title: Polyfluoroalkyl chemicals in the U.S. population: data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and comparisons with NHANES 1999-2000.
abstract: BACKGROUND
  Polyfluoroalkyl chemicals (PFCs) have been used since the 1950s in numerous commercial applications. Exposure of the general U.S. population to PFCs is widespread. Since 2002, the manufacturing practices for PFCs in the United States have changed considerably.
  
  
  OBJECTIVE
  We aimed to assess exposure to perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and eight other PFCs in a representative 2003-2004 sample of the general U.S. population >or= 12 years of age and to determine whether serum concentrations have changed since the 1999-2000 National Health and Nutrition Examination Survey (NHANES).
  
  
  METHODS
  By using automated solid-phase extraction coupled to isotope dilution-high-performance liquid chromatography-tandem mass spectrometry, we analyzed 2,094 serum samples collected from NHANES 2003-2004 participants.
  
  
  RESULTS
  We detected PFOS, PFOA, PFHxS, and PFNA in > 98% of the samples. Concentrations differed by race/ethnicity and sex. Geometric mean concentrations were significantly lower (approximately 32% for PFOS, 25% for PFOA, 10% for PFHxS) and higher (100%, PFNA) than the concentrations reported in NHANES 1999-2000 (p < 0.001).
  
  
  CONCLUSIONS
  In the general U.S. population in 2003-2004, PFOS, PFOA, PFHxS, and PFNA serum concentrations were measurable in each demographic population group studied. Geometric mean concentrations of PFOS, PFOA, and PFHxS in 2003-2004 were lower than in 1999-2000. The apparent reductions in concentrations of PFOS, PFOA, and PFHxS most likely are related to discontinuation in 2002 of industrial production by electrochemical fluorination of PFOS and related perfluorooctanesulfonyl fluoride 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: Lee-Yang
authors.initials: LY
authors.lastname: Wong
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kuklenyik
authors.forename: John A
authors.initials: JA
authors.lastname: Reidy
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
mesh_terms: D000293:Adolescent; D000328:Adult; D017738:Alkanesulfonic Acids / Q000097:blood*; D002210:Caprylates / Q000097:blood; D002648:Child; D002851:Chromatography, High Pressure Liquid; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000097:blood; D005260:Female; D005466:Fluorocarbons / Q000097:blood*; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D053719:Tandem Mass Spectrometry; D014481:United States
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D004785:Environmental Pollutants; D005466:Fluorocarbons; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid