Multispecies toxicity test for silver nanoparticles to derive hazardous concentration based on species sensitivity distribution for the protection of aquatic ecosystems

With increasing concerns about the release of silver nanoparticles (AgNPs) into the environment and the risks they pose to ecological and human health, a number of studies of AgNP toxicity to aquatic organisms have been conducted. USEPA and EU JRC have published risk assessment reports for AgNPs. However, most previous studies have focused on the adverse effects of AgNPs on individual species. Hazardous concentration (HC) of AgNPs for protection of aquatic ecosystems that are based on species sensitivity distributions (SSDs) have not yet been derived because sufficient data have not been available. In this study, we conducted multispecies toxicity tests, including acute assays using eight species from five different taxonomic groups (bacteria, algae, flagellates, crustaceans and fish) and chronic assays using six species from four different taxonomic groups (algae, flagellates, crustaceans and fish). Using the results of these assays, we used a SSD approach to derive an AgNP aquatic HC₅ (Hazard concentrations at the 5% species) of 0.614 μg/L. To our knowledge, this is the first report of a proposed HC of AgNPs for the protection of aquatic ecosystems that is based on SSDs and uses chronic toxicity data.

随着人们对银纳米颗粒（silver nanoparticles, AgNPs）释放进入环境及其对生态系统与人类健康构成的风险的担忧日益加剧，学界已开展大量关于银纳米颗粒对水生生物毒性的研究。美国环境保护署（USEPA）与欧盟联合研究中心（EU JRC）已发布针对银纳米颗粒的风险评估报告。然而，既往绝大多数研究均聚焦于银纳米颗粒对单一物种的不良影响。由于缺乏足够的实验数据，基于物种敏感性分布（species sensitivity distributions, SSDs）的、用于保护水生生态系统的银纳米颗粒有害浓度（Hazardous concentration, HC）尚未被推导得出。本研究开展了多物种毒性试验：其中急性毒性试验采用了来自5个不同分类群的8个物种（涵盖细菌、藻类、鞭毛虫、甲壳类与鱼类），慢性毒性试验则采用了来自4个不同分类群的6个物种（涵盖藻类、鞭毛虫、甲壳类与鱼类）。基于上述试验结果，本研究采用物种敏感性分布法，推导出银纳米颗粒的水生5%物种有害浓度（HC₅，即仅5%的水生物种会受该浓度及以上水平影响的有害浓度）为0.614 μg/L。据我们所知，本研究是首次基于物种敏感性分布法并采用慢性毒性数据，提出用于保护水生生态系统的银纳米颗粒有害浓度的相关报告。