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.

我们进行了木蛙t（Lithobates sylvaticus）中多环芳族化合物（PAC）的累积消除实验）利用加拿大阿萨巴斯卡油砂地区的河流沉积物。当动物直接与被PAC污染的沉积物直接接触时，与通过筛网与沉积物分离并仅暴露于含水PAC的情况相比，木蛙t中的PAC平均高出约2倍。这些结果表明，沉积物的暴露/摄入对t中PAC积累的贡献与通过水途径的暴露一样多。暴露的t中烷基取代的PAC的浓度比未取代的（母体）PAC的浓度高约10倍。生物蓄积系数在0.01到4.93之间，母体PAC具有比烷基化PAC高的生物蓄积系数。尽管有些化合物（例如，C4-萘）具有更高的生物蓄积潜力，可以作为有效的暴露指标。在这里，我们对两栖类幼虫中PAC（52种分析物）的毒代动力学和生物蓄积性进行了全面分析，并着重考虑了PAC在底栖生物和表皮生物中的生物蓄积性和潜在生物影响时暴露沉积物的重要性。