Toxicokinetics and bioaccumulation of polycyclic aromatic compounds in wood frog tadpoles (Lithobates sylvaticus) exposed to Athabasca oil sands sediment

• Published in: Aquatic toxicology 2019-02, Vol.207, p.217-225
• Main Authors: Bilodeau, J.C., Gutierrez Villagomez, J.M., Kimpe, L.E., Thomas, P.J., Pauli, B.D., Trudeau, V.L., Blais, J.M.
• Format: Article
• Language: English
• Subjects: Alberta; Alkylation; Amphibian larvae; Animals; Environmental Monitoring; Geologic Sediments - chemistry; Larva - metabolism; Oil and Gas Fields; Oil sands sediment; Polycyclic aromatic compounds; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - toxicity; Ranidae - metabolism; Toxicokinetics; Uptake and elimination; Water Pollutants, Chemical - toxicity
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2018.11.006

•We determined the toxicokinetic parameters for PAC accumulation in tadpoles.•Sediment is a major source of PACs to tadpoles.•Alkyl PACs were 10x higher than parent PACs in tadpoles exposed to MacKay River sediment. We performed accumulation-elimination experiments of polycyclic aromatic compounds (PACs) in wood frog tadpoles (Lithobates sylvaticus) using river sediment from Canada’s Athabasca oil sands region. The PACs in wood frog tadpoles were ∼2x higher on average when the animals were in direct contact with PAC-contaminated sediment than when they were separated from the sediment with a screen and exposed only to aqueous PACs. These results suggest that sediment exposure/ingestion contributes as much to PAC accumulation in tadpoles as exposure via aqueous pathways. Alkyl-substituted PAC concentrations in exposed tadpoles exceeded those of the unsubstituted (parent) PACs by about 10 × . Bioaccumulation factors ranged between 0.01 and 4.93, with parent PACs having higher bioaccumulation factors than alkylated PACs. Wood frog tadpoles efficiently eliminated and metabolized most parent and alkyl-substituted PACs, though some compounds (e.g., C4-naphthalenes) had higher bioaccumulation potential and may serve as effective markers of exposure. Here we present a comprehensive analysis of the toxicokinetics and bioaccumulation of PACs (52 analytes) in amphibian larvae, and highlight the importance of sediment exposure when considering the bioaccumulation and potential biological impact of PACs in benthic and epibenthic organisms.