A new study published online on November 28, 2014 in the peer-reviewed journal Science of The Total Environment measured phthalate metabolites in breast milk of Korean mothers. Lim and colleagues stress that developing infants are highly vulnerable to the effects of endocrine disrupting chemicals (EDCs). Nevertheless, only limited information is available on phthalate exposure among breast-fed newborns. The authors therefore analyzed breast milk samples of 62 lactating mothers for six phthalate metabolites (mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), mono(2-ethyl-hexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and monoethyl phthalate (MEP). In several cases, parent compounds of these metabolites are commonly used in food packaging applications, including e.g. di-ethylhexyl phthalate (DEHP, CAS 117-81-7) and di-n-butyl phthalate (DnBP, CAS 84-74-2). The researchers found MEP in all samples, with a median concentration of 0.37 μg/l. MiBP, MnBP, and MEHP were found in 79–89% of samples, with median concentrations of 1.10, 1.70, and 2.08 μg/l, respectively. MEHHP and MEOHP were detected in only one sample. To assess the risk of infant phthalate exposure through milk ingestion, the authors assumed that the endocrine disrupting activity of phthalate monoesters is similar to that of diesters. They estimated diester exposure based on the known parent-metabolite ratios in breast milk. The estimates of median daily intakes of DEHP and metabolites for the breast-fed infant population showed that 8% exceeded a reference dose for anti-androgenicity. For DnBP and metabolites, 6% exceeded the general tolerable daily intake (TDI) value established by the European Food Safety Authority (EFSA). Since breast milk is often the infant’s only source of nourishment, efforts are needed to reduce phthalate exposure among lactating women, the authors conclude.

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Kim, S. et al. (2015). “Concentrations of phthalate metabolites in breast milk in Korea: Estimating exposure to phthalates and potential risks among breast-fed infants.Science of The Total Environment 508, 13–19 (published online November 28, 2014)