The Arizona Department of Health Services Cancer Registry has identified 7 cases of childhood leukemia in the Sierra Vista, Arizona area since 1995. Five of the childhood leukemia cases were identified as a class of lymphoid leukemia and 2 of the cases were a class of myeloid leukemia. Based on random variation, a total of 6 or fewer cases of leukemia would have been expected over those seven years. An analysis of the data suggests that the number of cases is statistically elevated for the time period 1995 to 2001. The objective of this report is to determine whether there are any documented environmental exposures from drinking water, ambient air or waste sites that may have placed residents of the Sierra Vista, Arizona area at greater risk of developing childhood leukemia.

A massive pile of wood debris caught fire and burned from October 27 to October 31, 2001, in northern Pinal County, Arizona. The fire consumed wood debris from citrus trees that had been stored in an approximately 25-acre area in Pinal County near the Queen Creek area. The fire generated a large quantity of smoke. Persons reported smelling the smoke up to 40 miles away from the fire. Meteorological conditions during the fire intermittently created conditions that limited lift, especially at night, causing smoke to settle in residential neighborhoods in the Queen Creek area. The Arizona Department of Health Services issued public health advisories for the evenings of October 29 and 30. This report summarizes the events that occurred during the fire and analyzes the data collected by the Arizona Department of Health Services and the Arizona Department of Environmental Quality to determine the extent of the public health threat from the fire.