title: Bisphenol A and phthalate metabolite urinary concentrations: Daily and across pregnancy variability.
abstract: Phthalates and bisphenol A (BPA) are high production volume and ubiquitous chemicals that are quickly metabolized in the body. Traditionally, studies have relied on single spot urine analyses to assess exposure; ignoring variability in concentrations throughout a day or over a longer period of time. We compared BPA and phthalate metabolite results from urine samples collected at five different time points. Participants (n=80) were asked to collect all voids in a 24 h period on a weekday and then again on a weekend before 20 weeks of pregnancy. During the second and third trimesters and in the postpartum period, single spot urines were collected. Variability over time in urinary concentrations was assessed using intraclass correlation coefficients (ICCs) and the sensitivity to correctly classify a single sample as high or low versus the geometric mean (GM) of all samples was calculated. We found low reproducibility and sensitivity of BPA and all phthalate metabolites throughout pregnancy and into the postpartum period but much higher reproducibility within a day. Time of day when the urine was collected was a significant predictor of specific gravity adjusted exposure levels. We concluded that, if the interest is in average exposures across pregnancy, maternal/fetal exposure estimation may be more accurate if multiple measurements, collected across the course of the entire pregnancy, rather than a single spot measure, are performed.
authors.affiliation: Health Canada, Ottawa, ON, Canada.
authors.forename: Mandy
authors.initials: M
authors.lastname: Fisher
authors.affiliation: Health Canada, Ottawa, ON, Canada.
authors.forename: Tye E
authors.initials: TE
authors.lastname: Arbuckle
authors.affiliation: The Ottawa Hospital Research Institute, Ottawa, ON, Canada.
authors.forename: Ranjeeta
authors.initials: R
authors.lastname: Mallick
authors.affiliation: Centre de toxicologie du Québec (CTQ) of the Institut national de santé publique du Québec (INSPQ), Québec, QC, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: LeBlanc
authors.affiliation: Harvard University School of Public Health, Boston, MA, USA.
authors.forename: Russ
authors.initials: R
authors.lastname: Hauser
authors.affiliation: Health Canada, Ottawa, ON, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Feeley
authors.affiliation: Health Canada, Ottawa, ON, Canada.
authors.forename: Diane
authors.initials: D
authors.lastname: Koniecki
authors.affiliation: The Ottawa Hospital Research Institute, Ottawa, ON, Canada.
authors.forename: Tim
authors.initials: T
authors.lastname: Ramsay
authors.affiliation: Centre de toxicologie du Québec (CTQ) of the Institut national de santé publique du Québec (INSPQ), Québec, QC, Canada.
authors.forename: Gilles
authors.initials: G
authors.lastname: Provencher
authors.affiliation: Centre de toxicologie du Québec (CTQ) of the Institut national de santé publique du Québec (INSPQ), Québec, QC, Canada.
authors.forename: René
authors.initials: R
authors.lastname: Bérubé
authors.affiliation: The Ottawa Hospital Research Institute, Ottawa, ON, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Walker
mesh_terms: D000293:Adolescent; D000328:Adult; D001559:Benzhydryl Compounds / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000652:urine*; D005260:Female; D006801:Humans; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D009864:Ontario; D010636:Phenols / Q000652:urine*; D010795:Phthalic Acids / Q000652:urine*; D049590:Postpartum Period / Q000652:urine; D011247:Pregnancy / Q000652:urine*; D011262:Pregnancy Trimester, Second / Q000652:urine; D011263:Pregnancy Trimester, Third / Q000652:urine; D015203:Reproducibility of Results; D055815:Young Adult; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D015415:Biomarkers; D004785:Environmental Pollutants; D010636:Phenols; D010795:Phthalic Acids; C032279:phthalic acid; C006780:bisphenol A; D000098826:Bisphenol A Compounds