Hexabromocyclododecane in Human Breast Milk: Levels and Enantiomeric Patterns

Samples of human breast milk (n = 33) from A Coruña (NW of Spain) collected in 2006 and 2007 were analyzed for HBCD diastereoisomers and enantiomers. HBCD was detected in 30 out of 33 human milk samples, at concentration levels ranging between 3 and 188 ng/g lw, with a median value of 27 ng/g lw, showing higher levels than those published for other countries. Diastereoisomeric pattern shows the predominance of the γ-isomer, with low contribution of the α-isomer and the β-isomer being below the limit of quantification. However, in six samples, there is a dominance of the α-isomer versus the γ-isomer. For the first time, HBCD enantiomeric analysis was carried out in human breast milk samples, showing a selective enantiomeric enrichment in human body. As regards α-HBCD, an enrichment of (−)-enantiomer was observed. However, in the case of γ-HBCD, no clear preference for one or the other enantiomer was found. Finally, and based on the calculated HBCD concentrations in human breast milk from Spain, the daily ingestion rate of HBCD was estimated. The nursing infant dietary intake for HBCD was set at 175 ng (kg of body weight)−1 day−1.