| Concentrations of Phthalate Metabolites in Milk, Urine, Saliva, and Serum of Lactating North Carolina Women Erin P. Hines,1 Antonia M. Calafat,2 Manori J. Silva,2 Pauline Mendola,3 and Suzanne E. Fenton1 1 Reproductive Toxicology Division, Developmental Biology Branch, Office of Research and Development, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA; 2 Division of Laboratory Science, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA; 3 Infant, Child, and Women’s Health Statistics, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics, Hyattsville, Maryland, USA Abstract
Background: Phthalates are ubiquitous in the environment, but concentrations in multiple media from breast-feeding U.S. women have not been evaluated. Objectives: The objective of this study was to accurately measure and compare the concentrations of oxidative monoester phthalate metabolites in milk and surrogate fluids (serum, saliva, and urine) of 33 lactating North Carolina women. Methods: We analyzed serum, saliva, urine, and milk for the oxidative phthalate metabolites mono(3-carboxypropyl) phthalate, mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) , mono(2-ethyl-5-hydroxyhexyl) phthalate, and mono(2-ethyl-5-oxohexyl) phthalate using isotope-dilution high-performance liquid chromatography tandem mass spectroscopy. Because only urine lacks esterases, we analyzed it for the hydrolytic phthalate monoesters. Results: We detected phthalate metabolites in few milk (< 10%) and saliva samples. MECPP was detected in > 80% of serum samples, but other metabolites were less common (3–22%) . Seven of the 10 urinary metabolites were detectable in ≥ 85% of samples. Monoethyl phthalate had the highest mean concentration in urine. Metabolite concentrations differed by body fluid (urine > serum > milk and saliva) . Questionnaire data suggest that frequent nail polish use, immunoglobulin A, and fasting serum glucose and triglyceride levels were increased among women with higher concentrations of urinary and/or serum phthalate metabolites ; motor vehicle age was inversely correlated with certain urinary phthalate concentrations. Conclusions: Our data suggest that phthalate metabolites are most frequently detected in urine of lactating women and are less often detected in serum, milk, or saliva. Urinary phthalate concentrations reflect maternal exposure and do not represent the concentrations of oxidative metabolites in other body fluids, especially milk. Key words: biomonitoring, breast milk, lactation, MAMA study, phthalates, saliva, serum, urine. Environ Health Perspect 117:86–92 (2009) . doi:10.1289/ehp.11610 available via http://dx.doi.org/ [Online 22 August 2008]
Address correspondence S.E. Fenton, U.S. Environmental Protection Agency, ORD/NHEERL, 2525 Hwy 54, MD-67, Reproductive Toxicology Division, Research Triangle Park, NC 27711 USA. Telephone: (919) 541-5220. Fax: (919) 541-4017. E-mail: fenton.suzanne@epa.gov We thank J. Reidy, E. Samandar, R. Wang, and J. Preau for technical assistance. We also thank the Westat, Inc. recruiting staff (A. Ware, B. Bradford, and B. Karasek) , and the U.S. EPA nursing staff (D. Levin, M.A. Bassett, and T. Montilla) . And we thank the participants in the Methods Advancement for Milk Analysis study, without whom none of this would be possible. This project received partial extramural funding through the recommendation of the National Children’s Study Intra-agency Coordinating Committee. The research described in this article has been reviewed by the National Health and Environmental Effects Research Laboratory, U.S. Environmetal Protection Agency (EPA) , and the Centers for Disease Control and Prevention and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the U.S. EPA, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Also, the findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. The authors declare they have no competing financial interests. Received 23 April 2008 ; accepted 22 August 2008.
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