纳米材料对水生生物毒性效应及其机制的研究进展

随着纳米材料的广泛应用,排放到环境中的纳米材料越来越多,且多数纳米材料可进入水体并通过食物链在水生生物体内累积,进而对水生生物产生毒性作用。纳米材料按组分的不同主要有纳米金属氧化物、纳米金属粒子、碳纳米材料、量子点、有机聚合物等,不同纳米材料尺寸大小、材料成分、表面修饰材料等理化特征的差异对水生生物的毒性大小及机制各有不同。本文分别归纳了各种纳米材料对水生生物模型（如鱼类、贝类、水蚤、藻类等）的纳米毒性作用及可能的致毒机制。分析表明,各类纳米材料不同的理化特征可能产生不一样的毒性作用,但决定毒性的关键因素到底是其粒径尺寸大小、材料组分还是表面修饰物等至今尚无准确定论。氧化损伤、金属离子释放等是研究较多的机制,而从基因芯片、表观遗传修饰等分子水平对毒性机制进行研究的报道很少,可能是未来的研究方向,其是否可以作为毒性评价指标尚有待进一步深入探讨,且环境因素等也可对纳米材料的毒性作用产生影响。纳米材料对水生生物的毒性机制及风险评价仍任重而道远。

Advances on Toxicity and Toxic Mechanisms of Nanomaterials to Aquatic Organisms

An increasing number of nanomaterials with extensive application are discharged into environment. Most nanomaterials released into aquatic environment accumulate in aquatic organisms through food chains and then pose toxic effects to these organisms. Nanomaterials are classified into nano metal oxides, metal nanoparticles, carbon nanomaterials, quantum dots, and organic polymers according to their components. Different sizes, components, and surface modifications of nanomaterials may pose different nanotoxicity and toxic mechanisms to kinds of aquatic organisms. This article reviewed the nanotoxicity and possible toxic mechanisms of nanomaterials to aquatic biological models, such as fish, shellfish, daphnia, and algae. Differences in physical or chemical characteristics can vary nanotoxicity and toxic mechanisms, and it is not clear whether sizes, components, or surface modifications would be critical factors of nanomaterials. The most studied mechanisms are oxidative damage and release of metal ions, while few reports focus on molecular mechanisms such as microarray and epigenetic modifications, which could be a new trend in the future. Therefore, further investigations should concern whether these molecular mechanisms could be used as toxicological evaluation indicators, while taking into consideration of environmental factors which might alter the toxicity of nanomaterials. More studies need to be conducted on toxic mechanisms and risk evaluation of nanomaterials.