Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt.
Environ Int. 2011 Feb;37(2):443-8. doi: 10.1016/j.envint.2010.11.008. Epub 2010 Dec 17.
Tetrabromobisphenol-A (TBBP-A), hexabromocyclododecane (HBCD) and its degradation products were determined in 34 human milk samples from Birmingham, UK. TBBP-A was detected in 36% of samples (average=0.06 ng g(-1) lw), with HBCDs detected in all samples (average ΣHBCDs=5.95 ng g(-1) lw). α-HBCD comprised 62-95% ΣHBCDs while β- and γ-HBCD constituted 2-18% and 3-33% respectively. Enantioselective enrichment of (-)-α-HBCD (average enantiomer fraction=0.29) was observed indicating potential enantioselectivity associated with HBCD absorption, metabolism and/or excretion. The degradation products pentabromocyclododecenes (average=0.04 ng g(-1) lw; n=9) and tetrabromocyclododecadienes (average=0.15 ng g(-1) lw; n=25) were detected for the first time in human tissues. Average exposures of a nursing infant to ΣHBCDs and TBBP-A (35 and 1 ng kg(-1) bw day(-1) respectively) via breast milk exceeded upper-bound dietary intakes of both UK adults and toddlers. Using a simple pharmacokinetic model, intakes of UK adults via inhalation, diet and dust ingestion were converted to predicted body burdens. Predictions compared well with those observed for HBCDs but observed body burdens of TBBP-A exceeded predictions. This may indicate the human half-life of TBBP-A is greater than observed previously, that intakes may be underestimated, or that concentrations reported here reflect recent elevated episodic exposure.
四溴双酚 A（TBBP-A）、六溴环十二烷（HBCD）及其降解产物在英国伯明翰的 34 个人乳样本中进行了测定。在 36%的样本中检测到 TBBP-A（平均含量为 0.06ng/g lw），所有样本中均检测到 HBCDs（ΣHBCDs 的平均含量为 5.95ng/g lw）。α-HBCD 占 ΣHBCDs 的 62-95%，而 β-HBCD 和 γ-HBCD 分别占 2-18%和 3-33%。（-）-α-HBCD 的对映体选择性富集（平均对映体分数=0.29）表明 HBCD 吸收、代谢和/或排泄可能存在对映体选择性。五溴环十二烯（平均含量=0.04ng/g lw；n=9）和四溴环十二二烯（平均含量=0.15ng/g lw；n=25）的降解产物首次在人体组织中检测到。通过母乳，哺乳期婴儿对 ΣHBCDs 和 TBBP-A 的平均暴露量（分别为 35 和 1ng/kg bw/day）超过了英国成年人和幼儿的饮食摄入上限。使用简单的药代动力学模型，将 UK 成年人通过吸入、饮食和灰尘摄入的摄入量转换为预测的体内负荷。预测值与 HBCDs 的观察值非常吻合，但 TBBP-A 的观察到的体内负荷值超过了预测值。这可能表明 TBBP-A 的人体半衰期比之前观察到的要长，或者摄入量可能被低估，或者这里报告的浓度反映了最近的突发性暴露。
