RENO (AP) - A new study says elevated levels of tungsten began showing up in trees in Fallon several years before an unusually large number of the town's children developed leukemia.
University of Arizona researcher Paul Sheppard, who says the amount of tungsten in tree rings from Fallon quadrupled from 1990 to 2002, while the level in three nearby towns remained the same.
Previous research by Sheppard found elevated levels of tungsten and cobalt in airborne and surface dust in Fallon.
He says more research is needed to determine whether there is a link between the metal and the cancer cluster.
Sheppard's findings are the latest to suggest toxins and genetics play a role in the cancer cluster plaguing the town 60 miles east of Reno.
Since 1997, 17 children with ties to Fallon have been diagnosed with acute lymphocytic leukemia. Three have died.
The tree-ring study by Sheppard and others was published in the May issue of the journal Environmental Health Perspectives.
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