title: Children's urinary phthalate metabolites and fractional exhaled nitric oxide in an urban cohort.
abstract: BACKGROUND
  Phthalates are used widely in consumer products. Exposure to several phthalates has been associated with respiratory symptoms and decreased lung function. Associations between children's phthalate exposures and fractional exhaled nitric oxide (Fe(NO)), a biomarker of airway inflammation, have not been examined.
  
  
  OBJECTIVE
  We hypothesized that urinary concentrations of four phthalate metabolites would be positively associated with Fe(NO) and that these associations would be stronger among children with seroatopy or wheeze.
  
  
  METHODS
  In an urban ongoing birth cohort, 244 children had phthalate metabolites determined in urine collected on the same day as Fe(NO) measurement. Repeated sampling gathered 313 observations between ages 4.9 and 9.1 years. Seroatopy was assessed by specific IgE. Wheeze in the past year was assessed by validated questionnaire. Regression models used generalized estimating equations.
  
  
  RESULTS
  Log-unit increases in urinary concentrations of metabolites of diethyl phthalate (DEP) and butylbenzyl phthalate (BBzP) were associated with a 6.6% (95% confidence interval [CI] 0.5-13.1%) and 8.7% (95% CI, 1.9-16.0%) increase in Fe(NO), respectively, adjusting for other phthalate metabolites and potential covariates/confounders. There was no association between concentrations of metabolites of di(2-ethylhexyl) phthalate or di-n-butyl phthalate and Fe(NO). There was no significant interaction by seroatopy. The BBzP metabolite association was significantly stronger among children who wheeze (P = 0.016).
  
  
  CONCLUSIONS
  Independent associations between exposures to DEP and BBzP and Fe(NO) in a cohort of inner-city children were observed. These results suggest that these two ubiquitous phthalates, previously shown to have substantial contributions from inhalation, are positively associated with airway inflammation in children.
authors.affiliation: Columbia Center for Children’s Environmental Health, Mailman School of Public Health, Columbia University, 722 W. 168th Street, New York, NY 10032, USA. acj2109@columbia.edu
authors.forename: Allan C
authors.initials: AC
authors.lastname: Just
authors.forename: Robin M
authors.initials: RM
authors.lastname: Whyatt
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Miller
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Rundle
authors.forename: Qixuan
authors.initials: Q
authors.lastname: Chen
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Calafat
authors.forename: Adnan
authors.initials: A
authors.lastname: Divjan
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Rosa
authors.forename: Hanjie
authors.initials: H
authors.lastname: Zhang
authors.forename: Frederica P
authors.initials: FP
authors.lastname: Perera
authors.forename: Inge F
authors.initials: IF
authors.lastname: Goldstein
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Perzanowski
mesh_terms: D016902:Air Pollution, Indoor / Q000009:adverse effects / Q000032:analysis; D000485:Allergens / Q000097:blood; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D045853:Exhalation / Q000187:drug effects / Q000276:immunology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D009519:New York City; D009569:Nitric Oxide / Q000032:analysis*; D010795:Phthalic Acids / Q000009:adverse effects / Q000652:urine*; D012120:Respiration Disorders / Q000139:chemically induced* / Q000276:immunology; D014504:Urban Health
chemical_list: D000485:Allergens; D015415:Biomarkers; D010795:Phthalic Acids; D009569:Nitric Oxide; D007073:Immunoglobulin E