FALLON - Elevated levels of the radioactive isotope polonium-210 were found in 17 private wells in the Lahontan Valley, according to a study released by the U.S. Geological Survey to the public Friday afternoon at the county commission chambers.
Although there is no known health risk at this time, officials said the need to get the information to the public as soon as possible was important. Research to determine whether there is a potential risk is already being conducted by federal and state agencies.
Twenty-five wells were tested in a large area east of the city of Fallon. Seventeen contained elevated levels of polonium-210. Thirteen had concentrations greater than 15 picocuries per liter, which is the U.S. Environmental Protection Agency's maximum containment level for gross alpha radioactivity in public-supply wells. Concentrations in the untreated, unfiltered water ranged from less than 0.1 picocuries per liter to 67.7 picocuries per liter. Most of the wells tested provide water for human and/or domestic animal consumption, and were more than 100 feet deep.
The public water supply for Fallon and NAS Fallon are known to be safe and were not part of the study, according to the USGS. The study did not investigate any links between the occurrence of polonium-210 and Fallon childhood leukemia cluster, which sickened 17 children and claimed the lives of three between 1997 and 2004.
"All indications are that the elevated levels stem entirely from natural geological causes within the Lahontan Valley," according to a press release from USGS. "There is no indication of any kind that this problem stems from any human activity."
Polonium-210, or Po-210, is a low-melting, volatile and rare natural element, according to the Los Alamos National Laboratory Web site. It is a carcinogen, and damage arises from the complete absorption of the energy of the alpha particle into tissue.
Because of the potential for a hazard, Dairy Farmers of America required dairies with the elevated samples to discard their milk to ensure public safety until it is determined to be safe.
"It is better to error on the side of caution," said Donna Rice, director of the Nevada Department of Agriculture.