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.

The United States Environmental Protection Agency asked the Arizona Department of Health Services, Office of Environmental Health, to provide an evaluation of the health hazards that may result from exposure to soil and soil gas contaminants present on the West-Cap site, located just north of the Tucson International Airport. Improper waste disposal practices from previous industrial activities at the site have resulted in contamination of on-site soil and soil gas. The objective of this health assessment is to assess the potential adverse health impact to on-site workers from exposure to the on-site contaminated soil and soil gas. Community exposures are not presented in this public health assessment.

This health consultation evaluates results of irrigation well samples collected by the Arizona Department of Environmental Quality in October 2003. Previous results obtained by the Blue Ridge Elementary School District in the summer of 2003 indicated trichloroethylene levels above the U.S. Environmental Protection Agency’s Maximum Contaminant Level. In addition, the most recent (2002) Annual Water Quality Report from the drinking water supplier, Arizona Water Company, was reviewed. A previous health consultation (Blue Ridge Elementary School, Lakeside, Navajo County, Arizona Health Consultation-April 30, 2003) reviewed environmental conditions at Blue Ridge Elementary School. Parents and school staff were concerned that environmental exposures were causing students to be absent from school. Drinking water quality reports, indoor air quality data, food safety, environmental sanitation records, student attendance rates, and the results of an annual parent satisfaction survey were evaluated in the consultation. Arizona Department of Health Services concluded that environmental conditions at Blue Ridge Elementary School posed no apparent public health hazard, and that attendance rates were similar to statewide attendance rates. As part of the 2003 health consultation, ADHS requested that the school district conduct water sampling from the on-site irrigation water wells for the school grounds. Those sampling results were not available when the 2003 health consultation was completed.