The disease causes patients to produce too many immature white blood cells, weakening the body's immune system and hampering the blood's ability to clot and carry oxygen. Nationally, four of five children survive ALL, and there have been no deaths among the Fallon children. If environmental contaminants are causing Fallon's cluster, as many residents here believe, experts also would expect to see AML cases. Many suspect the city's water, but a panel of cancer experts discounted the theory because high levels of naturally occurring arsenic had been present in the groundwater for at least 60 years before the cancers appeared. Arsenic has been linked to bladder, lung and skin cancers but not leukemia.
Some parents blame a combination of exposures.
The Navy says its pilots rarely dump fuel. Todd, the state epidemiologist, says jet-fuel chemicals have not been found in city water, and even if dumped fuel evaporated, prevailing winds would carry the vapors away from Fallon. Yet Todd, like the families, isn't willing to attribute 12 cancer cases to coincidence. The Environmental Protection Agency has ordered the city to reduce arsenic levels from the current 100 parts per billion to 10 by 2003. The Bush administration has said it will try to relax that national standard, adopted in the waning days of the Clinton administration.