title: Urinary concentrations of four parabens in the U.S. population: NHANES 2005-2006.
abstract: BACKGROUND
  Parabens are widely used as antimicrobial preservatives in cosmetics, -pharmaceuticals, and food and beverage processing.
  
  
  OBJECTIVE
  We assessed exposure to methyl, ethyl, propyl, and butyl parabens in a representative sample of persons >or= 6 years of age in the U.S. general population from the 2005-2006 National Health and Nutrition Examination Survey.
  
  
  METHODS
  We analyzed 2,548 urine samples by using online solid-phase extraction coupled to isotope dilution-high-performance liquid chromatography/tandem mass spectrometry.
  
  
  RESULTS
  We detected methyl paraben (MP) and propyl paraben (PP) in 99.1% and 92.7% of the samples, respectively. We detected ethyl (42.4%) and butyl (47%) parabens less frequently and at median concentrations at least one order of magnitude lower than MP (63.5 microg/L) and PP (8.7 microg/L). Least-square geometric mean (LSGM) concentrations of MP were significantly higher (p <or= 0.01) among non-Hispanic blacks than among non-Hispanic whites except at older ages (>or= 60 years). Adolescent and adult females had significantly higher (p < 0.01) LSGM concentrations of MP and PP than did adolescent and adult males. Females were more likely than males [adjusted odds ratios (ORs) and 95% confidence intervals (CIs): MP, 3.2 (2.99-5.27); PP, 4.19 (2.34-7.49)] and non-Hispanic blacks were more likely than non-Hispanic whites [MP, 4.99 (2.62-9.50); PP, 3.6 (1.86-7.05)] to have concentrations above the 95th percentile.
  
  
  CONCLUSIONS
  The general U.S. population was exposed to several parabens during 2005-2006. Differences in the urinary concentrations of MP and PP by sex and race/ethnicity likely reflect the use of personal care products containing these compounds.
authors.affiliation: Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341 , USA. Acalafat@cdc.gov
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Calafat
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Ye
authors.forename: Lee-Yang
authors.initials: LY
authors.lastname: Wong
authors.forename: Amber M
authors.initials: AM
authors.lastname: Bishop
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002851:Chromatography, High Pressure Liquid; D004781:Environmental Exposure; D004782:Environmental Health; D004784:Environmental Monitoring; D005260:Female; D005520:Food Preservatives / Q000009:adverse effects / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010226:Parabens / Q000009:adverse effects / Q000032:analysis*; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects / Q000032:analysis; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D014481:United States; D055815:Young Adult
chemical_list: D005520:Food Preservatives; D010226:Parabens; D011310:Preservatives, Pharmaceutical; C012313:ethyl-p-hydroxybenzoate; C038091:butylparaben; C015358:methylparaben; C006068:propylparaben