title: Chemical and toxicological characterizations of hydraulic fracturing flowback and produced water.
abstract: Hydraulic fracturing (HF) has emerged as a major method of unconventional oil and gas recovery. The toxicity of hydraulic fracturing flowback and produced water (HF-FPW) has not been previously reported and is complicated by the combined complexity of organic and inorganic constituents in HF fluids and deep formation water. In this study, we characterized the solids, salts, and organic signatures in an HF-FPW sample from the Duvernay Formation, Alberta, Canada. Untargeted HPLC-Orbitrap revealed numerous unknown dissolved polar organics. Among the most prominent peaks, a substituted tri-phenyl phosphate was identified which is likely an oxidation product of a common polymer antioxidant. Acute toxicity of zebrafish embryo was attributable to high salinity and organic contaminants in HF-FPW with LC50 values ranging from 0.6% to 3.9%, depending on the HF-FPW fractions and embryo developmental stages. Induction of ethoxyresorufin-O-deethylase (EROD) activity was detected, due in part to polycyclic aromatic hydrocarbons (PAHs), and suspended solids might have a synergistic effect on EROD induction. This study demonstrates that toxicological profiling of real HF-FPW sample presents great challenges for assessing the potential risks and impacts posed by HF-FPW spills.
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada.
authors.forename: Yuhe
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada.
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Flynn
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Folkerts
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada.
authors.forename: Dongliang
authors.initials: D
authors.lastname: Ruan
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Alessi
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada.
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, T6G 2E9 Alberta, Canada. Electronic address: greg.goss@ualberta.ca.
authors.forename: Greg G
authors.initials: GG
authors.lastname: Goss
mesh_terms: D019363:Cytochrome P-450 CYP1A1; D000067071:Hydraulic Fracking; D062065:Wastewater / Q000737:chemistry*; D014867:Water; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D019363:Cytochrome P-450 CYP1A1; D062065:Wastewater; D014867:Water; D014874:Water Pollutants, Chemical
keywords: Aquatic toxicity; Aryl phosphate esters; Hydraulic fracturing flowback and produced water (HF-FPW); PAH; Synergistic effect