Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Institution of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Environ Int. 2019 Sep;130:104939. doi: 10.1016/j.envint.2019.104939. Epub 2019 Jun 25.
Currently, there is limited information about the mechanism of the human transplacental transfer for organochlorine pesticides (OCPs). This study aimed to evaluate the transplacental transfer of OCPs to better understand the influencing factors of exposure and transplacental efficiency. The study involved quantitative determination of OCPs and the enantiomer fraction (EF) of chiral OCPs in pregnant women from Wuhan, China. The results indicate that the exposure levels of OCPs varied in the order: maternal serum > cord serum > placenta. Chiral contaminants, such as α-HCH, o,p'-DDD and o,p'-DDT, were non-racemic in the three biological matrices, wherein EF < 0.5, EF < 0.5, EF > 0.5. For HCHs, the concentration ratio between cord serum and maternal serum (R) <1, while for DDXs, the R ≈ 1, indicating that the transport efficiency of different pollutants is related to the physicochemical properties. These results showed that placenta seems to be a more efficient barrier for β-HCH than for p,p'-DDE. The concentration ratios across placenta significantly lower than 1 and the enantiomeric selective transfer imply that some OCPs may have more complicated maternal-fetus transfer mechanisms, involving both simple diffusion and active transport. To the best of our knowledge, this is the first study to investigate the transfer of OCPs and their enantiomer fractions across placenta. These findings could expand the database of chemical exposure in biological matrices and improve the understanding of the mechanisms of transplacental transfer of OCPs.
目前，有关人类胎盘对有机氯农药（OCPs）的转移机制的信息有限。本研究旨在评估 OCPs 的胎盘转移，以更好地了解暴露和胎盘效率的影响因素。该研究涉及定量测定来自中国武汉的孕妇的 OCPs 和手性 OCPs 的对映体分数（EF）。结果表明，OCPs 的暴露水平顺序为：母体血清＞脐带血清＞胎盘。在这三种生物基质中，手性污染物，如α-HCH、o,p'-DDD 和 o,p'-DDT，是非对映体的，其中 EF<0.5，EF<0.5，EF>0.5。对于 HCHs，脐带血清与母体血清之间的浓度比（R）<1，而对于 DDXs，R≈1，这表明不同污染物的传输效率与物理化学性质有关。这些结果表明，胎盘对β-HCH 的传输效率似乎高于对 p,p'-DDE。胎盘跨膜浓度比显著低于 1 且对映体选择性转移表明，一些 OCPs 可能具有更复杂的母体-胎儿转移机制，涉及简单扩散和主动转运。据我们所知，这是首次研究 OCPs 及其对映体分数在胎盘内的转移。这些发现可以扩展生物基质中化学暴露的数据库，并提高对 OCPs 胎盘转移机制的理解。
