Survey on human contamination by brominated flame retardants and chlorinated/brominated dioxins for the health risk factor of mother and child

为了清除人类对Co-PXBs的暴露，研究了日本多产妇和初产妇母乳中Co-PXBs的浓度（采样第5天和第30天）。Co-PXBs的浓度范围在0.42至1.41 pg TEQ/g脂质之间，这是我们首次发现Co-PXBs暴露于人体。就母乳中TEQ的平均水平而言，多产和初产之间没有差异，而co - pcb的情况则没有差异。有趣的是，当同一名妇女在第5天和第30天的母乳样本中Co-PCBs的水平进行比较时，第5天的母乳样本高于第30天的样本，几乎所有样本都进行了分析。然而，在CO-PXBs的情况下，这种趋势并不总是被观察到。然后，Co-PXBs的丰富同系物为#126A， #126B和#169，估计该Co-PXBs #126B的人类暴露来源于食用鱼类。然后比较了四种二恶英类似物对日本母乳总TEQ浓度的贡献率。主要类似物为pcdd /DFs、Co-PCBs和Co-PXBs， pxdd /DFs可忽略不计，显示出多胞胎母乳中Co-PXBs的高贡献率。由于理论上Co-PXBs组中存在数百种同系物，因此需要对Co-PXBs污染进行进一步的详细调查，以评估哺乳婴儿接触Co-PXBs是否会造成健康风险，需要进一步的研究。为了更好地了解日本食品中Co-PXBs污染的性质和程度，有必要对日常食品中的Co-PXBs进行进一步调查。

In order to clear human exposure by Co-PXBs, it was investigated the Co-PXBs concentration in the breast milk (sampling day; 5 and 30 days) of Japanese multiparae and primiparae. The concentration of Co-PXBs ranged between 0.42 and 1.41 pg TEQ/g lipid, and this observation is our first finding for human exposure by Co-PXBs. With respect the average TEQ level in mother's milk, there is no difference between of multiparae and primiparae, not in the case of CO-PCBs. Interestingly, when the level of Co-PCBs at 5 and 30 days of same woman was compared, that at 5 days-breast milk samples were higher than that at 30days-samples for almost sample analyzed. However, in the case of CO-PXBs, such tendency was not always observed.Then, the abundant congeners of Co-PXBs were #126A, #126 B and #169, and it was estimated that human exposure by this Co-PXBs #126B is derived from the eating of fish. Then, it was compared the contribution ratio of four kinds of dioxin analogues for total TEQ concentration in mother's milk of Japan. Major analogues were PCDDs/DFs, Co-PCBs and Co-PXBs, and PXDDs/DFs were negligible level, showing unexpected high contribution ratio of Co-PXBs in the breast milk of multiparae. As there are theoretically more few hundreds congeners in the Co-PXBs group, and therefore it needs further detail survey of Co-PXBs contaminationFurther study is warranted to evaluate whether Co-PXBs exposures to nursing infants pose a health risk. Additional investigations of Co-PXBss in the daily foods are warranted to better understand the nature and extent of Co-PXBs contamination of Japanese food supply.