Elucidation of environmental and human emission by PBDDs/DFs and PXDDs/DFs in Japan

多溴联苯醚（PBDEs）和四溴双酚A（TBBPA）被大量用作溴化阻燃剂（BFR），以降低计算机、家具、纺织品和汽车等广泛制造产品的火灾风险。此外，有充分证据表明，上述类似工艺或焚烧含有此类阻燃化学品的消费品会导致多溴二苯并对二恶英/呋喃（PBDD/DF）和一溴多氯二苯并对二恶英/呋喃（PXDD/DF）的形成。已发现这些化学品以及溴化阻燃剂存在于整个环境中。从食物、空气和水中摄入这些污染物被怀疑是人类的主要途径。比较了濑户内海沉积物中PCDDs/DFs、PXDDs/DFs和PBDDs/DFs的含量。几乎为PCDDs/DFs，显示PCDDs/DFs（1.3 - 13 ng/g d.w.）>PBDDs/DFs（15 - 16，000 pg/g d.w.）> PXDD/DF（1.0 - 90 pg/g d.w）。特别是在水岛县的样品中发现了极高的PBDDs /DFs污染，检测到高浓度的TeBDD/DFs、PeBDD和HxBDD的2，3，7，8-取代异构体。初产妇乳房样本中的平均TEQ浓度（20.3 pg TEQ/g脂质）是经产妇乳房样本中平均TEQ浓度（10.8 pg TEQ/g脂质）的两倍多。作为一个非常有趣的现象，人们认识到，多氯二苯并对二恶英/多氯二苯并呋喃的PXDDs/DF比率按毒性当量浓度计算在4%和46%之间。

Polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) are used in large quantities as brominated flame-retardants (BFRs) to reduce the risk of fire in a wide range of manufacture products such as computers, furnitures, textiles and automobiles. Inaddition, there is sufficient evidence that the above similar process or incineration of consumer products containing such flame-retardant chemicals results in the formation of polybrominated dibenzo-p-dioxins/furans (PBDD/DFs) and monobromo-polychlorinated dibenzo-p-dioxins/furans (PXDD/DFs). These chemicals, as well as the BFRs, have been found to occur throughout the environment. And the intake of these contaminants from food, air and water is suspected to be the primary route of human. The levels of PCDDs/DFs, PXDDs/DFs and PBDDs/DFs in the sediments from Setouchi-Sea were compared. Almost was PCDDs/DFs, showing the levels of PCDDs/DFs (1.3 - 13 ng/gd.w)>PBDDs/DFs (15 - 16,000 pg/g d.w.)>PXDDs/DFs (1.0 - 90 pg/g d.w ). Especially, extreme high pollution by PBDDs /DFs was observed in the sample of Mizushima, and high concentrations of TeBDD/DF, PeBDD and HxBDD as 2,3,7,8-substituted isomer were detected.The TEQ levels of PCDDs/DFs, PXDDs/DFs and PBDDs/DFs in the mixed breast milk, cow's milk and powdered milk were investigated. Average TEQ concentration (20.3 pg TEQ/g lipid) in breast samples from primiparae was over two-fold against that (10.8 pg TEQ/g lipid) from multiparae. As an extremely interesting phenomenon, it was recognized that the ratio of PXDDs/DF for PCDDs/DFs calculated as TEQ concentration ranged between 4 and 46 %.