Environmental fate of data poor inorganic contaminants- Developing novel tools and a better fundamental understanding

每年都有成千上万种具有新特性和反应性的新产品和新材料被开发出来。事实上，许多用于制造太阳能电池、高性能磁铁、电子产品和催化剂的关键技术材料都含有镧系元素或高活性纳米材料。虽然这些新兴产品应用广泛，产量也在不断扩大，但关于其潜在环境影响的数据却很少。对这些新材料进行生态风险评估的一个关键缺失因素是对它们在复杂环境介质中的浓度、物种形成和命运的可靠确定。我们小组的总体研究目标是确定，更好地理解和量化控制环境系统中金属的命运和生物利用度的主要生物物理化学过程。“发现”基金将用于发展严格评估纳米材料和稀土金属的生态风险所需的基础科学和分析能力。资金将支持我们研究的最基本方面，具体推进三个相关领域的研究：(i)发展我们的分析能力，以测量复杂系统中低浓度的小纳米颗粒，并区分人为和自然NP；（ii）提高我们对自然系统中决定纳米材料命运的主要物理化学过程（溶解、团聚、异质团聚等）的基本理解；（iii）增加我们对自然系统中金属的化学形态如何与其生物利用度相关的机制理解。对于纳米粒子，它们的胶体稳定性（相对于团聚）和溶解肯定会影响它们的生物利用度。分析的发展将为我们提供一种新的能力来测量最小的纳米颗粒（1-20纳米）在真实和模拟的自然系统中的命运。我们将通过改变重要的环境参数来进行粒子命运的机理研究。即将增加的飞行时间-电感耦合质谱仪（ICP-TOFMS）将为我们提供区分工程纳米材料与天然胶体的能力，并允许我们在接近自然条件下更仔细地检查异质团聚。最后，工作将旨在阐明稀土金属配合物的明显生物利用度背后的机制，并确定大于预期的生物吸收是否会导致生物效应增加。如上所述，拟议的工作本质上是跨学科和基础性的，旨在通过仔细检查控制新出现的无机污染物的命运和生物利用度的分子基础来增加我们对环境风险的总体理解。

Thousands of new products and materials, with novel properties and reactivity, are being developed each year. Indeed, many of the technology critical materials used to fabricate solar cells, high performance magnets, electronics and catalysts incorporate either the lanthanide series elements or highly reactive nanomaterials. Although these emerging products have numerous applications and a greatly expanding production, few data are available about their potential environmental impacts. One critical missing element of ecological risk assessments for these novel materials are robust determinations of their concentrations, speciation and fate in complex environmental media. The overall research objective of our group is to identify, better understand and quantify the main biophysicochemical processes that control the fate and bioavailability of metals in environmental systems. The Discovery grant will be used to develop the underpinning science and analytical capacity that is required to rigorously evaluate the ecological risk of nanomaterials and rare earth metals. Funding will support the most fundamental aspects of our research, by specifically advancing three related fields of study: (i)development of our analytical capacity to measure low concentrations of small nanoparticles in complex systems and to distinguish anthropogenic from natural NP; (ii)improvements to our fundamental understanding of the main physicochemical processes (dissolution, agglomeration, heteroagglomeration, etc.) that determine the fate of nanomaterials in natural systems; (iii)increasing our mechanistic understanding on how the chemical speciation of metals in natural systems is related to their bioavailability. For nanoparticles, their colloidal stability (with respect to agglomeration) and dissolution are certain to influence their bioavailability. Analytical developments will be pursued to provide us with a novel ability to measure the fate of the smallest nanoparticles (1-20 nm) in both real and simulated natural systems. We will perform mechanistic studies on particle fate by varying important environmental parameters. The imminent addition of a time of flight - inductively coupled mass spectrometer (ICP-TOFMS) will provide us with the capacity to distinguish engineered nanomaterials from natural colloids and allow us to more closely examine heteroagglomeration under near natural conditions. Finally, work will be designed to eludicate the mechanism underlying the apparent bioavailability of rare earth metal complexes and to determine whether or not the greater than expected biouptake leads to increased biological effects. As seen above, the proposed work is extremely interdisciplinary and fundamental in nature and is designed to increase our overall understanding of environmental risk by carefully examining the molecular basis controlling the fate and bioavailability of emerging inorganic contaminants.