clustera on Oct 15th 2008
Scientists investigating the Fallon cancer cluster unveiled further results Friday about tungsten, an element found in abundance in the town where
17 children have been diagnosed with leukemia since 1997.
The preliminary results of one study indicate that tungsten-laced water caused sterility in older male mice. In another study, an analysis of tree leaves in Fallon showed that wind-borne tungsten collects on plants there in larger proportions than most other metals.
Those at the University of Nevada, Reno symposium theorized the Fallon epidemic might have been fueled by environmental factors that harmed the genes of the children who developed leukemia.
Of the 17 children in the cluster, three have died. The last child in the group was diagnosed in 2004.
Dr. William Murphy of the University of Nevada School of Medicine said even though the cancer cluster “seems to have abated,” it’s still important to determine the cause.
He and other team members said the Fallon case is unique because the cluster developed so fast in such a small area, and some of the factors that caused it may still exist there.
The research was funded by $750,000 in federal grants obtained by U.S. Sen. Harry Reid, D-Nev., for the Fallon Families organization.
Jeff Braccini, whose son Jeremy, 10, has recovered from leukemia, is part of a parents group that lobbied Reid for the money. Braccini said the research isn’t “just about our kids, it’s about your kids and their kids.”
Dr. Mark Witten, a toxicologist at the University of Arizona, has been researching the Fallon cluster and a similar outbreak in Sierra Vista, Ariz., since 2002.
On Friday, he presented preliminary findings of a study of mice that were given tungsten in water. He said the tungsten concentration in the water was a median amount between the concentrations found in Fallon and Sierra Vista.
The study involved older male mice who were exposed to tungsten and were then supposed to mate and have offspring. The “pup” mice were then examined for signs of genetic damage that might be linked to cancers. The study is based on the fact that the fathers of Fallon leukemia patients were older than average fathers when they had the children who developed leukemia.
But the male mice failed to get the female mice pregnant.
“What we found there were damaged testicular cells in the group of male mice that was fed the tungsten-only water,” he said.
Dr. Paul Sheppard, an Arizona tree-ring scientist and Witten’s research partner, showed in previous studies that both Fallon and Sierra Vista have unusually high amounts of tungsten in their environments. High levels of the metal were found in tree-ring, air and water samples.
On Friday, Sheppard said his most recent study showed high levels of tungsten, as compared to other metals, on tree leaves in Fallon. The samples were collected from 95 trees, he said.
Witten and Sheppard said their research can’t be used to link tungsten to leukemia.
“You need biomedical research to look at that,” Sheppard said.