Two dairy farms have dumped milk after the discovery of a naturally occurring radioactive isotope in 25 nearby drinking water wells.
Officials from Sorensen's Dairy and Oasis Dairy said they will stop selling milk until it is tested for the isotope, polonium-210, by the Food and Drug Administration. Officials said there's no known health risk at this time.
A study released Friday by the U.S. Geological Survey found the radioactive isotope in 24 private wells and one public well around Fallon, about 60 miles east of Reno. Polonium-210 is known to cause
cancer in humans.
All dairies around Fallon sell their milk to the Dairy Farmers of America cooperative, which in turn markets the milk to a dairy in Reno and plants in northern California.
Fallon farmer Bret Sorensen said he began dumping 6,000 gallons of milk Friday morning at the cooperative's request.
Dr. Anette Rink, a supervisor at the Nevada Department of Agriculture, said she expects to have test results back from the FDA by Monday. Milk is not normally sampled for polonium-210 because the cows' bodies filter out most of the metal, Rink said.
Concentrations of polonium-210 found in the 25 wells ranged from less than 0.1 to 67.7 picocuries per liter. Thirteen had amounts greater than 15, which is the maximum allowed by the Environmental Protection Agency for public wells. The EPA does not regulate private wells.
Alexander Litvinenko, a former Russian security agent, was killed in London last year with a dose of polonium-210 much larger than the amount detected in Fallon.
USGS researchers conducted the well tests as part of a University of Nevada, Reno, study investigating a possible link between groundwater contamination and 17 leukemia cases around Fallon since 1997. Health officials say about one leukemia case in five years would be expected.
(Copyright 2007 by The Associated Press. All Rights Reserved.)