- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Fresh Out of Arsenic-73
15 November 2000 7:00 pm
Researchers trying to gauge the dangers of arsenic have run into a roadblock: They need an arsenic isotope for their studies, and the only place in the world that makes it has run out. It could take until mid-2001 before enough is produced to restock the two dozen labs around the world that need the isotope.
The shortage comes at a particularly bad time. In May, the U.S. Environmental Protection Agency (EPA) proposed a costly reduction of arsenic levels, a natural contaminant, in drinking water. EPA is also funding a burst of research on how arsenic causes cancer, because pinning down this elusive mechanism could reveal whether the limit needs to be so stringent. To understand the mechanism, researchers are using arsenic-73 to find genes that metabolize arsenic and to explore how these metabolites enter cells and damage DNA.
But the Department of Energy's Los Alamos National Laboratory in New Mexico hasn't produced any arsenic-73 since early 1999. They made the isotope by smashing protons from an accelerator into a rubidium bromide target, but their source of these protons--a tritium production program--shut down. A new isotope production facility was slated to open early next year, but the massive fires that swept through the region this spring have pushed back the scheduled completion date to mid-2002. Los Alamos ran out of its arsenic-73 inventory around July.
"None of us knew about it until it was too late" to make other plans, says Marc Mass, an EPA toxicologist. There are alternative tracers, he says, but they're costly and too insensitive for some experiments. Los Alamos officials say they can make arsenic-73 at another accelerator, possibly in Canada--but it may be another 6 months before any arsenic-73 comes available, says Gene Peterson, manager of the lab's Isotope Production and Distribution Program.
That's little comfort to arsenic researchers, who are at their wits' end. Toxicologist Vas Aposhian of the University of Arizona in Tucson, who bought up the last few millicuries of arsenic-73 this summer, says that he and his colleagues are "going to scream bloody murder" when their lab's supply runs out in a few weeks. Miroslav Styblo, a biochemist at the University of North Carolina, Chapel Hill, is trying to persuade colleagues at an accelerator in his native Prague to make a batch of arsenic-73. But "so far," he says, "we don't have realistic promises."