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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
                                                                                    continued on back
      U.S. Environmental Protection Agency
      Office of Research and Development

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      NANOTECHNOLOGY  RESEARCH  PROGRAM
      continuedfrom fmnt
      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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