could detoxify Native American artifacts
BOSTON — In a sequel to the smallpoxcontaminated
blankets hand out, museums inadvertently began
another round of toxic giving to Native Americans
in the 1990s — returning headdresses and
other artifacts that were laced with mercury.
Now scientists are looking to a microbe that
converts mercury into a form that evaporates,
with hopes of cleaning up the artifacts before
giving back more of them to their rightful tribes.
"Do we give them something covered in
mercury just to have given them their things
back? No — it is not OK,” says Munira
Albuthi, a microbiologist at the University
of Colorado Denver who did the research to see
if such a microbial method is possible. “Mercury
is a potent neurotoxin.“
The neurotoxic effects of headgear laced with
mercury had been recognized anecdotally for
years. At Alice’s tea party, the Mad Hatter
wasn't angry — he was crazy from wearing
and working with hats, which used to be cured
The 1990 Native American Graves Protection
and Repatriation Act required federal agencies
and institutions to return Native American cultural
items and remains to their respective peoples.
But when museums began giving back ceremonial
head gear and other artifacts, many of the recipients
ended up ill. The specimens were laced with
mercury, a component of the pesticides that
museums had used for years for preservation.
Once the problem of the poisoned artifacts
was recognized, scientists had to figure out
a culturally sensitive means of getting rid
of the toxin.
“A lot of tribes see these artifacts
as live spirits — these are relatives
to a lot of people,” says Albuthi, who
presented the work in Boston at the 108th
meeting of the American Society for Microbiology.
"So we needed to use something you would
be OK with using on yourself.“
Albuthi began working with Cupriavidus
metallidurans, a microbe that flourishes
on metal and is not dangerous to humans. It
has a set of proteins that turns mercury into
a form that evaporates into the air.
After contaminating paper, a watery broth and
auger plates with the neurotoxin, she used a
pipette to put the bacterium onto the items.
Seven days later, 40 percent of the mercury
had been removed from the broth, 50 percent
was removed from the auger plates and 60 percent
was removed from the paper. Because paper is
porous and organic, it is most like the specimens
that museums are dealing with, she notes.
Albuthi also investigated whether different
temperatures or humidities enhanced the microbes’
mercury-morphing powers. She found that the
microbes worked best at room temperature and
60 percent humidity, with about 80 percent of
the mercury evaporated from the items.
The experiments used mercury concentrations
of 10 parts per million, which are much higher
than the quantities on most museum specimens,
saysAlbuthi. “So maybe we'll be able to
get 100 percent, if there isn't as much to begin
with,” she says.
“This is a very interesting and particularly
challenging project. They were very constrained
in terms of what they could treat things with,”
comments Gregory Hecht, a microbiologist at
Rowan University in Glassboro, N. J. “And
microbes are probably the best way to get around
:www.sciencenews.org; June 2nd, 2008