title: Urine and serum biomonitoring of exposure to environmental estrogens II: Soy isoflavones and zearalenone in pregnant women.
abstract: Urine and serum biomonitoring was used to measure internal exposure to selected dietary estrogens in a cohort of 30 pregnant women. Exposure was measured over a period comprising one-half day in the field (6 h) and one day in a clinic (24 h). Biomonitoring of the dietary phytoestrogens genistein (GEN), daidzein (DDZ) and equol (EQ), as well as the mycoestrogen, zearalenone (ZEN) and its congeners, was conducted using UPLC-MS/MS. Biomonitoring revealed evidence of internal exposure to naturally occurring dietary estrogens during pregnancy. Urinary concentrations of total GEN, DDZ and EQ were similar to levels reported for general adult U.S.
  
  
  METHODS
  Measurable concentrations of total (parent and metabolites) GEN, DDZ and EQ were present in 240, 207 and 2 of 270 serum samples, respectively. Six out of 30 subjects had measurable concentrations of unconjugated GEN and/or DDZ in serum between 0.6 and 7.1 nM. Urine to serum total isoflavone ratios for GEN, DDZ and EQ were 13, 47, and 180, respectively. ZEN and its reductive metabolite, α-zearalenol (α-ZEL), were present in pregnant women (11 out of 30 subjects) as conjugates at levels near the limit of quantification. The average total urinary concentration was 0.10 μg/L for ZEN and 0.11 μg/L for α-ZEL.
authors.affiliation: Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA. Electronic address: stefanie.fleck@fda.hhs.gov.
authors.forename: Stefanie C
authors.initials: SC
authors.lastname: Fleck
authors.affiliation: Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA. Electronic address: mona.churchwell@fda.hhs.gov.
authors.forename: Mona I
authors.initials: MI
authors.lastname: Churchwell
authors.affiliation: Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA. Electronic address: daniel.doerge@fda.hhs.gov.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Doerge
authors.affiliation: Health Effects and Exposure Science, Pacific Northwest National Laboratory, Richland, WA 99352, USA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 93771, USA. Electronic address: jt@pnnl.gov.
authors.forename: Justin G
authors.initials: JG
authors.lastname: Teeguarden
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004032:Diet; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D060754:Equol / Q000032:analysis; D004967:Estrogens / Q000008:administration & dosage*; D005260:Female; D019833:Genistein / Q000032:analysis; D006801:Humans; D007529:Isoflavones / Q000032:analysis*; D048789:Phytoestrogens / Q000097:blood* / Q000652:urine*; D011247:Pregnancy; D013025:Glycine max / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods; D015025:Zearalenone / Q000032:analysis*
chemical_list: D004967:Estrogens; D007529:Isoflavones; D048789:Phytoestrogens; D060754:Equol; D015025:Zearalenone; C004742:daidzein; D019833:Genistein
keywords: Biomonitoring; Endocrine disruptors; Exposure; Pregnancy; Soy isoflavones; Zearalenone