Environmental Health and Preventive Medicine

, Volume 14, Issue 3, pp 180–187

Exposure assessment of phthalate esters in Japanese pregnant women by using urinary metabolite analysis

  • Yayoi Suzuki
  • Mayu Niwa
  • Jun Yoshinaga
  • Chiho Watanabe
  • Yoshifumi Mizumoto
  • Shigeko Serizawa
  • Hiroaki Shiraishi
Regular Article

Abstract

Objectives

Our objectives were (1) to evaluate whether single spot urine is suitable media for longer-term phthalate esters exposure assessment, and (2) to estimate intake level of phthalate esters of Japanese pregnant women using urinary metabolites as an indicator of prenatal exposure level in their offspring.

Methods

We analyzed nine metabolites (MMP, MEP, MnBP, MBzP, MEHP, MEOHP, MEHHP, MINP, MnOP) of seven phthalate esters in spot urine samples from 50 pregnant women by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Using four urine samples collected from each of 12 subjects from 50 pregnant women within 5–12 weeks, we compared intra- and interindividual variation in urinary metabolites by calculation of intraclass correlation coefficient (ICC). We estimated daily intakes of 50 pregnant women from their urinary metabolite concentrations.

Results

ICCs for seven phthalate metabolite concentrations in single spot urine samples were: MMP (0.57), MEP (0.47), MnBP (0.69), MBzP (0.28), MEHP (0.51), MEHHP (0.43), and MEOHP (0.41) in 12 pregnant women. Phthalate ester metabolites had high detection rates in 50 subjects. The mean daily intake ranged from 0.01 to 2 μg/kg per day. The daily intake levels in all subjects were lower than corresponding tolerable daily intake (TDI) set by the European Food Safety Authority (EFSA), though maximum value for DnBP of 6.91 μg/kg per day accounted for 70% of TDI value.

Conclusions

Higher ICCs indicated that phthalate metabolite levels in single spot urine could reflect longer-term exposure to the corresponding diesters of subjects. Although the current exposure level was less than TDIs, further studies and exposure monitoring are needed to reveal the toxicity of phthalate esters to sensitive subpopulation.

Keywords

Phthalate esters Biomarkers Urinary metabolites Intraclass correlation coefficient Daily intake 

Abbreviations

MMP

Monomethyl phthalate

MEP

Monoethyl phthalate

MnBP

Mono-n-butyl phthalate

MBzP

Monobenzyl phthalate

MEHP

Mono-2-ethylhexyl phthalate

MEHHP

Mono-(2-ethyl-5-hydroxyhexyl)phthalate

MEOHP

Mono-(2-ethyl-5-oxohexyl)phthalate

MINP

Mono-iso-nonyl phthalate

MnOP

Mono-n-octyl phthalate

MOE

The Ministry of the Environment in Japan

EFSA

European Food Safety Authority

Copyright information

© The Japanese Society for Hygiene 2009

Authors and Affiliations

  • Yayoi Suzuki
    • 1
  • Mayu Niwa
    • 1
  • Jun Yoshinaga
    • 1
  • Chiho Watanabe
    • 2
  • Yoshifumi Mizumoto
    • 3
  • Shigeko Serizawa
    • 4
  • Hiroaki Shiraishi
    • 4
  1. 1.Department of Environmental StudiesThe University of TokyoKashiwaJapan
  2. 2.Department of Human EcologyThe University of TokyoTokyoJapan
  3. 3.Department of Obstetrics and GynecologyCentral Hospital of Self-Defense ForceTokyoJapan
  4. 4.National Institute for Environmental StudiesIbarakiJapan

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