| Depuration of Polybrominated Diphenyl Ethers (PBDEs) and Polychlorinated Biphenyls (PCBs) in Breast Milk from California First-Time Mothers (Primiparae) Kim Hooper,1 Jianwen She,1 Margaret Sharp,1 Joan Chow,1 Nicholas Jewell,2 Rosanne Gephart,3 and Arthur Holden1 1Environmental Chemistry Laboratory, California Department of Toxic Substances Control, Berkeley, California, USA; 2Division of Biostatistics, School of Public Health, University of California, Berkeley, California, USA; 3Woman's Health and Birth Center, Santa Rosa, California, USA Abstract
Background: Little is known about the rates of loss (depuration) of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) from mothers during lactation. Depuration rates affect infant exposure to chemicals during breast-feeding, and fetal and lactational transfers during subsequent pregnancies. Objective: Our objective in this study was to estimate depuration rates of PBDEs and PCBs using serial samples of breast milk. Method: Nine first-time mothers (primiparae) each collected samples at 4, 6, 8, 12, 16, 20, and 24 weeks after birth. Nine additional primiparae each collected two samples at varying time intervals (18 to > 85 weeks after birth) . Analytical precision was assessed to evaluate the accuracy of measured monthly percentage declines in PBDEs and PCBs. Results: The four major PBDE congeners decreased 2 or 3% ± 1% per month over the 6-month period. These decreases were consistent over a 50-fold range (21–1,330 ng/g lipid weight) of initial PBDE concentrations in breast milk. The change in PCB-153 ranged from + 0.3% to –0.6% per month, with heterogeneous slopes and greater intraindividual variability. PBDE and PCB concentrations declined 1% per month over longer periods (up to 136 weeks) . Conclusions: Our data indicate that PBDEs and PCBs are not substantially (4–18%) reduced in primiparae after 6 months of breast-feeding. Consequently, the fetal and lactational exposures for a second child may not be markedly lower than those for the first. Participants were volunteers from a larger study population (n = 82) , and were typical in their PBDE/PCB levels and in many demographic and lifestyle factors. These similarities suggest that our results may have broader applicability. Key words: breast-feeding, breast milk, brominated flame retardants, depuration, exposure assessment, lactation, PBDEs, PCBs. Environ Health Perspect 115:1271–1275 (2007) . doi:10.1289/ehp.10166 available via http://dx.doi.org/ [Online 28 June 2007]
Address correspondence to K. Hooper, Environmental Chemistry Laboratory, 700 Heinz St., Berkeley, CA 94710 USA. Telephone: (510) 540-3499. Fax: (510) 540-2305. E-mail: khooper@dtsc.ca.gov We thank the many first-time mothers of California who participated in these studies. This study received support from Pollution Prevention grant NP979442010 from U.S. Environmental Protection Agency Region IX. Views expressed are those of the authors and not necessarily of the sponsoring agencies. The authors declare they have no competing financial interests. Received 13 February 2007 ; accepted 28 June 2007.
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