Fuchsman Phyllis C, Barber Timothy R, Lawton Jennifer C, Leigh Katrina B
ENVIRON International, P.O. Box 405, Burton, Ohio 44021, USA.
Environ Toxicol Chem. 2006 Oct;25(10):2601-12. doi: 10.1897/05-614r.1.
Cause-effect sediment-quality benchmarks for the protection of benthic invertebrates are needed for polychlorinated biphenyls (PCBs) to support predictive risk assessments and retrospective evaluations of the causes of observed sediment toxicity. An in-depth evaluation of PCB aquatic toxicity and organic carbon partitioning was conducted to predict sediment effect concentrations using the equilibrium partitioning (EqP) approach. This evaluation was limited to invertebrate toxicity data, because PCBs may exert toxicity to invertebrates and fish via different toxicological mechanisms. As a result of differences in organic carbon partitioning among PCBs of differing levels of chlorination, the estimated EqP benchmarks increase with increasing degree of chlorination for various commercial and environmental PCB mixtures. Studies of spiked sediment toxicity using PCBs were reviewed, and their results generally were consistent with EqP predictions. Additionally, toxicity and benthic community data were reviewed for eight PCB-contaminated sites; these data also showed agreement with EqP predictions. None of these lines of evidence supports previously proposed, empirical sediment-quality guidelines for PCBs. Reasons for the lack of agreement between cause-effect and association-based benchmarks are discussed, and areas of future research to further refine EqP predictions for PCBs are identified.
为了支持对多氯联苯（PCBs）沉积物毒性原因的预测性风险评估和回顾性评估，需要制定用于保护底栖无脊椎动物的因果沉积物质量基准。利用平衡分配（EqP）方法，对多氯联苯的水生毒性和有机碳分配进行了深入评估，以预测沉积物效应浓度。该评估仅限于无脊椎动物毒性数据，因为多氯联苯可能通过不同的毒理学机制对无脊椎动物和鱼类产生毒性。由于不同氯化程度的多氯联苯在有机碳分配上存在差异，对于各种商业和环境多氯联苯混合物，估计的EqP基准随着氯化程度的增加而增加。对使用多氯联苯进行的加标沉积物毒性研究进行了综述，其结果总体上与EqP预测一致。此外，还对八个多氯联苯污染场地的毒性和底栖生物群落数据进行了综述；这些数据也与EqP预测一致。这些证据均不支持先前提出的多氯联苯经验性沉积物质量指南。讨论了因果基准与基于关联的基准之间缺乏一致性的原因，并确定了未来进一步完善多氯联苯EqP预测的研究领域。
