title: The influence of season and living environment on children's urinary 1-hydroxypyrene levels in Ulaanbaatar, Mongolia.
abstract: BACKGROUND
  Heating indoor living environments elevates air pollution in Ulaanbaatar, Mongolia.
  
  
  OBJECTIVE
  This study was conducted to investigate the influence of season and living environment on children's urinary 1-hydroxypyrene (1-OHP) levels in Ulaanbaatar, Mongolia.
  
  
  METHODS
  Our study subjects were 320 children aged 11-15 years living in gers, brick houses and apartments, in ger and non-ger areas of Ulaanbaatar. Spot urine samples and questionnaires were collected three times from each subject in three seasons, September (warm) and December (cold) in 2011 and March (moderate) in 2012. Urinary 1-OHP was analyzed by high-performance liquid chromatography with fluorescent detection (HPLC/FLD). Generalized estimating equation (GEE) models were applied to estimate the seasonal and residential effects on 1-OHP levels, adjusting for demographic and environmental factors.
  
  
  RESULTS
  Children's urinary 1-OHP levels showed significant seasonal differences with 0.30 ± 0.57 μmol/mol creatinine in cold season, 0.14 ± 0.12 μmol/mol creatinine in moderate season, and 0.14 ± 0.21 μmol/mol creatinine in warm season. After controlling confounding factors, the GEE model showed that season, living area, and housing type had significant influence on children's urinary 1-OHP levels. Urinary 1-OHP levels in the cold and moderate seasons were, respectively 2.13 and 1.37 times higher than the warm season. Urinary 1-OHP levels for children living in ger areas were 1.27 times higher than those living in non-ger areas. Children who lived in gers or brick houses had 1.58 and 1.34 times higher 1-OHP levels, respectively, compared with those living in apartments. Children's urinary 1-OHP levels were associated with either estimated NO2 or SO2 concentrations at their home addresses in Ulaanbaatar.
  
  
  CONCLUSIONS
  Mongolian children's urinary 1-OHP levels were significantly elevated during the cold season, and for those living in ger areas, gers, or brick houses in Ulaanbaatar. Children's urinary 1-OHP levels were associated PAH co-pollutants SO2 and NO2, suggesting elevated 1-OHP levels may be attributable to PAH emissions from coal burning and traffic respectively, with indoor emissions from stoves further contributing to elevated 1-OHP in some children.
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Rm. 722, No.17, Xu-Zhou Road, Taipei 100, Taiwan.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Chen
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Rm. 722, No.17, Xu-Zhou Road, Taipei 100, Taiwan.
authors.forename: Yu-Kai
authors.initials: YK
authors.lastname: Huang
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Rm. 722, No.17, Xu-Zhou Road, Taipei 100, Taiwan; Department of Health Policy and Management, School of Public Health, Health Sciences University of Mongolia, S. Zorig St, Main campus, P.O-48, Box-111, Ulaanbaatar, Mongolia.
authors.forename: Munkh-Erdene
authors.initials: ME
authors.lastname: Luvsan
authors.affiliation: School of Public Health, Health Sciences University of Mongolia, S. Zorig St, Main campus, P.O-48, Box-111, Ulaanbaatar, Mongolia.
authors.forename: Enkhjargal
authors.initials: E
authors.lastname: Gombojav
authors.affiliation: School of Public Health, Health Sciences University of Mongolia, S. Zorig St, Main campus, P.O-48, Box-111, Ulaanbaatar, Mongolia.
authors.forename: Chimedsuren
authors.initials: C
authors.lastname: Ochir
authors.affiliation: School of Public Health, Health Sciences University of Mongolia, S. Zorig St, Main campus, P.O-48, Box-111, Ulaanbaatar, Mongolia; Custom's Professional Inspection Office of Buyant-Ukhaa Port, Khan-Uul District, 10th khoroo, Chinggis Khan International Airport, Ulaanbaatar, Mongolia.
authors.forename: Jargal
authors.initials: J
authors.lastname: Bulgan
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Rm. 722, No.17, Xu-Zhou Road, Taipei 100, Taiwan; Global Health Center, College of Public Health, National Taiwan University, Rm. 108, No.17, Xu-Zhou Road, Taipei 100, Taiwan. Electronic address: ccchan@ntu.edu.tw.
authors.forename: Chang-Chuan
authors.initials: CC
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000393:Air Pollutants / Q000032:analysis / Q000652:urine*; D002648:Child; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005260:Female; D006798:Housing; D006801:Humans; D008297:Male; D008986:Mongolia; D009585:Nitrogen Dioxide / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D011721:Pyrenes / Q000652:urine*; D012044:Regression Analysis; D012621:Seasons; D013458:Sulfur Dioxide / Q000032:analysis
chemical_list: D000393:Air Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D013458:Sulfur Dioxide; C033146:1-hydroxypyrene; D009585:Nitrogen Dioxide
keywords: Air pollution; Ger; Mongolia; Polycyclic aromatic hydrocarbons; Urinary 1-hydroxypyrene