title: Association of polycyclic aromatic hydrocarbons and asthma among children 6-19 years: NHANES 2001-2008 and NHANES 2011-2012.
abstract: BACKGROUND
  Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals that can induce oxidative stress and related cytotoxicity. Whether environmental exposure of PAHs has effects on asthma in the general population is still unclear. This study investigated the association of urinary PAHs with asthma in U.S. children.
  
  
  METHODS
  15 447 children who participated in the US National Health and Nutrition Examination Survey 2001-2008 and 2011-2012 were studied. Ten urinary PAHs were analyzed for their association with asthma or asthma related symptoms. Multivariate logistic regression was applied to assess associations between urinary PAHs and asthma adjusted for age, gender, ethnicity, body mass index and the poverty income ratio.
  
  
  RESULTS
  When stratified by age and sex, we found a remarkable association between urinary 2-phenanthrene and diagnosed asthma in boys (OR: 2.353, 95% CI: 1.156-4.792; P = 0.021) aged 13-19 years old. Positive association was observed between ever wheeze and 4-phenanthrene among girls aged 13-19 years (OR: 4.086, 95% CI: 1.326-12.584, P = 0.043). Moreover, an overall positive association between 1-pyrene and diagnosed asthma was observed. However, no association existed between levels of 1-napthol, 2-napthol, 3-fluorene, 2-fluorene, 3-phenanthrene, 1-phenanthrene or 9-fluorene with asthma or asthma symptom in this population.
  
  
  CONCLUSIONS
  This data provide epidemiological evidences that urinary PAHs are positively associated with asthma in children aged 6-19 years. However, the underlying mechanisms still need further exploration.
authors.affiliation: State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Xu
authors.affiliation: Department of Surgery, Shanghai East Hospital, Tongji University, No 150 Jimo Road, Shanghai 200120, China. Electronic address: zhaoyanjiang@gmail.com.
authors.forename: Zhao-Yan
authors.initials: ZY
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China. Electronic address: aihuagu@njmu.edu.cn.
authors.forename: Aihua
authors.initials: A
authors.lastname: Gu
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000652:urine*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009749:Nutrition Surveys; D011084:Polycyclic Aromatic Hydrocarbons / Q000652:urine*; D014481:United States; D055815:Young Adult
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons
keywords: Asthma; National health and nutrition examination survey; Polycyclic aromatic hydrocarbons