The rapid development and application of nanotechnology have led to increasing concern about the environmental implications of released nanomaterials and potential risks to public health and aquatic ecosystems. Information on the joint effect of nanomaterials and co-existing contaminants such as heavy metals is still inadequate. Our work investigated the effect of Al₂O₃ nanoparticles (NPs; nano-Al₂O₃) on the toxic effect of Pb in the unicellular marine phytoplankton Isochrysis galbana. Results showed that a dose–response effect of nano-Al₂O₃ was found. Significant enhancement of fluorescence in cell cytoplasm rather than cell membrane occurred in the presence of nano-Al₂O₃, indicating that nano-Al₂O₃ can penetrate cells and affect the fluorescence emitted from the chloropigments inside them. The presence of nano-Al₂O₃ has no impact on the toxic effect of Pb at an NP concentration of 1 mg/L but increased that at NP concentrations of 10 mg/L and 100 mg/L. A synergistic effect was also found for the toxic effect of Pb in the presence of 10 mg/L nano-Al₂O₃. The presence of 100 mg/L nano-Al₂O₃ significantly increased the bio-uptake of Pb in the range of 0.25 mg/L to 2.0 mg/L Pb, and the maximum accumulated Pb in algae can reach up to 18.22 ng/10⁵ cells with 100 mg/L nano-Al₂O₃ compared with Pb alone at 2.0 mg/L(12.53 ng/10⁵ cells). Inside cells, Pb loaded onto nano-Al₂O₃ can be more toxic than the same amount of free Pb species. The results of toxicity tests and accumulated Pb in algae imply that, in addition to the total Pb cell content, the bioavailability of Pb inside algae should be taken into consideration in evaluating the joint toxicity effect. Our work enhances understanding of the combined toxicity of NPs and co-existing heavy metals and is of practical significance in the natural environment.

纳米技术的迅速发展和应用已引起人们对释放的纳米材料对环境的影响以及对公共健康和水生生态系统的潜在风险的日益关注。关于纳米材料和诸如重金属等共存污染物的联合效应的信息仍然不足。我们的工作研究了Al ₂ O ₃纳米颗粒（NPs; nano-Al ₂ O ₃）对Pb在单细胞海洋浮游植物等鞭金藻中的毒性作用的影响。结果表明，纳米Al ₂ O ₃的剂量反应效应被找到。在存在纳米Al ₂ O ₃的情况下，细胞质而非细胞膜中的荧光显着增强，这表明纳米Al ₂ O ₃可以穿透细胞并影响从其内部的氯颜料发出的荧光。纳米Al ₂ O _3的存在对NP浓度为1 mg / L的Pb的毒性没有影响，但对NP浓度为10 mg / L和100 mg / L的Pb的毒性作用没有影响。在存在10 mg / L纳米Al ₂ O ₃的情况下，还发现了Pb的协同作用。100 mg / L纳米Al ₂ O _3的存在在0.25 mg / L至2.0 mg / L Pb范围内，Pb的生物吸收量显着增加，并且在100 mg / L纳米Al ₂ O中，藻类中最大的Pb累积积累量可达18.22 ng / 10 ^5个细胞。与2.0 mg / L的单独Pb（12.53 ng / 10 ^5个细胞）相比，Pb为₃。在电池内部，将Pb负载到纳米Al ₂ O _3上可能比同等数量的游离Pb更具毒性。毒性测试和藻类中Pb积累的结果表明，除了评估Pb细胞的总含量外，在评估关节毒性效果时还应考虑到Pb在藻类中的生物利用度。我们的工作加深了对NP和共存重金属的综合毒性的了解，在自然环境中具有实际意义。