Summary

Nanotechnology relies on the ability to design, manipulate, and manufacture materials at the nanoscale.1 The emerging field of nanotechnology has the potential to lead to substantial advances in many sectors— energy, medicine, electronics, and clean technologies, for example— while contributing to substantial economic growth. Engineered nanomaterials (ENMs) are already in industrial and consumer products, including drug-delivery systems, stain-resistant clothing, solar cells, cosmetics, and food additives. It is the nanoscale-specific properties of ENMs (for example, their electronic, optical, or chemical-reactive qualities) that are key to research and commercial applications.

The nanotechnology sector, which generated about $225 billion in product sales in 2009, is predicted to expand rapidly over the next decade with the development of new technologies that have new capabilities. The increasing production and use of ENMs may lead to greater exposures of workers, consumers, and the environment, and the unique scale-specific and novel properties of the materials raise questions about their potential effects on human health and the environment. In light of the rising use of ENMs, this report was motivated by the need for a research strategy to address critical gaps in knowledge related to the unique properties and environmental, health, and safety (EHS) risks of ENMs. Major challenges in developing such a strategy include

•  Great diversity of nanomaterial types and variants.

•  Lack of capabilities to monitor rapid changes in current, emerging, and potential ENM applications and to identify and address the potential consequences for EHS risks.

•  Lack of standard test materials and adequate models for investigating EHS risks, leading to great uncertainty in describing and quantifying nanomaterial hazards and exposures.

To address these challenges, the Environmental Protection Agency (EPA) asked the National Research Council to perform an independent study to de-

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1Nanoscale refers to materials on the order of one billionth of a meter.



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Summary Nanotechnology relies on the ability to design, manipulate, and manufac- ture materials at the nanoscale.1 The emerging field of nanotechnology has the potential to lead to substantial advances in many sectors—energy, medicine, electronics, and clean technologies, for example—while contributing to substan- tial economic growth. Engineered nanomaterials (ENMs) are already in indus- trial and consumer products, including drug-delivery systems, stain-resistant clothing, solar cells, cosmetics, and food additives. It is the nanoscale-specific properties of ENMs (for example, their electronic, optical, or chemical-reactive qualities) that are key to research and commercial applications. The nanotechnology sector, which generated about $225 billion in product sales in 2009, is predicted to expand rapidly over the next decade with the de- velopment of new technologies that have new capabilities. The increasing pro- duction and use of ENMs may lead to greater exposures of workers, consumers, and the environment, and the unique scale-specific and novel properties of the materials raise questions about their potential effects on human health and the environment. In light of the rising use of ENMs, this report was motivated by the need for a research strategy to address critical gaps in knowledge related to the unique properties and environmental, health, and safety (EHS) risks of ENMs. Major challenges in developing such a strategy include  Great diversity of nanomaterial types and variants.  Lack of capabilities to monitor rapid changes in current, emerging, and potential ENM applications and to identify and address the potential conse- quences for EHS risks.  Lack of standard test materials and adequate models for investigating EHS risks, leading to great uncertainty in describing and quantifying nanomate- rial hazards and exposures. To address these challenges, the Environmental Protection Agency (EPA) asked the National Research Council to perform an independent study to de- 1 Nanoscale refers to materials on the order of one billionth of a meter. 3

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4 Summary velop and monitor the implementation of an integrated research strategy on EHS risks of 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 prepared this report. The committee was charged to create a conceptual framework for EHS- related research, to develop a research plan with short-term and long-term re- search priorities, and to estimate resources needed to implement the research plan2. In a subsequent report, the committee will evaluate research progress. In this report, the committee presents a strategic approach for developing the science and research infrastructure needed to address uncertainties regarding the potential EHS risks of ENMs. This approach begins with a discussion of the need for a research strategy. The committee next describes a new conceptual framework that structures its approach, focusing on emerging materials that may pose unanticipated risks, and on the properties of ENMs and their influence on hazards and exposure. The committee then identifies critical research gaps re- flecting the elements of the framework, and the tools needed for addressing these gaps. Together with the conceptual framework and the identified gaps and tools, the committee develops the research portfolio, identifying where changes in course are needed, and where additional cross-cutting research would add value. Resources needed to implement the research priorities are identified. Last, the committee discusses the need for mechanisms to ensure implementation of the research strategy and evaluation of research progress that will be conducted in the subsequent report. WHY IS ANOTHER STRATEGY FOR ENVIRONMENTAL, HEALTH, AND SAFTETY RESEARCH NEEDED? As nanotechnology has burgeoned, questions about the possible risks posed by ENMs have been raised, fueled in part by the increased production, by a growing awareness that adequate methods are not available to detect and char- acterize the materials in the environment, and by recognition that the materials are in products or environments where exposures potentially can occur. In re- sponse to those concerns, there has been an increase over the last decade both in funding for research and in peer-reviewed publications addressing EHS effects of ENMs, in particular from the U.S. National Nanotechnology Initiative (NNI), “the government’s central locus for the coordination of federal agency invest- ments in nanoscale research and development” (NRC 2009).3 Over the last decade, many assessments of the potential EHS effects of nanotechnology have been conducted worldwide by government agencies (in- 2 See Chapter 1 for the committee’s statement of task. 3 NRC (National Research Council). 2009. Review of the Federal Strategy for Nanotechnology-Related Environmental, Health, and Safety Research. Washington, DC: National Academies Press.

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Environmental, Health, and Safety Aspects of Engineered Nanomaterials 5 cluding the NNI), academic institutions, and industry (see Table 1-1). Those efforts have helped to translate and communicate information on the potential EHS effects of nanotechnology among researchers who are generating the scien- tific evidence, the businesses that use nanotechnology, the consumers who are using products with ENMs, and the various regulators who are overseeing ENMs. In the United States, the NNI has coordinated the efforts of regulatory and research agencies in identifying and addressing cross-agency research needs. The NNI guidance is complemented by agency-specific research strate- gies. In addition, the 2009 National Research Council review of the federal strategy highlighted the coordinating functions of the NNI and identified ele- ments that are integral to a research strategy, including input from various stakeholders and mechanisms to ensure that the research strategy will be sup- ported and funded. The 2009 report also identified limitations of the NNI ap- proach. The NNI’s 2011 Draft EHS Strategy addresses some of the limitations and further develops a framework for coordination among federal agencies and mechanisms to support the implementation of the strategy.4 Despite some progress in assessing research needs and in funding and conducting research, developers, regulators, and consumers of nanotechnology- enabled products remain uncertain about the variety and quantity of nanomateri- als in commerce or in development, their possible applications, and any poten- tial risks. There is insufficient connection and integration between generation of data and analyses on emergent risks and strategies for preventing and managing the risks. Based on the committee’s review of the current state of research and its re- lation to the needs of developers, regulators, and users of ENMs, three particular gaps are evident. First, little research progress has been made on some key top- ics, such as the effects of ingested ENMs on human health. Second, there is little research on the potential health and environmental effects of the more complex ENMs that are expected to enter commerce over the next decade. Third, system- integrative approaches are needed that can address all forms of ENMs based on their properties and an understanding of the underlying biologic interactions that determine exposure and risk. In spite of the need to provide more certain infor- mation on potential EHS risks, the gaps in understanding identified in many scientific workshops over the last decade have not been aggressively addressed with needed research. Common themes identified in workshops include the need for standardized materials, standardized methods to evaluate exposures, both in the workplace and in the environment, and harmonized methods for in vitro to in vivo validation in hazard assessments. In addition, rapidly evolving research approaches reflect an increasing emphasis on high-throughput screening and predictive modeling, both essential for managing the complexity of ENMs. 4 The final version of the strategy was released in October 2011. However, because this report had already gone through peer review, the final version of the NNI EHS strat- egy was not reviewed or commented on by the committee.

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6 Summary Thus, there is a need for a research strategy that is independent of any one stakeholder group, that has human and environmental health as the primary fo- cus, that builds on past efforts and is flexible in anticipating and adjusting to emerging challenges, and that provides decision-makers with timely, relevant, and accessible information. THE COMMITTEE’S CONCEPTUAL FRAMEWORK The diverse properties of nanomaterials make them challenging from the perspective of risk assessment. The variety of ENM types and the variation within types make it difficult to define their composition, structure, and proper- ties without extensive characterization. The countless assemblages of atoms and structures and the plethora of inorganic and organic macromolecular coatings affect ENM surface chemistry and thus their behavior in the environment and in organisms. Depending on the environment where a nanomaterial is present (for example, lung fluid, surface water, or air), its surface properties may change, affecting its behavior, so that making predictions about such behavior and poten- tial effects is challenging. Because of the variety of ENMs with differing proper- ties, it is difficult to identify materials or classes of materials that may behave similarly with respect to fate, transport, toxicity, and risk. In developing the new conceptual framework for considering ENM-related risks and for shaping the direction of the research portfolio (see Figure S-1), the committee considered properties that might be identified in a new nanomaterial that could pose a new, enhanced, or ill-defined risk. There is a need for an ap- proach that promotes scientifically sound investigations of emerging risks and provides timely results relevant to the rapidly developing nanomaterial industry without relying on case-by-case evaluations of the nanomaterials. The committee’s conceptual framework is characterized by three key fea- tures:  A value-chain5 and life-cycle perspective that considers potential ef- fects originating in the production and use of nanomaterials, nanomaterial- containing products, and the wastes generated.  A focus on determining how nanomaterial properties (for example, size, surface characteristics, solubility, and crystallinity) affect key processes 5 A value chain is a chain of activities that extends from the generation of nanomateri- als to the production of primary and secondary products that are based on them. Activi- ties along the value chain imply inputs of energy and materials at each stage and the crea- tion of waste streams. For example, such ENMs as quantum dots (QDs) and single- walled carbon nanotubes (SWCNTs) might be combined as QD-SWCNT composites in primary products, such as thin films. Thin films might then be incorporated into solar cells (secondary products), which are then used in housing materials (tertiary products). All the products that form the value chain have their own life cycles associated with their manufacture, transport, processing, use, and end of life.

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Environmental, Health, and Safety Aspects of Engineered Nanomaterials 7 (for example, agglomeration, aggregation, dissolution, and deposition) that are relevant to predicting both hazard and exposure.  The application of three principles that help guide our understanding of ENMs and research gaps when addressing ENM risks. The three principles ad- dress the emergent nature of ENM risks, the plausibility or likelihood of signifi- cant risks, and the potential severity of an effect.6 Figure S-1, which is not intended to show a linear process, depicts sources of nanomaterials originating throughout their value chains and life cycles and considers the environmental or physiologic context of these materials and the processes that they affect. The circle, identified as “critical elements of nanoma- terial interactions,” represents the physical, chemical, and biologic properties or processes that are considered most critical for assessing exposure, hazard, and hence risk. Those elements exist on many levels of biologic organization, in- cluding molecules, cells, tissues, organisms, populations, and ecosystems. The committee asks, What are the most important elements to examine to determine whether a nanomaterial is harmful? It has placed these elements at the center of the proposed research framework. The lower half of the figure depicts tools that can support a research agenda on the critical elements of nanomaterial interac- tions. The tools include materials (standardized ENMs that represent a variety of characteristics of interest), methods (standardized approaches for characterizing, measuring, and testing ENMs), models (for example, for assessing availability, concentration, exposure, and dose), and informatics7 (methods and systems for systematically capturing, archiving, and sharing research results). The vertical arrows between the tools and the circle containing the critical elements represent the interplay between what is learned about the processes that influence expo- sure and hazard and the continuing evolution of the tools for carrying out re- search. The committee’s framework assumes that EHS research priorities can be determined on the basis of judgments regarding the relationships between nanomaterial properties and the processes that govern their interactions with organisms and ecosystems. These interactions will ultimately shed light on the emergent and plausible risks posed by the materials. Addressing gaps in our knowledge of these processes requires the recognition that many of the key re- search questions are systems issues—that is, they can be addressed only by con- sidering the interactions of the various components along the life cycle of nano- 6 The principles help in identifying nanomaterials that require closer scrutiny regarding risk, irrespective of whether they are established, emerging, or experimental ENMs. The principles also help to avoid a reliance on rigid definitions of ENMs. 7 Informatics is defined here as the infrastructure and information science and technol- ogy needed to integrate data, information, and knowledge. An overall purpose of infor- matics in the context of EHS aspects of nanotechnology is to organize data so that they can be mined to determine how nanomaterial properties affect their exposure and hazard potential and overall risks to the environment and human health.

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8 Summary materials. For example, this framework considers the evaluation of hazard and the evaluation of exposure as occurring in concert, rather than sequentially. The conceptual framework supports a strategic approach to nanotechnol- ogy-EHS research. Critical gaps in knowledge (Chapter 3) and the need for im- proved tools—including materials, methods, models, and informatics—to ex- plore them (Chapter 4) figure prominently in identifying priorities for research (Chapter 5). CRITICAL RESEARCH GAPS Despite the substantial research already done on potential EHS risks posed by ENMs, critical gaps remain. The committee, using its collective judgment and informed by the research literature, identified the most pressing research gaps that need to be addressed to understand the potential environmental and human health effects of nanotechnology. The gaps, identified below, are dis- cussed in the context of the source-to-outcome paradigm reflected in the com- mittee’s framework (Figure S-1); tracking the lifecycle of an ENM as it is incor- porated into a product during manufacturing, transported and transformed by processes that may facilitate exposure to humans and organisms, made biologi- cally available to organisms or ecosystems, and finally, assessing its potential effects on organisms and ecosystems. FIGURE S-1 Conceptual framework for informing the committee’s research strategy.

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Environmental, Health, and Safety Aspects of Engineered Nanomaterials 9 The types of ENMs in products, the sources of exposure, and the expected magnitudes of the exposures typically are not known. Therefore, there is consid- erable uncertainty about potential exposures of populations—workers, consum- ers, and ecosystems. Because the nanotechnology market is projected to change rapidly, today’s exposure scenarios may not resemble those of the future. After identification of sources, exposures need to be assessed. Exposure assessment should include evaluation of modifications of ENMs across their lifecycle, as materials may undergo both subtle and extreme changes as they move through biologic and environmental systems that affect their size, surface chemistry, and reactivity. Human exposures potentially occur through inhalation, oral, and dermal routes. Research gaps in understanding both general and occupational exposures persist.  More is known about inhalation exposures because of past research on particles than about other routes of exposure. It is not clear, however, under what conditions airborne exposure to ENMs occur and what the exposure levels are likely to be, although application-specific processes could result in inhala- tion exposure.  Little is known about dermal and ingestion exposures relevant to ex- pected exposures of consumers to personal-care products and through food. Little is known about the transport and distribution of ENMs in the human body and in the environment. When ENMs enter the human body, their surfaces may be modified by native biomolecules. Similarly, ENMs in the environment undergo transformations—for example, dissolution, aggregation, disaggregation, and chemical transformation.  Research is needed to understand these biomolecular modifications in the human body.  There is also a need to understand environmental transformation proc- esses and their variation with ENM structure as these environmental modifica- tions of ENMs can affect transport, fate, exposure, and toxicity. After release throughout the life cycle, ENMs may enter the environment and reach organisms. The connection between the amount of an ENM at the interface with an organism and its relevant bioavailability is largely unknown. There are considerable uncertainties in understanding dose, biodistribution, and bioaccumulation of ENMs in humans and organisms.  Doses used in biokinetic animal studies and for extrapolating from in vivo to in vitro studies need to be informed by relevant data on human expo- sures, whether in the workplace, in a laboratory, or in consumer use. In the environment ENMs will persist or accumulate mainly in the solid and aqueous phases. Such environmental media may act as diluting agents, but

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10 Summary only if the ENMs do not distribute and concentrate in particular compartments (for example, sediment or organisms).  There is a need to understand the potential for ENMs to distribute into particular environments. This requires an ability to measure and characterize ENMs in different environmental media. Relative to human health exposure assessment, monitoring for environmental exposure to ENMs is in its infancy. The responses of humans, other organisms, and ecosystems to ENMs are central to an understanding of risks. Most toxicity studies test a single material; however, there is incomplete information on effects of the array of ENMs used in products. Toxicologic studies usually focus on effects of acute exposures, and there is a lack of information on effects of chronic exposures. Additional research is needed to understand potential human health risks from ENMs.  Most ENM hazard assessments have relied on in vitro testing with doses that are often orders of magnitude higher than realistic exposures. It is important to understand what biologic effects occur at realistic ENM doses and dose rates and how ENM properties (for example surface coating) and exposure methods (for example, inhalation vs instillation) influence the magnitude of these effects.  There is a need to develop data that addresses correlation between in vitro and in vivo responses. These data are vital for developing high-throughput screening strategies for ENMs. There are considerable gaps in our understanding of the potential risks of ENMs to ecologic receptors. There are a large number of exposure routes and receptors, and the relationship among organism effects, population effects, and ecosystem responses are complex.  Research is needed to guide identification of appropriate ecologic re- ceptors, to develop appropriate ENM assays, and to conduct model ecosystem studies that address potential effects on a larger scale, such as a population, a community, or an ecosystem.  Although numerous standard screening-level toxicity tests for specific aquatic and terrestrial organisms have been proposed for evaluating effects of ENMs, data are needed to assess whether standard tests can predict ecosystem effects of ENMs. TOOLS AND APPROACHES NEEDED TO ADDRESS RESEARCH GAPS To address these research gaps, the committee identified tools needed for characterizing how the properties of ENMs influence their biologic and envi- ronmental interactions (Figure S-1). Primary research needs related to tools in-

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Environmental, Health, and Safety Aspects of Engineered Nanomaterials 11 clude access to well-characterized nanomaterials; methods for characterizing, measuring, and testing materials in environmental and biologic samples and for assessing exposure and toxicity; exposure and effects modeling; and informatics. Identifying ENM properties relevant to biologic and environmental inter- actions will require well-characterized libraries of materials for hypothesis- testing, as well as reference or standard test materials that may be used as benchmarks for making comparisons among studies, for validating protocols or measurements, or for testing specific hypotheses related to material properties and specific outcomes. Research or commercial materials are needed to study their biologic or ecologic effects, as these materials have the greatest potential to be released into the environment.  The lack of widespread access to such materials and the lack of agree- ment as to which materials to consider as standards impede progress toward correlating ENM properties with their effects, make comparisons among studies difficult, and limit the utility of data gathered through informatics.  The types of materials needed and used will depend on the purpose of the research. Each type of material needs to be characterized sufficiently for test results to be reproducible and for relationships between observed effects and material structure and composition to be defined. Chemical and physical information on ENMs in environmental and bio- logic matrices is needed. Many existing analytic techniques in material sciences and other disciplines are applicable to ENMs, but their use in measuring and characterizing low concentrations and heterogeneous matrices will require addi- tional development or, in some cases, development of new approaches.  Tools and processes are needed for detecting, tracking, and characteriz- ing ENMs in situ or in vivo at low concentrations; methods also are needed for assessing ENM transformations. Protocols and techniques are needed for assessing the toxicity of ENMs.  Existing toxicity-testing protocols for chemicals will need to be adapted or new methods will need to be developed and validated to include relevant cell types and organisms, appropriate dosimetry, and toxicity end points.  Mechanistic data are needed for understanding the relevance of short- term high-dose effects to longer-term risks. Therefore, protocols should be de- veloped and validated for extrapolating from short-term effects to long-term low-dose risks.  In vitro and ultimately in silico toxicity-testing protocols need to be de- veloped and applied to yield toxicity information that correlates with in vivo responses. This will require standardized and validated in vitro methods (for example, standardized cell types and exposure protocols) that represent specific

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12 Summary exposure routes and validation of results from in vitro studies against responses in relevant in vivo studies.  Additional protocols are needed for predicting population or ecosystem effects of chronic ENM exposures of specific organisms and for assessing the indirect effects of ENMs, for example, their effects on carbon and nitrogen cy- cling. To understand exposures to ENMs, standard testing protocols are needed to assess the properties that influence the transport, transformation, persistence, accumulation, and bioavailability of ENMs.  These protocols need to be assessed and validated among various ENM types and classes and under various environmental conditions (for example, freshwater, seawater, and groundwater environments).  Standard protocols and analytic methods that measure particle number, surface area, and mass concentration also are needed to assess airborne exposure to ENMs in epidemiologic and occupational studies. The variety of ENM types and properties will require the development and use of models to predict exposure to ENMs and the effects of exposure; that is, models of exposure, bioavailability, mechanistic toxicity, biodistribution, and dosimetry. Because of the paucity of data on the behavior of ENMs in organisms and in the environment and on the quantities of ENMs in environmental media, the development of more useful exposure models requires information regarding ENM sources, transport, transformations, fate, and bioavailability.  Developing models for predicting releases of ENMs into the environ- ment throughout their life cycle and value chain will require information on the types of materials being produced and used, types of applications, and intended uses.  To understand the transport of the ENMs into the environment, existing exposure models need to be modified to include processes most relevant to ENM distribution in the environment and human exposure.  Appropriate metrics for incorporating transformations and persistence into exposure models (for example, half-life time, size, or change in number concentration) need to be determined. If in vitro assays are to be used as a predictive tool, mechanisms of toxic- ity of ENMs need to be a major research focus to assess whether mechanisms operative in vitro also apply in vivo.  Models of effects should consider at least each of the four generally recognized mechanisms of toxicity: inflammation and oxidative stress, immu-

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Environmental, Health, and Safety Aspects of Engineered Nanomaterials 13 nologic mechanisms, protein aggregation and misfolding, and DNA-damage mechanisms. However, there may be other mechanisms that have yet to be iden- tified.  For modeling ecologic effects, more data need to be collected on sub- lethal end points of toxicity, including effects on organism growth, behavior, reproduction, development, and metabolism.  Data at the cellular or organism scale cannot predict effects at the community and ecosystem levels. Data should be collected on these effects (for example, on community structure and nutrient cycling) to determine potential model assays that can be used to improve prediction of chronic effects in a broad array of representative organisms and changes in ecosystem function. With regard to dosimetric models for using exposure concentrations to predict dose, models are needed to determine biodistribution––including uptake, translocation, and elimination pathways and mechanisms, and to predict bioavailability of ENMs. Informatics are needed to collect, analyze, and share the highly diverse set of data types and formats being generated to predict the potential exposure and effects of ENMs on the basis of their properties. Given the rapidity at which nanomaterials and their products are being introduced into commerce, an infor- matics infrastructure is needed to address the identified data gaps and support more efficient approaches for methods and model development and for data- sharing among the broad disciplines involved in nanotechnology research, de- velopment, translation, and regulation. However, optimal use of informatics requires collaboration among academe, industry, regulatory bodies, and others. The benefits of collaboration are numerous and include the sharing of data and models, the use of Web-based tools for rapid dissemination and communication between disciplines, and ultimately acceleration of research. However, there are scientific and technical barriers to the use of informatics, as well as organiza- tional and cultural challenges that need to be overcome. RESEARCH PRIORITIES AND RESOURCE NEEDS Having considered the research gaps and the needed tools, the committee identified four broad, cross-cutting high-priority categories that form the back- bone of its recommended research strategy. Because of the diversity of nanoma- terials and the breadth of their potential applications, the committee considered that a prescriptive approach to addressing the EHS aspects of nanomaterials would be short-sighted and would probably fail to anticipate the rapid evolution of this field and its potential effects. Rather, in selecting the four broad catego- ries, the committee envisions a risk-based system that is iteratively informed and shaped by research outcomes and that supports approaches to environmental and human-health protection even as our knowledge of ENMs is expanding and the research strategy is evolving.

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14 Summary The committee considers the four categories to be of equal priority and in- terrelated. This report describes aspects of these categories that need to be ad- dressed in the short term (within 5 years)—on the grounds that these activities can be readily organized, resourced, and accomplished with available knowl- edge and tools—and others that will evolve over longer terms, which indicate the iterative nature of the research agenda. The research categories are the following:  Identification, characterization, and quantification of the origins of nanomaterial 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 expo- sures to measure the quantity and characteristics of materials being released and to model releases throughout their life cycle. Industry involvement will be needed for understanding trends in nanomaterial markets.  Processes that affect both potential hazards and exposure. Research topics in this necessarily broad category 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 modi- fication on aggregation and nanoparticle bioavailability, reactivity, and toxicity potential; processes that affect nanomaterial transport across biologic or syn- thetic membranes; and the development of relationships between the structure of nanomaterials and their transport, fate, and effects. As an element of this re- search category, instrumentation and standard methods will need to be devel- oped to relate ENM properties to their hazard and exposure potential and to de- termine the types and extent of ENM transformations in environmental and biologic systems.  Nanomaterial interactions in complex systems ranging from subcellu- lar systems to ecosystems. Research is unified by the need to understand how ENMs interact with complex systems, whether subcellular components, single cells, organisms, or ecosystems. Each level of these systems is complex with many embedded, interrelated processes that may interact in different ways (for example, synergistically or antagonistically) in response to ENMs. Examples of research in this category include efforts to understand the relationship between in vitro and in vivo responses; prediction of system-level effects, such as ecosys- tem functions (for example, nutrient cycling), in response to ENMs; and assess- ment of the effects of ENMs on the endocrine and developmental systems of organisms.  Adaptive research and knowledge infrastructure for accelerating re- search progress and providing rapid feedback to advance research. This cate- gory of activities will help to integrate the research agenda and provide support for work in the other categories. Activities would include making characterized nanomaterials widely available, refining analytic methods continuously to define the structures of the materials throughout their lifespan, defining methods and

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Environmental, Health, and Safety Aspects of Engineered Nanomaterials 15 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, the encouraged and sustained curation and annotation of data, and the assign- ment of credit to those who share datasets and models. The committee surveyed the status of existing resources needed to imple- ment a strategic research plan within the context of these research-priority cate- gories, and concluded that there is a gap between the research and associated activities funded and the level of activity that would foster greater progress to- ward providing information and tools to support the committee’s research strat- egy. In considering how to address this gap, the committee took a pragmatic approach that was informed by its expert judgment based on the research priori- ties identified and knowledge of the cost of research activities, balanced with understanding of the current funding constraints. On the basis of this approach, the committee concludes that its strategy affords an opportunity for realignment of the substantial federal resources being dedicated to nanotechnology-related EHS research—$123.5 million in the president’s FY 2012 budget request (5.8% of the total nanotechnology R&D budget). Such realignment will require fed- eral-agency cooperation and resource leveraging. However, infusion of modest additional resources could have a substantial effect on infrastructure that is critical for supporting an effective R&D program to advance the strategy. These additional resources will need to be garnered through a coordinated effort on the part of those involved with ENMs to lever- age additional resources from public, private, and international initiatives to support critical cross-cutting research. Cross-cutting activities are encompassed in the high-priority research categories and will need to be supported by greater coordinated investment in five areas: nanotechnology-related EHS informatics; investment in translating advanced nanomaterial measurement and characteriza- tion approaches to EHS-relevant applications; investment in developing and providing benchmark nanomaterials; investment in identifying and characteriz- ing nanomaterial sources throughout the value chain and life cycle of products; and investment in developing and maintaining research networks that provide human infrastructure for collaborative research, information-sharing, and trans- lation of knowledge to effective use. Without budgetary increases in each of these areas, the committee anticipates that the federal government’s ability to derive strategic value from investments in nanotechnology-related EHS research will remain insufficient. Specifically, to ensure the development and implementation of the strat- egy,  It is assumed that core EHS R&D funding by federal agencies should remain at about $120 million8 per year over the next 5 years. Any reduction in 8 This figure is an estimate from the president’s FY2012 budget request of $123.5 mil- lion.

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16 Summary this total would be a setback to EHS research and would slow progress in ad- dressing the committee’s priorities.  Over time, funded research should be aligned with the strategic priori- ties identified by the committee and in the NNI strategy.  Additional multiagency funding should be made available for five cross-cutting endeavors that are critical for providing needed infrastructure and materials to support a strategic R&D program and for ensuring that research findings can be readily translated into practical action by stakeholders. The five are informatics ($5 million per year), instrumentation ($10 million per year), materials ($3-5 million per year), sources ($2 million per year), and networking ($2 million per year).9  Funding in each of those five endeavors is critically needed in the short term and should be sustained for 5 years. IMPLEMENTATION AND EVALUATION To advance the research strategy, mechanisms will be needed to ensure its effective implementation, to evaluate research progress, and to refine the strat- egy as the base of evidence evolves—elements that the committee considered integral to its charge. Implementation will also require the integration of the various participants, both domestically and internationally, involved in nanotechnology-related EHS, including the NNI and the federal agencies; the private sector, such as nanomaterial developers and users; and the broader scien- tific and stakeholder communities, such as academic researchers. Successful implementation will require mechanisms that improve coordi- nation and modify institutional arrangements. Such modifications have been articulated by stakeholder groups involved in the nanotechnology-related EHS research enterprise. The committee concludes that attention to these implemen- tation mechanisms are as integral to the success of the research strategy as the research priorities themselves, a key finding of the 2009 NRC review of the fed- eral strategy. Active engagement of stakeholders is needed at all stages of strat- egy development, implementation, and revision to ensure that the research strat- egy is responsive to those who have a stake in its outcomes. Development of public-private partnerships can help to leverage resources to advance the re- search needed and to foster independent governance and operational transpar- ency in the process. The committee considers that the current structure of the NNI, which serves primarily coordinating and information-sharing roles, hinders its accountability for effective implementation of the research strategy. Because the NNI has only coordinating functions, it has no “top-down” budgetary or management authority to direct nanotechnology-related EHS research. The committee finds that effective implementation of its strategy will require an en- tity that has sufficient management and budgetary authority to direct develop- 9 The specified amounts are the minimums that should be available for each endeavor.

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Environmental, Health, and Safety Aspects of Engineered Nanomaterials 17 ment and implementation of a federal EHS strategy across NNI agencies and to ensure integration of federally supported EHS research with research undertaken by the private sector, the academic community, and international organizations. There is a concern that the dual and potentially conflicting roles of the NNI—developing and promoting nanotechnology and its applications while identifying and mitigating risks that arise from such applications—impede im- plementation and evaluation of the EHS risk research. That duality is reflected in the diverse missions of the agencies and departments that make up the NNI. Numerous stakeholders have called for a separation of the two roles in the NNI, and such separation has historical precedent. To implement the research strategy effectively, a clear separation of management and budgetary authority and ac- countability is needed between the functions of developing and promoting appli- cations of nanotechnology and of understanding and assessing potential health and environmental implications. Such a separation is needed to ensure that pro- gress in implementing an effective nanotechnology-related EHS research strat- egy is not hampered. The separation of management of applications-targeted from management of implications-targeted research needs to be achieved through means that do not impede the free flow of ideas and results between the two lines of research. In its second report, the committee will assess progress in understanding the EHS aspects of nanotechnology and the extent to which high-priority re- search has been initiated or implemented. The timeframe for the completion of the second report is too short to have substantial new research programs, let alone research outcomes, in place. But the committee considers that it is suffi- cient to see progress in initiating research in each of the four high-priority cate- gories and progress in developing the infrastructure, accountability, and coordi- nation mechanisms needed for implementation of the strategy. Progress in addressing those foundational elements will go a long way toward ensuring ef- fective support and management of the research needed to provide information for identifying, assessing, and managing the potential EHS consequences of ENMs. CONCLUDING REMARKS Despite the promise of nanotechnology, without strategic research into emergent risks associated with it—and a clear understanding of how to manage and avoid potential risks—the future of safe and sustainable nanotechnology- based materials, products, and processes is uncertain. In today’s fast-paced and interconnected world, a worthwhile economic and social return on government and industry investment in nanotechnology is unlikely to be fully realized with- out research on risk, including research on translation of knowledge into evi- dence-informed and socially responsible decision-making.