Model nanoparticles for environmental risk studies

纳米技术的迅速发展产生了大量的纳米粒子，其中许多已经投入工业生产。然而，工程纳米材料的环境行为目前尚不清楚，对人类健康和生物群的潜在危害是一个主要问题。实际上没有发表过关于纳米颗粒生态毒性的研究，而且有限数量的人体毒性研究显示了相反的结果。这主要是由于纳米材料具有复杂的物理化学性质，这些性质与相同材料的体积性质不同，并且受表面组成和粒度等因素的支配。因此，迫切需要更好地了解纳米材料的物理化学性质及其毒性作用，并据此制定标准（生态）毒性试验。了解生态风险需要了解在水环境、水生实验介质和处于危险中的物种中对纳米材料的暴露。现有的检测方法范围有限、昂贵和/或复杂。在开发出新的方法或传感器之前，检测纳米颗粒的生物暴露将特别成问题；然而，了解暴露是了解纳米颗粒生态风险的第一步。为了促进未来对纳米材料（生态）毒性的研究，这项拟议的研究旨在产生一组表征良好的纳米颗粒，这些纳米颗粒将显示出一系列似乎影响（生态）毒性的性质。重点将放在两种金属纳米粒子上，二氧化钛和氧化锌，这两种金属纳米粒子被提议用于广泛的用途。目标将是创造具有独特富集稳定同位素比率的金属纳米颗粒。因此，标准物质不仅可以很好地表征物理化学性质，而且还可以合成具有不同同位素组成的物质，这将使其在实验室和环境实验中都可追溯。介质和生物体中的浓度将使用富集的稳定同位素进行量化。这种工具组合将允许评估生物摄取和颗粒特性之间的明确关系；以及暴露与生物体压力测量之间的明确关系。将测试该材料的反应性（溶解度、表面电荷、结块）作为pH值、离子强度和模型水介质（淡水和海水）中有机物存在的函数。生态风险将在海洋双壳类（Corbula sp.）和淡水双壳类（Dreissena sp.）的实验条件下进行评估。

The rapid expansion of nanotechnologies has resulted in a vast array of nanoparticles, many of which are already in industrial production. However, the environmental behaviour of engineered nanomaterial is currently unknown and the potential to harm human health and biota is a major concern. There are virtually no published studies of nanoparticle ecotoxicity, and a limited number of human toxicity studies show contrasting results. This is mainly due to nanomaterials having complex physicochemical properties that vary from the bulk properties of the same materials and are governed by such factors as surface composition and particle size. There is therefore an urgent need to gain a better understanding of the physicochemical properties of nanomaterials and their toxic effects, and from this to develop standard (eco)toxicity tests. Understanding ecological risks will require understanding exposure to nanomaterial in the water environment, in aquatic experimental media and within species that are at risk. Existing detection methods are limited in scope, expensive and/or complex. Detecting biological exposures to nanoparticles will be especially problematic until new methods or sensors are developed; yet understanding exposure is the first step in understanding ecological risks from nanoparticles. To facilitate future work on nanomaterial (eco)toxicity, the proposed study aims to generate a set of well characterised nanoparticles that will show the range of properties that appear to influence (eco)toxicity. The focus will be on two metallo-nanoparticles, TiO2 and ZnO, which are being proposed for a wide number of uses. The goal will be to create metallo-nanoparticles with unique enriched stable isotope ratios. Thus the reference material will not only be well characterised physicochemically, but also synthesised to have distinct isotopic composition which will make it traceable in both laboratory and environmental experiments. Concentrations in media and in organisms will be quantified using the enriched stable isotope. This combination of tools will allow the assesment of unambiguous relationships between bio-uptake and particle characteristics; and unambiguous relationships between exposure and measures of organism stress. The material will be tested for its reactivity (solubility, surface charge, agglomeration) as a function of pH, ionic strength and the presence of organic matter in model aqueous media (fresh water and seawater). Ecorisk will be assessed under experimental conditions on a marine (Corbula sp.) and a freshwater (Dreissena sp.) bivalve.