Researchers know that exposure to some chemicals causes leukemia. They know how it happens and have identified specific genetic mutations that lead to the development of the disease, Caligiuri said. But other pollutants also are believed to damage chromosomes, which can lead to genetic mutations. Pesticides, hair dyes, solvents and glues are among the suspects, Caligiuri said. Other scientists have identified X-rays, asbestos and caffeine as possible causes of chromosome breaks.
Many scientists believe that the chemical exposure is the main cause.
Examining the air, soil and water as they exist today won't necessarily tell researchers what caused a current disease because environmental problems typically don't influence cancer rates for at least 10 years. If the people of Marion County developed leukemia because of chemical exposure in the environment, the exposure could have taken place decades earlier, Caligiuri said. Not everyone exposed to the same chemical stew develops leukemia, however, because most people have an enzyme that repairs broken chromosomes quickly. But people with sufficient amounts of this enzyme also can develop leukemia. The good news is that doctors have found effective treatments for leukemia, said Dr. Frederick Ruymann, chief of hematology and oncology at Children's Hospital.