Integrated analysis of petroleum biomarkers and polycyclic aromatic compounds in lake sediment cores from an oil sands region * Alexandre P.J. Salat a , David C. Eickmeyer a , Linda E. Kimpe a , Roland I. Hall b , Brent B. Wolfe c , Lukas J. Mundy d , Vance L. Trudeau a , Jules M. Blais a, * a University of Ottawa, Ottawa, ON, Canada b Department of Biology, University of Waterloo, Waterloo, ON, Canada c Department of Geography and Environmental Studies, Wilfrid Laurier University, Waterloo, Ontario, Canada d Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada article info Article history: Received 22 July 2020 Received in revised form 5 November 2020 Accepted 9 November 2020 Available online xxx Keywords: Oil sands monitoring Paleolimnology Peace-Athabasca Delta Embarras Breakthrough Bitumen abstract We examined polycyclic aromatic compounds (PACs) and petroleum biomarkers (steranes, hopanes, and terpanes) in radiometrically-dated lake sediment cores from the Athabasca oil sands region (AOSR) and the Peace-Athabasca Delta (PAD) region in Alberta (Canada) to determine whether contributions from petroleum hydrocarbons have changed over time. Two floodplain lakes in the PAD (PAD 30, PAD 31) recorded increased flux of alkylated PACs and increased petrogenic (petroleum-derived) hydrocarbons after ~1980, coincident with a decline of sediment organic carbon content and a rise of bulk sedimen- tation rate, likely due to increased Athabasca River flow. A large expansion of upstream oilsands mining, upgrading, and refining may also have contributed to the observed shift to more petrogenic hydrocar- bons to sediments since the 1980s. Alkylated PAC flux increased in the floodplain lake analyzed within the AOSR (Saline Lake) since the 1970se1980s, coincident with a sharp rise in sediment organic carbon content and increased contributions of petrogenic hydrocarbons. These changes identify increased supply of petrogenic PACs occurred as Athabasca River floodwaters waned, and may implicate aerial contributions of petrogenic hydrocarbons from oilsands activity. PACs and petroleum biomarkers (ster- anes, hopanes, and terpanes) in sediment cores from Saline Lake, PAD 30 and PAD 31 revealed a pre- dominance of petrogenic hydrocarbons in these lakes. In contrast, we recorded minimal petrogenic hydrocarbons in the reference lakes outside the surface minable area of the AOSR and PAD (Mariana Lake and BM11), though we noted slight increases in petrogenic contributions to modern (2010e2016) sed- iments. We show how a combined analysis of PACs and petroleum biomarkers in sediments is useful to quantify petrogenic contributions to lakes with added confidence and highlight the potential for pe- troleum biomarkers in lake sediment cores as a novel and effective method to track petroleum hydro- carbons in lake sediment. © 2020 Published by Elsevier Ltd. Credit author statement Salat Alexandre: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Data curation, Writing e original draft, Visualization. Eickmeyer David: Methodology, Soft- ware, Validation, Formal analysis, Resources, Writing e review & editing. Kimpe Linda: Methodology, Software, Validation, Resources, Project administration. Hall Roland: Resources, Writing e review & editing. Wolfe Brent: Resources, Writing e review & editing. Mundy Lukas: Conceptualization, Resources, Writing e review & editing, Funding acquisition. Trudeau Vance: Writing e review & editing, Funding acquisition. Blais Jules: Conceptualiza- tion, Methodology, Validation, Investigation, Resources, Writing e review & editing, Visualization, Supervision, Project administra- tion, Funding acquisition. 1. Introduction The Athabasca Oil Sands Region (AOSR), one of three distinct * This paper has been recommended for acceptance by Admir C. Targino. * Corresponding author. University of Ottawa, Department of Biology, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada. E-mail address: jules.blais@uottawa.ca (J.M. Blais). Contents lists available at ScienceDirect Environmental Pollution journal homepage: www.elsevier.com/locate/envpol https://doi.org/10.1016/j.envpol.2020.116060 0269-7491/© 2020 Published by Elsevier Ltd. Environmental Pollution xxx (xxxx) xxx Please cite this article as: A.P.J. Salat, D.C. Eickmeyer, L.E. Kimpe et al., Integrated analysis of petroleum biomarkers and polycyclic aromatic compounds in lake sediment cores from an oil sands region, Environmental Pollution, https://doi.org/10.1016/j.envpol.2020.116060