RENO, Nev. - New findings suggest the heavy metal tungsten is a common link in childhood leukemia cases in three Western states.
An analysis of tree rings in Fallon, south Sacramento, Calif., and Sierra Vista how elevated levels of tungsten in trees, the Reno Gazette-Journal reported today.
The discovery of tungsten in the distinctly different communities has led scientists to suspect that the metal contamination is caused at least in part by an industrial source.
Eight Sacramento children have been diagnosed with leukemia. In Fallon, a farming and military community 60 miles east of Reno, the disease has sickened 13 children since 1997. Three have died.
Ten children in Sierra Vista have been diagnosed with the disease.
Federal records show natural tungsten or metal from Fallon industry could leach into tap water there.
Surface water carrying tungsten could enter the underground lake that supplies city drinking water, first thought to be isolated since ancient times, scientists said. They know this because they found in the 600-foot-deep water traces of fallout from Nevada atomic tests, meaning at least one contaminant has reached the water since the 1960s.
“There’s a pathway to the drinking water,’’ Amos Rafferty, a retired mining geologist from Reno, told the newspaper.
“It has to be a possibility that tungsten from surface pollution made its way down to the deep aquifer. There’s a lot of tungsten in that water, but you can’t tell if it’s natural or contains some levels of industrial metal.’’
Researchers aren’t sure about the origin of the tungsten found in trees.
But at least one scientist said the unexpectedly high levels of the metal in all three communities is a strong indication the element may play a role in cancer clusters.
“It’s a big clue,’’ said Mark Witten, an Arizona toxicologist, who is investigating the possible tungsten-leukemia link independently of the federal agencies involved in the Fallon probe.
“The metal could be involved in leukemia and possibly other cancers,’’ he said. “You’ve got three hot areas for tungsten and three outbreaks of childhood leukemia in those places. I think we’re on to something.’’
California health officials have said there’s no record in south Sacramento of any industry that makes tungsten products or discharges the metal. They also deny the cancer rates there are above expected levels and have declined to do environmental investigations around the square-mile census tract where
activists said they documented high rates of childhood leukemia and other rare
But Environmental Protection Agency records, obtained by the Gazette-Journal under the Freedom of Information Act, show at least one site in south Sacramento was investigated for heavy metals contamination.
The EPA listed high soil levels of lead, zinc and copper as elements of concern. Because tungsten wasn’t considered a heath threat, no tests were done for the metal, and it isn’t mentioned in the reports.
Unlike Sacramento, Fallon has a documented source of industrial tungsten.
For 50 years, the town has been home to Kennametal Inc., which has an in-town tungsten-carbide processing plant and an ore refinery 10 miles north of the community. The refinery operated without air pollution controls for more than 20 years.
Initial reports from the leukemia probe showed the basalt aquifer, where Fallon gets its drinking water, has been isolated for thousands of years. Therefore, officials believed high tungsten levels found in that underground lake must be naturally occurring.
But U.S. Geological Survey records show that tritium, a byproduct of Nevada atomic bomb tests that is found in surface soils all over the world, made its way down to the aquifer some time after the above-ground nuclear tests of the 1960s.