Research Progress on Environmental, Health, and Safety Aspects of Engineered Nanomaterials (2013)

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Summary Nanotechnology relies on the ability to design, manipulate, and manufacture materials at the nanoscale.1 Investments in nanotechnology and in the production of engineered nanomaterials (ENMs) continue to grow; the global market for nan- otechnology is expected to exceed $3 trillion by 2015. The novel physical and chemical characteristics of ENMs are being exploited in new applications and have motivated research on the potential human health and environmental risks associated with these materials because of concerns about their behavior in biolog- ic systems. Given the global use of ENMs, research on their environmental, health, and safety (EHS) aspects necessarily extends globally and involves a multidisci- plinary and international group of stakeholders, including academic researchers, the industrial sector, nongovernment organizations (NGOs), and the public. Over the last decade, there has been more funding for research and a corre- sponding increase in peer-reviewed publications on EHS aspects of ENMs. How- ever, in spite of progress in understanding some aspects of risks posed by ENMs, uncertainty persists about the potential implications of the materials for consum- ers, workers, and ecosystems. In that context, the US Environmental Protection Agency (EPA) asked the National Research Council to perform an independent study to develop and monitor an integrated research strategy on EHS risks posed by ENMs. In response to EPA’s request, the National Research Council convened the Committee to Develop a Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials, which produced its first report in 2012, A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials. In this second report, the committee evaluates the trajectory of research progress on the basis of indicators or criteria established in its first report. (See Appendix B for complete statement of task.) This report expands on the need for a strategic approach for developing the research infrastructure for addressing uncertainties regarding the potential EHS risks associated with ENMs that was begun in the first report. The approach hinges on the vision put forth in Figure S-1, which describes the nanotechnology EHS research enterprise and shows the inter- related and interdependent research activities that are driven by the production of 1 Nanoscale refers to materials on the order of one billionth of a meter. 3 

4 Research Progress on EHS Aspects of Engineered Nanomaterials ENMs. The diagram presents an integrated and strategic system for developing data that will provide for characterization of ENMs, for refinement of experi- mental methods, for support of model development, and for storage and retrieval of information through the “knowledge commons”. The potential success of the enterprise rests on involvement of the global community of stakeholders, includ- ing researchers, manufacturers of ENMs, regulators, and components of civil soci- ety that are invested in addressing potential health and environmental risks posed by ENMs. Many of the elements of this enterprise are in place, but the committee concludes that their further development and integration are essential for advanc- ing progress. The committee’s second report considers findings that were presented in its first report and other recently released US and European Union efforts that provide global perspectives for advancing nanotechnology EHS research. It ex- amines trajectories of research and implementation progress and identifies barri- ers to progress and steps to ensure progress. To advance the concepts described in the research enterprise (Figure S-1), the committee envisions a time beyond its current research recommendations to consider how questions about risk can be best approached in an adaptive fashion with the goal of generating infor- mation needed to design materials and processes so as to avoid and control po- tential risks. ASSESSMENT OF PROGRESS This report is released a short time after of the committee’s first report. Using indicators developed based on priorities from that report (see Boxes S-1 and S-2 for indicators of research and implementation progress, respectively), the committee evaluated progress in this second report. For its evaluation, the committee developed a color scheme to categorize progress qualitatively by considering new activities since preparation of its first report and the trajectory of research progress. Because of the many concomitant nanotechnology EHS reviews and planning efforts, the committee did not attempt to attribute progress to any particular effort. Rather, it classified progress on the basis of committee consensus whereby green implies substantial progress (there are new activities, and sustained progress is expected), yellow implies moderate or mixed progress, and red implies little progress (there is minimal activity, and little change is expected). (The committee’s assessment of progress is indicated in the color circles in Boxes S-1 and S-2.) In the following sections, the committee provides a brief evaluation of the research and implementation indicators, together with the steps needed to speed progress to a pace at which “getting to green”2 is achievable. (Additional details regarding the evaluation of progress are described in Chapters 3 and 4.) 2 “Getting to green” is the title of Chapter 4, and indicates the steps needed to achieve progress in the research and implementation indicators identified in Boxes S-1 and S-2. 

Summary 5 INVENTORIES MATERIALS REFERENCE ENM RELEASES LABORATORY KNOWLEDGE REAL  WORLD COMMONS WORLD VALIDATION SCREENING TOOLS METHODS/INSTRUMENTS MODELS METHODS/INSTRUMENTS RISK DECISION MAKING FIGURE S-1 Nanotechnology environmental, health, and safety research enterprise. The diagram shows the integrated and interdependent research activities that are driven by the production of ENMs. The production of ENMs is captured by the orange oval, labeled “materials”, which includes reference materials, ENM releases, and inventories. (An inventory is a quantitative estimate of the location and amounts of nanomaterials pro- duced, including the properties of the nanomaterial.) The knowledge commons (red box) is the locus for collaborative development of methods, models, and materials, and for archiving and sharing data. The “laboratory world” and “real world” (green boxes) feed into the knowledge commons. The laboratory world comprises process-based and mech- anism-based research that is directed at understanding the physical, chemical, and biolog- ic properties or processes that are most critical for assessing exposures and hazards and hence risk (NRC 2012, p. 55). The “real world” includes complex systems research in- volving observational studies that examine the effects of ENMs on people and ecosys- tems. The purple boxes capture the range of methods, tools, models, and instruments that support generation of research in the laboratory world, the real world, and the knowledge commons. Research Progress Adaptive Research and Knowledge Infrastructure for Accelerating Research Progress and Providing Rapid Feedback to Advance Research In the first report, the committee identified a need for an adaptive infra- structure for research and knowledge generation to accelerate and advance nano- technology EHS research. The components of the infrastructure include charac- terized materials for reference and research purposes; nanomaterial libraries; 

6 Research Progress on EHS Aspects of Engineered Nanomaterials instruments and methods for measuring nanomaterials and their transformations; methods or assays for quantifying the effects of nanomaterials; databases, ontol- ogies3, and tools for sharing research results; and models for uncovering rela- tionships among the data. In this second report, the committee determined that research progress ranges from green for detecting and characterizing ENMs in relatively well-characterized media to yellow for development of libraries of well-characterized ENMs, development of methods for quantifying effects of ENMs in experimental systems, and the extent of joining existing databases and advancing systems for sharing research results. BOX S-1 Status of Indicators of Progress in Research4 Adaptive Research and Knowledge Infrastructure for Accelerating Research Progress and Providing Rapid Feedback to Advance the Research  Extent of development of libraries of well-characterized nanomaterials, including those prevalent in commerce and reference and standard materials Development of methods for detecting, characterizing, tracking, and monitoring nanomaterials and their transformations in simple, well- characterized media Development of methods to quantify effects of nanomaterials in experimental systems.  Extent of joining of existing databases, including development of common informatics ontologies Advancement of systems for sharing the results of research and fostering development of predictive models of nanomaterial behaviors Quantifying and Characterizing the Origins of Nanomaterial Releases  Developing inventories of current and near-term production of nanomaterials  Developing inventories of intended uses of nanomaterials and value-chain transfers  Identifying critical release points along the value chain  Identifying critical populations or systems exposed  Characterizing released materials in complex environments  Modeling nanomaterial releases along the value chain (Continued) 3 Ontologies—specifications of the terms and their logical relationships used in a par- ticular field—are used to improve search capabilities and allow mapping of relationships among databases and informatics systems. 4 The wording and ordering of some indicators have been modified from NRC (2012, pp. 181–182). Details of the modifications are noted in the descriptions of the indicators in Chapter 3. 

Summary 7 BOX S-1 Continued Processes That Affect Both Exposure and Hazard  Steps taken toward development of a knowledge infrastructure able to describe the diversity and dynamics of nanomaterials and their transformations in complex biologic and environmental media  Progress in developing instrumentation to measure key nanomaterial properties and changes in them in complex biologic and environmental media  Initiation of interdisciplinary research that can relate native nanomaterial structures to transformations that occur in organisms and as a result of biologic processes  Extent of use of experimental research results in initial models for predicting nanomaterial behavior in complex biologic and environmental settings Nanomaterial Interactions in Complex Systems Ranging from Subcellular Systems to Ecosystems  Extent of initiation of studies that address the impacts of nanomaterials on a variety of end points in complex systems, such as studies that link in vitro to in vivo observations, that examine effects on important biologic pathways, and that investigate ecosystem effects  Extent of adaptation of existing system-level tools (such as individual species tests, microcosms, and organ-system models) to support studies of nanomaterials in such systems  Development of a set of screening tools that reflect important characteristics or toxicity pathways of the complex systems described above  Steps toward development of models for exposure and potential ecologic effects  Identification of benchmark (positive and negative) and reference materials for use in such studies and measurement tools and methods to estimate exposure and dose in complex systems Quantifying and Characterizing the Origins of Material Releases Knowledge of human and ecosystem exposures requires detailed infor- mation on the quantities and characteristics of ENMs produced and the products in which they are used, on how they are introduced into the environment, on how they are transported and transformed in humans and ecosystems, and on the populations exposed. Progress in this research priority ranged from yellow to red. Yellow was assigned for the extent of progress in developing inventories of ENMs, in identi- fying critical release points along the value chain, in identifying critical popula- tions or systems exposed, and in characterizing released materials in complex environments. Because those are prerequisites for model development, the abil- ity to model releases along the value chain was denoted as red. 

8 Research Progress on EHS Aspects of Engineered Nanomaterials BOX S-2 Status of Indicators of Progress in Implementation (NRC 2012, p. 183) Enhancing Interagency Coordination  Progress toward establishing a mechanism to ensure sufficient management and budgetary authority to develop and implement an EHS- research strategy among NNI agencies  Extent to which the NNCO is annually identifying funding needs for interagency collaboration on critical high-priority research Providing for Stakeholder Engagement in the Research Strategy  Progress toward actively engaging diverse stakeholders in a continuing manner in all aspects of strategy development, implementation, and revision Conducting and Communicating the results of research funded through public-private partnerships  Progress toward establishment of effective public-private partnerships, as measured by such steps as completion of partnership agreements, issuance of requests for proposal, and establishment of a sound governance structure Managing Potential Conflicts of Interest  Progress toward achieving a clear separation in management and budgetary authority and accountability between the functions of developing and promoting applications of nanotechnology and understanding and assessing its potential health and environmental implications  Continued separate tracking and reporting of EHS research activities and funding distinct from those for other, more basic or application- oriented research Processes that Affect Both Exposure and Hazard In its first report, the committee highlighted the need to identify the criti- cal nanomaterial interactions that affect ENM behaviors and recommended iden- tifying cross-cutting processes common to assessing exposure and hazard. This topic includes cataloging the types of ENM transformations in complex matri- ces, developing instrumentation for monitoring transformations in vivo or in complex environmental media, and developing models for predicting ENM be- haviors. There is a need for an infrastructure for archiving data on ENM behav- ior for model development. Progress ranged from yellow for initiation of studies to characterize ENM transformations and for studies that relate ENM properties 

Summary 9 to observed effects in more complex systems to red for development of new instrumentation for measuring transformations in situ, in vivo, or in single parti- cles. Nanomaterial Interactions in Complex Systems Ranging from Subcellular Systems to Ecosystems In its first report, the committee recognized the need to improve under- standing of interactions of ENMs in a variety of complex systems—from single cells to subcellular organelles to individual organisms to ecosystems. A first step is to identify relevant exposure sources, concentrations, and cellular, organismal, and ecologic targets so that potential effects on complex systems can be ad- dressed. Research progress indicators for this category ranged from yellow to red with none denoted as green. Indicators were yellow for initiation of studies that address effects of ENMs in complex systems, adaptation of system-level tools to support studies of these systems, and steps toward development of mod- els for assessing ecologic exposures and effects. Indicators were red for develop- ing screening tools that reflect important toxicity pathways and for identifying benchmark and reference ENMs for use in studies to characterize exposure or dose. Research Progress Indicators: Getting to Green The research enterprise (Figure S-1) provides a means of capturing the flow of activities and examining the pathways needed to advance research pro- gress to get to green. As such the figure provides a means of illustrating barriers to research progress. The discussion focuses on six major categories: nano- material sources and development of reference materials, processes that affect nanomaterial exposure and hazard, the knowledge commons, model develop- ment, methods and instrumentation, and nanomaterial interactions in complex systems. Nanomaterial Sources and Development of Reference Materials Relevant ENMs include reference materials, materials from inventories, and materials released and modified across their value chain and life cycle. ENMs form the central element of research studies in the knowledge commons, the laboratory world, and the real world. The appropriate design and characteri- zation of ENMs are needed for developing libraries, informing the design of future ENMs, developing the data to populate the knowledge commons, devel- oping new methods and instrumentation, and conducting mechanistic studies and studies in complex media. The nanotechnology EHS research community has relied on commonly available ENMs to conduct most studies. There is no process for determining 

10 Research Progress on EHS Aspects of Engineered Nanomaterials which nanomaterials should have high priority for development on the basis of research needs. Elements for advancing the development and distribution of reference nanomaterials for research and analytic purposes to get to green in- clude the following:  A mechanism for identifying and setting priorities among nanomateri- als and libraries for development.  Adoption and use of appropriate and standardized material descriptors for the design, development, and sharing of ENMs.  Improved synthesis and purification methods for ENMs.  Collaboration among the scientists who are studying mechanisms and complex systems to optimize materials for study.  New methods and approaches for rapid characterization of reference materials.  Instrumentation for characterizing complex nanoscale species (materi- als of unknown origin, mixtures, and released materials).  Information-management plans and appropriate research infrastructure for collecting information on nanomaterial production and uses along the value chain. Fundamental Processes That Affect Nanomaterial Exposure and Hazard Research in this category occurs both in the laboratory world and the real world (Figure S-1) and involves experimental approaches to understand the physical, chemical, and biologic processes that affect exposure and hazard. Hy- pothesized ENM properties are scrutinized in well-defined laboratory experi- ments and in observations of ENM behavior in complex systems, from in vivo experiments to models of ecosystem interactions. The research is informed by development of methods and instrumentation that are needed for understanding ENM transformations, distribution, and effects. Continued efforts to elucidate mechanisms of ENM interactions with or- ganisms and ecosystems are critical for achieving the long-term goal of predict- ing ENM effects. The ability to make such predictions will allow evaluation of risks posed by ENMs at the design stage, in model predictions, and in validated screening assays. Continued progress in understanding mechanisms of ENM behavior will require advances in instrument development and an improved da- ta-integration infrastructure. Informatics: The Knowledge Commons The knowledge commons, the focal point of Figure S-1, is the locus for collaborative development of methods, models, and materials, and its success requires increased integration with research in the laboratory world and the real world and with development of materials. The knowledge commons serves three 

Summary 11 functions: a collaborative environment for the development and validation of predictive models, a collaborative environment for methods development, and a collaborative environment for the design of ENMs with the objective of improv- ing manufacturing processes to reduce risks. The strength of the knowledge commons is its ability to knit existing and new capabilities together in an overarching framework that provides a means of linking the various components of nanotechnology EHS research; such integra- tion has not yet occurred. In addition, such new initiatives as the National Nano- technology Initiative (NNI) Nanotechnology Knowledge Infrastructure (NKI) and the Materials Genome Initiative could augment the knowledge commons by providing additional linkages and informatics expertise. The knowledge com- mons would also have a key role in integrating participation of all sectors— including government and academic researchers, NGOs, regulators, and indus- try—to generate the data and knowledge that are required as inputs. Model Development An important outcome of the knowledge commons will be the develop- ment of a suite of models for predicting physical characteristics of ENMs, out- comes of toxicity testing, and exposures. There has been some progress in de- velopment of some types of models, but there is a lack of consistency in approaches and interoperability of data to support effective model development. Development of integrated models is needed to link behavior of ENMs to their characteristics and to properties of systems into which they are released. Getting to green in the development of predictive models will require sub- stantial data development from mechanistic and complex-system studies and characterization of physical properties of a variety of ENMs in different envi- ronments. Initial models will need to be developed iteratively using emerging data. Early outputs of the models can inform data needs and influence decisions about experimental approaches and instrumentation needs. Methods and Instrumentation Methods and instrumentation are defined as tools required for detecting and characterizing ENMs and their properties in relevant media. Progress in development of methods and instrumentation has varied because of the different applications of the tools; there has been some progress in characterizing newly manufactured ENMs in well-understood, simple media but little in detecting and characterizing ENMs in complex environments. Progress in developing methods and instrumentation will require charac- terization and quantification of the properties of ENMs in complex biologic and environmental media and measurement of the properties of single particles so that specific ENM properties can be associated with observed behaviors and effects. 

12 Research Progress on EHS Aspects of Engineered Nanomaterials Nanomaterial Interactions in Complex Systems Ranging from Subcellular Systems to Ecosystems Research on nanomaterial interactions in complex systems cuts across the laboratory world and the real world (Figure S-1). A critical barrier to advancing understanding of ENM interactions in complex systems is the lack of mechanis- tic data: an increasing volume of toxicity data is being produced, but the ability to use the data to predict ENM risks with any certainty is constrained because of the types of studies conducted. To provide more useful information on potential human and environmental risk, studies need to focus on more complex experi- mental-design issues—such as relevant dose and dosimetry; dose–response rela- tionships and time-course characteristics; appropriate target cells, tissues, and organisms; and examination of more biologic pathways—concomitantly with better characterization of ENM test substances and incorporation of standardized reference materials as controls. The data, in a common format, should be shared among investigators, and results of in vivo studies (at relevant concentrations) should be compared with results of in situ and in vitro screening assays to foster development of these more expedient testing strategies. Validated screening tools also need to be de- veloped so that information can be compared across experiments and used in modeling efforts to predict potential effects on humans and ecosystems. Implementation Progress and Steps Needed to Get to Green In the committee’s first report, it identified mechanisms to ensure imple- mentation of the EHS research strategy: enhancing interagency coordination; providing for stakeholder engagement in the research strategy; conducting and communicating results of research funded through public–private partnerships; and managing conflicts of interest. Collectively, those mechanisms represent support needed for the nanotechnology EHS research enterprise (Figure S-1), given the broad potential reach of nanotechnology in our society and economy and the EHS issues that span the missions of many stakeholders. Progress in addressing implementation indicators ranged from yellow to red; no indicators were denoted as green (see Box S-2). Enhancing Interagency Coordination In its first report, the committee acknowledged the value of the coordinat- ing role played by NNI and pointed to changes that have enhanced interagency coordination, including the naming of an EHS coordinator to the National Nano- technology Coordination Office (NNCO) and the NNI’s release of its 2011 EHS research strategy. However, the committee concluded that accountability for implementation of the NNI’s EHS research strategy is hampered by the absence of an entity that has sufficient management and budgetary authority to direct 

Summary 13 implementation among NNI agencies and to ensure integration of the strategy with EHS research being undertaken nationally and abroad. Ensuring implemen- tation of the strategy and gauging progress in high-priority research also require an assessment of the effectiveness of available mechanisms for interagency col- laboration and frequent review of funding needs. The committee determined that some progress had been made by the NNI in increasing collaborations in EHS research and in tracking how research aligns with its broader goals and strategy. In spite of increased collaboration among federal agencies, the committee did not discern substantial progress toward es- tablishing a mechanism to ensure sufficient management and budgetary authori- ty to develop and implement an EHS research strategy among NNI agencies, and it designated this indicator red. The need for a stronger, convening authority to direct EHS research efforts conducted under the NNI has been similarly raised in several independent reviews of the NNI and its strategy (for example, by the President’s Council of Advisors on Science and Technology and the Government Accountability Office). The committee gave a yellow rating to the extent to which the NNCO is identifying funding needs for collaborative efforts between agencies to acceler- ate high-priority research progress. To move this indicator toward green will require processes to estimate funding needs periodically and to track and report progress toward meeting the needs. Providing for Stakeholder Engagement in the Research Strategy The committee determined that some progress had been made toward ac- tively engaging diverse stakeholders in a continuing manner in all aspects of strategy development, implementation, and revision (indicator yellow). The committee notes recent examples, including the NIOSH-sponsored Safe Nano by Design Conference in Albany, NY, in 2012. To advance progress in this indicator, the committee considers that addi- tional effort is needed to foster engagement with stakeholders, including sup- porting the NIOSH forum as an annual event. Similar forums should be created, perhaps around other EHS themes, including consumers, the environment, or the value chain. Such forums could be expanded to standing bodies to ensure con- tinued engagement. In addition, the committee recommends creation of a Stake- holder Advisory Council by NNCO to help to assess the effectiveness of and opportunities for stakeholder engagement. Conducting and Communicating the Results of Research Funded Through Public–Private Partnerships Public–private partnerships are needed to expand and enrich EHS research through focused collaborations with stakeholders (for example, ENM manufac- turers) and to expand and leverage federal funding. The committee determined 

14 Research Progress on EHS Aspects of Engineered Nanomaterials that little or no progress had been made in creating well-defined effective part- nerships, as measured by execution of partnership agreements, issuance of re- quests for proposals, and the establishment of a governance structure; it desig- nated this indicator red. NIOSH provides the closest current example: exposure surveys conducted at nanomaterial-manufacturing facilities. Other examples of public–private partnerships are the European-based Nanotechnology Capacity Building NGOs (NanoCap) that addressed nanotech- nology EHS risks and the NNI’s signature initiatives5. Another blueprint outside the realm of nanotechnology is the Health Effects Institute (HEI); a nonprofit organization chartered to provide science on the health effects of air pollution and funded 50:50 by EPA and the motor-vehicle industry. Getting to green on the establishment of public–private partnerships may require an approach similar to the model of HEI but with a focus on nanotech- nology EHS issues. Critical elements of such a public–private partnership would need to include an independent and accountable governance structure, adequate and shared funding, specific and agreed-on goals, transparent sharing of results and information, and appropriate confidentiality agreements that balance the proprietary needs of industry participants with the public need to share infor- mation and make decision-making processes transparent. Managing Potential Conflicts of Interest In its first report, the committee noted that the NNI’s dual functions— developing and promoting nanotechnology and its applications and mitigating risks arising from such applications—pose tension or even actual conflict be- tween its respective goals. The clearest manifestation of the tension is the dis- parate allocation of resources between the two functions and the inadequacy of EHS risk research funding. The risks of early-stage technology development are intrinsically riddled with uncertainties; the science needed to provide definitive answers is highly complex and integrative and takes many years to develop. When faced with those nuances, an organization that is evaluated largely accord- ing to its success in technology development may not be perceived as able to set EHS research priorities among either resources or study topics effectively. The committee determined that little progress had been made in establish- ing a clear separation in management and budgetary authority and accountability between the functions of developing and promoting applications of nanotech- nology and understanding and assessing its potential health and environmental implications, and this indicator was designated red. Some progress was made in continued separate tracking and reporting of EHS research activities and funding as evidenced in the research-project funding data in the NNI’s EHS research 5 The signature initiatives, although not focused on EHS issues, are collaborations that are intended to spur the advancement of nanotechnology. The NKI is one of the signature initiatives. 

Summary 15 strategy and in the NNI’s supplement to the president’s 2013 budget. This indi- cator was designated yellow. The committee maintains that the NNI would benefit from a clearer sepa- ration of authority and accountability for its EHS research enterprise in relation to its mandate to promote nanotechnology development and commercialization. But it acknowledges that absent a change in the NNI’s statutory mandate, estab- lishment of wholly separate management and budgetary structures and authori- ties for the dual functions may not be realistic. Nonetheless, other steps could be taken at both the agency level and across the NNI as a whole to address this concern. Agencies should create and adhere to strong scientific-integrity policies governing both intramural and extramural research and should consider creating an ombudsman position to receive, investigate, and resolve complaints or con- cerns about bias and conflicts of interest related to nanotechnology research. The NNCO should develop and disseminate best practices for identifying, managing, and preventing conflicts of interest and bias in the planning, conduct, and report- ing of research. GOING BEYOND GREEN Beyond advancing progress on the indicators, the committee projects to a time beyond the domain of its current research recommendations to consider how questions about risk can be best approached in an adaptive and continuing manner so as to update priorities for research and identify concerns. The committee has repeatedly concluded that more engaged and broadly reaching governance is needed for nanotechnology EHS research. Unlike other “big science” initiatives, such as the Human Genome Project, the applications of nanotechnology permeate every sector of our society and economy; this means that the research spans the missions and jurisdictions of many diverse govern- ment agencies and intersects with activities and interests of many stakeholders. Also unlike some initiatives that focus principally or exclusively on technology development and applications, the NNI and its associated agencies are involved in research touching on both applications and implications. Governance process- es must actively engage all relevant groups in the process of managing nano- technology EHS research while addressing perceived or actual conflicts of inter- est. An integrated and well-coordinated program on both national and global scales would help to ensure that research findings provide the evidence needed to inform EHS decisions so that risks can be effectively managed and, ideally, prevented. Such governance requires empowered leadership: if all agencies are responsible, to some degree, for nanotechnology EHS research, no single agency can be held clearly accountable for its management and progress. The gap in empowered nanotechnology EHS research leadership at the federal level has made coordination and communication challenging and left the enterprise open to perceptions of conflicts between technology development and risk-related research. The committee considers that progress could be accelerated if one of 

16 Research Progress on EHS Aspects of Engineered Nanomaterials the NNI agencies that has EHS in its mission were designated as the lead agency for directing EHS research throughout the federal government. Alternatively, a new entity could serve that function. Whatever organization oversees the nanotechnology EHS research strate- gy, among its most important functions will be to secure and maintain adequate funding for the program, inasmuch as the research strategies outlined by the NNI and the present committee cannot be accomplished without a sustained commitment over at least the next decade. In addition to funding, it is critical that the best researchers nationally and abroad be engaged in this effort and that incentives be established to encourage joint planning and information exchange to address the multidisciplinary research. An essential element of effective governance and sustenance of the re- search is a means of ensuring that all stakeholders have access to the growing and evolving body of knowledge—the knowledge commons. Such a resource will provide information relevant to nanotechnology EHS research at multiple levels of detail and thus can improve public understanding, inform policy- makers, offer data for future researchers, and shape the focus of future research. For researchers, the knowledge commons will provide access to existing data and will add mechanisms to curate, annotate, and link datasets, so that it will be possible to “bank” the data for consideration by future researchers. The availa- bility of such an inventory would also facilitate oversight of the nanomaterial research program itself and provide greater accountability for research progress. The knowledge commons would provide a context for addressing the recognized need for improved taxonomies of ENM structures, experiments, characteristics, models, effects, and uses. A pragmatic approach would be the development of ontologies that map one set of defined terms onto other commonly used sets to permit data to be fully shared even if researchers adopt different conventions for nomenclature, formatting, and reporting. CONCLUDING REMARKS Characterization of the risks posed by ENMs across their life cycles is a scientific challenge that requires integrated, quantitative, and systems-level sci- entific approaches. It is also an institutional challenge that stretches the conven- tional roles of agencies and researchers and that looks to how future concerns can be addressed and anticipated. Strong governance is vital if effective, timely, and actionable research is to be ensured. Empowered leadership at the federal level with oversight by a single agency would begin to address many of the or- ganizational barriers. There should be sustained funding for this research and for the infrastructure needed to support data-sharing. The necessary ideal of respon- sible development of nanotechnology is both daunting and important, but there is no doubt that it is attainable if we plan well for research and for the manage- ment of the infrastructure needed to shape and disseminate its findings.