Guo Jingyi, Liu Na, Xie Qiting, Zhu Lizhong, Ge Fei
College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China.
College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; College of Environment and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
Environ Pollut. 2023 May 1;324:121181. doi: 10.1016/j.envpol.2023.121181. Epub 2023 Jan 31.
Ubiquitous microplastics (MPs) may affect the trophic transfer of nanoparticles (NPs), in turn threatening aquatic organisms and even human health. Thus, this study explored the influence of polystyrene microplastics (PS MPs) on the biotoxicity and biomagnification of ZnO nanoparticles (ZnO NPs) in the aquatic food chain from Chlorella vulgaris (C. vulgaris) to Daphnia magna (D. magna). The results showed that PS MPs facilitated the biotoxicity of ZnO NPs towards D. magna after dietary exposure. Compared to the control (single ZnO NPs), the heart rate and the level of reactive oxygen species were remarkably increased by 21.25% and 16.32% in the combined system (PS MPs + ZnO NPs), respectively. Notably, PS MPs suppressed the ZnO NPs accumulation in C. vulgaris, while remarkably facilitating the trophic transfer of ZnO NPs to D. magna. The biomagnification of ZnO NPs was evident with a maximal biomagnification factor (BMF) of 1.49 under acute dietary exposure of PS MPs (72 h), but was absent in the single ZnO NPs system (BMF <0.90). Moreover, PS MPs resulted in a larger biomagnification of ZnO NPs with a maximal BMF of 2.11 under chronic dietary exposure (21 days). Furthermore, the Zn element (including ZnO NPs and released Zn) was observed to accumulate in the intestine, thus causing ultrastructural damage and lipid droplet (LD) aggregate. Overall, these findings highlight the importance of considering the impact of MPs on co-existed pollutants and contribute to a better understanding of the ecological risks of MPs in aquatic ecosystems.
无处不在的微塑料（MPs）可能会影响纳米颗粒（NPs）的营养传递，进而威胁水生生物甚至人类健康。因此，本研究探讨了聚苯乙烯微塑料（PS MPs）对从普通小球藻（C. vulgaris）到大型溞（D. magna）的水生食物链中氧化锌纳米颗粒（ZnO NPs）的生物毒性和生物放大作用的影响。结果表明，经饮食暴露后，PS MPs促进了ZnO NPs对大型溞的生物毒性。与对照组（单一ZnO NPs）相比，联合系统（PS MPs + ZnO NPs）中的心率和活性氧水平分别显著提高了21.25%和16.32%。值得注意的是，PS MPs抑制了ZnO NPs在普通小球藻中的积累，同时显著促进了ZnO NPs向大型溞的营养传递。在PS MPs急性饮食暴露（72小时）下，ZnO NPs的生物放大作用明显，最大生物放大系数（BMF）为1.49，但在单一ZnO NPs系统中不存在生物放大作用（BMF < 0.90）。此外，在慢性饮食暴露（21天）下，PS MPs导致ZnO NPs的生物放大作用更大，最大BMF为2.11。此外，观察到锌元素（包括ZnO NPs和释放的锌）在肠道中积累，从而导致超微结构损伤和脂滴（LD）聚集。总体而言，这些发现突出了考虑MPs对共存污染物影响的重要性，并有助于更好地理解水生生态系统中MPs的生态风险。
