Rajala Juho Elias, Mäenpää Kimmo, Vehniäinen Eeva-Riikka, Väisänen Ari, Scott-Fordsmand Janeck James, Akkanen Jarkko, Kukkonen Jussi Vilho Kalevi
Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland.
Department of Biology, University of Eastern Finland, 80101, Joensuu, Finland.
Arch Environ Contam Toxicol. 2016 Oct;71(3):405-14. doi: 10.1007/s00244-016-0294-4. Epub 2016 Jul 12.
The increased use of silver nanoparticles (AgNP) in industrial and consumer products worldwide has resulted in their release to aquatic environments. Previous studies have mainly focused on the effects of AgNP on pelagic species, whereas few studies have assessed the risks to benthic invertebrates despite the fact that the sediments act as a large potential sink for NPs. In this study, the toxicity of sediment-associated AgNP was evaluated using the standard sediment toxicity test for chemicals provided by the Organization of Economic Cooperation and Development. The freshwater benthic oligochaete worm Lumbriculus variegatus was exposed to sediment-associated AgNP in artificial and natural sediments at concentrations ranging from 91 to 1098 mg Ag/kg sediment dry weight. Silver nitrate (AgNO3) was used as a reference compound for Ag toxicity. The measured end points of toxicity were mortality, reproduction, and total biomass. In addition, the impact of sediment-associated AgNP on the feeding rate of L. variegatus was studied in a similar test set-up as mentioned previously. The addition of AgNP into the sediment significantly affected the feeding rate and reproduction of the test species only at the highest concentration (1098 mg/kg) of Ag in the natural sediment with the lowest pH. In comparison, the addition of AgNO3 resulted in reproductive toxicity in every tested sediment, and Ag was more toxic when spiked as AgNO3 than AgNP. In general, sediments were observed to have a high capacity to eliminate the AgNP-derived toxicity. However, the capacity of sediments to eliminate the toxicity of Ag follows a different pattern when spiked as AgNP than AgNO3. The results of this study emphasize the importance of sediment-toxicity testing and the role of sediment properties when evaluating the environmental effects and behavior of AgNP in sediments.
全球范围内，银纳米颗粒（AgNP）在工业和消费品中的使用增加，导致其释放到水生环境中。以往的研究主要集中在AgNP对浮游物种的影响，而尽管沉积物是纳米颗粒的一个巨大潜在汇，但很少有研究评估其对底栖无脊椎动物的风险。在本研究中，使用经济合作与发展组织提供的化学品标准沉积物毒性试验，评估了与沉积物相关的AgNP的毒性。将淡水底栖寡毛类蠕虫颤蚓暴露于人工和天然沉积物中与沉积物相关的AgNP，浓度范围为91至1098毫克银/千克沉积物干重。硝酸银（AgNO₃）用作银毒性的参考化合物。测量的毒性终点为死亡率、繁殖率和总生物量。此外，在与上述类似的试验设置中，研究了与沉积物相关的AgNP对颤蚓摄食率的影响。仅在天然沉积物中pH值最低且银浓度最高（1098毫克/千克）时，向沉积物中添加AgNP才会显著影响受试物种的摄食率和繁殖率。相比之下，添加AgNO₃在每种受试沉积物中均导致生殖毒性，并且以AgNO₃形式添加的银比AgNP毒性更大。总体而言，观察到沉积物具有较高的消除AgNP衍生毒性的能力。然而，当以AgNP形式添加时，沉积物消除银毒性的能力与以AgNO₃形式添加时遵循不同的模式。本研究结果强调了沉积物毒性测试的重要性以及在评估沉积物中AgNP的环境影响和行为时沉积物性质的作用。
