Using Emerging Science and Technologies to Address Persistent and Future Environmental Challenges - Science For Environmental Protection: The Road Ahead - page 54

a 2012 NRC report, A Research Strategy for the Environmental, Health, and
Safety Aspects of Nanotechnology (NRC 2012).
First, do nanoparticles present different properties and inherent risks from
smaller molecules or larger particles? To answer this question, it will be impor-
tant for EPA to adapt and develop new science and tools that strengthen the cor-
relation between the structure and identity of a nanomaterial and the hazard
posed by it. That means that new analytic tools or approaches that permit reli-
able and rapid assessment of engineered-nanomaterial structure and purity are
needed. Rapid tests to screen for hazards and set priorities among materials for
further testing are essential to keep pace with the development of new materials
and to make efficient use of resources available to test materials. To model and
predict the properties of the new materials, it will be necessary to develop pre-
cisely defined reference materials to ensure that inputs to predictive models and
informatics efforts are robust and reliable. The measurement tools, rapid screen-
ing approaches, defined reference materials, and modeling and informatics ap-
proaches, advanced in an integrated fashion, can determine more rapidly what, if
any, unique hazards are associated with this emerging technology.
Second, what are the likely routes and venues of exposure to engineered
nanomaterials? Consumer-use patterns, production methods, and life-cycle ef-
fects of emerging technologies are unknown. To identify likely ways in which
exposure can occur, it will be important for EPA to use physical science, engi-
neering, and social science tools in a multidisciplinary approach that seeks to
understand the life cycle of the materials, the supply chains that incorporate
them, the projections for market growth, and consumer behaviors in using
nanomaterial-containing products. By identifying the intersection between the
most likely exposures and unique hazards, EPA can focus on further characteriz-
ing the potential risk and using science to inform policies needed to monitor and
manage the risk.
Third, how can nanomaterials be detected, tracked, and monitored in com-
plex biologic and environmental media? To complement the science to assess
unique hazards and realistic exposures described earlier in this section, EPA will
require tools to monitor the distribution of and potential exposures to nanomate-
rials. The characterization of pristine nanomaterials has been a challenge given
the lack of specialized tools for detecting and measuring them. Once distributed,
nanomaterials pose even greater challenges to detection, tracking, and monitor-
ing than small molecules or micron-scale particles. This is because nanomateri-
als tend to have distributions of sizes and surface coatings, their high surface
area leads to agglomeration or deposition, their surface chemistry has been
shown to be dynamic, and their speciation can be complex. EPA and its collabo-
rators and contractors will need to invent, develop, or refine tools to detect,
track, and monitor nanomaterials. In some cases, the solution may be to inte-
grate the use of existing tools. In others, new tools will be required. In addition
to direct detection of the materials, strategies that exploit the use of biomarkers
as described earlier in this chapter may prove essential for understanding expo-
sures.