Washington Post
March 29, 2004


By Rick Weiss, Washington Post Staff Writer

The first study to look at the health effects of microscopic,
manufactured "nanoparticles" on aquatic animals has found
troubling evidence that the molecules -- which scientists are
starting to make for research and industry -- can trigger organ
damage and other toxic effects.

At modest concentrations in aquarium water, the minuscule
particles -- which are made of carbon atoms and are less than
one-thousandth the diameter of a human hair -- triggered
damaging biochemical reactions in the brains of fish. They also
wiped out entire populations of "water fleas," tiny animals
that fill an ecologically crucial niche near the bottom of the
aquatic food chain.

The study, described at a scientific meeting yesterday, was
small and has yet to be peer reviewed or published in a
scientific journal. And although some companies anticipate
making tons of the particles within the next few years, current
production levels are relatively low, so the risk of exposure
for humans and other animals is still quite small.

Nonetheless, the findings underscore the growing recognition
that the hot new field of nanotechnology, which federal
officials have said will be at the heart of America's "next
industrial revolution," may bring with it a number of
old-fashioned trade-offs in terms of potential environmental
damage and health risks.

Other animal studies have suggested that a related class of
nanoparticles causes lung injuries when inhaled, raising
concerns about worker safety in the small but growing number of
nanoparticle factories.

Federal agencies including the Food and Drug Administration,
the Environmental Protection Agency and the Occupational Safety
and Health Administration have acknowledged that current
regulations may not adequately protect against nanoparticles'
unique toxicities, but those agencies have only recently begun
considering how to respond.

"There are many potential benefits of nanotechnology, but its
hazards and risks are poorly understood," said Eva
Oberdoerster, an environmental toxicologist at Southern
Methodist University in Dallas, who led the new studies.

Nanotechnology is an emerging field of science that deals with
engineered molecules a few billionths of a meter in size.
Because of the novel arrangements of the atoms in these
molecules -- and because the laws of physics behave differently
at such scales -- nanoparticles display bizarre chemical
properties. Those properties make them potentially useful in
products including stain-proof fabrics and computer components,
but also make them potentially biologically disruptive.

The new research focused on C 60 fullerenes, also known as
buckyballs, which resemble microscopic soccer balls. Scientists
hope to use them as drug delivery systems, components of fuel
cells and as tools to clean up contaminated land. But
buckyballs can also steal electrons from surrounding molecules
-- a process known as oxidation and a common mechanism of
tissue damage.

In her experiments, Oberdoerster kept young largemouth bass in
10-liter aquariums filled with fullerene-spiked water at
concentrations of 0.5 parts per million -- similar to that
encountered with more common pollutants in U.S. ports. After 48
hours, the fish were removed and their brains studied for
evidence of lipid peroxidation, a tissue-burning chemical
reaction that toxicologists use as a standard of biological

The level of brain damage was "severe," Oberdoerster reported
yesterday at the national meeting of the American Chemical
Society in Anaheim -- about 17 times higher than seen in fish
kept in clean water for comparison.

"Given the rapid onset of brain damage, it is important to
further test and assess the risks and benefits of this new
technology before use becomes even more widespread," she said
in a statement.

In a telephone interview, Oberdoerster said some of the tissue
damage may be caused directly by the buckyballs and some may be
inflicted by immune system cells responding to the exposure.

Oberdoerster also found that buckyballs caused die-offs of
Daphnia, or water fleas -- crustaceans just a few millimeters
long that eat algae and serve as food for other aquatic
animals. Because of their crucial role in the food chain,
Daphnia is a common test organism for aquatic toxicity.

At about the same concentration used for the fish, half the
Daphnia were dead within 48 hours -- an effect Oberdoerster
characterized as "moderately toxic," more deadly than nickel
but less so than copper.

The new findings are somewhat surprising because many
scientists had predicted that buckyballs would not linger in
water but would quickly form clumps and sink, said John R.
Bucher, deputy director of the environmental toxicology program
at the National Institute of Environmental Health Sciences in
Research Triangle Park, N.C., a branch of the National
Institutes of Health.

"Everyone assumed they'd just become part of the muck, if you
will," Bucher said. "This is telling us we need to pay
attention to this area."

Bucher is part of a multi-year federal effort, still largely in
the planning stage, to test the toxicity of several kinds of
nanoparticles -- an effort made difficult, he noted, because
companies have been reluctant to reveal the precise formulas
they are using to make their novel nano-products.

E. Clayton Teague, director of the National Nanotechnology
Coordination Office, which advises the White House on
nanotechnology issues, said progress in designing those studies
is "proceeding very nicely," though results are still several
years away.

"All of the relevant agencies are now very actively looking at
existing regulations to examine the degree to which they do or
might not cover adequately these new nanoscale materials," he
said. "I think that most people still believe that with some
modifications ... the existing regulations will be effective
in covering these new materials."

2004 The Washington Post Company