Department of Civil and Environmental Engineering, Stanford University, Stanford, California, USA.
Environ Toxicol Chem. 2011 Aug;30(8):1819-26. doi: 10.1002/etc.574. Epub 2011 Jun 14.
The benthic community was analyzed to evaluate pollution-induced changes for the polychlorinated biphenyl (PCB)-contaminated site at Hunters Point (HP) relative to 30 reference sites in San Francisco Bay, California, USA. An analysis based on functional traits of feeding, reproduction, and position in the sediment shows that HP is depauperate in deposit feeders, subsurface carnivores, and species with no protective barrier. Sediment chemistry analysis shows that PCBs are the major risk drivers at HP (1,570 ppb) and that the reference sites contain very low levels of PCB contamination (9 ppb). Different feeding traits support the existence of direct pathways of exposure, which can be mechanistically linked to PCB bioaccumulation by biodynamic modeling. The model shows that the deposit feeder Neanthes arenaceodentata accumulates approximately 20 times more PCBs in its lipids than the facultative deposit feeder Macoma balthica and up to 130 times more than the filter feeder Mytilus edulis. The comparison of different exposure scenarios suggests that PCB tissue concentrations at HP are two orders of magnitude higher than at the reference sites. At full scale, in situ sorbent amendment with activated carbon may reduce PCB bioaccumulation at HP by up to 85 to 90% under favorable field and treatment conditions. The modeling framework further demonstrates that such expected remedial success corresponds to exposure conditions suggested as the cleanup goal for HP. However, concentrations remain slightly higher than at the reference sites. The present study demonstrates how the remedial success of a sorbent amendment, which lowers the PCB availability, can be compared to reference conditions and traditional cleanup goals, which are commonly based on bulk sediment concentrations.
本研究分析了底栖生物群落，以评估 Hunters Point（HP）多氯联苯（PCB）污染场地相对于美国加利福尼亚州旧金山湾 30 个参比位点的污染诱导变化。基于摄食、繁殖和在沉积物中位置的功能特征分析表明，HP 缺乏沉积物摄食者、底栖肉食动物和无保护屏障的物种。沉积物化学分析表明，PCBs 是 HP 的主要风险驱动因素（1570 ppb），而参比位点的 PCB 污染水平非常低（9 ppb）。不同的摄食特征支持存在直接暴露途径，这可以通过生物动力学建模与 PCB 生物积累的机制联系起来。该模型表明，沉积物摄食者 Neanthes arenaceodentata 在其脂质中积累的 PCBs 约比兼性沉积物摄食者 Macoma balthica 多 20 倍，比滤食者 Mytilus edulis 多 130 倍。不同暴露情景的比较表明，HP 组织中的 PCB 浓度比参比位点高两个数量级。在原位条件下，使用活性炭进行全规模的吸附剂修复，在有利的现场和处理条件下，可使 HP 中的 PCB 生物积累减少 85%至 90%。该建模框架进一步表明，这种预期的修复成功对应于 HP 的清理目标所建议的暴露条件。然而，浓度仍略高于参比位点。本研究展示了如何将降低 PCB 有效性的吸附剂修复的修复成功与参比条件和传统的清理目标进行比较，传统的清理目标通常基于沉积物的总量浓度。
