title: Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.
abstract: Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta, Canada , T6G 2H1.
authors.forename: William
authors.initials: W
authors.lastname: Shotyk
authors.affiliation: Department of the Sciences of Agriculture, Food and Environment, University of Foggia , 71122, Foggia, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Zaccone
authors.affiliation: Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta, Canada , T6G 2H1.
authors.forename: Tommy
authors.initials: T
authors.lastname: Noernberg
authors.affiliation: Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta, Canada , T6G 2H1.
authors.forename: Rick
authors.initials: R
authors.lastname: Pelletier
authors.affiliation: Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta, Canada , T6G 2H1.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Bicalho
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta , Edmonton, Alberta, Canada , T6G 2E3.
authors.forename: Duane G
authors.initials: DG
authors.lastname: Froese
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta , Edmonton, Alberta, Canada , T6G 2E3.
authors.forename: Lauren
authors.initials: L
authors.lastname: Davies
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D002170:Canada; D003077:Coke / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006838:Hydrocarbons; D008906:Mining; D061329:Oil and Gas Fields; D010578:Petroleum / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011446:Prospective Studies; D012914:Snow / Q000737:chemistry; D012987:Soil; D044003:Sphagnopsida; D053833:Wetlands
chemical_list: D000393:Air Pollutants; D003077:Coke; D004391:Dust; D006838:Hydrocarbons; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; C006647:asphalt