Office of Research & Development, U.S. EPA, Gulf Breeze, FL 32561, USA.
Office of Research & Development, U.S. EPA, Gulf Breeze, FL 32561, USA.
Mar Pollut Bull. 2021 Feb;163:111941. doi: 10.1016/j.marpolbul.2020.111941. Epub 2020 Dec 18.
To address knowledge gaps and the lack of benchmarks on the toxicity of dilbit oiled sediments, weathered Cold Lake Blend (CLB) and Western Canadian Select (WCS) were assessed in 10-day sediment tests with the amphipods Hyalella azteca and Leptocheirus plumulosus. Lowest observed effect concentrations (LOECs) and 20% effect levels (EC20s) were determined for wet weight sediment concentrations of TPH and total PAHs normalized to 1% organic carbon. LOECs and EC20s for TPH ranged from 216 to 1165 mg/kg sediment in H. azteca, and from 64 to 75 mg/kg sediment in L. plumulosus. Dilbit LOECs and EC20s for total PAHs ranged from 2.9 to 11.8 mg/kg sediment in H. azteca, and from 0.75 to 0.87 mg/kg in L. plumulosus. Comparison of toxicity-based benchmarks derived from the current study to sediment concentrations from past spills indicate that dilbit spills in aquatic habitats may pose substantial risks to freshwater and estuarine benthic organisms.
为了弥补关于稀释沥青污染沉积物毒性方面的知识空白和缺乏基准数据的问题，我们用 10 天的沉积物测试来评估风化后的冷湖混合油（CLB）和西部加拿大精选油（WCS），使用的指示生物是食泥蚤属的霍氏泥蚤（Hyalella azteca）和罗氏沼虾属的罗氏沼虾（Leptocheirus plumulosus）。我们确定了用总石油烃（TPH）和总多环芳烃（PAHs）归一化到 1%有机碳的湿重沉积物浓度表示的最低观察效应浓度（LOEC）和 20%效应浓度（EC20）。在霍氏泥蚤中，TPH 的 LOEC 和 EC20 范围为 216 至 1165 毫克/千克沉积物，在罗氏沼虾中为 64 至 75 毫克/千克沉积物。在霍氏泥蚤中，稀释沥青的总多环芳烃的 LOEC 和 EC20 范围为 2.9 至 11.8 毫克/千克沉积物，在罗氏沼虾中为 0.75 至 0.87 毫克/千克沉积物。将当前研究中基于毒性的基准数据与过去溢油事件中的沉积物浓度进行比较表明，在水生栖息地中发生的稀释沥青溢油事件可能会对淡水和河口底栖生物构成重大风险。
