KENNY C. GUINN
Governor ALLEN BIAGGI
Administrator

Churchill County, Nevada -- Leukemia Investigation
BACKGROUND

   The cluster of childhood leukemia cases was brought to the attention of public health officials in Nevada in the late summer of 2000, when it was learned that five cases of Acute Lymphocytic Leukemia (ALL) had been diagnosed in Churchill County within a few months of each other. The State Health Division immediately consulted with the Centers for Disease Control and Prevention (CDC) on appropriate steps for an investigation.

To date, fourteen children have been diagnosed with ALL and one with Acute Myelocytic Leukemia (AML), all of whom lived in Churchill County for varying lengths of time prior to diagnosis.

The first phase of the investigation commenced in September 2000 and involved interviewing each of the case families to determine where they had lived, how the water was supplied to those households, what sources of water were used for drinking and cooking, household chemical exposures, parental occupation and associated chemical exposures, military history, and family medical history. This information is used to learn if there are any common characteristics present among all or most of the case families.

In February 2001, the Nevada State Health Division initially convened an Expert Review Committee to look at the data collected to that point in time and develop recommendations for subsequent steps in the investigation.

In March 2001, the Expert Review Committee provided a report in which they recommended that the Health Division conduct a cross-sectional exposure assessment and an environmental pathways study in conjunction with scientists at the CDC and Agency for Toxic Substances and Disease Registry (ATSDR). The following August protocols for human testing were approved and plans for environmental and biological testing were finalized.

Simultaneously, CDC began to randomly select comparison (control) families and enrolling case families in the cross-sectional exposure assessment, which includes biological and environmental sampling,. In September 2001, biological testing began in Churchill County. Two weeks later, environmental testing began of water, soil, dust, air, and radiological analysis of soil and dust samples.

CDC completed the collection of biological specimens in October 2001. The Nevada Division of Environmental Protection (NDEP) completed collection of environmental samples in November 2001. The biological specimens are currently being analyzed at CDC. The environmental samples are being analyzed in several laboratories throughout the nation.

Based on the addition of a 15th case of ALL diagnosed in December 2001, plans are currently being developed to collect appropriate specimens in order to have complete data for the investigation.