title: Variability and exposure classification of urinary phenol and paraben metabolite concentrations in reproductive-aged women.
abstract: BACKGROUND
  Human exposure to phenols and parabens is widespread. Within-person variability of urinary concentrations in healthy women is not well characterized.
  
  
  OBJECTIVE
  To characterize the variability of urinary phenol and paraben concentrations across two months and evaluate the ability of a single spot urine sample to characterize exposure.
  
  
  METHODS
  143 women provided 509 spot urine samples collected across two months of study (3-5 samples/woman). We measured urinary concentrations of 8 phenols: bisphenol A (BPA), benzophenone-3 (BP-3), benzophenone-1 (BP-1), 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (2,4,5-TCP), 2,4,6-trichlorophenol (2,4,6-TCP), triclosan (TCS); and 8 parabens and their metabolites (benzyl (BzP), butyl (BuP), ethyl (EtP), heptyl (HeP), methyl (MeP), propyl (PrP), 4-hydroxybenzoic acid (4-HB), 3,4-dihydroxybenzoic acid (3,4-DHB)). Biomarker variability was characterized using the intraclass correlation coefficient (ICC) and surrogate category analyses were conducted.
  
  
  RESULTS
  ICCs ranged from very low for BPA (0.04) to moderate for BP-3, BP-1, TCS, BzP, and MeP (0.66, 0.58, 0.55, 0.54, and 0.62, respectively). Surrogate analyses suggested that BP-1, BP-3, TCS, 2,4-DCP, BuP, and PrP may be characterized by a single spot sample (sensitivity range 0.76-0.86) but that additional samples were necessary for BPA, HeP, 4-HB, and 3,4-DHB (sensitivity range 0.47-0.61).
  
  
  CONCLUSIONS
  Urinary phenol and paraben metabolite concentrations were variable across two months in healthy women but the degree of reliability differed by the specific biomarker. A small number of samples may sufficiently characterize typical concentrations for BP-3, BP-1, TCS, BuP, and PrP; but additional biospecimens may be necessary to characterize exposure for other compounds, including BPA.
authors: Department of Global and Community Health, College of Health and Human Services, George Mason University, Fairfax, VA 22030, USA. Electronic address: apollac2@gmu.edu.
authors: Anna Z
authors: AZ
authors: Pollack
authors: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 6100 Executive Blvd., Rockville, MD 20852, USA. Electronic address: perkinsn@mail.nih.gov.
authors: Neil J
authors: NJ
authors: Perkins
authors: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 6100 Executive Blvd., Rockville, MD 20852, USA. Electronic address: lindsey.sjaarda@nih.gov.
authors: Lindsey
authors: L
authors: Sjaarda
authors: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 6100 Executive Blvd., Rockville, MD 20852, USA. Electronic address: mumfords@mail.nih.gov.
authors: Sunni L
authors: SL
authors: Mumford
authors: Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA; Department of Environmental Health Sciences, University at Albany, School of Public Health, Empire State Plaza, P.O. Box 509, Albany, NY 12201-0509, USA. Electronic address: kurunthachalam.kannan@health.ny.gov.
authors: Kurunthachalam
authors: K
authors: Kannan
authors: Universite Grenoble Alpes, IAB, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, F-38000 Grenoble, France; INSERM, IAB, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, F-38000 Grenoble, France. Electronic address: Claire.philippat@inserm.fr.
authors: Claire
authors: C
authors: Philippat
authors: Department of Epidemiology and Environmental Health, University at Buffalo, The State University of New York, 410 Kimball Hall, Buffalo, NY 14214, USA. Electronic address: jww@buffalo.edu.
authors: Jean
authors: J
authors: Wactawski-Wende
authors: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 6100 Executive Blvd., Rockville, MD 20852, USA. Electronic address: schistee@mail.nih.gov.
authors: Enrique F
authors: EF
authors: Schisterman
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D010226:Parabens / Q000378:metabolism*; D010636:Phenols / Q000652:urine*; D055815:Young Adult
chemical_list: D010226:Parabens; D010636:Phenols
keywords: Benzophenone-3; Bisphenol A; Dichlorophenol; Intra-individual variability; Parabens; Reliability, Triclosan