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NANOTECHNOLOGY
RESEARCH PROGRAM
Research Investigates Human Health Effects of Nanomaterials
Issue:
Extremely small nanomaterials
can exhibit unique characteristics
that are leading scientists to
question what implications they
may have for our health.
Nanotechnology is a relatively
new science and, as a result, the
health implications associated
with engineered nanomaterials
have not been determined. Much
of today's information on health
effects is from decades of
understanding the effects from
natural or incidentally formed
nano-sized materials such as
ultrafme particles from dust or
incomplete combustion.
Research is needed to determine
whether exposure to
manufactured nanomaterials can
lead to adverse effects to the
heart, lungs, skin; alter
reproductive performance; or
contribute to cancer.
The scientific challenge to
understand the potential human
health risk of manufactured
nanomaterials is significant.
There are already many types of
manufactured nanomaterials
commercially available or are
under development. In many
cases, the same type of
nanomaterial can be produced by
several different processes, giving
rise to a number of versions that
may require separate assessments.
Other scientific issues include:
• Nanomaterials may enter the
body by routes not typically
found with other chemicals
because of their small size.
• If nanomaterials of certain sizes
are able to enter the body, they
may pass through cell membranes
or cross the blood-brain barrier
because of their small size. In
some cases this is a beneficial
characteristic when used for drug
delivery and disease treatments.
This characteristic could also
result in unintended impacts for
manufactured nanomaterials not
designed for disease therapies.
• Nanomaterials may interact with
environmental media and
pollutants to produce by-products
that may have the potential to
cause health effects.
As with all toxicological
assessment, it will be necessary to
develop information on:
• Route of exposure (inhalation,
oral, or dermal) that carries the
greatest risk,
• Physical and chemical
characterization of nanomaterials
• Dose-response relationship of
manufactured nanomaterials and
toxicity
Scientific Objectives:
Researchers in EPA's
Nanotechnology Research
Program, in the Office of
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U.S. Environmental Protection Agency
Office of Research and Development
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NANOTECHNOLOGY RESEARCH PROGRAM
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Research and Development
(ORD), are studying
nanomaterials to understand the
potential unintended
consequences from accidental or
intentional exposure to humans.
This information will be used to
prevent or minimize exposure
during manufacturing, use, and
disposal of products made with
nanomaterials. The program is
designed to develop scientific
methods and tools for
determining the potential risks.
The research program has a three-
pronged approach for assessing
the potential toxicity of
nanomaterials:
• Identify and characterize the
physical and chemical properties
of manufactured nanomaterials
• Identify alternative testing
methods and approaches to
predict toxicity in humans which
includes identification of
biomarkers of nanomaterial
exposure and/or toxicity
• Assess the toxicity of
nanomaterials in animals. These
studies will include research to
identify host susceptibility and
sensitivity facts that may
influence toxicity.
Nanoparticles can generate local
toxic effects as well as systemic
(entire body) effects.
Toxicological assessment of
engineered nanomaterials will
consider both local and systemic
toxic responses.
Previous research on particles has
shown that not all individuals
respond in the same way or to the
same degree. Individual and
population susceptibility factors
can influence the magnitude of
toxicity, deposition, fate, and
persistence of nanomaterials.
The impact of susceptibility
factors on manufactured
nanomaterials is not known and
provides the opportunity for EPA
scientists to identify what
susceptibility factors impact the
toxicity of engineered
nanomaterials.
Application and Impact:
The results of EPA's health
effects research will inform safety
assessments of manufactured
nanomaterials and determine the
potential adverse effects of
products that contain them.
Nanotechnology science is being
used to:
• Recommend safe exposure
levels that would protect
susceptible subpopulations
• Investigate occupational safety
and health issues associated with
aerosolized nanoparticles
• Investigate workplace exposure
monitoring and protocols
• Develop personal protection for
activities involving manufactured
nanomaterials in the workplace
CONTACT
Doug Wolf, National Health and Environmental
Effects Research Laboratory, EPA's Office of
Research and Development, wolf.doug@epa.gov,
919-541-4137
JULY 2009
U.S. Environmental Protection Agency
Office of Research and Development
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