Collaborative Research: The Unintended Ecological Consequences of Nanomaterials: Effects of nanotitania in benthic systems

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1067751/1067439Gray/KellySociety is seeing the rapid transition of nanotechnology as it moves from discovery to commercialization. This revolution in atomic and molecular engineering promises many environmental and human health benefits such as dramatic improvements in efficiency, reduced resource use and waste production, and astounding improvements in medical diagnostics and therapeutics. Yet, the risks posed by nanotechnology to ecological and environmental health have not been rigorously assessed, and without these data a meaningful regulatory framework to protect human and environmental health and safety and guide the development of nanomaterials cannot be formulated. The defining characteristic of nanomaterials (NMs) is their size (at least one dimension of 100 nm or less), which falls into a transitional zone between individual atoms and molecules, and bulk materials. The small sizes, novel shapes, and high surface areas promote unusual and novel physicochemical properties to NMs and make possible nearly infinite possibilities for surface functionalization, targeted reactivity and robust material development. These very features, however, open unimagined opportunity for engineering, scientific and medical applications may also pose threats to human health and ecosystem integrity. At this time it is virtually impossible to make predictions about NM environmental fate and impact. Subtle changes in size, shape and surface functionality have profound effects on chemical and physical behavior. Furthermore, the protocols to screen and then, interrogate systems at the mechanistic level and to determine dose effects rigorously are lacking. The purpose of the proposed research is to study fundamental interactions of a representative nanomaterial (various forms of nanotitania) in biological and environmental systems at increasing scale, from subcellular through ecosystem, in order to develop a testing and measurement strategy that comprehensively characterizes the ecotoxicity of nano-scaled TiO2. The applicants propose a three-year collaborative research project that involves environmental engineers and scientists from Northwestern University (NU) and ecologists Loyola University of Chicago (LUC). This project combines the unique capabilities of nanomaterial synthesis and characterization that exist at NU with those at LUC in the field of ecology that will allow us to elucidate the effects of NM on the structure and function of benthic ecosystems. The proposed work is based on a long running collaboration among NU and LUC researchers and will be performed in novel experimental facilities well adapted to interrogating NM effects in biological systems at multiple scales. In view of the collaborative strengths and established infrastructure surrounding this project, the intellectual merit of the proposed study promises to make critical advances in understanding the relationships between NM characteristics, environmental fate and biological consequence and to probe the mechanistic basis for ecosystem responses to NM exposure. With the ability to synthesize state-of-the-art TiO2 NMs that are currently the more widely used nanoscale materials and are likely to be used even more extensively in the future, this research will improve the characterization of the environmental, health and safety aspects of NM by detailing the physical and chemical properties of the nanotitania under study. This will be accomplished by measuring the fate, transport and environmental stability of NM under relevant conditions, and conducting ecotoxicological testing at multiple scales. The broader impacts of the results of this study will not only inform the systematic evaluation of NM health and safety and serve as a model for developing the necessary scientific basis for meaningful policy formulation, but they will also illustrate a strategy to supply critical feedback to the design and production of environmentally-safe NMs. This research promises transformative insights that parallel the technology revolution of nanotechnology, itself and will help to guide NM development along routes of reduced ecotoxicity. They propose to move beyond the identification of biomarkers associated with single component responses (e.g., reactive oxygen species) to discover meaningful NM definitions based on properties not simply size and bioindicators that signal complex chemical and biological interactions at the system level. The results of this research will illustrate the feasibility of comprehensive ecotoxicological testing, but will also reveal the extent to which screening results are predictive of system level response. The broader impacts of this proposed collaborative research are also strongly connected to education at the pre-college, undergraduate, graduate and post-graduate levels, as well as to community level outreach. The research team will promote interdisciplinary exchange among ecologists, environmental engineers, molecular biologists and analytical chemists. Both NU and LUC have strong commitments to undergraduate education and actively involve undergrads in research. A strong mentoring environment exists at both NU and LUC and will nurture the scientific development of a diverse team of students.