Ase Marie
authors.initials: AM
authors.lastname: Hansen
authors.forename: Ole
authors.initials: O
authors.lastname: Raaschou-Nielsen
authors.forename: Lisbeth Ehlert
authors.initials: LE
authors.lastname: Knudsen
mesh_terms: D000293:Adolescent; D000393:Air Pollutants / Q000378:metabolism*; D015415:Biomarkers / Q000652:urine; D002648:Child; D002675:Child, Preschool; D002947:Cities; D003718:Denmark; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D011721:Pyrenes / Q000032:analysis*; D012423:Rural Health; D013997:Time Factors; D014504:Urban Health
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; C033146:1-hydroxypyrene