U.S. Water News Online
EUGENE, Ore. -- University of Oregon researchers have
developed an arsenic "trap" that has the potential to clean up
contaminated water or treat poisoning victims.
Arsenic is a chemical element and a naturally occurring poison
that contaminates water supplies around the globe.
Darren Johnson, a chemistry professor, and graduate student Jake
Vickaryous have created a molecule made of sulphur and carbon that
hooks on to arsenic.
Three sulphur-based molecules join with two arsenic atoms to form
a kind of pyramid-shaped molecule that's more stable than the sulphur
molecule alone. Once locked into the structure Johnson describes as a
"molecular claw," the arsenic does not combine with any other
If the molecule proves stable enough to avoid linking up with any
other molecules, it could effectively remove arsenic from human
tissue or offer a way to make arsenic-tainted wells safe for drinking
"One thing this could potentially do is provide some new
environmental remediation and sensing tools," Johnson said.
The federal government currently requires that public water
systems have no more than 50 parts per billion of lead and will
reduce that to 10 parts per billion in 2006.
About 10 percent of U.S. groundwater has arsenic concentrations
above 10 parts per billion, while 20 percent of the wells in the
Willamette Valley exceed that level.
Even tiny amounts of arsenic in the human body are potentially
damaging. The research might eventually lead to a treatment for
arsenic poisoning, but development is a lot farther down the road
because the molecule that traps arsenic can only be created in a
highly toxic, arsenic-based solvent.
Johnson and Vickaryous will try to develop a water-soluble version
of the molecule that's harmless to humans. They also have to make
sure their molecule won't break down over time or spit out the
arsenic in exchange for another metallic element.
"We need to give the molecule a lot of different metallic
molecules and see if it always chooses arsenic," Johnson said. "We'd
love to make something non-toxic that we could give to people that
would clear arsenic out of their body, or out of the environment."
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