A comprehensive, quantitative risk assessment is presented of the toxicological risks from buried Exxon Valdez subsurface oil residues (SSOR) to a subpopulation of sea otters (Enhydra lutris) at Northern Knight Island (NKI) in Prince William Sound, Alaska, as it has been asserted that this subpopulation of sea otters may be experiencing adverse effects from the SSOR. The central questions in this study are: could the risk to NKI sea otters from exposure to polycyclic aromatic hydrocarbons (PAHs) in SSOR, as characterized in 2001–2003, result in individual health effects, and, if so, could that exposure cause subpopulation-level effects? We follow the U.S. Environmental Protection Agency (USEPA) risk paradigm by: (a) identifying potential routes of exposure to PAHs from SSOR; (b) developing a quantitative simulation model of exposures using the best available scientific information; (c) developing scenarios based on calculated probabilities of sea otter exposures to SSOR; (d) simulating exposures for 500,000 modeled sea otters and extracting the 99.9% quantile most highly exposed individuals; and (e) comparing projected exposures to chronic toxicity reference values. Results indicate that, even under conservative assumptions in the model, maximum-exposed sea otters would not receive a dose of PAHs sufficient to cause any health effects; consequently, no plausible toxicological risk exists from SSOR to the sea otter subpopulation at NKI.

对从埋藏的埃克森瓦尔迪兹地下石油残留物 (SSOR) 到海獭亚群 ( Enhydra lutris )的毒理学风险进行了全面、定量的风险评估。) 在阿拉斯加威廉王子湾的北骑士岛 (NKI)，因为有人断言，这个海獭亚群可能正在经历 SSOR 的不利影响。本研究的核心问题是：在 SSOR 中暴露于多环芳烃 (PAH) 对 NKI 海獭的风险（如 2001-2003 年的特征）是否会导致个体健康影响，如果是，这种暴露是否会导致亚种群-级效果？我们通过以下方式遵循美国环境保护署 (USEPA) 风险范式：(a) 从 SSOR 中识别暴露于 PAH 的潜在途径；(b) 使用现有的最佳科学信息开发暴露的定量模拟模型；(c) 根据海獭暴露于 SSOR 的计算概率制定情景；(d) 模拟 500 次暴露，000 只海獭模型，并提取了 99.9% 分位数最高的个体；(e) 比较慢性毒性参考值的预计暴露量。结果表明，即使在模型中的保守假设下，最大暴露量的海獭也不会受到足以导致任何健康影响的多环芳烃剂量；因此，从 SSOR 到 NKI 的海獭亚群不存在合理的毒理学风险。