Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
Environ Sci Pollut Res Int. 2023 Sep;30(44):99735-99747. doi: 10.1007/s11356-023-29304-z. Epub 2023 Aug 24.
Indoor dust is the main source of human exposure to brominated flame retardants (BFRs). In this study, in vitro colon-extended physiologically-based extraction test (CE-PBET) with Tenax as a sorptive sink was applied to evaluate the oral bioaccessibility of twenty-two polybrominated diphenyl ethers (PBDEs) and seven novel BFRs (NBFRs) via indoor dust ingestion. The mean bioaccessibilities of two NBFRs pentabromotoluene (PBT) and 1,2-Bis(2,4,6-tribromophenoxy) ethane (BTBPE) were first proposed, reaching 36.0% and 26.7%, respectively. In order to maintain homeostasis of the gastrointestinal tract, 0.4 g Tenax was added in CE-PEBT, which increased BFRs bioaccessibility by up to a factor of 1.4-1.9. The highest bioaccessibility of legacy PBDEs was tri-BDEs (73.3%), while 2-ethylhexyl-tetrabromo-benzoate (EHTBB), one of penta-BDE alternatives, showed the highest (62.2%) among NBFRs. The influence of food nutrients, liquid to solid (L/S) ratio, and octanol-water partition coefficient (K) on bioaccessibility was assessed. The oral bioaccessibility of BFRs increased with existence of protein or carbohydrate while lipid did the opposite. The bioaccessibilities of PBDEs and NBFRs were relatively higher with 200:1 L/S ratio. PBDEs bioaccessibility generally decreased with increasing LogK. No significant correlation was observed between NBFRs bioaccessibility and LogK. This study comprehensively evaluated the bioaccessibilities of legacy and emerging BFRs via dust ingestion using Tenax-assisted CE-PBET, and highlighted the significance to fully consider potential influencing factors on BFRs bioaccessibility in further human exposure estimation.
室内灰尘是人类接触溴系阻燃剂（BFRs）的主要来源。本研究采用 Tenax 作为吸附阱的体外结肠延长生理基础提取测试（CE-PBET），通过室内灰尘摄入评估了 22 种多溴二苯醚（PBDEs）和 7 种新型 BFRs（NBFRs）的口服生物可利用性。首次提出了两种 NBFRs 五溴甲苯（PBT）和 1,2-双（2,4,6-三溴苯氧基）乙烷（BTBPE）的平均生物可利用度，分别达到 36.0%和 26.7%。为了维持胃肠道的体内平衡，在 CE-PEBT 中添加了 0.4 g Tenax，使 BFRs 的生物可利用度提高了 1.4-1.9 倍。传统 PBDEs 的最高生物可利用度为三溴二苯醚（73.3%），而五溴二苯醚替代品之一的 2-乙基己基四溴邻苯二甲酸酯（EHTBB）在 NBFRs 中表现出最高（62.2%）的生物可利用度。评估了食物营养素、液固比（L/S）和辛醇-水分配系数（K）对生物可利用性的影响。BFRs 的口服生物可利用性随着蛋白质或碳水化合物的存在而增加，而脂质则相反。200:1 的 L/S 比时，PBDEs 和 NBFRs 的生物可利用性相对较高。随着 LogK 的增加，PBDEs 的生物可利用性通常会降低。NBFRs 的生物可利用性与 LogK 之间没有观察到显著相关性。本研究采用 Tenax 辅助 CE-PBET 通过灰尘摄入全面评估了传统和新兴 BFRs 的生物可利用性，并强调在进一步的人类暴露评估中充分考虑 BFRs 生物可利用性的潜在影响因素的重要性。
