1

Introduction

Despite the increase in funding for research and the rising numbers of peer-reviewed publications over the past decade that address the environmental, health, and safety (EHS) aspects of engineered nanomaterials (ENMs) (NRC 2012; NSET 2012; PCAST 2012), uncertainty about the implications of potential exposures of consumers, workers, and ecosystems to these materials persists. Consumers and workers want to know which of these materials they are exposed to and whether the materials can harm them (see Appendix C). Industry is concerned about being able to predict with sufficient certainty whether products that it makes and markets will pose any EHS issues and what measures should be taken regarding manufacturing practices and worldwide distribution to minimize any potential risk. However, there remains a disconnect between the research that is being carried out and its relevance to and use by decision-makers and regulators to make informed public health and environmental policy and regulatory decisions.

Although those broad topics remain to be better addressed, progress has been made in understanding some aspects of EHS risks posed by ENMs. There is now greater understanding of the dynamic behavior of ENMs; minimum characterization standards, which are still evolving, are now more widely accepted by the field; some reference materials have been distributed and evaluated with models; models for estimating environmental exposures to ENMs have been proposed; and methods for characterizing ENMs in relevant matrices have been developed. However, research on the potential EHS implications of ENMs still lacks context, particularly with regard to future risks, because materials and their uses are changing rapidly. Consequently, the continued focus on available and well-studied materials (such as titanium dioxide) may be misplaced; it is possible that the issues most salient for the future are not being addressed. Some relevant topics have received little attention, such as possible effects of ingested ENMs on human health, measurement of nanoscale characteristics that influence their behavior in situ (for example, the structure of surface coatings), and processes that affect biouptake.



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1 Introduction Despite the increase in funding for research and the rising numbers of peer-reviewed publications over the past decade that address the environmental, health, and safety (EHS) aspects of engineered nanomaterials (ENMs) (NRC 2012; NSET 2012; PCAST 2012), uncertainty about the implications of poten- tial exposures of consumers, workers, and ecosystems to these materials persists. Consumers and workers want to know which of these materials they are exposed to and whether the materials can harm them (see Appendix C). Industry is con- cerned about being able to predict with sufficient certainty whether products that it makes and markets will pose any EHS issues and what measures should be taken regarding manufacturing practices and worldwide distribution to minimize any potential risk. However, there remains a disconnect between the research that is being carried out and its relevance to and use by decision-makers and regulators to make informed public health and environmental policy and regula- tory decisions. Although those broad topics remain to be better addressed, progress has been made in understanding some aspects of EHS risks posed by ENMs. There is now greater understanding of the dynamic behavior of ENMs; minimum char- acterization standards, which are still evolving, are now more widely accepted by the field; some reference materials have been distributed and evaluated with models; models for estimating environmental exposures to ENMs have been proposed; and methods for characterizing ENMs in relevant matrices have been developed. However, research on the potential EHS implications of ENMs still lacks context, particularly with regard to future risks, because materials and their uses are changing rapidly. Consequently, the continued focus on available and well-studied materials (such as titanium dioxide) may be misplaced; it is possi- ble that the issues most salient for the future are not being addressed. Some rele- vant topics have received little attention, such as possible effects of ingested ENMs on human health, measurement of nanoscale characteristics that influence their behavior in situ (for example, the structure of surface coatings), and pro- cesses that affect biouptake. 17

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18 Research Progress on EHS Aspects of Engineered Nanomaterials Investments in nanotechnology and the production of ENMs continue to grow; the global market for nanotechnology products is projected to exceed $3 trillion by 2015 (Lux 2008a,b). Industry practices are changing, moving from the use of nanotechnology for enhancement of existing technologies to manufac- turing of new products that depend on novel materials and the functionality of nanotechnology (Maynard 2009). Industries are no longer touting nanotechnolo- gy initiatives; rather, nanotechnology is becoming embedded in their business practices. However, EHS research efforts are not keeping pace with the evolving applications of nanotechnology, and this issue has motivated development of the research agendas on EHS aspects of ENMs for more than a decade. That context was crucial in the timing of the first report from the present committee, A Re- search Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials, which was released in January 2012, and remains relevant for this second report. STUDY SCOPE The US Environmental Protection Agency (EPA) requested that the Na- tional Research Council perform an independent study to develop and monitor the implementation of an integrated strategy for research on EHS aspects of ENMs (see Appendix B for complete statement of task). 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 in 2009. In its first report, as requested, the committee created a conceptual framework for EHS-related research, developed a research plan with short-term and long-term priorities, and estimated resources needed to imple- ment the research plan. For this second report, the committee was tasked with evaluating research progress and updating the research priorities and resource estimates on the basis of results of studies and emerging trends in the nanotech- nology industry. Specifically, the committee was asked to address the following:  What research progress has been made in understanding the environ- mental, health, and safety aspects of nanotechnology? How does the research progress affect relevance of the initial set of research priorities?  How have market and regulatory conditions changed and how does this affect the research priorities?  Are the criteria for evaluating the research progress on the environmen- tal, health, and safety aspects of nanotechnology appropriate?  Considering the criteria developed, to what extent have short-term and long-term research priorities been initiated and implemented?

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Introduction 19 OVERVIEW OF FIRST REPORT The committee’s first report, A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials (NRC 2012), presented a strategic approach for developing the science and research infrastructure need- ed to address uncertainties regarding the potential EHS risks posed by ENMs. The report began by detailing why a research strategy is needed. In describing the rationale for the report, the committee emphasized the complexity of the issues (including the variety of the materials and the applications of materials science), the limitations of the available evidence, and the inadequacy of linkag- es between current research findings and the evidence needed to prevent and manage potential EHS risks. The committee recognized that there had already been considerable effort in the United States and abroad to identify research needs to support the development and safe use of nanotechnology, especially in the National Nanotechnology Initiative (NNI). Nevertheless, EPA sought to re- fine existing approaches further. The first report described a conceptual framework that structured the committee’s approach, focusing on emerging ENMs that may pose unanticipated risks and on the influence of properties of ENMs on hazards and exposures (Figure 1-1). The committee then identified critical research gaps that reflected elements of the framework and the tools needed for addressing the gaps. In addi- tion to the conceptual framework and the gaps and tools, the committee identi- fied four broad high-priority research topics that formed the backbone of its pro- posed research strategy. The committee recognized the evolving nature of ENM research and, in selecting the four broad categories, envisioned a risk-based sys- tem that would be informed and shaped by research outcomes and would sup- port approaches to environmental and human-health protection. The research categories were the following (NRC 2012, pp. 14-15):  “Identification, characterization, and quantification of the origins of na- nomaterial releases. Research in this category would develop inventories on ENMs being produced and used, identify and characterize the ENMs being re- leased and the populations and environments being exposed, and assess exposures to measure the quantity and characteristics of materials being released and to mod- el releases throughout their life cycle.  “Processes that affect both potential hazards and exposure. Research topics . . . would include the role of nanoparticle-macromolecular interactions in regulating and modifying nanoparticle behavior on scales ranging from genes to ecosystems; the effects of particle-surface modification on aggregation and nano- particle bioavailability, reactivity, and toxicity potential; processes that affect na- nomaterial transport across biologic or synthetic membranes; and the development of relationships between the structure of nanomaterials and their transport, fate, and effects. As an element of this research category, instrumentation and standard

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20 Research Progress on EHS Aspects of Engineered Nanomaterials methods will need to be developed to relate ENM properties to their hazard and exposure potential and to determine the types and extent of ENM transformations in environmental and biologic systems.  “Nanomaterial interactions in complex systems ranging from subcellular systems to ecosystems. . . . Examples of research in this category include efforts to understand the relationships between in vitro and in vivo responses; prediction of system-level effects, such as ecosystem functions (for example, nutrient cycling), in response to ENMs; and assessment of the effects of ENMs on endocrine and developmental systems of organisms.  “Adaptive research and knowledge infrastructure for accelerating re- search progress and providing rapid feedback to advance research. . . . Activities would include making characterized nanomaterials widely available, refining ana- lytic methods continuously to define the structures of the materials throughout their lifespan, defining methods and protocols to assess effects, and increasing the availability and quality of the data and models. Informatics would be fostered by the joining of existing databases and [the] encouraged and sustained curation and annotation of data.” FIGURE 1-1 Conceptual framework for the committee’s research strategy depicting “sources of nanomaterials originating throughout the lifecycle and value chain, and there- fore the environmental or physiologic context that these materials are embedded in, and the processes that they affect. The circle, identified as ‘critical elements of nanomaterial interactions,’ represents the physical, chemical, and biologic properties or processes that are considered to be the most critical for assessing exposures and hazards and hence risk” (NRC 2012, p. 55). The lower rectangle “depicts tools needed to support an informative research agenda on critical elements of nanomaterial interactions” (p. 56).

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Introduction 21 The committee identified financial resources needed to implement re- search in those categories. In examining resources, it recognized the differential level of research funding for the applications of nanotechnology and the poten- tial implications, but it took a pragmatic approach, recognizing funding con- straints, that was centered on current funding levels and informed by expert judgment. The committee recognized a gap between the amount of federal fund- ing and the level of activity required to support the research strategy. It conclud- ed that the core EHS research and development funding1 by federal agencies should remain constant for at least 5 years because any reduction in funding would be a setback for EHS research. Moreover, additional modest resources from public, private, and international initiatives should be made available for 5 years in five critical categories: informatics ($5 million per year), nanomaterial characterization ($10 million per year), developing benchmark ENMs ($3-5 million per year), characterization of sources ($2 million per year), and devel- opment of networks to support collaborative research ($2 million per year). These additional resources would total $22-24 million per year. The committee discussed the need for mechanisms to ensure implementa- tion of the research strategy and evaluation of research progress. Mechanisms for effective implementation of an EHS research strategy are as essential to the success of the strategy as is the substance of the identified research (NRC 2009). Integration of domestic and foreign participants involved in nanotechnology- related research—including the NNI and federal agencies, the private sector (for example, ENM developers and users), and the broader scientific and stakeholder communities (for example, academic researchers)—was seen as critical for im- plementation. Mechanisms identified for implementation included fostering interagency interaction, collaboration, and accountability; developing and implementing mechanisms for stakeholder engagement; advancing integration among sectors and institutions involved in EHS research, such as public–private partnerships; and structural changes that address conflicts of interest. In considering its task, the committee developed indicators that would serve as criteria for gauging the extent of research and implementation progress in this second report (see Boxes 1-1 and 1-2 for summaries of indicators of re- search and implementation progress, respectively). Given the short timeframe between the first and second reports, the committee considered that it would be sufficient to anticipate progress in initiating research in each of the four high- priority categories identified and in developing the infrastructure, accountability, and coordination mechanisms needed for implementation of the research strate- gy. The interval was far too short for substantial new research programs to be in place, let alone for evaluation of research outcomes (NRC 2012). 1 The committee estimated this funding to be about $120 million on the basis of the re- quested FY 2012 budget. However, the president’s 2013 budget revised the 2012 estimate to $102.7 million (NSET 2012).

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22 Research Progress on EHS Aspects of Engineered Nanomaterials BOX 1-1 Research-Progress Indicators 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 relevant media.  Development of methods to quantify effects of nanomaterials in experimental systems.  Advancement of systems for sharing results of research and fostering development of predictive models for nanomaterial behaviors.  Extent of joining together of existing databases, including development of common informatics ontologies. Quantifying and characterizing the origins of nanomaterial releases Progress indicators will be related to short-term activities:  Developing inventories of current and near-term production of nanomaterials.  Developing inventories of intended use of nanomaterials and value-chain transfers.  Identifying critical release points along the value chain.  Identifying critical populations or systems exposed.  Characterizing released materials and associated receptor environments.  Modeling nanomaterial releases along the value chain. Processes affecting 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 relevant biologic and environmental media.  Progress toward developing instrumentation to measure key nanomaterial properties and changes in them in relevant 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 heretofore underrepresented fields of research, such as those seeking to relate in vitro to in vivo observations, to predict ecosystem effects, or to examine effects on the endocrine or developmental systems.  Steps toward development of models for exposure and potential effects along the ecologic food chain. (Continued)

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Introduction 23 BOX 1-1 Continued  Extent of refinement of a set of screening tools that reflect important characteristics or toxicity pathways of the complex systems described above.  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.  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.2 Source: NRC 2012, pp. 181-182. BOX 1-2 Indicators of Progress in Implementation 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 National Nanotechnology Coordination Office] 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. Source: NRC 2012, p. 183. 2 In this report the committee differentiates between benchmark materials and refer- ence materials. Additional details are provided in Chapter 3.

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24 Research Progress on EHS Aspects of Engineered Nanomaterials With regard to evaluation of research over the longer term, the committee considered that criteria developed by the National Research Council Committee on Research Priorities for Airborne Particulate Matter3 (NRC 1998, 1999) should be applied in evaluating research progress periodically. Those criteria are listed below and discussed in more detail in the committee’s first report (see NRC 2012, pp. 182-187).  Scientific value: Does the research fill critical knowledge and data gaps?  Decision-making value: Does the research reduce uncertainties and in- form decision-making by key stakeholders, for example, decisions about risk as- sessment and risk management?  Feasibility and timing: Is the research technically and economically fea- sible, and can it be done in a timeframe responsive to stakeholder and decision- maker needs?  Interaction and collaboration: How well does the research agenda fos- ter the collaboration and interaction needed among scientific disciplines, agencies, academe, and private sector, especially in addressing cross-cutting issues? Are the scientific expertise, capacity, and resources appropriately used to enhance scien- tific creativity, quality, and productivity?  Integration: How well is the research agenda coordinated and integrated with respect to planning, budgeting, and management, including between govern- ment and private organizations?  Accessibility: How well is information about research plans, budgets, progress, and results made accessible to agencies, research organizations, and in- terested stakeholders? CONTEXT FOR AND APPROACH TO SECOND REPORT Several developments during and after completion of the first report influ- enced the committee’s approach to this second report. Notably, the NNI devel- oped and released its own environmental, health, and safety research strategy (NEHI 2011). That strategy builds on previous NNI EHS research-strategy doc- uments (NEHI 2006, 2007, 2008) and helps to develop a framework for coordi- nation among federal agencies and mechanisms to support implementation of the strategy. The committee’s original charge to develop and monitor implemen- tation of a research strategy was written in the absence of the 2011 federal EHS research strategy. In addition, there have been other government, academic, in- dustrial, and international efforts, some of which are described in Chapters 2-4 of this report. 3 That committee was asked by Congress to address uncertainties in the scientific evi- dence related to airborne particulate matter (PM) after the 1997 decision to establish a new National Ambient Air Quality Standard for fine PM.

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Introduction 25 Given the short period between the two reports, the committee in this re- port emphasizes institutional responses to the first report that have implications for conduct of future research. However, considering its charge, the committee assesses the trajectory of progress in the research and implementation indicators identified in the first report while focusing on implementation efforts and tool development necessary to move the research enterprise forward. The committee believes that the indicators remain appropriate for evaluating research and im- plementation progress.4 The committee was not able to reevaluate the resource estimates from the first report, as more current funding information was not available. The committee has developed a graphical construct in Chapter 4 (shown here as Figure 1-2) that complements Figure 1-1 and provides a vision for the EHS nanotechnology research enterprise. Figure 1-2 describes the interrelated and interdependent research activities that are driven by ENM production and highlights the importance of a coordinated research infrastructure. INVENTORIES MATERIALS REFERENCE ENM RELEASES LABORATORY KNOWLEDGE REAL  WORLD COMMONS WORLD VALIDATION SCREENING TOOLS METHODS/INSTRUMENTS MODELS METHODS/INSTRUMENTS RISK DECISION MAKING FIGURE 1-2 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 or current production capacity, including the properties of the nanomaterial.) The knowledge commons (red box) is the locus for collaborative development of methods, 4 In the period between the first and second reports, no substantial changes in market or regulatory conditions that would influence research priorities were noted.

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26 Research Progress on EHS Aspects of Engineered Nanomaterials 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 mechanism-based research that is directed at understanding the physical, chemical, and biologic properties or processes that are most critical for as- sessing exposures and hazards and hence risk (NRC 2012, p. 55). The “real world” in- cludes complex systems research involving observational studies that examine the effects of ENMs on people and ecosystems. 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. As part of its data-gathering efforts, the committee held a workshop on November 7, 2012. The workshop was organized to gain input from federal agencies, researchers, industry, and nongovernment organizations to help in gauging the extent of research progress and understanding efforts that are under way to address scientific uncertainties and research infrastructure needs (see Appendix C for a summary of the workshop). The committee also used its ex- pert judgment based on literature reviews and knowledge of the state of the sci- ence to evaluate the extent of research and implementation progress. Chapter 2 reviews recent reports on EHS aspects of ENMs and the com- mittee’s impressions drawn from the workshop. Chapter 3 assesses progress in research and implementation, classifying the research trajectory into three broad categories—substantial progress (green), moderate or mixed progress (yellow), and little progress (red). Chapter 4 analyzes findings from Chapter 3 and sug- gests pathways for advancing the research enterprise (Figure 1-2). Finally, Chapter 5 considers the overall charge and offers a vision for optimizing the research efforts of the EHS nanotechnology community and provides steps to address the longer-term criteria identified in the committee’s first report. REFERENCES Lux Research. 2008a. Nanomaterials State of the Market Q3 2008: Stealth Success, Broad Impact. Lux Research, July 1, 2008 [online]. Available: https://portal.luxresearchinc. com/research/document_excerpt/3735 [accessed Mar. 11, 2013]. Lux Research. 2008b. Overhyped Technology Starts to Reach Potential: Nanotech to Impact $3.1 Trillion in Manufactured Goods in 2015. Press release: July 22, 2008 [online]. Available: http://www.nanotechwire.com/news.asp?nid=6340 [assessed Mar. 11, 2013]. Maynard, A.D. 2009. Commentary: Oversight of engineered nanomaterials in the work- place. J. Law Med. Ethics 27(4):651-658. NEHI (Nanotechnology Environmental Health Implications Working Group). 2006. En- vironmental, Health, and Safety Research Needs for Engineering Nanoscale Mate- rials. Nanotechnology Environmental Health Implications Working Group, Na- noscale Science, Engineering, and Technology Subcommittee, Committee on Technology, National Science and Technology Council. September 2006 [online]. Available: http://www.nano.gov/NNI_EHS_research_needs.pdf [accessed Mar. 11, 2013].

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Introduction 27 NEHI (Nanotechnology Environmental Health Implications Working Group). 2007. Priori- tization of Environmental, Safety and Health Research Needs for Engineered Na- noscale Materials: An Interim Document for Public Comment. Nanotechnology En- vironmental Health Implications Working Group, Nanoscale Science, Engineering, and Technology Subcommittee, Committee on Technology, National Science and Technology Council. August 2007 [online]. Available: http://nanotech.law.asu.edu/ Documents/2010/08/Prioritization_EHS_Research_Needs_Engineered_Nanoscal e_Materials_527_8119.pdf [accessed Mar. 11, 2013]. NEHI (Nanotechnology Environmental Health Implications Working Group). 2008. Strategy for Nanotechnology-Related Environmental, Health, and Safety Research. National Nanotechnology Initiative. Nanotechnology Environmental Health Impli- cations Working Group, Subcommittee on Nanoscale Science, Engineering, and Technology, Committee on Technology, National Science and Technology Coun- cil. February 2008 [online]. Available: http://www.nano.gov/NNI_EHS_Research_ Strategy.pdf [accessed Mar. 11, 2013]. NEHI (Nanotechnology Environmental Health Implications Working Group). 2011. Na- tional Nanotechnology Initiative 2011 Environmental, Health, and Safety Strategy, October 2011. Nanotechnology Environmental Health Implications Working Group, Subcommittee on Nanoscale Science, Engineering, and Technology, Committee on Technology, National Science and Technology Council [online]. Available: http:// www.nano.gov/sites/default/files/pub_resource/nni_2011_ehs_research_strategy.pdf [accessed Mar. 11, 2013]. NRC (National Research Council). 1998. Research Priorities for Airborne Particulate Matter. I. Immediate Priorities and Long-Range Research Portfolio. Washington, DC: National Academy Press. NRC (National Research Council). 1999. Research Priorities for Airborne Particulate Matter. II. Evaluating Research Progress and Updating the Portfolio. Washington, DC: National Academy Press. NRC (National Research Council). 2009. Review of the Federal Strategy for Nanotech- nology-Related Environmental, Health, and Safety Research. Washington, DC: National Academies Press. NRC (National Research Council). 2012. A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials. Washington, DC: National Academies Press. NSET (Nanoscale Science, Engineering, and Technology Subcommittee). 2012. The National Nanotechnology Initiative: Research and Development Leading to a Rev- olution in Technology and Industry: Supplement to the President's FY 2013 Budg- et. Subcommittee on Nanoscale Science, Engineering, and Technology, National Science and Technology Council. February 2012 [online]. Available: http://www. nano.gov/sites/default/files/pub_resource/nni_2013_budget_supplement.pdf [ac- cessed Mar. 11, 2013]. PCAST (President’s Council of Advisors on Science and Technology). 2012. Report to the President and Congress on the Fourth Assessment of the National Nanotech- nology Initiative. April 2012 [online]. Available: http://nano.gov/sites/default/files/ pub_resource/pcast_2012_nanotechnology_final.pdf [accessed Dec. 5, 2010].