Tracking relevant nanomaterial transformations, exposure, uptake and effects in freshwater and soil systems

纳米材料（NM）是非常小的颗粒，比人类头发的宽度小得多。它们被合成以提供与较大形式的相同材料不同的性能，现在它们被广泛用于各种产品中。NMs提供的特性包括增强的强度，反射光或与其他化学物质反应的能力，以及高效的导电性。NM的价值现已得到广泛认可，许多公司开始在普通消费品（如防晒霜和化妆品）以及工业产品（如织物和建筑材料）中使用NM。这意味着少量的NMs将从日常产品使用中进入更广泛的环境。最近的大量研究都在评估NMs对人类和环境的安全性。这些研究大多着眼于新制造的NMs。然而，越来越明显的是，一旦纳米颗粒被释放到更广阔的环境中，它们就不会停留在它们的制造状态——它们会改变或“转化”。转化可以影响纳米颗粒的大小、电荷、表面涂层以及它们与其他物质（如土壤颗粒或其他化学物质）结合的能力。转化既发生在向环境转移的过程中（例如通过污水处理厂），也发生在NMs到达更广泛的环境本身（河流、沉积物和土壤）时。我们了解纳米粒子的转化过程和环境命运是非常重要的，因为它们会影响它们对人类和环境的毒性。这个项目的目的是更详细地研究这些NM转换。我们希望更好地了解不同类型的NMs是否以相同或不同的方式进行转换。我们将使用不同类型的纳米材料进行研究，包括由银、二氧化钛、聚苯乙烯（一种塑料）和石墨烯（一种碳）制成的纳米材料。我们将首先使用实验室方法，模拟在污水处理过程中、在自然水域和土壤中纳米粒子的变化方式，以创造我们将研究的转化材料。我们将测试这些新的和改变的NMs如何影响一系列常见的水生和土壤生物，并比较它们在“原始”状态下与在不同时间环境中转化后的毒性。在我们的测试中，我们将测量每种物质被生物体吸收到不同组织中的量，以及这是否会影响它们的生长和繁殖。我们还将测量不同基因的活性，这些基因可能会受到生物体吸收不同NMs的影响。我们预测，每一种NM都将以一种改变其产生有害影响的可能性的方式进行转化。每个测试将重复使用不同的土壤和水通常发现在英国，以确定如何变化在不同的条件下。最后，我们将建造定制的大型暴露系统（“mesocosms”），旨在模拟污水排放的河流和污泥扩散的土壤，并在其中种植各种常见的英国本土植物，无脊椎动物和鱼类（在水中）。通过对这些中生态系统进行几个月的跟踪研究，我们可以模拟出在真实的英国环境中可能发生的情况，即我们改造后的微生态系统的命运和影响。我们将使用这些结果来改进模型，这些模型能够预测我们转换后的NMs将如何表现以及它们将产生的影响。综上所述，我们的研究结果将有助于我们预测纳米颗粒的毒性，以确保其安全性，支持纳米技术产业的未来发展。为此，我们将运行和协调一个英国纳米学者和监管机构平台，并将通过主要的欧盟（纳米安全集群）和全球（经济合作与讨论组织）政策工作组以及公众展示我们的结果，以便尽可能广泛地接触受众。

Nanomaterials (NM) are very small particles much less than the width of a human hair. They are synthesised to provide different properties from larger forms of the same material and they are now used in a wide range of products. The properties that NMs provide include enhanced strength, an ability to reflect light or to react with other chemicals, and efficient electrical conductance. The value of NM is now very widely recognised and many companies are starting to use them in common consumer products, such as sunscreens and cosmetics, plus industry products, such as fabrics and building materials. This means that small quantities of NMs will reach the wider environment from everyday product use.A great deal of recent research has gone into assessing the safety of NMs for humans and the environment. Most of these studies have looked at NMs in their newly-manufactured forms. It is increasingly apparent, however, that once NMs are released into the wider environment, they do not stay in their manufactured state - they change or 'transform'. Transformations can affect NM size, charge, their surface coatings and their ability to bind to other things such as soil particles or other chemicals. Transformations occur both during transfer to the environment (e.g. via sewage works) and once NMs reach the wider environment itself (rivers, sediments and soils). It is of huge importance that we understand the transformation processes and environmental fate(s) of NMs as they can affect their toxicity to humans and the environment. The aim of this project is to study these NM transformations in more detail. We want to better understand whether different types of NMs are transformed in the same or different ways. We will conduct our work with different types of NMs, including those made from silver, titanium dioxide, polystyrene (a type of plastic) and graphene (a type of carbon). We will first use laboratory methods that mimic the ways that NMs are changed during sewage treatment and in natural waters and soils to create the transformed materials that we will then study. We will test how these new and changed NMs affect a range of common aquatic and soil organisms and contrasting their toxicity in their "pristine" state with that after they have been transformed in the environment for different times. During our tests, we will measure how much of each material is taken up by the organisms into different tissues and whether this affects how they grow and reproduce. We will also measure the activity of different genes that are likely to be affected as organisms take up different NMs. We predict that each NM will be transformed in a way that changes its likelihood to cause harmful effects. Each test will be repeated using different soils and waters typically found across the UK, to determine how transformations vary under different conditions.Finally, we will build custom-made, large exposure systems ('mesocosms') designed to mimic the rivers into which sewage works discharged and soils upon which sludge is spread, and populate them with a wide range of common UK native plants, invertebrates and fish (in the waters). By following these mesocosms for several months, we can simulate what may actually be happening in real UK environments in terms of the fate and effects of our transformed NMs. We will use the results to improve models able to predict how our transformed NMs will behave and the effects they will have. Taken together, our results should help us to predict the toxicity of NMs to help assure their safety, supporting the growth of the nanotechnology industry into the future. To this latter end we will run and coordinate a UK Nano-Academics & Regulators Platform, and will also present our results through major European Union (NanoSafety Cluster) and worldwide (Organisation for Economic Cooperation and Discussion) policy working groups, as well as to the public, so reaching as wide an audience as possible.