title: Perfluoroalkyl acids in children and their mothers: Association with drinking water and time trends of inner exposures--Results of the Duisburg birth cohort and Bochum cohort studies.
abstract: BACKGROUND
  Perfluoroalkyl acids (PFAAs) are widely distributed in the environment and humans are globally exposed with them. Contaminated drinking water can considerably contribute to the inner exposure levels.
  
  
  OBJECTIVE
  We report the results of a human biomonitoring study with mother-child pairs living in two German cities, one city with PFAA contaminated drinking water in the sub μg/l-range (Bochum) and the other one without contamination (Duisburg). Furthermore, we studied time trends of exposure levels within the Duisburg cohort study.
  
  
  METHODS
  We measured seven PFAAs (PFOS, PFOA, PFHxS, PFNA, PFBS, PFDeA, PFDoA) in blood samples by high performance liquid chromatography and tandem mass spectrometry. Samples were taken during pregnancy, from umbilical cord blood (2000-2002), 6-7 years (5th follow-up) and 8-10 years after birth (7th follow-up). The consumption of drinking water was recorded by a standardized questionnaire. Statistical analyses were calculated with multiple linear regression models.
  
  
  RESULTS
  Children and mothers from Bochum showed higher PFOS and PFOA plasma concentrations than from Duisburg. The median concentrations (μg/l) for children were: PFOS 4.7 vs. 3.3; PFOA 6.0 vs. 3.6μg/l (p≤0.05). Consumption of >0.7 l (children) and >0.9 l (mothers) drinking water/day was associated with 13-18% higher PFOS, PFOA and PFHxS concentrations in children (p≤0.01), and 22% higher PFOA in mothers (p≤0.05). Within the Duisburg cohort, PFAA levels in children peaked in the 5th follow-up study (medians (μg/l): cord plasma: 2.7 (PFOS); 1.9 (PFOA); 5th follow-up: 3.6 (PFOS); 4.6 (PFOA); 7th follow-up: 3.3 (PFOS); 3.6 (PFOA)). PFOS concentrations in mothers declined from pregnancy to the 5th follow-up (medians: 8.7 vs. 4.0μg/l).
  
  
  CONCLUSIONS
  Residents exposed to PFOS and PFOA through drinking water showed significantly higher PFOS and PFOA concentrations in blood plasma. Although PFAA concentrations in the children slightly decreased from the 5th to the 7th follow-up, we detected increasing exposure trends with increasing age in the 7th follow-up.
authors.affiliation: Department of Hygiene, Social and Environmental Medicine, Ruhr University Bochum, Universitätsstr. 150, 44 801 Bochum, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Wilhelm
authors.affiliation: Department of Hygiene, Social and Environmental Medicine, Ruhr University Bochum, Universitätsstr. 150, 44 801 Bochum, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Wittsiepe
authors.affiliation: Department of Chemical Safety and Toxicology/Biomonitoring, Bavarian Health and Food Safety Authority, Pfarrstr. 3, 80 538 Munich, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Völkel
authors.affiliation: Department of Chemical Safety and Toxicology/Biomonitoring, Bavarian Health and Food Safety Authority, Pfarrstr. 3, 80 538 Munich, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Fromme
authors.affiliation: Department of Hygiene, Social and Environmental Medicine, Ruhr University Bochum, Universitätsstr. 150, 44 801 Bochum, Germany. Electronic address: kasper-sonnenberg@hygiene.rub.de.
authors.forename: Monika
authors.initials: M
authors.lastname: Kasper-Sonnenberg
mesh_terms: D000328:Adult; D017738:Alkanesulfonic Acids / Q000097:blood*; D002210:Caprylates / Q000097:blood*; D015331:Cohort Studies; D004326:Drinking; D060766:Drinking Water / Q000737:chemistry*; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D005466:Fluorocarbons / Q000097:blood*; D005858:Germany; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000097:blood*; D008297:Male; D018811:Maternal Exposure / Q000706:statistics & numerical data; D011247:Pregnancy; D014874:Water Pollutants, Chemical / Q000097:blood*; D014881:Water Supply
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D060766:Drinking Water; D005466:Fluorocarbons; D006845:Hydrocarbons, Fluorinated; D014874:Water Pollutants, Chemical; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid
keywords: Cohort studies; Drinking water; Human biomonitoring; Mother–child pairs; Perfluoroalkyl acids (PFAAs)