Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis Oregon, USA.
Environ Toxicol Chem. 2017 Sep;36(9):2290-2298. doi: 10.1002/etc.3802. Epub 2017 Apr 17.
Using effects-directed analysis, we investigated associations previously observed between polycyclic aromatic hydrocarbons (PAHs) and embryotoxicity in field-deployed low-density polyethylene (LDPE). We conducted effects-directed analysis using a zebrafish embryo assay and iterative fractionation of extracts of LDPE that were deployed in the Portland Harbor superfund megasite, Oregon (USA). Whole extracts induced toxicity including mortality, edema, and notochord distortion at 20% effect concentration (EC20) values of approximately 100, 100, and 10 mg LDPE/mL, respectively. Through fractionation, we determined that PAHs at concentrations similar to previous research did not contribute markedly to toxicity. We also eliminated pesticides, phthalates, musks, and other substances identified in toxic fractions by testing surrogate mixtures. We identified free fatty acids as lethal components of LDPE extracts and confirmed their toxicity with authentic standards. We found chromatographic evidence that dithiocarbamates are responsible for notochord and other sublethal effects, although exact matches were not obtained. Fatty acids and dithiocarbamates were previously unrecorded components of LDPE extracts and likely contribute to the toxicity of the whole mixture. The present study demonstrates the success of effects-directed analysis in nontargeted hazard identification using the zebrafish embryo test as a self-contained battery of bioassays that allows identification of multiple chemicals with different modes of action. This is the first effects-directed analysis to combine LDPE and zebrafish, approaches that are widely applicable to identifying developmental hazards in the bioavailable fraction of hydrophobic organic compounds. Environ Toxicol Chem 2017;36:2290-2298. © 2017 SETAC.
采用效应导向分析方法，我们研究了先前在野外部署的低密度聚乙烯（LDPE）中多环芳烃（PAHs）与胚胎毒性之间观察到的关联。我们使用斑马鱼胚胎测定法和迭代分级分离方法，对在俄勒冈州波特兰港超级基金大型工地部署的 LDPE 提取物进行了效应导向分析。全提取物在 20%效应浓度（EC20）值下分别引起约 100、100 和 10mg LDPE/mL 的死亡率、水肿和脊索畸形等毒性；通过分级分离，我们发现浓度与先前研究相似的 PAHs 并未对毒性有明显贡献。我们还通过测试替代混合物，消除了在有毒馏分中鉴定出的农药、邻苯二甲酸酯、麝香和其他物质。我们确定游离脂肪酸是 LDPE 提取物的致死成分，并使用真实标准确认了其毒性。我们发现色谱证据表明，二硫代氨基甲酸盐是脊索和其他亚致死效应的原因，尽管没有获得完全匹配。脂肪酸和二硫代氨基甲酸盐是 LDPE 提取物中以前未记录的成分，可能是整个混合物毒性的原因。本研究表明，效应导向分析在使用斑马鱼胚胎测试作为一个自含生物测定试剂盒的非靶向危害识别方面取得了成功，该试剂盒允许鉴定具有不同作用模式的多种化学物质。这是首次将 LDPE 和斑马鱼结合起来的效应导向分析，这些方法广泛适用于鉴定疏水性有机化合物生物可利用部分的发育危害。Environ Toxicol Chem 2017;36:2290-2298。 © 2017 SETAC。
