Department of Zoology, Center for Fisheries, Aquaculture, and Aquatic Sciences, Southern Illinois University Carbondale, 1125 Lincoln Drive, Carbondale, IL, 62901, USA.
Biology and Environmental Studies, Alma College, Alma, MI, 48801, USA.
Arch Environ Contam Toxicol. 2018 Apr;74(3):361-371. doi: 10.1007/s00244-017-0418-5. Epub 2017 Jun 10.
Current methods for evaluating exposure in ecosystems contaminated with hydrophobic organic contaminants typically focus on sediment exposure. However, a comprehensive environmental assessment requires a more holistic approach that not only estimates sediment concentrations, but also accounts for exposure by quantifying other pathways, such as bioavailability, bioaccumulation, trophic transfer potential, and transport of hydrophobic organic contaminants within and outside of the aquatic system. The current study evaluated the ability of multiple metrics to estimate exposure in an aquatic ecosystem. This study utilized a small lake contaminated with polychlorinated biphenyls (PCBs) to evaluate exposure to multiple trophic levels as well as the transport of these contaminants within and outside of the lake. The PCBs were localized to sediments in one area of the lake, yet this area served as the source of PCBs to aquatic invertebrates, emerging insects, and fish and terrestrial spiders in the riparian ecosystem. The Tenax extractable and biota PCB concentrations indicated tissue concentrations were localized to benthic invertebrates and riparian spiders in a specific cove. Fish data, however, demonstrated that fish throughout the lake had PCB tissue concentrations, leading to wider exposure risk. The inclusion of PCB exposure measures at several trophic levels provided multiple lines of evidence to the scope of exposure through the aquatic and riparian food web, which aids in assessing risk and developing potential future remediation strategies.
当前评估受疏水性有机污染物污染的生态系统中暴露情况的方法通常侧重于沉积物暴露。然而，全面的环境评估需要更全面的方法，不仅要估计沉积物浓度，还要通过量化其他途径（如生物利用度、生物积累、营养转移潜力以及水生系统内外疏水性有机污染物的迁移）来评估暴露情况。本研究评估了多种指标评估水生生态系统中暴露情况的能力。本研究利用一个受到多氯联苯（PCBs）污染的小湖，评估了多个营养级别的暴露情况，以及这些污染物在湖泊内外的迁移情况。PCBs 在湖泊的一个区域集中在沉积物中，但该区域成为水生无脊椎动物、新出现的昆虫以及湖岸生态系统中的鱼类和陆生蜘蛛的 PCBs 来源。Tenax 可提取和生物 PCB 浓度表明组织浓度集中在特定海湾的底栖无脊椎动物和湖岸蜘蛛中。然而，鱼类数据表明，整个湖泊中的鱼类都有 PCB 组织浓度，导致暴露风险更大。在几个营养级别的 PCB 暴露措施的纳入提供了通过水生和湖岸食物网暴露范围的多条证据，这有助于评估风险和制定潜在的未来修复策略。
