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与人类健康构成的风险的担忧与日俱增，诸多关于AgNPs对水生生物毒性的研究已相继开展。美国环境保护署（USEPA）与欧盟联合研究中心（EU JRC）已发布针对AgNPs的风险评估报告。然而，既往多数研究仅聚焦于AgNPs对单一物种的不良影响。基于物种敏感性分布（species sensitivity distributions, SSDs）、用于保护水生生态系统的AgNPs有害浓度（Hazard concentration, HC）尚未被推导得出，其核心原因在于相关充足数据的缺失。本研究开展了多物种毒性测试：包含针对5个不同分类群（细菌、藻类、鞭毛藻、甲壳类与鱼类）的8个物种的急性毒性试验，以及针对4个不同分类群（藻类、鞭毛藻、甲壳类与鱼类）的6个物种的慢性毒性试验。基于上述试验结果，本研究通过SSDs方法推导得到AgNPs的水生HC₅（5%物种危害浓度）为0.614 μg/L。据我们所知，这是首份基于SSDs并使用慢性毒性数据，提出用于保护水生生态系统的AgNPs有害浓度的研究报告。