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How Much is Too Much? It’s No Small Question
may come in small packages, but what are the effects
of those small packages on humans and the
environment? New research on nanomaterials – materials
billionths of a meter in size – at North Carolina
State University’s College of Veterinary Medicine
may help answer some of those questions.
The prefix nano- comes from the Greek word for dwarf.
And nanoparticles are very small indeed. Any particle
between 1 and 100 nanometers is considered to be a
nanoparticle. Nanomaterials have many uses: They can
make items stronger or lighter, and even heat- or stain-resistant.
They are used in tennis rackets, cosmetics, electronics
and drug delivery.
Monteiro-Riviere, professor of investigative dermatology
and toxicology at NC State’s Center
for Chemical Toxicology Research and Pharmacokinetics,
is studying how nanomaterials interact with the skin,
specifically absorption and toxicity. Her research
is funded through a three-year, $340,000 Environmental
Protection Agency (EPA) Science to Achieve Results
In the study, Monteiro-Riviere will investigate several
classes of nanomaterials, including fullerenes, quantum
dots, single-wall and multi-wall nanotubes and
nanofibers, as well as bucky balls – a spherical grouping of carbon chains. “Many
of these nanomaterials come in a variety of sizes, shapes and compositions,
so you can’t just look at one. I’m trying to evaluate the effects
of engineered nanomaterials on cells,” she said.
can be exceptionally strong and so miniaturized,
such as in semiconductors and microchips. The concern
is that people are manufacturing these things but they
aren’t evaluating what’s going to happen
when occupational exposure occurs or these nanomaterials
accumulate in the environment.”
studies of multi-wall carbon structures have shown
cause irritation and incorporate themselves into
the keratinocytes (skin cells). Monteiro-Riviere
wants to find out if nanomaterials will penetrate through all the layers
of the skin. If nanomaterials penetrate into the
dermis, where the capillaries
are, they can get picked up and transported through the bloodstream, and
may localize in other target organs.
“People are handling these materials on a daily
basis, but there is limited research or literature
out there on the materials’ toxicity,” she
said. “Nanomaterials can be very versatile. You
can make them water soluble or lipid soluble, you can
manipulate them for your own good, use them for drug
delivery, but how are you going to dispose of them?
How are they being released into the atmosphere?”
to Monteiro-Riviere, many nanoparticles are made
of carbon, which means they aren’t really
going to degrade. “How long are they going to
exist in our environment? Some early research has shown
these particles can find their way into the smallest
part of the lung and may cause problems. And their
small size makes them difficult to detect. However,
we really do not know their impact on human health.
It is just too early to speculate.”
Monteiro-Riviere’s research has been featured
recently in a number of scientific publications, including
selection as an editor’s choice in the journal
Science. “I’m getting many calls and e-mails
from reporters looking for more information about this
research; my work is even featured in an exhibit at
the London Science Museum,” she said.
“It’s a new and exciting field but when
we develop all these unique nanomaterials, we need
to know what the effects are on the body and the environment.
We have to be very careful. Hopefully we can use the
research results to help other agencies develop guidelines
for exposure to nanomaterials,” Monteiro-Riviere
- thomas -