Friday, Feb. 7, 2003 | 11:11 a.m.
Federal research of a childhood leukemia cluster in the farming and military town of Fallon has failed to pinpoint a cause, but scientists said high amounts of arsenic and tungsten in residents and drinking water warrant more studies.
Since 1997, 16 cases of childhood leukemia have been diagnosed in Fallon, 60 miles east of Reno. Fallon is the home of the "Top Gun" Navy fighter pilot training base and has roots in farming and mining.
Three of the children with leukemia have died, but no additional cases have been diagnosed since December 2001.
Nationally, an average of three cases of the childhood leukemia occur per 100,000 people. Churchill County, where Fallon is located, has about 27,000 residents.
Centers for Disease Control and Prevention and state scientists said Thursday that the elevated levels of arsenic and tungsten and some pesticides in biological and water samples from Churchill County are "very important findings" that will prompt further research.
None of the results were conclusively linked to childhood leukemia, however, the researchers announced Thursday at a Fallon community meeting attended by about 300 people, including state legislators and families of sick children. It was the most extensive use of biological and environmental samples ever in a federal cancer cluster investigation, she said.
"We've learned a lot, but we haven't found the cause of this leukemia cluster," Dr. Carol Rubin, head of the research team from the CDC in Atlanta, said.
In the meantime, she recommended residents drink bottled water.
Since elevated levels of arsenic, tungsten, pesticides and six additional metals -- antimony, barium, cesium, cobalt, molybdenum and uranium -- were found, the CDC plans to compare families with leukemia to disease-free families to see if genes are affected by the contaminants.
The entire community has been exposed to other metals "higher than the national average," state epidemiologist Randall Todd said.
"If the community is exposed, why do some people get leukemia and others don't? That is one of the questions," Todd said. The research that has been done and is continuing in Fallon may one day lead scientists closer to finding a cause, he said.
Fallon residents who were tested also had slightly higher amounts of six pesticides and DDE -- a byproduct of the outlawed pesticide DDT -- than the average American. But there was no difference between sickened children and others in Fallon.
The leukemia-stricken children had older fathers than other Fallon children surveyed, researchers learned.
Eager to hear more detailed scientific analysis, many of the audience members asked scientists Thursday evening about other potential sources of the cancer, including everything from military radars to industrial pollution. Men and women wearing work boots and jeans sat alongside local and state politicians in suits.
They applauded once, when Capt. Brad Goetsch, commander of Fallon Naval Air Station, scolded local media and nervous residents for jumping to conclusions without first reviewing scientific data.
Arsenic occurs naturally in the Fallon area. The city is building a water treatment center to address the problem. Rubin advised residents to buy bottled water because of arsenic's health effects. It has been linked to skin, stomach and bladder cancer but not leukemia.
Tungsten, used to strengthen steel, was mined for years here, although the mines are shut down now. There's also a tungsten carbide plant in Fallon. Tungsten is an element used in electrical applications and as a hardening alloy.
The CDC announced in August that the metal was found in unexpectedly high levels in the urine of eight out of 10 Fallon residents tested. Nationally, one in 10 Americans has comparatively high levels. Scientists said one Fallon resident had a tungsten level more than 150 times the amount determined as high.
A University of Arizona scientist searching for links between Fallon and a leukemia cluster in Sierra Vista, Ariz., where nine children have the disease and one died, said this week that his preliminary research indicates that tungsten alters the cell growth of acute lymphocytic leukemia or ALL, the disease type found in Fallon.
ALL -- the most common form of childhood cancer -- weakens blood and bone marrow, spongy tissue inside large bones. It initially causes children to tire and may make them bruise or bleed easily. It can be fatal, but most children who are diagnosed survive.
Pediatric research professor Dr. Mark Witten, an independent toxicologist and pediatrics professor at the University of Arizona in Tucson, initially suspected jet fuel caused the leukemia clusters in Fallon and Arizona, but shifted his research to tungsten based on preliminary federal findings.
Witten discovered that tungsten changes the growth of leukemia cells in the laboratory. His said he has not reached final conclusions, however.
The CDC and Nevada state epidemiologist Randall Todd cautioned that Witten's research must be duplicated and other studies conducted.
The CDC has asked the National Institutes of Health to begin researching possible links between tungsten and cancer. Tungsten has been nominated by the CDC for priority to conduct national studies.
To compare other places similar to Fallon, the CDC and the Nevada State Health Division are studying tungsten in Pahrump, about 60 miles west of Las Vegas, and Lovelock in northern Nevada.
Testing in Pahrump and Lovelock, expected to begin later this month, should produce results this summer.
Families said they are willing to continue scientific studies.
"Of course it's frustrating. But I know they're working at it," Carinsa Rivers said before the community meeting. Her daughter Sareynah was diagnosed in March 2000 and has completed chemotherapy to combat the life-threatening blood disease.
"I wish I'd brought my diary," Sareynah said. She was planning to celebrate her 6th birthday today. She said she was going to eat brownies at school and go ice skating this evening.
She smiled and wandered away from her mother, who called out, "Don't drink the water."
Parents searching for answers have assembled an ever-shifting lineup of possible suspects. Leakage from a gas pipeline nearby ruining the water supply. Jet fuel from the fighters that train overhead. Agricultural chemicals. Some parents suspect the disease was passed as a virus from cats or cows to children.
"They're trying so hard to prove that it's not this and that, that they're not looking at other things," said Tammi Beardsley, whose son Zac, 7, is still undergoing treatment.
"Along the way," she said, "what if the real guy got away?"
Federal scientists acknowledge that they might have arrived too late to determine the cause.
"It's frustrating to the scientists," Rubin said. "There's nothing we wanted more than to be able to come back to the people of Fallon and show them the source."
The CDC tested air, dust, dirt, water, and 250 people in the Fallon area, identifying more than 300 pesticides, organic compounds and infectious diseases.
Most contaminants, including those produced by jet and auto fuel, were at levels near or below national averages.
Results from another study by the Agency for Toxic Substances and Disease Registry will be released next week. It is designed to track "pathways" of past contaminants that might no longer remain in Fallon.
"It goes in baby steps," Barbara deBraga said in describing the research. The director of Infusion Center at Churchill County Community Hospital has treated most of the sickened Fallon children.
"Slow-motion baby steps," added deBraga. To read the Centers for Disease Control and Prevention Fallon Report go to: www.cdc.gov/nceh/clusters/Fallon/
