A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials (2012) / Chapter Skim
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2 A Conceptual Framework for Considering Environmental, Health, and Safety Risks of Nanomaterials
2 A Conceptual Framework for Considering Environmental, Health, and Safety Risks of Nanomaterials
Pages 48-69
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From page 48... ...
As discussed in Chapter 1, the environmental and human health risks posed by these novel materials remain largely unknown, but the materials' widespread use provides a strong motivation for investment in research directed at potential adverse effects. The vast variety of nanomaterials and their novel properties provide a strong basis for systematic, coordinated, and integrated research efforts to understand what properties of the materials influence their hazard and exposure potential and what applications present the greatest likelihood of exposure and adverse effects on human health and the environment.
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From page 49... ...
that do not appropriately reflect the potential for harm. Framing risks associated with an ENM in terms of established definitions provides some insight into emergent risks.
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From page 50... ...
The conceptual framework, described later in this chapter, reflects a coordinated, strategic research effort that is characterized by three key features: A reliance on principles that help to identify emergent, plausible, and severe risks resulting from designing and engineering materials at the nanoscale, rather than an adherence to rigid definitions of ENMs. A value-chain and life-cycle perspective that considers the potential harm originating in the production and use of nanomaterials, nanomaterialcontaining products, and the wastes generated.
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From page 51... ...
With regard to improving the utility of risk assessment, the committee authoring that report focused on improvements in scoping the problem at hand and understanding a broad set of risk-management options so that the ensuing risk assessment would be more relevant to the questions that decision-makers might ask of the scientific-knowledge base. An important conclusion of the committee's work was that risk assessment, rather than being viewed as an end in itself, should be considered as a method for informing research and commercialization efforts and for evaluating the relative merits of various riskmanagement options.
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From page 52... ...
Nanomaterial development, informed by an evolving risk assessment, presents the opportunity to identify and reduce, at the design stage, the in herent potential for exposure to and the hazards of nanomaterials. Applica tion of green-chemistry principles and design practices to nanomaterial de velopment can help to ensure that nanomaterials are designed to minimize risk whatever their application.
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From page 53... ...
Refined approaches to addressing In designing the research strategy for ENMs, a uncertainty and variability in all premium should be placed on a "value of information" phases of the risk assessment from analysis that underscores how the information gleaned characterizing potential release through from the research will be used to reduce uncertainty or potential exposure to hazard and risk will to refine an appreciation of variability in exposure or be a critical component of information risk. Methods for doing that are available and are needs in this risk-research strategy.
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From page 54... ...
that are not present with molecules in solution. Also, the relative impacts of kinetic compared with thermodynamic factors in controlling the environmental behavior of nanoparticles may be expected to differ from conventional chemical species for which there has been success in predicting phenomena, such as bioaccumulation or transport from, for example, use of structure-function relationships to calculate fugacity.
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From page 55... ...
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 exposure and hazards and hence risk. Those elements exist on many levels of biologic organization, including molecular, cellular, tissue, organism, population, and ecosystem.
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From page 56... ...
Each nanomaterial or product containing nanomaterials along the steps of the value chain has an associated life cycle of production, distribution, use, and end-of-life releases that may affect human health and the environment. The principle of including a value-chain and life-cycle perspective in the committee's conceptual framework is fundamental for assessing the risks posed by nanomaterials and is discussed in greater detail below.
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From page 57... ...
Table 2-2 illustrates potential releases of and exposures to carbon nanotubes across the value chain and life cycle of a textile application.
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From page 58... ...
; also CNT raw materials release and polymers and (next row)
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From page 59... ...
. row - primary chemicals, and secondary secondary product during second-hand stores incinerators.
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From page 60... ...
. It has been shown that the production of non-nanomaterial wastes from the production of carbon nanotubes (Plata et al.
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Although the committee recognizes that indirect collateral effects associated with the life cycle of materials and energy use in nanomaterial production may in some cases be the dominant effects on human health and the environment, the committee's research framework is focused on identifying EHS issues resulting directly from contact with nanomaterials released along the value chain and life cycle. Notably absent from the proposed framework is a consideration of important issues relating to nanomaterial fabrication, complex nanostructures and devices, and comprehensive life-cycle considerations concerning energy and materials use, reflecting a deliberate focus of this committee on nanomaterials rather than nanotechnology and a heavy emphasis on toxicologic research.
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From page 62... ...
Providing bases for assessing risk to human health and the envi ronment. In addition, a broader framework that combines life-cycle assessment and risk analysis may help to inform our understanding of potential risks and environmental impacts of ENMs (Evans et al.
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From page 63... ...
Identifying emergent risk depends on new research that assesses a novel material's behavior and potential to cause harm. Emergent risk is defined in terms of the potential of a material to cause harm in unanticipated or poorly understood ways rather than being based solely on its physical structure or physicochemical properties.
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From page 64... ...
It also helps to capture the reduction in harm that may result from research on the identification, assessment, and management of emergent risk. The principle offers a qualitative reality check that helps to guard against extensive research efforts that are unlikely to have a substantial effect on human health or environmental protection.
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From page 65... ...
For example, generating and handling multiwalled carbon nanotubes in a workplace -- materials that have demonstrated novel properties that include, for example, strength and electric conductivity -- may present a plausible and emergent risk. It is only recently that production of these materials has started commercially; there are indications that some forms
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From page 66... ...
The principles provide a systematic basis for identifying and setting priorities among properties of nanomaterials as research subjects in addressing risks.1 Criteria for Selecting Research Priorities Each of the above types of materials (they are not exclusive) , illustrates key research questions that need to be addressed if emergent and plausible risks are to be identified, characterized, assessed, and managed.
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From page 67... ...
2009. Nanolifecycle: A Lifecycle Assessment Study of the Route and Extent of Human Exposure via Inhalation for Commercially Available Prod ucts and Applications Containing Carbon Nanotubes.
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2008. Monitoring multiwalled carbon nanotube exposure in carbon nanotube research facility.
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From page 69... ...
Nanostructured Materials and Non manufacturing Definitions: Data Gaps and Research Needs. Presentation at Nanotechnology and Life Cycle Analysis Workshop, November 5-6, 2009, Chi cago, IL [online]
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