1530563(Lowry)/1530594(Unrine)<br/><br/>The development of nano-enabled agricultural chemicals is proceeding rapidly. Nano-enabled agricultural fertilizers and pesticides have a greater potential for direct, massive introduction of manmade nanomaterials (MNMs) into the environment than any other use of MNMs. However, the effects of nano-enhanced agricultural chemicals on terrestrial ecosystems are inadequately studied and largely unknown. Moreover, the properties of these MNMs, and their complex behaviour in soils makes predicting their fate in soils difficult using the risk assessment framework for traditional chemicals. This international interdisciplinary project addresses essential gaps in knowledge about how soil properties, MNM properties, MNM concentration, and transformations affect the spatial and temporal behaviour of agriculturally relevant metal (hydr)oxide MNMs in soils and their uptake by important crop plants including wheat and tomato. In addition, the toxicity potential, uptake into soil organisms, and potential for long-term ecological impacts will be assessed. New methods to track and characterize MNMs in soil at realistic concentrations will be also developed. This new knowledge will help to understand the risks associated with MNMs used in agricultural products, but also help to design safer and more effective nano-enabled pesticides and fertilizers.<br/><br/>MNMs are constantly changing size, composition, and distribution as they age in soils. The particulate nature and inherent instability of NMNs in soils makes many of the test methods for assessing environmental fate unsuitable for MNMs without modification. These features also make MNM fate likely to be concentration dependent in ways that traditional chemicals are not. Information about the rates of change of MNMs in soils, and how these changes affect the distribution of NMNs between soil and pore water, and bioavailability and toxicity of MNMs over time is acutely needed to accurately assess fate and toxicity potential, and to be able to develop realistic and site-specific models for NMN fate and effects. This project addresses essential gaps in knowledge about how soil properties, MNM properties, MNM concentration, and reaction kinetics affect the spatial and temporal behaviour of metal-oxide MNM-enabled pesticides and fertilizers in soils. Specifically, the PIs will assess how these variables influence transformation and distribution in soils, toxicity and multigenerational effects on soil organisms, bioaccumulation/trophic transfer, phytoavailability, and therefore the potential for ecological impacts or human exposures from consumption of key food crops. This project will also develop novel methods to track MNMs in soils and will provide guidance for new assays for assessing fate, bioavailability, and toxicity potential of agriculturally relevant MNMs. The PIs focus on Cu- and Zn-based metal (hydr)oxides that are used commercially as pesticides or are marketed as micronutrient fertilizer additives. <br/><br/>The proposed study will provide a more comprehensive understanding of the fate and risks of MNMs used in agricultural products, facilitate efficient and safe design of nanomaterial-based agriculture products through increasing understanding of how the risks and benefits of these products relate to the MNM properties, and provide simple screening tests that can be applied to MNM-based agriculture products to predict their fate and toxicity risks. Overall, this project will create robust models and validated assays for the evaluation of environmental impacts of MNM-enhanced pesticides and fertilizers, and provide a science-based approach to safe design of agriculture products and their management. The project?s findings will facilitate development of consistent science-based regulations and promote uninterrupted trade of agricultural products (both agrochemicals and food) between the US and the EU. Educational activities will include providing internship opportunities with their industry partners, lab rotations at their international partners, and hosting two undergraduate students per year as part of the CEINT REU program.