Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Molecular EXposomics, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany.
Department of Waters and Soil, Umweltbundesamt, Wörlitzer Platz 1, 06844, Dessau, Germany.
Environ Sci Pollut Res Int. 2018 Feb;25(5):3977-3984. doi: 10.1007/s11356-016-7558-4. Epub 2016 Sep 10.
Dioxins and dioxin-like compounds can be analyzed by bioanalytical screening methods to evaluate their biotoxicity. In vitro bioassays, based on 7-ethoxyresorufin-O-deethylase (EROD) and the activity of cytochrome P450 1A1 and the aryl hydrogen receptor (AhR) pathway, are employed for the evaluation of bioanalytical equivalents (BEQ) of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) from a wide variety of sample matrices. Here, we present the evaluation of 11 humic soil samples derived from forest stands across Germany and a comparison of the BEQ values against toxic equivalents (TEQ, PCDD/Fs+PCBs) derived by chemical analysis. BEQ values ranged from 8.8 to 34.1 while TEQ values from 13.9 to 60.5 pg/g dry weight. Additional two subsequent mineral layers were analyzed to identify the BEQ/TEQ gradient vertically, showing a TEQ decrease of 85.1 and 93.8 % from the humic to the first and second mineral layers, respectively. For BEQ values, a decrease as well as an increase was detected. BEQ measurements were performed with and without sample clean-up. Omitting clean-up revealed about 20 times increased BEQ values presumably due to non-persistent bioactive compounds not detected by chemical analysis. The results we present suggest that the EROD assay can be used for the screening of large sample quantities for the identification of samples showing dioxin and dioxin-like contaminations even at low levels, which can then be further analyzed by chemical analysis to identify the congener composition. The study also shows that EROD results give a qualitative image of the contamination. EROD seems to be interfered with cross-contaminants specifically for soils with high biological activity as forest layers.
二恶英和类二恶英化合物可以通过生物分析筛选方法进行分析，以评估其生物毒性。基于 7-乙氧基resorufin-O-去乙基酶（EROD）和细胞色素 P450 1A1 及芳基氢受体（AhR）途径的体外生物测定法，用于评估来自各种样品基质的多氯二苯并对二恶英（PCDDs）、多氯二苯并呋喃（PCDFs）和多氯联苯（PCBs）的生物分析当量（BEQ）。在这里，我们评估了来自德国各地森林的 11 个腐殖土样本，并将 BEQ 值与化学分析得出的毒性当量（TEQ，PCDD/Fs+PCBs）进行了比较。BEQ 值范围为 8.8 至 34.1，而 TEQ 值范围为 13.9 至 60.5 pg/g 干重。另外分析了两个后续的矿物质层，以确定垂直方向上的 BEQ/TEQ 梯度，显示从腐殖质到第一和第二矿物质层，TEQ 分别降低了 85.1%和 93.8%。对于 BEQ 值，检测到减少和增加。进行了 BEQ 测量，包括和不包括样品净化。不进行净化会导致 BEQ 值增加约 20 倍，这可能是由于非持久性生物活性化合物未被化学分析检测到。我们提出的结果表明，EROD 测定法可用于筛选大量样品，以识别即使在低水平下也显示出二恶英和类二恶英污染的样品，然后可以通过化学分析进一步分析，以确定同系物组成。该研究还表明，EROD 结果提供了污染的定性图像。对于具有高生物活性的森林层等土壤，EROD 似乎受到特定的交叉污染物干扰。
