University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu, Finland.
University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu, Finland.
Sci Total Environ. 2019 Apr 20;662:88-98. doi: 10.1016/j.scitotenv.2019.01.209. Epub 2019 Jan 19.
There are several methods for studying metal-contaminated freshwater sediments, but more information is needed on which methods to include in ecological risk assessment. In this study, we compliment the traditional Sediment Quality Triad (SQT) approach - including information on chemistry, toxicity and ecological status - with studies on metal bioavailability and metal body residues in local organisms. We studied four mining-affected boreal lakes in Finland by conducting chemical analyses of sediment and water, toxicity tests (L. variegatus, V. fischeri, C. riparius, L. stagnalis), and analysis of benthic organism community structure. In addition, we studied the relationships between metal loading, toxicity, metal bioavailability, and metal body residues in the field-collected biota. Chemistry and benthic organism community structures show adverse effects in those lakes, where the metal concentrations are the highest. However, toxicity was connected to low sediment pH during the experiment, rather than to high metal concentrations. Toxicity was observed in 4 out of 6 toxicity tests including growth test with L. variegatus, bulk sediment test with V. fischeri, and the L. stagnalis toxicity test. The C. riparius test did not show toxicity. Metal body residues in biota were not high enough to induce adverse effects (0.1-4.1 mg Cu/kg fw, 0.01-0.3 mg Ni/kg fw, 2.9-26.7 mg Zn/kg fw and 0.01-0.7 mg As/kg fw). Chemical analyses, metal bioavailability assessment and benthic community structures survey revealed adverse effects in the sediments, where metal concentrations are highest (Lake SJ and Lake KS). Standard toxicity tests were not suitable for studying acid, sulfide-rich sediments and, therefore, benthic structure study and chemical analyses are believed to give more reliable results of the ecological status of these sediments.
有几种方法可以研究受金属污染的淡水沉积物，但在生态风险评估中需要更多关于应包括哪些方法的信息。在这项研究中，我们补充了传统的沉积物质量三联体（SQT）方法——包括化学、毒性和生态状况信息——并对当地生物体内金属生物利用度和金属体残留进行了研究。我们通过对沉积物和水进行化学分析、毒性测试（L. variegatus、V. fischeri、C. riparius、L. stagnalis）以及底栖生物群落结构分析，研究了芬兰受采矿影响的四个北方湖泊。此外，我们还研究了现场采集生物体内金属负荷、毒性、金属生物利用度和金属体残留之间的关系。化学和底栖生物群落结构显示，在那些金属浓度最高的湖泊中存在不利影响。然而，毒性与实验期间的低沉积物 pH 值有关，而不是与高金属浓度有关。在包括 L. variegatus 生长试验、V. fischeri 整体沉积物试验和 L. stagnalis 毒性试验在内的 6 项毒性测试中的 4 项中观察到毒性。C. riparius 测试未显示毒性。生物体内的金属体残留量不足以引起不良反应（0.1-4.1mgCu/kgfw，0.01-0.3mgNi/kgfw，2.9-26.7mgZn/kgfw 和 0.01-0.7mgAs/kgfw）。化学分析、金属生物利用度评估和底栖生物群落结构调查显示，在金属浓度最高的沉积物中（SJ 湖和 KS 湖）存在不利影响。标准毒性测试不适合研究酸性、富硫沉积物，因此，底栖结构研究和化学分析被认为可以更可靠地反映这些沉积物的生态状况。
