Hexabromocyclododecanes in breast milk from residents in Shenzhen, China: Implications for infant exposure.

Hexabromocyclododecanes (HBCDs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmentalmedia. However, little is known about HBCD exposure for humans, especially in China. This study aimed to investigate the levels and profiles of hexabromocyclododecanes (HBCDs) in human breast milk and to estimate the daily HBCD intake for infants in Shenzhen, China. Levels of the HBCD diastereoisomers alpha-, beta-, and gamma-HBCD in 180 breast milk samples collected fromprimiparas in Shenzhenwere measured. The concentrations of alpha-, beta-, and gamma-HBCD (Sigma HBCDs) rangedwithin 0.103-15.1 ng/g lipid and had a median of 1.82 ng/g lipid. SHBCDs levels inmilk in the present study are comparable to those in milk fromother countries and regions but are markedly higher than those for most populations in other regions of China. Among the diastereoisomers, alpha-HBCD was predominant, accounting for 97.6% of the concentration of Sigma HBCDs. The estimated daily intake of SHBCDs via breast milk for infants in Shenzhen ranged from 0.481 to 100 ng/kg bw/daywith amedian of 8.40 ng/kg bw/day, however, whichwas unlikely to raises a health concern based on the margin of exposure (MOE) approach. The duration of residence was found to have a significant positive correlation with the HBCD levels in the human breast milk (p < 0.05). To our knowledge, this is the first report on HBCD levels in breast milk from Shenzhen residents. (c) 2017 Elsevier B. V. All rights reserved.