Transatlantic Initiative for Nanotechnology and the Environment

我们开发了一个受生命周期观点启发的概念模型(CM)，该模型表明陆地生态系统作为通过陆地应用含MNM的生物固体引入的氧化锌、二氧化钛和银(第1层)制造纳米材料(MNM)的主要储存库的重要性。我们围绕三个关键假设来研究MNM在农业生态系统中的运输、命运、行为、生物有效性和效应：假设(H1)表面化学是影响MNM在陆地环境中的命运和运输的主要因素，以及生物利用度和对生物受体的影响；假说(H2)一旦释放到环境中，原始的MNM表面将通过与有机和无机配体(大分子)的相互作用或通过其他生物地球化学转化(老化效应形成a-MNM)来修饰；假设(H3)生态受体将通过特定的生态和毒物基因组反应与原始金属和金属氧化物MNM、a-MNM和/或溶解的组成金属离子和整体氧化物的相互作用，反映它们的联合作用。实验方法：将对通过模拟老化产生的Tier 1和Tier 2(CeO2，碳纳米管)MNm和a-MNm进行详细的物理化学表征，这些材料将用于关键生态受体(细菌、土壤无脊椎动物和植物)的柱传输(Tier 1和2)、生物利用度和效应(Tier 1)研究。将使用生态受体物种的子集为第一级MNM收集校准和验证pBRM所需的数据。然后，将通过使用中试规模的WWT设施对第一级MNMS进行实际污水处理的重复研究，验证CM和模拟MNMS老化的模型结果。为了便利这些和未来在与环境有关的情况下对多国核国家进行的调查，将开发新的现场工具。预期结果：拟议的研究将产生关于经过污水处理厂的重要类型的MNM以及添加到土壤中并在土壤中老化的MNM的转化的第一批数据。这些数据将对评估引入农业生态系统的最不发达国家潜在的直接和间接生态和人类健康风险至关重要。在模拟老化材料和含有生物固体和土壤的MNM上产生的用于测试H1和H2的数据可能表明，在现实环境情景下需要实验考虑的MNM特性的排列可以显著减少。此外，这项工作的结果将首次验证使用实验室控制实验中产生的基因和蛋白质表达谱作为在环境现实条件下暴露或影响的指标。拟议的研究和建模工作的一个重要成果将是开发第一代经过验证的预测模型，用于预测农业生态系统中几类重要的MNM的环境命运、行为、生物有效性和影响。

We have developed a life cycle perspective inspired conceptual model (CM) that suggests the importance of terrestrial ecosystems as a major repository of ZnO, TiO2, and Ag (Tier 1) manufactured nanomaterials (MNMs) introduced via the land application of MNM-containing biosolids. We propose to investigate the transport, fate, behavior, bioavailability, and effects of MNMs in(to) agroecosystems under environmentally realistic scenarios organized around three key hypotheses: Hypothesis (H1) Surface chemistry is the primary factor influencing the fate and transport of MNMs in the terrestrial environment as well as the bioavailability and effects to biological receptors; Hypothesis (H2) Once released to the environment, pristine MNM surfaces will be modified by interactions with organic and inorganic ligands (macromolecules) or via other biogeochemical transformations (aging effects forming a-MNMs); Hypothesis (H3) Ecoreceptors will respond to interactions with pristine metal and metal oxide MNMs, a-MNMs, and/or dissolved constituent metal ions and bulk oxides by specific ecological and toxicogenomic responses that will reflect their combined effects. Experimental Approach: Detailed physicochemical characterization will be conducted on Tier 1 and Tier 2 (CeO2, carbon nanotubes) MNMs and a-MNMs produced by simulating aging and these materials will be utilized in column transport (Tier 1 and 2), bioavailability, and effects (Tier 1) studies to key ecoreceptors (bacteria, soil invertebrates, and plants). Data needed to calibrate and validate the pBRM will be collected for Tier 1 MNMs using a subset of ecoreceptor species. The CM and model results from the simulated aging of MNMs will then be validated by repeating studies of Tier 1 MNMs subjected to actual WWTP using a pilot scale WWT facility. To facilitate these and future investigations of MNMs under environmentally relevant scenarios, novel in situ tools will be developed. Expected Results: The proposed research will generate among the first data on the transformations of important classes of MNMs subjected to WWTP as well as those added to and aged in soil. These data will be critical for evaluating potential direct and indirect ecological and human health risks of MNMs introduced to agroecosystems. Data generated on the simulated aged materials and on the MNM containing biosolids and soils to test H1 & H2, may indicate that the permutations of MNM properties required to be experimentally considered under realistic environmental scenarios can be significantly reduced. Furthermore, the results of this work will provide the first validation of using gene and protein expression profiles generated in laboratory controlled experiments as an indicator of exposure or effects under environmentally realistic conditions. An important output from the proposed research and modeling efforts will be the development of first generation validated predictive models of the environmental fate, behavior, bioavailability, and effects of several important classes of MNMs in agroecosystems.