Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
Yangtze Institute for Conservation and Development, Hohai University, Nanjing 210098, China.
Environ Sci Process Impacts. 2022 Apr 21;24(4):586-597. doi: 10.1039/d2em00014h.
Nanoplastics and metal oxide nanoparticles are serious threats that inevitably enter the environment. Their similar particle properties likely lead to interaction and thus cause more unpredictable ecotoxicity to organisms. In this study, it was found that polystyrene nanoplastics (PS NPs) aggravate the toxic effect of iron oxide nanoparticles (FeO NPs) on L. by inducing severe oxidative stress and root deformation, and the expansion of damaged cells from the xylem to the epidermis was observed using confocal laser scanning. Exposure to PS NPs + FeO NPs correspondingly elevated iron accumulation in the roots and leaves by 1.39 and 1.17 times compared to the amount observed with FeO NPs individually. Examination of the physicochemical properties, iron ion release, and molecular interactions of the NPs indicated that PS NPs interact with FeO NPs to form heteroaggregates and facilitate leaching of iron ions, which resulted in aggravating the toxic effect. These were alleviated by the addition of humic acid (HA), which dispersed the heteroaggregates and reduced the release of iron ions. The findings in the present study provide new perspectives for the ecotoxicological risk of binary nano-pollution in the natural environment.
纳米塑料和金属氧化物纳米颗粒是严重的威胁，不可避免地会进入环境。它们相似的颗粒性质可能导致相互作用，从而对生物体产生更不可预测的生态毒性。在本研究中，发现聚苯乙烯纳米塑料（PS NPs）通过诱导严重的氧化应激和根变形，加剧了氧化铁纳米颗粒（FeO NPs）对 L. 的毒性作用，利用共聚焦激光扫描观察到从木质部到表皮的受损细胞的扩张。与单独使用 FeO NPs 相比，暴露于 PS NPs + FeO NPs 会使根和叶中的铁积累分别增加 1.39 倍和 1.17 倍。对 NPs 的物理化学性质、铁离子释放和分子相互作用的研究表明，PS NPs 与 FeO NPs 相互作用形成异质聚集体，并促进铁离子的浸出，从而加剧了毒性作用。添加腐殖酸（HA）可缓解这种情况，因为 HA 可分散异质聚集体并减少铁离子的释放。本研究的结果为自然环境中二元纳米污染的生态毒性风险提供了新的视角。
