Biomedical Engineering Reference
In-Depth Information
understand the thinking behind the actions being taken. The rest of the chapter will address how
each of the above governing bodies have dealt with the issues of learning about inventory through
registration and notification, about intended uses through labeling, product performance by adverse
reaction reporting, and the encouragement of directed research to demonstrate safety.
15.4 LACK OF RELIABLE DATA
As referenced above, an equally daunting task for regulators is the real and potential effect of the
release of engineered nanoparticles (ENPs) into the environment. As discussed below, the same sort
of information problems exist. Reliable data are inadequate to address the core question of whether
toxic and/or hazardous materials can be released into the environment during the manufacture, use
of, or end-of-life stage of nano-enabled products. Questions thus abound as to whether nano applica-
tions will lead to environmental degradation, particularly from bioaccumulation of nanomaterials
in biological systems.
*
Stander and Theodore note that concerns arise because following exposure, chemical substances,
including nanomaterials, can elude defense mechanisms and enter the body via various pathways,
including inhalation, absorption through the skin, and ingestion.
†
There is also the risk of the release
and absorption or inhalation from equipment malfunctions or unanticipated problems during use
of products.
‡
The evaluation process to determine the possibility of a risk resulting from nanomaterials expo-
sure is difficult.§
§
A typical comment is that “…determining the hazard potentials and possible risks
posed by the special physical and chemical properties of ENPs requires more detailed study. On one
hand, there is currently no evidence that ENPs pose a significant threat to the environment; on the
other, many gaps in our knowledge remain with regard to ENP ecotoxicity. The lack of evidence
should by no means be interpreted to imply that environmental damage cannot occur.”
¶
15.5 LACK OF RELIABLE TOOLS
The tools used to assess risk are still under development. Presently, ecotoxicological research
focuses primarily on controlled laboratory studies involving cell cultures or model organisms often
using unrealistically maximum dosages to trigger effects. In laboratory studies, however, they can
lead to analytical artifacts because some ENPs form large aggregates that can significantly alter the
bioavailability and thus the toxicity of a material. Also, laboratory studies follow protocols origi-
nally developed for conventional organic chemicals and pesticides and do not in all cases consider
the specific properties of nanomaterials.
Moreover, natural ecosystems are considerably more complex than a Petri dish, limiting the
interpretability of laboratory results. Fortunately, no reported accidents involving major releases
of ENPs into the environment have been documented to date. Ecological research on the behavior
of ENPs must look to numerous studies from the geosciences that have examined the behavior of
naturally occurring nanoparticles in the environment, but ENPs differ in certain respects from
those occurring naturally. While natural nanoparticles are randomly structured and diffusely dis-
tributed in the environment, industrially produced suspensions or powders contain pure nanoma-
terials of very uniform size, shape, and structure. In the environment, nanomaterials can undergo
a range of chemical processes that depend on many factors (e.g., pH value, salinity, concentration
*
Stander, L. and L. Theodore. Environmental implications of nanotechnology—An update.
International Journal of
Environmental Research and Public Health
8(2): 470- 479. http://www.mdpi.com/1660-4601/8/2/470.
†
Id.
‡
Id.
§
NanoWerk, LLC. 2012. Nanotechnology and the environment—Hazard potentials and risks. http://www.nanowerk.com/
spotlight/spotid=25937.php.
¶
Id.
