Getting to Green - Research Progress on Environmental Health and Safety Aspects of Engineered Nanomaterials - page 52

Steps to Ensure Progress Toward Elucidating Mechanisms
Continued, vigorous activity to elucidate mechanisms of ENM interactions with organisms and
ecosystems is critical for reaching the long-term goal of predicting 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. The interdependences described in Figure 4-1 and the state of research
progress indicated in Box 3-1 imply that continued progress in understanding mechanisms of ENM
behavior will require advances in instrument development and increased availability of up-to-date
instrumentation to researchers. Another key impediment to progress is the relative lack of a data-
integration infrastructure and of validated models that reflect field-tested theories.
NANOMATERIAL SOURCES AND DEVELOPMENT OF REFERENCE MATERIALS
The committee's nanotechnology EHS research strategy is driven by the need to assess potential
risks associated with the accelerating production of new ENMs and materials that are present in an
increasing number of products. As shown in Figure 4-1, ENMs are the central element of
nanotechnology-related research studies in the knowledge commons, the laboratory world (mechanism-
driven research), and the real world (investigations in complex systems). Three primary types of ENMs
(shown in the figure) are the focus of these studies: reference materials, nanomaterial-enabled products
(inventories), and released nanoscale species (ENM releases). Reference materials were described in the
committee's first report and include individual ENMs and libraries of ENMs that are used to conduct
targeted studies to answer EHS-research questions. Nanomaterial-enabled products are ENMs found in
the inventory of substances being incorporated into commercial products. ENM releases are materials that
come from products that may be transformed as they are released.
The need for appropriately designed and adequately characterized ENMs was highlighted in the
first report (NRC 2012, pp. 181-182). That report called for
Developing nanomaterials and libraries:
 Extent of development of libraries of well-characterized nanomaterials, including those
prevalent in commerce and reference and standard materials.
Providing feedback to inform the design of appropriate nanomaterials:
 Development of inventories of current and near-term production of nanomaterials.
 Development of inventories of intended use of nanomaterials and value-chain transfers.
 Identification of critical release points along the value chain.
 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 those complex systems.
In addition to those direct calls for action, the need for nanomaterials to support other research
priorities was implicit as described elsewhere in this chapter. Appropriate ENMs are needed to carry out
research that will generate data needed to populate the knowledge commons, to develop new methods and
instruments, to conduct mechanistic studies, and to perform investigations in complex media.
Research to characterize ENM production and releases along the value chain was generally
considered to show moderate progress (yellow). However, very little progress was considered to have
occurred in modeling releases along the value chain (denoted as red). Moreover, the lack of a systematic
process for collecting information on the production of ENMs and the lack of a process for providing
feedback from the research enterprise to improve the sustainability of ENMs together limit the pace of the
entire research enterprise.