title: Breastfeeding: a potential excretion route for mothers and implications for infant exposure to perfluoroalkyl acids.
abstract: BACKGROUND
  The presence of perfluoroalkyl acids (PFAAs) in breast milk has been documented, but their lactational transfer has been rarely studied. Determination of the elimination rates of these chemicals during breastfeeding is important and critical for assessing exposure in mothers and infants.
  
  
  OBJECTIVE
  We aimed to investigate the association between breastfeeding and maternal serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS). For a subset of the population, for whom we also have their infants' measurements, we investigated associations of breastfeeding with infant serum PFAA concentrations.
  
  
  METHODS
  The present analysis included 633 women from the C8 Science Panel Study who had a child < 3.5 years of age and who provided blood samples and reported detailed information on breastfeeding at the time of survey. PFAA serum concentrations were available for all mothers and 8% (n = 49) of the infants. Maternal and infant serum concentrations were regressed on duration of breastfeeding.
  
  
  RESULTS
  Each month of breastfeeding was associated with lower maternal serum concentrations of PFOA (-3%; 95% CI: -5, -2%), PFOS (-3%; 95% CI: -3, -2%), PFNA (-2%; 95% CI: -2, -1%), and PFHxS (-1%; 95% CI: -2, 0%). The infant PFOA and PFOS serum concentrations were 6% (95% CI: 1, 10%) and 4% (95% CI: 1, 7%) higher per month of breastfeeding.
  
  
  CONCLUSIONS
  Breast milk is the optimal food for infants, but is also a PFAA excretion route for lactating mothers and exposure route for nursing infants.
authors.affiliation: London School of Hygiene & Tropical Medicine, London, United Kingdom.
authors.forename: Debapriya
authors.initials: D
authors.lastname: Mondal
authors.forename: Rosana Hernandez
authors.initials: RH
authors.lastname: Weldon
authors.forename: Ben G
authors.initials: BG
authors.lastname: Armstrong
authors.forename: Lorna J
authors.initials: LJ
authors.lastname: Gibson
authors.forename: Maria-Jose
authors.initials: MJ
authors.lastname: Lopez-Espinosa
authors.forename: Hyeong-Moo
authors.initials: HM
authors.lastname: Shin
authors.forename: Tony
authors.initials: T
authors.lastname: Fletcher
mesh_terms: D000367:Age Factors; D017738:Alkanesulfonic Acids / Q000032:analysis / Q000097:blood; D001942:Breast Feeding / Q000009:adverse effects*; D002210:Caprylates / Q000032:analysis / Q000097:blood; D004785:Environmental Pollutants / Q000032:analysis* / Q000097:blood; D005227:Fatty Acids; D005260:Female; D005466:Fluorocarbons / Q000032:analysis / Q000097:blood; D006801:Humans; D008131:London; D008895:Milk, Human / Q000737:chemistry*; D013451:Sulfonic Acids / Q000032:analysis / Q000097:blood; D011795:Surveys and Questionnaires
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D004785:Environmental Pollutants; D005227:Fatty Acids; D005466:Fluorocarbons; D013451:Sulfonic Acids; C471071:perfluorohexanesulfonic acid; C101816:perfluoro-n-nonanoic acid; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid