Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E9 , Canada.
Department of Laboratory Medicine and Pathology , University of Alberta , Edmonton , Alberta T6G 2G3 , Canada.
Environ Sci Technol. 2018 Mar 20;52(6):3820-3830. doi: 10.1021/acs.est.7b06557. Epub 2018 Feb 8.
Hydraulic fracturing (HF) has emerged as a major recovery method of unconventional oil and gas reservoirs and concerns have been raised regarding the environmental impact of releases of Flowback and Produced Water (FPW) to aquatic ecosystems. To investigate potential effects of HF-FPW on fish embryo development, HF-FPW samples were collected from two different wells and the organic fractions were isolated from both aqueous and particle phases to eliminate the confounding effects of high salinity. Each organic extract was characterized by non-target analysis with HPLC-Orbitrap-MS, with targeted analysis for polycyclic aromatic hydrocarbons provided as markers of petroleum-affected water. The organic profiles differed between samples, including PAHs and alkyl PAHs, and major substances identified by non-target analysis included polyethylene glycols, alkyl ethoxylates, octylphenol ethoxylates, and other high molecular weight (C) ethylene oxide polymeric material. Zebrafish embryos were exposed to various concentrations of FPW organic extracts to investigate acute (7-day) and developmental toxicity in early life stages. The acute toxicity (LD) of the extracted FPW fractions ranged from 2.8× to 26× the original organic content. Each extracted FPW fraction significantly increased spinal malformation, pericardial edema, and delayed hatch in exposed embryos and altered the expression of a suite of target genes related to biotransformation, oxidative stress, and endocrine-mediation in developing zebrafish embryos. These results provide novel information on the variation of organic profiles and developmental toxicity among different sources and fractions of HF-FPWs.
水力压裂（HF）已成为非常规油气藏的主要采油方法，但人们对返排液和采出水（FPW）排放到水生生态系统对环境的影响表示担忧。为了研究 HF-FPW 对鱼类胚胎发育的潜在影响，从两口不同的井中采集了 HF-FPW 样品，并从水相和颗粒相分离出有机部分，以消除高盐度的干扰。每个有机提取物都通过 HPLC-Orbitrap-MS 进行非靶向分析进行了特征描述，并用多环芳烃作为受石油影响水的标记物进行了靶向分析。样品之间的有机图谱存在差异，包括多环芳烃和烷基多环芳烃，非靶向分析鉴定的主要物质包括聚乙二醇、烷基乙氧基化物、辛基酚乙氧基化物和其他高分子量（C）环氧乙烷聚合材料。将斑马鱼胚胎暴露于不同浓度的 FPW 有机提取物中，以研究早期生命阶段的急性（7 天）和发育毒性。提取的 FPW 馏分的急性毒性（LD）是原始有机含量的 2.8×至 26×。每个提取的 FPW 馏分均显著增加了暴露胚胎的脊柱畸形、心包水肿和孵化延迟，并改变了一系列与生物转化、氧化应激和内分泌调解相关的靶基因在发育中的斑马鱼胚胎中的表达。这些结果提供了关于不同来源和 HF-FPW 馏分之间有机图谱变化和发育毒性的新信息。
