Assessment of Progress - Research Progress on Environmental Health and Safety Aspects of Engineered Nanomaterials - page 29

CPSC, EPA, NIOSH, and OSHA—are collaborating with nonprofit, industry, and international groups
under the auspices of the International Life Sciences Institute (ILSI) Research Foundation's Nanorelease
Project (ILSI 2013a). In 2013, work on refinement of testing methods is expected to lead to a round-robin
approach to testing products for release of ENMs.
Although efforts to address release of ENMs from products are under way, additional efforts will
be needed. In particular, the focus on large-production-volume ENMs may limit our ability to assess
emerging materials before they enter the marketplace in consumer products. In addition, the focus on
aerosol releases provides an incomplete perspective on all pathways of release to the environment.
Expansion of these efforts will be critical for the assessment of potential EHS risks posed by ENMs
throughout the value chain of nanomaterial-enabled products. Because a more comprehensive and
comparative view of where nanomaterials may be released along the value chain is needed to identify
where to mitigate risks, the indicator is yellow.
 Identifying critical populations or systems exposed
In its first report, the committee noted the importance of characterizing not only the quantity and
nature of ENMs to which humans and ecosystems are exposed but possible changes in exposed
populations and systems that occur during ENM releases throughout the life cycle and value chain.
Understanding the complexity of ecosystems (that is, the interaction of the abiotic and biotic and the
variety of environments and organisms) and of human populations (including such factors as age,
socioeconomic status, health status, behavior and activities, and exposure pathways) requires an
integrative research structure involving collaboration among disciplines and among stakeholders. As a
high-priority short-term research goal, the committee has suggested identifying exposed human
populations and the magnitude of exposure in different ecosystems after determination of critical release
points along the ENM value chain. There has been some research activity but little progress in identifying
critical human populations exposed to ENMs. NIOSH is developing public-private partnerships with
companies manufacturing ENMs and has conducted exposure assessments at their manufacturing sites
(for example, producers of titanium dioxide nanoparticles, CNTs, and carbon nanofibers) (NIOSH
2012a). That activity is a useful start in characterizing released ENMs in workplace environments.
However, considerable work is needed to measure exposures throughout the ENM life cycle and value
chain. For example, the influence of accumulation along the food chain on exposure and exposure to
different types of CNTs during production, distribution, use, and disposal need to be evaluated (Helland et
al. 2007).
Some consumer products may be of greater concern than others (for example, cosmetics applied
as sprays), given the form of the ENMs within products. Initial efforts by ILSI (2013b) and the EU
(Kuhlbusch et al. 2011) are leading to strategies to assess potential ENM exposures from consumer
products. Exposures from discarded products after disposal or end-of-life use (for example, from
landfills) need to be measured.
With respect to ecosystems, some individual research efforts to examine exposures to ENMs are
supported by federal funding. Examples include examination of titanium dioxide in wastewater outputs
(Westerhoff et al. 2011), CNTs in aquatic systems (von der Kammer et al. 2012), and movement of
ENMs through groundwater (Phenrat et al. 2010; Kim et al. 2012), and research into distribution of
ENMs into model ecosystems (Lowry et al. 2012b; Schierz et al. 2012). EPA has also funded several
projects to examine movement of ENMs in systems and to develop technologies for detecting
nanomaterials (EPA 2012). However, for the majority of ENMs, important questions remain: What is
their exposure potential in different environments, such as soil, water (aquifers), the food chain, and
wastewater? How do alterations in the chemistry of ENMs influence the potential for ecosystem
exposure?
Given the challenge of effectively measuring ENM exposures along the value chain and some,
but limited progress in identifying both human populations and ecosystems exposed, the committee has
labeled this indicator yellow.